Progress 10/01/13 to 09/30/14
Outputs
Target Audience: The target audience was comprised primarily of state, federaland county land managers as well as private individulas or farms. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Project updates and status have been presented at the annual meeting of the Montana Weed Control Association (MWCA), at biocontrol consortia meetings at the Northern Rockies Invasive Plant Council2014 Conference and at MWCA Biocontrol subcommittee meetings. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Invasive species are recognized to be a serious problem on the range and forested lands of the western United States. Noxious weeds have a serious economic impact on the productivity of these lands and in addition, the presence of these invaders compromises their ecological integrity. The exact economic impacts have not been calculated, but it is estimated that one major weed, spotted knapweed, costs Montana 42 million dollars annually. It must also be recognized that weeds are not only a local problem but they are of regional and international importance. Integrated weed control strategies are necessary for long-term and effective weed management. Biological control, the use of natural enemies, is an important component of this integrated management strategy. To improve biological control, this project seeks additional biological control agents for several noxious weeds in which biological control efforts are minimal or have just been initiated, determining their long-term impacts on ecological communities and on their target weed, to improve the mass rearing, redistribution and monitoring of these agents, and also disseminating this information to stakeholders through education and outreach. The objectives for this project are: 1) determine environmental safety of exotic candidates prior to release; 2) release, establish, and redistribute natural enemies, and 3) evaluate natural enemy efficacy, and study ecological/physiological basis for insect-host interactions. Biological control is in the early stages of initiation for many of our targeted weed species. Efforts reported are listed by the target weed. Russian knapweed - Approximately 26,000 Aulacidea acroptilonica were reared from galls collected from established field sites or at the MSU insectary. Over 16,370 were released at 6 field sites in Montana, and 2800 were placed at the insectary for additional rearing. The remaining wasps were consigned to other cooperators. Parasitism of the wasp was low in 2014, although additional parasitoid species were observed. The gall wasp is now established and increasing in population at least eight sites in Montana. The gall midge Jaapiella ivanokovi was also monitored in 2014. Populations were high at several sites. Grazing at some field sites significantly decrease both the midge and wasp population. Invasive hawkweed - Two releases of the gall wasp Aulacidea subterminalis were made in Flathead and Lincoln Counties in July 2014. Galls (with wasps in the pupal stage) were placed within a wire mesh container and placed with in a 1x1x1 m cage or at the base of hawkweed plants (open field release). The litter immediately surrounding the release area was partially removed exposing orange hawkweed stolons. Previous releases were monitored for plant density and for establishment. No infested plants were observed at any of the previous releases. The wasp was also reared in the containment lab for release in 2015. Approximately 840 galls were produced. A petition for the field release of the hoverfly Cheilosia urbana (Diptera: Syrphidae) for biological control of alien invasive hawkweeds in North America was submitted to the USDA-APHIS-Technical Advisory Group (TAG). Hoarycress - Several shipments of the gall mite Aceria drabae were received at the MSU quarantine lab from Eastern Europe in 2014 (collected by the BBCA). Mites were dead in several of these shipments however we were able to start a rearing colony from one shipment. An environmental assessment for the release of the mite was drafted and is in US Fish & Wildlife Section 7 Consultation for threatened & endangered species concerns. Rush skeletonweed - Host specificity testing continued for the Chondrilla crown moth, Oporopsamma wertheimsteini (Lepidoptera: Tortricidae). A collection of pupae was made in Armenia in 2014 and the resulting adults were used in caged choice tests in Bulgaria. No-choice tests are being conducted in Montana. Bindweed - To determine the effects of sub-lethal herbicide applications on gall induction and development of A. malherbae, a bioassay was conducted with four herbicides, each having different modes of action. Atrazine, glyphosate, imazapic, and picloram were applied at 25% of their recommended dosages on plants infested and not infested with A. malherbae. Sub-lethal herbicide applications had an adverse effect on plant stem height, total stem length, numbers of leaves or branches, or on above-ground or below-ground biomass; whereas A. malherbae did not. Synergistic impacts of herbicide applications and A. malherbae on growth parameters of field bindweed were not observed. Pre- and post-spray gall counts were not significantly different, indicating that gall induction and development was not altered by these sub-lethal dosages. The establishment and effectiveness of A. malherbae has been reported to vary across western North America, with genetic variation of field bindweed as a possible contributing factor. Four field bindweed populations, collected from Montana, California, Oregon, and New Mexico, were exposed to A. malherbae to determine if growth parameters conducive or detrimental to the development of the mite vary among plant populations. When grown in a common environment, plant height, stem length, and number of branches and leaves significantly varied among populations although biomass did not differ. Galling by A. malherbae did not impact field bindweed growth, except for slight reduction in root biomass of infested plants. Gall induction was lower on plants from New Mexico than Oregon. Field studies assessed the relationship between habitat characteristics and plant cover and the presence and abundance of the mite. Multidimensional scaling of site characteristics indicated a spatial relationship, though no habitat relationship, among established A. malherbae populations. In within-field studies, a significant positive relationship was observed between percent grass cover and mite abundance and a negative relationship between field bindweed and mite abundance. These projects will contribute to the selection of potentially new biological control agents for the control of noxious weeds. New agents are being investigated for the biological control of Russian knapweed, hoarycress, invasive hawkweeds, and rush skeletonweed. The target weeds have either no biological control agents currently available or the agents already established are not effective over the range of the target weed. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness.
Publications
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2014
Citation:
Konigsberg, Evelyn Rivka. 2014. Factors involved in the success and establishment of the field bindweed gall mite Aceria malherbae Nuzzaci. MS Thesis Montana State University. 88 pp.
- Type:
Other
Status:
Submitted
Year Published:
2014
Citation:
Littlefield, J., R. De Clerck-Floate, G. Grosskopf-Lachat and H. Hinz. 2014. A petition for the field release of the hoverfly Cheilosia urbana (Diptera: Syrphidae) for biological control of alien invasive hawkweeds in North America. Submitted to the USDA-APHIS-Technical Advisory Group (TAG). 110 p.
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Progress 10/01/09 to 09/30/14
Outputs
Target Audience: The target audience was comprised primarily of state, federal and county land managers as well as private individulas or farms. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Project updates and status have been presented at the annual meeting of the Montana Weed Control Association (MWCA), at biocontrol consortia meetings at the Northern Rockies Invasive Plant Council 2014 Conference and at MWCA Biocontrol subcommittee meetings. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Invasive species are recognized to be a serious problem on the range and forested lands of the western United States. Noxious weeds have a serious economic impact on the productivity of these lands and in addition, the presence of these invaders compromises their ecological integrity. The exact economic impacts have not been calculated, but it is estimated that one major weed, spotted knapweed, costs Montana 42 million dollars annually. It must also be recognized that weeds are not only a local problem but they are of regional and international importance. Integrated weed control strategies are necessary for long-term and effective weed management. Biological control, the use of natural enemies, is an important component of this integrated management strategy. To improve biological control, this project seeks additional biological control agents for several noxious weeds in which biological control efforts are minimal or have just been initiated, determining their long-term impacts on ecological communities and on their target weed, to improve the mass rearing, redistribution and monitoring of these agents, and also disseminating this information to stakeholders through education and outreach. The objectives for this project are: 1) determine environmental safety of exotic candidates prior to release; 2) release, establish, and redistribute natural enemies, and 3) evaluate natural enemy efficacy, and study ecological/physiological basis for insect-host interactions. Biological control is in the early stages of initiation for many of our targeted weed species. Efforts reported are listed by the target weed. Russian knapweed - Approximately 26,000 Aulacidea acroptilonica were reared from galls collected from established field sites or at the MSU insectary. Over 16,370 were released at 6 field sites in Montana, and 2800 were placed at the insectary for additional rearing. The remaining wasps were consigned to other cooperators. Parasitism of the wasp was low in 2014, although additional parasitoid species were observed. The gall wasp is now established and increasing in population at least eight sites in Montana. The gall midge Jaapiella ivanokovi was also monitored in 2014. Populations were high at several sites. Grazing at some field sites significantly decrease both the midge and wasp population. Invasive hawkweed - Two releases of the gall wasp Aulacidea subterminalis were made in Flathead and Lincoln Counties in July 2014. Galls (with wasps in the pupal stage) were placed within a wire mesh container and placed with in a 1x1x1 m cage or at the base of hawkweed plants (open field release). The litter immediately surrounding the release area was partially removed exposing orange hawkweed stolons. Previous releases were monitored for plant density and for establishment. No infested plants were observed at any of the previous releases. The wasp was also reared in the containment lab for release in 2015. Approximately 840 galls were produced. A petition for the field release of the hoverfly Cheilosia urbana (Diptera: Syrphidae) for biological control of alien invasive hawkweeds in North America was submitted to the USDA-APHIS-Technical Advisory Group (TAG). Hoarycress - Several shipments of the gall mite Aceria drabae were received at the MSU quarantine lab from Eastern Europe in 2014 (collected by the BBCA). Mites were dead in several of these shipments however we were able to start a rearing colony from one shipment. An environmental assessment for the release of the mite was drafted and is in US Fish & Wildlife Section 7 Consultation for threatened & endangered species concerns. Rush skeletonweed - Host specificity testing continued for the Chondrilla crown moth, Oporopsamma wertheimsteini (Lepidoptera: Tortricidae). A collection of pupae was made in Armenia in 2014 and the resulting adults were used in caged choice tests in Bulgaria. No-choice tests are being conducted in Montana. Bindweed - To determine the effects of sub-lethal herbicide applications on gall induction and development of A. malherbae, a bioassay was conducted with four herbicides, each having different modes of action. Atrazine, glyphosate, imazapic, and picloram were applied at 25% of their recommended dosages on plants infested and not infested with A. malherbae. Sub-lethal herbicide applications had an adverse effect on plant stem height, total stem length, numbers of leaves or branches, or on above-ground or below-ground biomass; whereas A. malherbae did not. Synergistic impacts of herbicide applications and A. malherbae on growth parameters of field bindweed were not observed. Pre- and post-spray gall counts were not significantly different, indicating that gall induction and development was not altered by these sub-lethal dosages. The establishment and effectiveness of A. malherbae has been reported to vary across western North America, with genetic variation of field bindweed as a possible contributing factor. Four field bindweed populations, collected from Montana, California, Oregon, and New Mexico, were exposed to A. malherbae to determine if growth parameters conducive or detrimental to the development of the mite vary among plant populations. When grown in a common environment, plant height, stem length, and number of branches and leaves significantly varied among populations although biomass did not differ. Galling by A. malherbae did not impact field bindweed growth, except for slight reduction in root biomass of infested plants. Gall induction was lower on plants from New Mexico than Oregon. Field studies assessed the relationship between habitat characteristics and plant cover and the presence and abundance of the mite. Multidimensional scaling of site characteristics indicated a spatial relationship, though no habitat relationship, among established A. malherbae populations. In within-field studies, a significant positive relationship was observed between percent grass cover and mite abundance and a negative relationship between field bindweed and mite abundance. These projects will contribute to the selection of potentially new biological control agents for the control of noxious weeds. New agents are being investigated for the biological control of Russian knapweed, hoarycress, invasive hawkweeds, and rush skeletonweed. The target weeds have either no biological control agents currently available or the agents already established are not effective over the range of the target weed. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness.
Publications
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2014
Citation:
Konigsberg, Evelyn Rivka. 2014. Factors involved in the success and establishment of the field bindweed gall mite Aceria malherbae Nuzzaci. MS Thesis Montana State University. 88 pp.
- Type:
Other
Status:
Submitted
Year Published:
2014
Citation:
Littlefield, J., R. De Clerck-Floate, G. Grosskopf-Lachat and H. Hinz. 2014. A petition for the field release of the hoverfly Cheilosia urbana (Diptera: Syrphidae) for biological control of alien invasive hawkweeds in North America. Submitted to the USDA-APHIS-Technical Advisory Group (TAG). 110 p.
|
Progress 01/01/13 to 09/30/13
Outputs
Target Audience: The target audience was comprised primarily of federal, state and county land managers as well as the general public. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Outreach activities included two training workshops: The rush skeletonweed root moth (USFS training), and Russian knapweed biocontrol (Crow Reservation weed workshop). Short presentations on the biological control of weeds and use of insect biocontrol agents. Target audience was land managers, land owners and general public. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Two biocontrol agents, Jaapiella ivannikovi (Diptera: Cecidomyiidae) and Aulacidea acroptilonica (Hymenoptera: Cynipidae) have been released and established on Russian knapweed: Rhaponticum (Acroptilon) repens. Jaapiella ivannikovi gall numbers observed in the spring 2013 were comparable to 2012 levels. At three sites, populations of the gall midge significantly increased during August and September. At the Charles M. Russell Wildlife Refuge, an estimated 140 thousand galls were present by the end of summer and that the midge had dispersed over 1.2 km from the initial release. This population explosion was likely a result of late season rains which stimulated late season emergence of many Russian knapweed stems. Parasitism of A. acroptilonica was evident again at our primary release site and also evident at our new releases as well. However this did not prevent the wasp at our Broadwater site from significantly expanding. Gall numbers increase from an estimated 120,000 in 2012 to several million galls in 2013. Unfortunately many were later consumed by livestock. We observed plants with several hundred galls. Although these were significantly stunted, overall impact on individual plants did not appear to be significant. Parasitoids will be identified and assessed for their impact on A. acroptilonica. A sampling grid 220 m x 220 m (total of 121 sample points) was established in spring of 2011 in southern Idaho to determine the population level and impact of Bradyrrhoa gilveolella (Lepidoptera: Pyralidae) on rush skeletonweed. At each point we determined Bradyrrhoa (feeding tubes, larvae, and adult presence) and rush skeletonweed densities. These were mapped to determine changes in the spatial distributions of moth and rush skeletonweed populations with time. In 2013 the adult emergence period had increased over a longer time period compared to 2011 and adults can now be observed from June into October. The numbers of moths “flushed” from the vegetation were counted in late July. At peak emergence ranged between 0 and 39 adults per point, however in 2013 moth numbers were lower but dispersed over a wider time period. The number of Bradyrrhoa larvae per root was lower in 2012 than that observed in 2011 (mean 1.2 larva /root; range 0-19 larvae). We are currently dissecting roots collected in 2013. Rush skeletonweed plant density and vegetation cover have remained relatively the same. We will continue to monitor plant density to determine long-term trends.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
McClay, A., M. Chandler, H.L Hinz, A. Gassmann, V. Battiste, and J. Littlefield. 2013. The road less taken: a classical biological control project operated through an NGO. In Y. Wu, T. Johnson, S. Sing, S. Raghu, G. Wheeler, P. Pratt, K. Warner, T. Center, J. Goolsby, and R. Reardon (eds). Proceedings of the XIII International Symposium on Biological Control of Weeds. September 1116, 2011 Waikoloa, Hawaii, USA. USDA Forest Service, Forest Health Technology FHTET2012-07. Pg 180.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Cortat, G., G. Grosskopf-Lachat, H. L. Hinz, R. DeClerck-Floate, J. Littlefield and C. Moffat. 2013. An update on biological control of invasive hawkweeds in North America. In Y. Wu, T. Johnson, S. Sing, S. Raghu, G. Wheeler, P. Pratt, K. Warner, T. Center, J. Goolsby, and R. Reardon (eds). Proceedings of the XIII International Symposium on Biological Control of Weeds. September 1116, 2011 Waikoloa, Hawaii, USA. USDA Forest Service, Forest Health Technology FHTET2012-07. Pg 50.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Littlefield, J. L., G. Markin, J. Kashefi, A. de Meij and J. Runyon. 2013. The release and recovery of Bradyrrhoa gilveolella on rush skeletonweed in southern Idaho. In Y. Wu, T. Johnson, S. Sing, S. Raghu, G. Wheeler, P. Pratt, K. Warner, T. Center, J. Goolsby, and R. Reardon (eds). Proceedings of the XIII International Symposium on Biological Control of Weeds. September 1116, 2011 Waikoloa, Hawaii, USA. USDA Forest Service, Forest Health Technology FHTET2012-07. Pg. 478.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Littlefield, J.L., R. J. Lavigne and M. E. Weber. 2013. The life history of Corythuca distincta, an endemic lace bug on Canada thistle in Wyoming. In Y. Wu, T. Johnson, S. Sing, S. Raghu, G. Wheeler, P. Pratt, K. Warner, T. Center, J. Goolsby, and R. Reardon (eds). Proceedings of the XIII International Symposium on Biological Control of Weeds. September 1116, 2011 Waikoloa, Hawaii, USA. USDA Forest Service, Forest Health Technology FHTET2012-07. Pg. 477.
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: The rush skeletonweed root moth, Bradyrrhoa gilveolella (Lepidoptera: Pyralidae, was redistributed to five locations in Idaho and Oregon. Adult moths were released at three levels (0, 50, 100, & 500 moths) at separate sites at each location. We have also initiated a spatial distribution study to characterize the within-site population distribution of Bradyrrhoa adults and larvae in relation to host density. We hope to delineate the population build-up of the moth, plant size preference and potential impact on skeletonweed. Host specificity testing of the rush skeletonweed crown moth, Oporopsamma wertheimsteini (Lepidoptera: Tortricidae, continued at the MSU quarantine facility in 2012. We performed no-choice tests on 27 plant species, including rush skeletonweed controls. Fifty four plant species plus several cultivars and three C. juncea biotypes have thus far been tested. Feeding and larval development was observed in all rush skeletonweed biotypes, two North American species, Krigia biflora and Micoseris lindleyi, and two introduced species: Scorzonia lacinata, and Tagopogon dubius. However, this non-target feeding and development was very marginal when compared with that of the C. juncea controls. Approximately 1,000 tansy ragwort flea beetles, Longitarsus jacobaeae, were released outlying tansy ragwort infestations. At many sites in Montana, flea beetle populations were at low levels in 2012; likely due to the decline of tansy ragwort density either from dry weather or the impacts of biocontrol agents (flea beetles or cinnabar moths). The Russian knapweed gall fly Jaapiella ivannikovi was located at 60% of previous release sites; although no significant increases have been observed in the overall Jaapiella population at these sites. We have an established population of the Russian knapweed gall wasp Aulacidea acroptilonica (Hymenoptera: Cynipdiae) in Montana. This population significantly increased in 2012 to where approximately 90% of plants at the site have galls (ranging upwards to 56 gall clusters per plant). Parasitism of Aulacidea acroptilonica was observed in 2012. Three or four species of parasitoids were reared from 2011 galls. These will be identified and parasitism rates will be closely monitored in 2013. Other insect galls were also collected from the site but failed to yield parasitoids or similar parasitoids to those attacking A. acroptilonica. PARTICIPANTS: J. Runyon, S. Sing, R. Progar & C. Jorgensen - US Forest Service; U. Schaffner, G. Grosskopf, G. Cortat, A. Gassman & H. Hinz - CABI, Delemont, Switzerland; J. Kashefi - USDA ARS, European Biological Control Lab. Greece; M. Christofaro - BBCA, Rome; M. Dolgorskaya & M. Volkovich - Russian Biocontrol Group, St. Petersburg; G. Adams & R. Merenz APHIS-PPQ & R. Hansen APHIS-CPHST; J. Simons & J. Milan - BLM, Montana & Idaho. TARGET AUDIENCES: These projects impact various federal, state, county and private stakeholders. Projects are part of a larger consortium or control effort on biological control weeds. Consortium groups have been developed for numerous weeds, and various stakeholders are associated with these groups. Stakeholders may include federal, state, county agencies as well a private organizations, companies or individuals. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
These projects will contribute to the selection of potentially new biological control agents for the control of noxious weeds. New agents are being investigated or released for the biological control of Russian knapweed, hoarycress, invasive hawkweeds, and rush skeletonweed. In addition Montana is supporting efforts to screen agents at CABI Europe for ox-eye daisy and common tansy. Target weeds selected either have no biological control agents currently available or the agents already established are not effective over the range of the target weed. Established agents such as Longitarsus jacobaeae have significantly decreases tansy ragwort density by 75-97% at some sites in Montana. Several agents have recently been established or released, e.g. Russian knapweed and orange hawkweed. Within the next two years we hope to have agents available to release against hoarycress. The success of these agents may not be determined for many years. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness.
Publications
- Littlefield J., J. Kashefi, A. deMeij, and J. Birdsall. 2012. A petition for the field release of the gall mite Aceria drabae (Acari: Eriophyidae) for the biological control of hoarycress in North America. TAG Petition 012-03. 77 pp.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Hawkweed - A stolon galling wasp, Aulacidea subterminalis (Hymenoptera: Cynipdiae) was released for the first time in the US. Over 400 galls were placed at three orange hawkweed sites in northwestern MT in July. Rush Skeletonweed - Host specificity testing of the crown moth Oporopsamma wertheimsteini was conducted at the MSU quarantine facility. We performed no-choice tests on 32 plant species, 4 cultivars and 3 biotypes of rush skeletonweed. A shipment of rush skeletonweed roots infested with the moth was received from Armenia. Over 160 adults emerged and laid eggs; which are being held in cold storage. These will be used to continue host testing in 2012. Sphenoptera foveola (Coleoptera: Buprestidae) was also collected by the Russian Biocontrol Group from sites located in Kazakhstan and then transported to field plots in Armenia to determine the utilization of North American Chondrilla juncea. In late 2010 we surveyed our release sites of the root moth Bradyrrhoa gilveolella. At one site in southern Idaho we observed infested plants over an area of ~ 7 ha. Although variable, percent infestation at the immediate release point approached 70%. In early August 2011, adults were observed over a much wider area (~ 46 ha) although still confined to a small geographic area. We estimated, based on adult counts, that the moth population exceeded 100,000 individuals at the site. We are presently examining the phenology of this population, working to develop effective collection and release techniques, and assessing the impact of B. gilveolella. Russian knapweed - Ten Jaapiella ivannikovi release sites are located in Montana. We have released 2850 galls & 2250 adults over the past three years, including those placed at an insectary site. Of seven sites monitored during late spring of 2011, the midge overwintered at four (two sites were destroyed by flooding). Of our ten release sites, only one had a good population of Jaapiella, although the numbers of galls observed were about equal to those of 2010. We have an established population of the Aulacidea acroptilonica in Montana. We saw a tenfold increase in the number of plants infested, and an estimated 1,500 galls were located. The dispersal of the wasp was well over 120 m from the initial release point (2009). Tansy Ragwort - The tansy ragwort flea beetle, Longitarsus jacobaeae has been successfully established in Montana. Two populations/ biotypes are currently being monitored. Beetle populations have significantly increased in the past several years, and at several sites tansy ragwort plant density appreciably decreased (between 75 and 97%). Approximately 1,200 beetles were released outlying tansy ragwort infestations in 2011. At some sites flea beetle populations were overall much lower compared to 2010. This population decrease was thought to be a result of a cold and very wet spring, and the decline of tansy ragwort density at these release sites due to either the flea beetle and/or the cinnabar moth. PARTICIPANTS: Collaborators and co-PIs on this project were: US Forest Service - J. Runyon & S. Sing; CABI Bioscience, Delemont, Switzerland - U. Schaffner, G. Grosskopf, G. Cortat, A. Gassman & H. Hinz; USDA ARS, European Biological Control Lab - J. Kashefi; BBCA, Rome - M. Christofaro; Russian Biocontrol Group, St. Petersburg,- M. Dolgorskaya & M. Volkovich; APHIS-PPQ & CPHST - G. Adams, R. Merenz & R. Hansen; BLM, Billings, MT - J. Simons; MCClay Ecoscience, A. McClay. Many collaborators are involved with the overseas collection and screening of new agents, while others are involved with the release and redistribution of agents. TARGET AUDIENCES: These projects impact various federal, state, county and private stakeholders. Projects are part of a larger consortium or control effort on biological control weeds. Consortium groups have been developed for numerous weeds and various stakeholders are associated with these groups. Stakeholders may include federal, state, county agencies as well a private organizations, companies or individuals. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
These projects will contribute to the selection of potentially new biological control agents for the control of noxious weeds. New agents are being investigated or released for the biological control of Russian knapweed, hoary cress, invasive hawkweeds, and rush skeletonweed. In addition Montana is supporting efforts to screen agents at CABI Europe for ox-eye daisy and common tansy. Target weeds selected either have no biological control agents currently available or the agents already established are not effective over the range of the target weed. Established agents such as Longitarsus jacobaeae have significantly decreases tansy ragwort density by 75-97% at some sites in Montana. Several agents have recently been established or released, e.g. Russian knapweed and orange hawkweed. Within the next two years we hope to have agents available to release against hoary cress. The success of these agents may not be determined for many years. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness.
Publications
- Winston, R., C. Randall, J. Littlefield, M. Schwarzlander, J. Birdsall, and E. Coombs. 2011. Biology and biological control of tansy ragwort. Forest Health Technology Enterprise Team. FHTET-2011-02. 112 pp.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: The tansy ragwort flea beetle, Longitarsus jacobaeae (Coleoptera: Chrysomelidae) has been successfully established in Montana. Two populations/ biotypes are currently being monitored. Beetle populations have significantly increased in the past several years, and at several sites tansy ragwort plant density appreciably decreased (between 75 and 97%). Approximately 7,000 beetles were released outlying tansy ragwort infestations in 2010. We received one shipment of Jaapiella ivannikovi collected by CABI cooperators in Uzbekistan in June of 2010. These midges were used to increase the genetic diversity of our existing laboratory colony. These colonies were later supplemented with field collected midges from Montana. Gall material was also provided to other cooperators within the region. We continue to rear the midge at the MSU. In 2010, 21 releases of the midge were made in Montana. We currently have a total of seven release sites. Galls were located at all sites although gall numbers were low at many sites. With the exception of one site, the midge was able to overwinter at our 2009 releases (four total sites). At our most productive site (Broadwater County) over one thousand galls developed over the summer, and midges dispersed over a 100 m from the initial release point. Gall numbers were much lower at our other sites. Distributions of galls at sites were periodically mapped to determined population increase, dispersal, and areas where they have or might overwinter successfully (to be map the following spring). We have sites located in Broadwater, Phillips, Fergus, Chouteau and Carbon Counties. A shipment of an estimated 400 stem galls of Aulacidea acroptilonica were received from CABI in March 2010. These were collected from field sites located in Uzbekistan and were placed in cold storage until May. In 2009 we reared approximately 560 galls in the greenhouse and at an insectary site. Adult emergence was very poor and only 18 total wasps emerged from both the field collected and lab reared galls. These were exposed to plants in our greenhouse and resulted in approximately new 23 galls. At our 2009 release in Broadwater Co., a survey conducted in September found 80 plants infested (nearly 100 total galls). The number of galls was more than what we expected at this site, and the wasp was able to disperse 30-40 m from the initial release. A rearing colony of the root boring moth Bradyrrhoa gilveolella (Lepidoptera: Pyralidae) has declined at Montana State University and no releases were made in 2010. Previous release sites were monitored in October 2010 and the recovery of larvae was made at one site. Several releases of the gall mite Aceria malherbae was provided to the US Forest Service, Forest Health unit. The establishment of the root beetle, Agrilus hyperici was confirmed in western Montana. This is the first confirmation of the establishment of the beetle since its release in 1955 and 1977. The distribution of the beetle in Montana appears to be limited. PARTICIPANTS: Collaborators and co-PI's on this project were: US Forest Service - J. Runyon, & S. Sing; CABI Bioscience, Delemont, Switzerland - U. Schaffner, G. Grosskopf, & H. Hinz; USDA ARS, European Biological Control Lab - J. Kashefi; USDA-ARS - A. Caesar; Biocontrol Group, St. Petersburg; BBCA, Rome - M. Christofaro; Nez Perce Bio-Control Center - M. Hanks & P. Brusven; BLM, Billings, MT; Montana State University - J. Story. TARGET AUDIENCES: These projects impact various federal, state, county and private stakeholders. Projects are part of a larger consortium or control effort on biological control weeds. Consortium groups have been developed for numerous weeds and various stakeholders are associated with these groups. Stakeholders may include federal, state, county agencies as well a private organizations, companies or individuals. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
These projects will contribute to the selection of potentially new biological control agents for the control of noxious weeds. New agents are being investigated for the biological control of Russian knapweed, hoarycress, invasive hawkweeds, and rush skeletonweed. These target weeds have either no biological control agents currently available or the agents already established are not effective over the range of the target weed. Established agents such as Longitarsus jacobaeae have significantly decreases tansy ragwort density by 75-97% at some sites in Montana. Within the next three years we hope to have agents available for field release against invasive hawkweeds and hoarycress. The success of these agents may not be determined for many years. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness.
Publications
- No publications reported this period
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Host specicifty testing was initated or continued for two bio-control agents. The mite, Metaculus lepidifolii (for perennial pepperweed) was collected in Turkey and a small colony of the mite was established for possible host specificity testing in 2010. Host specificity testing of a flower moth, Schinia cognate (Lepidoptera: Noctuidae) has been initiated, although mating problems and lack of oviposition under laboratory/ greenhouse conditions has impeded progress. The tansy ragwort flea beetle, Longitarsus jacobaeae has been successfully established in Montana. Beetle populations have significantly increased in 2008 and 2009 (in some cases over 34 beetles per plant were observed), and at several sites tansy ragwort plant density appreciably decreased. Approximately 12,000 beetles were released outlying tansy ragwort infestations. Two gall insects for Russian knapweed, Aulacidea acroptilonica and Jaapiella ivannikovi were released in Montana in 2009. Both gall insects will continue to be reared for field release in 2010 at MSU. The root boring moth Bradyrrhoa gilveolella continued to be reared and provided to cooperators. Approximately 7,000 individuals (mostly eggs) were shipped in 2009. Releases were also made at Craters of the Moon and Mountain Home, Idaho to determine the effectiveness of different release techniques. An adventive insect survey was conducted in western Montana to determine the establishment or distribution of these arthropods, and any possible feeding on non-target plant species. The following target weeds and associated insects were surveyed: poison hemlock - Agonopterix alstroemeriana; musk thistle and Canada thistle - Cassida rubiginosa, Larinus planus & Trichosircalus horridus; eurasian watermilfoil - Euhrychiopsis lecontei; toadflax - Rhinusa antirrhini & Brachypterolus pulicarius; mullein - Gymnetron tetrum; houndstongue - Mogulones cruciger; and scentless chamomile - Omphalapion hookeri & Rhopalomyia tripleurospermi. Most agents were found to be relatively widespread. None of the agents for scentless chamomile or houndstongue were observed. Euhrychiopsis lecontei was collected a several sites but at very low numbers. Several other adventive insects and mites were collected but still need to be identified. PARTICIPANTS: Collaborators and co-PI's on this project were: US Forest Service - J. Runyon; CABI Bioscience, Delemont, Switzerland - U. Schaffner, G. Grosskopf, & H. Hinz; USDA ARS, European Biological Control Lab - J. Kashefi; BBCA, Rome - M. Christofaro; Nez Perce Bio-Control Center - M. Hanks & P. Brusven; and BLM, Billings, MT. TARGET AUDIENCES: These projects impact various federal, state, county and private stakeholders. Projects are part of a larger consortium or control effort on biological control weeds. Consortium groups have been developed for numerous weeds and various stakeholders are associated with these groups. Stakeholders may include federal, state, county agencies as well a private organizations, companies or individuals. PROJECT MODIFICATIONS: No major changes in the project objectives occurred.
Impacts
This project contributed to the selection of potentially new biological control agents for the control of noxious weeds. New agents are being investigated for the biological control of Russian knapweed, hoarycress, invasive hawkweeds, and rush skeletonweed. These target weeds have either no biological control agents currently available or the agents already established are not effective over the range of the target weed.Within the next three years we hope to have agents available for field release against invasive hawkweeds and hoarycress. The success of these agents may not be determined for many years. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness.
Publications
- Markin, G., J. Littlefield, B. Chalgren, A. Odor, D. Williams, and T. Barbouletos. 2009. Development and implementation of an area wide management plan for the invasive weed, tansy ragwort, in northwestern Montana. Astract. Sixth International IPM Symposium, Portland, OR. March 24-26, 2009.
- Littlefield, J. L., G. Grosskopf, and L. Wilson. 2009. A petition for the field release of the gall wasp Aulacidea subterminalis (Hymenoptera: Cynipidae), for the biological control of invasive hawkweed in North America. Submitted to the USDA-APHIS-Technical Advisory Group (TAG 09-02). 83 p.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Host specificity testing of the hawkweed gall cynipid, Aulacidea subterminalis was completed. Sixty-seven different plant species were tested at CABI Europe and MSU. Galls were only induced on four exotic species: Hieracium pilosella (its native host), H. aurantiacum, H. flagellare, and H. floridundum. No native or other test plants were infested. Based on these results a petition for its release has been submitted to the USDA-APHIS for review. Host specificity tests for the gall mite Aceria drabae have been completed. Of the eighty plant species and numerous varieties/cultivars tested, the mite was specific to its intended host Lepidium draba. Long-term term monitoring of the mite, Aceria malherbae continues at one site in Phillips County, Montana. After eight years no significant decline in the population of field bindweed has been observed. A recent survey of the spread of the mite indicated long range dispersal throughout the eastern half of Montana. Persistence of the mite at several releases in western portion of the state has been low; with few mites recovered. Site and habitat characteristics have been collected for a number of mite infestations to correlate the performance of the mite with microhabitat conditions. Two gall insects for Russian knapweed, Aulacidea acroptilonica and Jaapiella ivannikovi are currently being reared at the MSU quarantine laboratory with field release planned for 2009. The tansy ragwort flea beetle, Longitarsus jacobaeae has been successfully established in Montana. Two populations are currently being monitored. Beetle populations have significant increased in 2008 to where redistribution of the beetle can occur. The root boring moth Bradyrrhoa gilveolella continues to be reared and provided to cooperators. Recovery of the moth has been made at field sites although it is too early to determine if the moth has become established. A follow up study of the bionomics of the gall midge, Cystiphora schmidti indicated significant impact of predators and parasitoid on the population development of the midge. Host specificity testing of a flower moth, Schinia cognate has been initiated. PARTICIPANTS: Cooperating Agencies on this project were the: USDA ARS- European Biological Control Lab - J. Kashefi; US Forest Service - G. Markin (retired), Flathead & Kootenia NF, Forest Health; University Wyoming - T. Collier; CABI Europe, Delemont, Switzerland - U. Schaffner, G. Grosskopf, & H. Hinz; APHIS, Ft Collins, CO. - R. Hansen & PPQ MT; BLM - J. Milan & J. Simons; US Fish & Wildlife Service - CMR Wildlife Refuge; BBCA, Rome, Italy - M. Christofaro; Nez Perce Biological Control Center; and USDA, ARS - D. Berner. TARGET AUDIENCES: Invasive weeds are recognized to have an adverse economic and ecological impact on crop and rangeland productivity. To manage these invasive weeds, biological control must be effectively utilized by seeking effective agents, determining their long-term impacts on ecological communities and/or on their target weed, and improving their mass rearing, redistribution and monitoring. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
New agents are being investigated for the biological control of Russian knapweed, hoarycress, invasive hawkweeds, and rush skeletonweed. The target weeds have either no biological control agents currently available or the agents already established are not effective over the range of the target weed. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness
Publications
- Littlefield, J. L., Markin, G. P., Puliafico, K. P., and deMeij, A. E. 2008. The release and establishment of the tansy ragwort flea beetle in the northern Rocky Mountains of Montana. In Proceedings of the XII International Symposium on Biological Control of Weeds. 23-27 April 2007, La Grande Motte, France. Littlefield, J.L., Markin, G. P., Kashefi J. and Prody, H. 2008. Habitat analysis of the rush skeletonweed Root moth, Bradyrrhoa gilveolella (Lepidoptera: Pyralidae). XII International Symposium on the Biological Control of Weeds. April 22-27, 2007. La Grande Motte, France.
- Puliafico, K. E., Littlefield, J. L., Markin, G., and Schaffner, U. 2008. Bionomics of the cold adaptive strain of Longitarsus jacobaeae (Waterhouse) (Coleoptera: Chrysomelidae) from Switzerland, a biological control agent of tansy ragwort (Senecio jacobaea). In Proceedings of the XII International Symposium on Biological Control of Weeds. 23-27 April 2007, La Grande Motte, France.
- Kashefi, J., Markin G, and Littlefield, J. 2008. Field studies of the biology of the moth Bradyrrhoa gilveolla (Treitschke) (Lepidoptera: Pyralidae) as a potential biocontrol agent for Chondrilla juncea. In Proceedings of the XII International Symposium on Biological Control of Weeds. 23-27 April 2007, La Grande Motte, France.
- Grosskopf, G., Wilson, L. M., and Littlefield, J.L. 2008. Host range investigations of potential biological control agents of alien invasive hawkweeds (Hieracium spp.) in the United States and Canada. In Proceedings of the XII International Symposium on Biological Control of Weeds. 23-27 April 2007, La Grande Motte, France.
- Markin, G., and Littlefield, J. L. 2008. Biological control of tansy ragwort (Senecio jacobaeae L.) by the cinnabar moth, Tyria jacobaeae (CL) (Lepidoptera:Arctiidae), in the Northern Rockies. In Proceedings of the XII International Symposium on Biological Control of Weeds. 23-27 April 2007, La Grande Motte, France.
- Littlefield, J.L., Grosskopf, G., and Wilson, L. 2008. A petition for the field release of the gall wasp Aulacidea subterminalis (Hymenoptera: Cynipidae), for the biological control of invasive hawkweed in North America. Submitted to the USDA-APHIS-Technical Advisory Group (TAG). 83 p.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Research was conducted on the prerelease screening and post release impacts of several biological control agents of invasive weeds. Host specificity tests of the hoarycress gall mite, Aceria drabae, continues; although mites received from USDA-ARS from Greece and BBCA-Rome from Bulgaria were dead on arrival. These tests will be completed in the spring of 2008. Prerelease screening of a flower infesting noctuid, Schinia cognate, for rush skeletonweed was initiated. Pupae were received from Greece but none emerged as adults; perhaps due to rearing or shipping conditions. Tansy Ragwort biological control has been successfully utilized to limit the spread and density of tansy ragwort in the northwestern potions of Montana. Although the cinnabar moth has been the most effective agent in Montana, Longitarsus jacobaeae is also being evaluated. Several populations of the flea beetle were reared at the MSU quarantine lab. These populations were used for biological studies to
determine differences in the phenology and survivorship of the beetles under different environmental conditions. In addition, the Swiss strain of the beetle was released in the field in isolated ragwort patches. Monitoring plots were established in the tansy ragwort area to determine long term impact on plant density due to the flea beetles. Populations of the tansy ragwort flea beetle have significantly increased in 2007. Both the Oregon (a high elevation population) and Swiss populations have established in Montana. Due to the relatively high population of the beetle we expect to observe impacts on ragwort density starting next year. A habitat matching study continued with the rush skeletonweed root moth Bradyrrhoa gilveolella. Potential release sites in the US and sites with the moth in Greece were characterized as to habitat. These will sites will be compared using multivariate analysis. A survey to determine the distribution in Montana of the field bindweed gall mite, Aceria
malherbae, was initiated. Mites were located in 23 counties, primarily in the eastern half of the state. Additional habitat information was gathered and is currently being analyzed to determine if certain environmental factors are more conducive to the establishment and occurrence of the mite.
PARTICIPANTS: Individuals: J. L. Littlefield (PI) - Montana State University, A. DeMeij (Co PI) - Montana State University, G. Markin (Co PI) - US Forest Service, Rocky Mountain Research Station, U. Schaffner (Co PI) - CABI Europe, H. Hinz (Co PI) - CABI Europe, G. Grosskopf (Co PI) - CABI Europe, J. Kashefi (Co PI) - USDA-ARS-EBCL Greece, L. Wilson (Co PI) - University of Idaho. Partner Organizations: Montana Department of Agriculture, US Forest Service Rocky Mountain Research Station, CABI Europe - Switzerland Centre, USDA-ARS European Biological Control Laboratory, BBCA Rome Italy USDA-ARS NPARL, British Columbia Ministry of Forestry, Bureau of Land Management - Billings. MT, Bureau of Indian Affairs - Billing, MT, USDA-APHIS- PPQ Montana, Wyoming Weed & Pest, University of Idaho, University of Wyoming, Nez Perce Biocontrol Center. Collaborators/Contacts Idaho Rush Skeletonweed Task Force - L. Kinter, M. Hanks, M. Schwartzlander, P. Brusvan; Hoarycress Consortium - M.
Schwartzlander, J. Gaskin, M. Christofaro; Montana Tansy Ragwort Task Force - Montana Hawkweed Task Force; Montana Rush Skeletonweed Task Force; Invasive Hawkweed Biological Control Consortium - L. Wilson; Agriculture & Agri-Food Canada - R. DeFloate & R. Bourchier; British Columbia Ministry of Forestry - S. Turner; US Forest Service - A. Odor, D. Shotzberger, T. Barbouletos; University of Wyoming - T. Collier; Montana State University - S. Sing. Training:Outreach presentations are provided to user groups to update land managers as to the status of research and implementation projects on the biocontrol of invasive weed species. Undergraduate and graduate students are also employed through these projects.
TARGET AUDIENCES: Outreach presentations are providied to user groups to update land managers and other researchers as to the status of research and implemenation projects on the biocontrol of invasive weed species.
Impacts
These projects will contribute to the selection of potentially new biological control agents for the control of noxious weeds. New agents are being investigated for the biological control of Russian knapweed, hoarycress, invasive hawkweeds, and rush skeletonweed. The target weeds have either no biological control agents currently available or the agents already established are not effective over the range of the target weed. In addition, a better understanding of biological control and its implementation will be achieved by monitoring the impacts associated with these biological control agents. In particular the habitat specificity of these arthropods may delineate their potential range or effectiveness.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
Research on the biological control of several invasive weeds was conducted at Montana State University. Hawkweed - The gall wasp Aulacidea subterminalis has been tested on 36 plant species (a total of 463 replications) of which 29 are species native to North America. Galls were only induced on four exotic species: mouse ear hawkweed, H. pilosella (its native host); orange hawkweed, H. aurantiacum; whiplash hawkweed, H. flagellare; and H. floridundum. No native plants were infested. All host plants (with the exception of H. floribundum) are closely related based upon a proposed phylogeny by Gaskin and Wilson (unpublished data) of North American Hieraciums. Gall induction on H. floribundum in the Montanan tests appears atypical since this species was not infested in tests conducted by CABI. DNA testing of H. floribundum plants will be conducted to determine possible crossing with other hawkweeds species. Based upon test results from MSU, as well as testing of Aulacidea
subterminalis at CABI for importation into New Zealand, this wasp appears to be sufficiently host specific for introduction into North America. Hoarycress - A shipment of the gall mite, Aceria drabae was received in May of 2006 from Javid Kashefi (USDA-ARS) from Greece. These were used for host specificity tests. Testing was conducted on 210 plant replications consisting of 18 different plant species. Mites and mite galls were only observed on the target host whitetop (Lepidum draba). Approximately 62% of plants were infested with mites and all but one had galling. The closely related hairy hoarycress, Lepidium appelianum, was not infested. Previous testing indicted that this species or at least this particular haplotype is not a suitable host. In previous tests at MSU, Aceria drabae has only been observed to infest L. draba. Thus far 75 different plant species have been tested, although some species have a low number of replications. Russian knapweed - In the past two years naturally
occurring insects and plant pathogens associated with Russian knapweed have been surveyed at CMR Wildlife Refuge. Very few insects have been found in association with Russian knapweed. The most damaging appears to be several grasshopper species, primarily Melanaplus sanguinipes. Two plant pathogens have been collected for comparison with overseas pathogens being considered for biological control. Although widespread and common, the rust Puccinia acroptili, has been reported for the first time in the literature from Montana (CMR Wildlife Refuge) and Wyoming (Fremont Co. near Bass Lake). A second pathogen, a leaf spot fungus Cercosporella acroptili was also located at the CMR National Wildlife Refuge. This fungus appears identical to an isolate from Turkey (FDWSRU 98-001) based on morphology and DNA ITS 1 and 2 sequences (GenBank #779164). This fungus can cause large numbers of leaves to prematurely die, although this damage appears to have little impact on the plant.
Impacts
For this project I have been investigating the use of insects and mites as potential biological control agents of several invasive weeds. By identifying the host range of these arthropods and determining aspects of their ecology and interactions with their hosts, we are hoping to select weed biocontrol agents that are environmentally safe and effective.
Publications
- Eskandari, F.M., M.B McMahon, W.L. Bruckart, and J. Littlefield. 2006. First Report of Leaf Spot Caused by a Cercosporella sp. on Acroptilon repens in the United States. Plant Dis. 90:833.
- Bruckart, W.L., F.M. Eskandari, A.C Becktell, D. Bean, J. Littlefield, A.L. Pilgeram, D.C. Sands, and M.C Aime. 2006. Puccinia acroptili on Russian Knapweed in Colorado, Montana, and Wyoming. Plant Dis. 90:971.
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Progress 01/01/05 to 12/31/05
Outputs
Host specificity testing of the gall wasp, Aulacidea subterminalis, was nearly completed in 2005. Twenty-one invasive and native hawkweed species and closely related native plants were tested. In all, a total 443 replications of 33 plant species have been tested to date. Galls are only inducted on four species of hawkweed, all invasive species. The wasp appears to be sufficiently host specific for release, although we would like to test one more distantly related plant species, Microseris nutans. A cold adapted strain of the tansy ragwort flea beetle, Longitarsus jacobaeae, has been collected from Switzerland in recent years for release in Montana. In autumn 2005, 24 beetle releases (2003-2005) were surveyed and 13 sites had low levels of adult beetles present. A Mediterranean strain of the beetle collected from Oregon was also released in Montana in 1998-2001. This strain was thought not to be established, but small but growing populations have been located during
surveys conducted in late 2004 and 2005. The impact, interaction and possible hybridization of these two populations of flea beetles will continue to be monitored. The rush skeletonweed root moth, Bradyrrhoa gilveolella, was again imported from northern Greece for rearing and release. Moth populations in Europe were low and only 14 adults were reared from infested roots collected from our Greek site. Over 200 viable eggs were obtained and were sent to the Nez Perce Biological Control Center, Idaho for additional rearing. A small rearing colony has also been established at MSU for biological studies. The gall mite, Aceria malherbae has been established at several sites in Montana. Redistribution of this mite continues in warmer areas of the state. Several studies on the ecology and biology of biological control agents for several invasive weeds have been initiated. A habitat specificity study of the root moth, Bradyrrhoa gilveolella on rush skeletonweed is being conducted to better
select potential release sites for its establishment. Several sites containing the moth were located in previous years in northern Greece and southern Bulgaria but additional sites were needed to make to analysis more robust. Three additional sites were surveyed by USDA-ARS cooperators in 2005. Developmental studies of the rush skeletonweed root moth are also continuing and will develop a degree-day model to better understand its phenology in the field. Dormancy (i.e. diapause) strategies of the tansy ragwort flea beetle are being investigated to determine the survival of beetles under highly variable environmental conditions, such as those found at tansy ragwort infestations in Montana. The two strains of the beetle that are established in Montana have different phenologies, the Swiss beetles overwinters as eggs whereas the Mediterranean beetles generally aestivate during the drier parts of the summer and emerge as adults to lay eggs in the late autumn. A host utilization study of
the gall wasp Aulacidea subterminalis has been initiated for several host hawkweed species to determine which may be a more suitable host or which may be impacted more severely by the wasp.
Impacts
For this project I have been investigating the use of insects and mites as potential biological control agents of several invasive weeds. By identifying the host range of these arthropods and determining aspects of their ecology and interactions with their hosts, we are hoping to select weed biocontrol agents that are environmentally safe and effective.
Publications
- Harris, P. and Littlefield, J. 2005. Aceria malherbae Nuzzaci. Field bindweed leaf- and bud-gall mite. Agriculture & Agri-Food Canada, Lethbridge Research Centre, Classical Biological Control of Weeds Established Biocontrol Agent Web Site. Http://res2.agr.ca/lethbridge/weedbio/agents/aacemal_e.htm
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Progress 01/01/04 to 12/31/04
Outputs
Cardaria/ Lepidium draba - Host specificity testing has been initiated for the gall forming eriophyid mite, Aceria drabae, from Greece. Approximately 53 plant species (including 9 Lepidium species) plus numerous varieties of economic Brassica have been tested to date. The mite appears to be highly host specific, only infesting its natural host Lepidium draba. Tansy Ragwort - Tansy ragwort is a recent invader in the northwestern potions of Montana. Biological control with two populations of the tansy ragwort flea beetle, Longitarsus jacobaeae, has been utilized to limit the spread and density of this weed. In fall 2003/ spring 2004, 11,000 Longitarsus eggs and 35 adult beetles were released in Montana. Recoveries of adults were made at several sites during surveys conducted in August and September 2004. Sites will be monitored for the establishment and impact of the tansy ragwort flea beetle in Montana. Factors limiting its establishment or spread will also be
investigated. Field Bindweed - Convolvulus arvensis is one of the most aggressive, perennial weeds of grain producing areas of North America. To control this weed the leaf galling mite Aceria malherbae has been utilized. Monitoring of previous releases continues to determine long term impacts of the mite. Additional releases of A. malherbae were made at several sites during 2004. One additional site located in Yellowstone Co. was discovered to have a well established mite population. Rush Skeletonweed - Several collections of rush skeletonweed roots infested with Bradyrrhoa gilveolella were made near Lake Prespa in northwestern Greece 2004. Roots were sent or hand carried to the quarantine laboratory located at Montana State University. Adults were reared from infested roots and the resulting larvae were used for field releases, establishing a laboratory colony, and for diet and feeding studies. Viable eggs were also sent to the Nez Perce Biocontrol Center to start a field insectary.
Releases have been made at five sites in southern Idaho during 2003 and 2004. Approximately 2,000 larvae were placed on plants at these field locations. Empty pupal cases were located at several sites indicating the likelihood that Bradyrrhoa will be able to survive the Idaho winters. Studies were also initiated to investigate the effects of temperature on the development of Bradyrrhoa larvae.
Impacts
In this project I have been investigating the use of insects and mites as potential biological control agents of several invasive weeds. By identifying the host range of these arthropods and determining aspects of their ecology and interactions with their hosts, we may be able to have weed biocontrol agents that are environmentally safe and effective in impacting weed populations.
Publications
- Littlefield, J.L. 2004. Field bindweed. In Coombs, E.M., J.K. Clark, G.L. Piper, and A.F. Cofrancesco (eds.) Biological control of invasive plants in the United States. Pp-150-151.
- Littlefield, J.L and W.L. Bruckart. 2004. Musk thistle. In Coombs, E.M., J.K. Clark, G.L. Piper, and A.F. Cofrancesco (eds.) Biological control of invasive plants in the United States. Pp-352-353.
- Littlefield, J.L. and E.M.Coombs 2004. Subanguina picridis. In Coombs, E.M., J.K. Clark, G.L. Piper, and A.F. Cofrancesco (eds.) Biological control of invasive plants in the United States. Pp-224-226.
- Littlefield, J.L. 2004. Russian knapweed. In Coombs, E.M., J.K. Clark, G.L. Piper, and A.F. Cofrancesco (eds.) Biological control of invasive plants in the United States. Pp-201-203.
- Littlefield, J.L. 2004. Aceria malherbae. In Coombs, E.M., J.K. Clark, G.L. Piper, and A.F. Cofrancesco (eds.) Biological control of invasive plants in the United States. Pp-153-154.
- Littlefield, J.L. 2004. Tyta lactuosa. In Coombs, E.M., J.K. Clark, G.L. Piper, and A.F. Cofrancesco (eds.) Biological control of invasive plants in the United States. Pp-155-157.
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Progress 01/01/03 to 12/31/03
Outputs
Hawkweed: Host specificity tests for Aulacidea subterminalis were conducted to determine its potential utilization of native hawkweeds. Twenty-nine plant species (255 different replications) were used in no-choice development tests. Galls were only formed in orange hawkweed, mouse-ear hawkweed, and Hieracium floribundum. Tansy ragwort: Biotypic differences in the phenology and host specificity of several populations of the tansy ragwort flea beetle for use in Montana were studied in Switzerland over the past three years. DNA analysis indicated that the Swiss population of the beetle is very similar to established North American populations introduced from Italy. Nine native North American Senecio and Packera were tested in open field and in no-choice greenhouse studies to determine the specificity of the flea beetle. None were utilized by the Swiss population. Approximately 18,000 eggs and 70 adult Longitarsus jacobaeae were released in Montana during 2002/2003.
Although we observed plants to be infested, no adults were located during the summer of 2003. Due to the dry, hot conditions impacting plant populations, adults could not be located at field sites. Rush skeletonweed: Two collections of roots infested with Bradyrrhoa gilveolella were made in Greece and processed at the MSU quarantine. A laboratory colony was established and over 1200 larvae were released at five field sites in Idaho. Habitat matching of skeletonweed sites, with and without the moth, in Greece and Bulgaria was initiated to determine optimal release site characteristics. Russian knapweed: Aceria acroptilonica (flower mite) and a chrysomelid (Galeruca sp) were collected from Uzbekistan and limited rearing and host specificity tests were conducted within the MSU containment. Spread, plant density, plant height, number of flowers and biomass of twenty Russian knapweed clones were determined for a fourth year. A sister study was also conducted in Turkey by Schaffner (CABI).
The two studies will be used to compare weed ecology in native verses introduced habitats. Field bindweed: One release of Aceria malherbae were made in Yellowstone county. Monitoring of previous releases indicated that the mite successfully overwintered at three sites located in Philips, Richland, and Yellowstone counties.
Impacts
In this project I have been investigating the use of insects and mites as potential biological control agents of several invasive weeds. By identifying the host range of these arthropods and determining aspects of their ecology and interactions with their hosts, we may be able to have weed biocontrol agents that are environmentally safe and effective in impacting weed populations.
Publications
- Puliafico, K. 2003. Molecular taxonomy, bionomics and host specificity of Longitarsus jacobaeae (Waterhouse)(Coleoptera: Chrysomelidae): the Swiss population revisited. M.S. Thesis. Montana State University. 119 pp.
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Progress 01/01/02 to 12/31/02
Outputs
Russian knapweed: Host testing has been completed for the gall flies, Urophora kasachstanica, and Urophora xanthippe. Open field tests using the gall flies were repeated at a site located in Uzbekistan in 2001, and the flowerheads processed in 2002. Both flies appear to be host specific, therefore a biological assessment for the release of the two Urophora species has been submitted. Aceria acroptiloni (flower mite) and a chrysomelid (prob. Galeruca sp) were collected from Uzbekistan and limited rearing and host specificity tests were conducted. Twenty Russian knapweed clones of various sizes were selected in Phillips County, Montana. These were monitored throughout the summer and fall for rate of spread, plant density, plant height, number of flowers and associated insect feeding. In the fall quadrates were clipped for biomass and flower heads were collected to determine seed production. A sister study was also conducted in Turkey by Schaffner (CABI). The two studies
will be used to compare weed ecology in native verses introduced habitats of the plant. Field bindweed: The phenology and population development of Aceria malherbae in Montana for the past three years. Releases were made at sites located in McCone, Gallatin, Phillips, Park and Yellowstone counties. Monitoring of 2001 releases indicated that the mite successfully overwintered at one site near Lambert, MT. Hawkweed: Host specificity tests for Aulacidea subterminalis were conducted to determine its potential utilization of native hawkweeds. Twenty-three plant species (134 different replications) were used in no-choice development tests. Galls were only formed in orange hawkweed and Hieracium floribundum. Tansy ragwort: Biotypic differences in the phenology and host specificity of several populations of the tansy ragwort flea beetle for use in Montana were studied in Switzerland. DNA analysis was conducted to determine the extent of genetic differences among the populations of the beetle
and the presence of Wolbachia. The Swiss population of the beetle appears to be more phenologically adapted to environmental conditions in Montana, and that the beetle is reasonably host specific, thus would be safe for release. A release permit was granted by APHIS and several releases of Longitarsus eggs were made in 2002 in the Flathead National Forest. Rush skeletonweed: In August 200 a small release consisting of plants infested with Bradyrrhoa gilveolella was made in Idaho. Two collections of infested roots were made in Greece and processed at the MSU quarantine to establish a laboratory colony. Habitat matching of skeletonweed sites with and without the moth in Europe will be conducted to determine optimal release site characteristics.
Impacts
Biological control is an important tool for the management of invasive noxious weeds. Projects on Russian knapweed, whitetop, field bindweed, tansy ragwort, rush skeletonweed,and invasive hawkweeds involve the initial stages of screening new biological control agents that are host specific and shows promise in effective limiting these weed species. Studies on the phenology and biologies of these arthropods will help to determine their best utilization in weed management.
Publications
- Littlefield J.L. and A. de Meij. 2002. Biological control of Russian knapweed - Host specificity testing of new agents. Big Horn Weed Steering Committee. Annual Progress Report, Riverton, WY. Nov. 2001.
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Progress 01/01/01 to 12/31/01
Outputs
Russian knapweed - Host specificity testing continued for the flower gall flies Urophora kasachstanica (UK)& Urophora xanthippe (UX), and for the mite Aceria sobhiani. No-choice oviposition tests were conducted on 26 plant species for the UK and 17 species were tested for UX. Open field tests using the gall flies were repeated at two sites located in Uzbekistan in 2001. Nine plant species were tested. Both flies appear to be host specific, thus we expect to have a biological assessment for the release of the two Urophora species completed in 2002. The mite was tested against 14 plant species. The specificity of the mite is not as narrow as the flies, thus it is uncertain whether we will petition for field release of this species. In addition, pre-release field sites were established. Twenty Russian knapweed clones (point infestations) of various sizes were selected in Phillips County, Montana. These were monitored throughout the summer and fall for rate of spread,
plant density, plant height, number of flowers and associated insect feeding. A sister study was also conducted in Turkey by U. Schaffner (CABI). The two studies will be used to compare weed ecology in native verses introduced habitats of the plant. Field bindweed mite - Field plots with the infestations of the gall mite, Aceria malherbae, were established near Roy, MT. Mite phenology and population development has been followed for the past two years to determine the potential impact of the mite on its host. Seven releases of the bindweed mites were made during the summer of 2001. Releases were made in Richland Co., Phillips Co., and Park Co., MT. Four of these releases were made on organic farms, along field borders or in portions of fields dedicated to the release. The other releases were made on relatively undisturbed locations within conservation easements or a wildlife refuge. Orange hawkweed - L. Wilson (Co-PI) U. of Idaho collected or provided approximately 22 different plant
species for testing. The majority of these were either invasive or native hawkweed species. Galls containing a cynipid wasp, Aulacidea subterminalis, were obtained from CABI Bioscience, Switzerland for testing. Adult wasps were reared from the galls and place on 18 plant species (48 different replications) in no-choice development tests. Although galls were formed in the control plants, the numbers were very low. Testing will continue in 2002. Tansy ragwort flea beetle - The objectives of this project are to determine biotypic differences in the phenology and host specificity of several populations of the tansy ragwort flea beetle, Longitarsus jacobaeae, for use in Montana. Study sites have been set up in Switzerland at various elevations to follow the phenology of tansy ragwort and the beetle. In addition, DNA analysis will be conducted to determine differences among the population of the beetle. Host specificity tests were set up in the field in Switzerland and in the quarantine lab
at MSU to determine possible utilization of native Senecio plants by the beetle.
Impacts
Biological control is an important tool for the management of invasive noxious weeds. Projects on Russian knapweed, whitetop (Cardaria spp) and invasive hawkweeds involves the initial stages of screening new biological control agents that are host specific and shows promise in effective limiting these weed species. Currently only one biocontrol agent is available for Acroptilon repens, and none for Cardaria and hawkweeds. Aceria malherbae has been established in Montana for the biocontrol of field bindweed. The increase of mite density and heavy damage to plants at established sites suggest that under suitable conditions the mite may prove to be an effective agent in reducing the competitive nature of field bindweed. The identification and release of a suitable population of the tansy ragwort flea beetle compatible with environmental conditions found in Montana will hopefully lead to long-term suppression of this weed in the Intermountain West.
Publications
- Littlefield, J., deMeij, A., Sobhian, R., Schaffner, U. and Kovacs, E. 2001. Potential Host Range of two Urophora Flies and an Eriophyid Mite for the Biological Control of Russian Knapweed. In L. Smith (ed.), Proceedings of the First International Knapweed Symposium of the Twenty-first Century. 15-16 March, Coeur d'Alene, ID. p. 102.
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Progress 01/01/00 to 12/31/00
Outputs
Russian knapweed (Acroptilon repens)- Studies continue for assessing the host specificity of two Urophora flies and an eriophyid mite for the biological control of Russian knapweed. Sixty-six replications of 29 plant species/ varieties have been dissected to determine the presence of Urophora oviposition. Of these, six species were probed and in five species, eggs were oviposited. U. kasachstanica (UK) seems to be the more host specific of the two flies. Eggs have only been oviposited in Russian knapweed and C. nigra. U. xanthippe (UX) has a slightly different oviposition preference, with eggs being observed in Russian knapweed, spotted knapweed, and C. americana. Larval development studies were also conducted. UK was found to only develop on Russian knapweed. UXs fail to induce galls in the control plants, therefore these tests need to be repeated. A colony of Aceria sobhiani is being maintained for host specificity testing. Plants tested were: Centaurea cyanus, C.
nigra, Antennaria dioca, Cacalia atriplicifolia, Hemizonia pugens, and Russian knapweed (control). After one week mites were only observed on Russian knapweed (except for one mite on C. cyanus). No mites were observed on other plant species. The host-range of potential biological control agents against Russian Knapweed was aslo studied under open field conditions in Uzbekistan.Test plants consisted of: a) plants on which partial or complete larval development were obtained in the laboratory host-range testing, b) a few representatives of indigenous North American test plant taxa, and c) test plant species of commercial value. Results are still being analyzed, but preliminary results of the Urophora flies suggest that the they are host specific. Field bindweed mite(Aceria malherbae)- One hundred and twenty-one 10 x 10 m field plots were established at the Fergus County site and were visited approximately every three weeks from June to late September. Plant density, phenological stage,
infestation and mite numbers were recorded to determine phenological development of the mite and its host. This site was also surveyed for mite infestation in June of 2000. The initial site of release was sprayed in July 1999. One small infestation was found about 0.8 miles from the original release and was used as the study site for the life history studies. Another infestation was located in July from which field releases were made. Two releases were made near Lambert, MT in July and two additional releases were made on organic farms in northwest of Lambert and north of Belgrade, MT. Galls were observed during the summer although at low levels. Aceria drabae, for the control of whitetop (Cardaria spp.)- Twelve species of native and economic mustards were tested against the eriophyid mite, Aceria drabae. No gall development was noted for any test species other than the control Cardaria draba. Although mite populations were able to persist over a month on a few native species, these
eventually declined to extinction. Additional testing of native species is still required before the mite can be considered for release.
Impacts
Aceria malherbae has been established in Montana for the biocontrol of field bindweed. The increase of mite density and heavy damage to plants at established sites suggest that under suitable conditions the mite may prove to be an effective agent in reducing the competitive nature of field bindweed. Projects on Russian knapweed and whitetop (Cardaria spp) involves the initial stages of screening new biological control agents that are host specific and shows promise in effective limiting these weed species. Currently only one biocontrol agent is available for Acroptilon repens and none for Cardaria.
Publications
- Littlefield, J. L. 2000. The use of Eriophyid mites a biological weed control agents in North America. In: N. Spencer (ed.). Proc. of X Internat. Symposium on Biol. Cont. of Weeds, Bozeman, MT. pp. 621-626.
- Littlefield, J. L. and R. Sobhian. 2000. Host specificity of Phyllocoptes nevadensis Roivainen (Acari: Eriophyidae), a candidate for the biological control off leafy and cypress spurges. In: N. Spencer (ed.). Proc. of X Internat. Symposium on Biol. Cont. of Weeds, Bozeman, MT. pp. 683.
- Littlefield, J.L., A. de Meij, and J. Helsley. 1999. Biological control of Russian knapweed - Host testing new agents. Russian Knapweed Consortium. Project Review 1999. Big Horn Basin Exotic Plant Steering Committee. Worland, WY.
- Littlefield J.L. , Littlefield J.L.. 2000. Biological control of Russian knapweed - Host testing new agents. Montana Department of Agriculture. 16 pp.
- Denke, P.M., S. Blodgett and J.L. Littlefield. 2000. Canada thistle biocontrol agent can be collected in alfalfa. Midwest Biological Control News. Vol. VII. No.1.
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Progress 01/01/99 to 12/31/99
Outputs
Russian knapweed (Acroptilon repens) - Host specificity tests of the vagrant mite Aceria sobhiani and two species of Urophora seedhead flies were conducted at the MSU Quarantine Laboratory. Thirty-two plant species including a Russian knapweed control were tested with the mite. The A. sobhiani appears to be restricted to the tribe Cardueae. Although Russian knapweed was the more suitable host, mites were also able to develop on Centaurea americana, Cynara cardunculus, C. scolymus (artichoke) and Silybum marianum. Additional testing will be conducted to determine the suitability of these species as hosts. Twenty-two plant species were tested in 1999 using two species of Urophora. Urophora kasachstanica appears to be host specific to Russian knapweed. Although eggs were also oviposited in Centaurea americana, no larval development occurred. Urophora xanthippe oviposited in a wider range of hosts: Russian knapweed, C. americana, spotted knapweed and yellow starthistle.
No-choice tests indicated that larvae could not develop on these potential hosts. Host testing of endangered and rare thistles was delay due to the plants not flowering. Hoarycress (Cardaria draba) - A preliminary host specificity test plant list for the whitetop mite, Aceria drabae, was completed and sent for review by various cooperators. Seeds of native mustards were collected and sent to Greece for host testing by J. Kashefi (USDA-ARS) during the spring of 1999. Field bindweed (Convolvulus arvensis) - Field plots were established at Fergus County to study the dispersal and distribution of the field bindweed mite, Aceria malherbae. Plant density, gall numbers and biomass samples were taken periodically.
Impacts
Aceria malherbae has been established in Montana for the biocontrol of field bindweed. The increase of mite density and heavy damage to plants at established sites suggest that under suitable conditions the mite may prove to be an effective agent in reducing the competitive nature of field bindweed. This establishment also suggest that the mite has a wide range of climatic adaptability and could potentially be established throughout the range of field bindweed in N.A.
Publications
- McClay, A.S., J.L. Littlefield, and J. Kashefi. 1999. Establishment of Aceria malherbae (Acari: Eriophyidae) as a biological control agent of field bindweed (Convolvulaceae) in the northern Great Plains. Can. Entomol. 131:541-547.
- Littlefield, J.L. and R. Sobhian. 1999. The host specificity of Phyllocoptes nevadensis Roivainen (Acari: Eriophyidae), a candidate for the biological control of leafy and cypress spurges. Abstract. X International Symposium on the Biological Control of Weeds, Bozeman, MT July 4-14.
- Littlefield, J.L.. 1999. The use of Eriophyid mites as biological control agents in North America. Abstract. X International Symposium on the Biological Control of Weeds, Bozeman, MT July 4-14. Littlefield, J.L., A. deMeij, and J. Helsley. 1999. Biological control of Russian knapweed - Host specificity testing of new agents. July 1, 1998 to June 30, 1999. Russian Knapweed Consortium. Project Review 1999. Big Horn Basin Exotic Plant Steering Committee, Worland, WY.
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Progress 01/01/98 to 12/31/98
Outputs
This project is investigating the use of Eriophyid gall mites as possible biological control agents of field bindweed, diffuse/spotted knapweed, Russian knapweed and hoary-cress. The mite Aceria malherbae has been imported from Greece for field bindweed control. Mites have been established at two locations. At one site in Fergus County, mites have dispersed over 50 m from the point of release, and have severely stunted plants in small patches. Host specificity testing is being conducted on three species of mites. Testing on Aceria thessalonicae on diffuse knapweed and Aceria drabae on whitetop continues, and testing of Aceria sobhiani on Russian knapweed has been initiated.
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 01/01/97 to 12/31/97
Outputs
This project is investigating the use of Eriophyid gall mites as possible biological control agents of field bindweed, diffuse/spotted knapweed, Russian knapweed and hoary-cress. The mite Aceria malherbae has been imported from Greece for field bindweed control. Mites have been established at two locations. At one site in Fergus County, mites have dispersed over 50 m from the point of release, and have severely stunted plants in small patches. Host specificity testing is being conducted on three species of mites. Testing on Aceria thessalonicae on diffuse knapweed and Aceria drabae on whitetop continues, and testing of Aceria sobhiani on Russian knapweed has been initiated.
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 01/01/96 to 12/30/96
Outputs
This project is investigating the use of Eriophyid gall mites as possible biological control agents of field bindweed, diffuse/spotted knapweed, Russian knapweed and hoary-cress. The mite Aceria malherbae has been imported from Greece for field bindweed control. From 1993 to 1996, over 507,000 mites have been field released at ten sites. Mites have been recovered at two locations. Laboratory studies were initiated to delineate the combined effects of temperature and A. malherbae on the growth and biomass of field bindweed. Significant differences in plant growth, biomass and root:shoot ratios were observed among the temperatures, with 20o C more optimum for development. Mites had little impact on plants grown at 15o C., whereas at 20o C root biomass was significantly less on mite infected plants although above ground biomass did not differ, and at 25o C root, leaf and stem biomass was significantly less in infested plants compared to the controls. Host testing is
being conducted on four species of mites. Testing is completed for Aceria centaureae on diffuse knapweed and Phyllocoptes nevadensis on leafy and cypress spurge. Testing on Aceria thessalonicae on diffuse knapweed and Aceria drabae on whitetop continues.
Impacts
(N/A)
Publications
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Progress 01/01/95 to 12/30/95
Outputs
Proj. 167 0139029 Littlefield JL Evaluation of gall mites as biological control agents of weeds. This project is investigating the use of Eriophyid gall mites as possible biological control agents of field bindweed, diffuse/spotted knapweed, Russian knapweed and hoary-cress. Field bindweed: The mite Aceria malherbae has been imported from Greece, and is being reared in the Insect Quarantine Lab for field and lab studies. Between 1993 and 1995, over 300,000 mites have been field released at ten sites. In 1995, we recovered mites at four locations. In addition, lab studies are currently being conducted to determine the impact of the mite under various temperature conditions. This year I will be investigating the effects of low level herbicide use on mite development. Host Specificity Testing: Host testing is being conducted on four species of mites. Testing is nearly complete for Aceria centaureae on diffuse knapweed and testing on Aceria thessalonicae is nearly half
completed. Phyllocoptes nevadensis was also tested on leafy and cypress spurge but the mite only damages cypress spurge. This spring we will initiate testing on two new species, Aceria acroptiloni for Russian knapweed and Aceria drabae on whitetop.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 01/01/94 to 12/30/94
Outputs
In 1994, an estimated 298,000 Aceria malherbe were released for the control of field bindweed. Eight releases, including the reinoculation of some 1993 sites, were made in Fergus, Flathead, Gallatin, Roosevelt, Teton, and Yellowstone counties. Host specificty of Aceria centaureae from Greece is being conducted with a total of 46 plant species thus far tested. Further testing of various safflower varieties, as well as, additional species of Asteraceae is needed. The host range of Aceria centaureae is apparently restricted to the Cardueae (Asteraceae) . Galls were induced on nearly all species of Centaurea . The only species attacked outside the genus Centaurea was burdock, Arctium minus. A second population of A. centaureae collected from France was also host tested on 11 plant species (family Asteraceae). Galls were induced on several species of Centaurea, as well as on safflower. The host specificity testing of Aceria thessalonicae is still in the preliminary stage
and to date 21 plant species have been tested. Both diffuse and spotted knapweed appear to be superior hosts.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 01/01/93 to 12/30/93
Outputs
Three shipments of the gall mite Aceria malherbe were received in 1993 at the Insect Quarantine Lab, Montana State University. Mites were collected by the USDA-ARS from Thessaloniki, Greece and from an establish release site located in Texas. Aceria malherbe were reared for field release on field bindweed. An estimated 60,000 mites were released at three sites located in Fergus, Yellowstone and Flathead Counties, Montana. Releases were made from late May to early July. Eleven plants infested with Aceria centaureae were received from the USDA-ARS, Biological Control of Weeds Lab, Thessaloniki, Greece on December 9, 1993. A small rearing colony has been established on diffuse knapweed plants (Montana and Greece). Host specificity studies will be initiated once I am able to augment the mite population to adequate numbers.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 01/01/92 to 12/30/92
Outputs
Developmental studies were conducted on Aphelinus nr. varipes (T90076 USSR, T90085 USSR & T91057 USSR), and A. asychis (T89119 France) (Aphelinidae). Studies were conducted at five temperatures:13,16.5,20, 23.5 and 27 oC. Days to mummification, adult emergence, adult longevity and percent emergence was calculated for each species. There were no significant differences in mean developmental time from egg to adult among parasitoids. Lower development thresholds were estimated between 8.1 to 9.5 oC and degree day requirements ranged from 172.5 to 194.5 days. Adult longevity was greater at lower temperatures, ranging from 8.2 to 33.0 days, whereas from 20 to 27 oC, longevity remained stable, from 1.5 to 4.7 days. The percent adult emergence from mummies was greatest between 16.5 and 23.5 oC (71 - 93%), but decreased significantly at 13 and 27 oC. Life table studies have also been initiated with three species of native parasitoids: Aphidius nr. matricariae, Lysiphlebus sp.,
and Diaeretiella rapae. In 1992, over 4100 individuals, representing 15 different cultures of Aphidiidae and Aphelinidae, were released in Stillwater and Gallatin counties against the Russian wheat aphid and oat bird-cherry aphid.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 01/01/91 to 12/30/91
Outputs
Life-table studies to determine the development, survivorship and adult longevity of exotic Russian wheat aphid parasitoids were conducted at five temperatures (13, 16.5, 20, 23.5 and 27 degrees C). Species utilized were Aphidius matricariae (T90067), Aphidius picipes (T89136) and Diaeretiella rapae (T89013, T90002). Development (egg to adult emergence) did not significantly differ among species except at 13 degree C, where the two Aphidius species developed more rapidly compared to the Diaeretiella cultures (range - 26.6 days A. matricariae to 29.9 days D. rapae (T90002)). Rates of development decreased after 20 degrees C and were fastest at 27 degree C (13.2 to 14.1 days). Lower developmental threshold were estimated to be between 8.3 and 9.1 degree C. Adult emergence from mummies was greater for the two D. rapae cultures compared to the Aphidius species. Percent emergence decreased with temperature, especially above 20 degree C. Emergence ranged from 43 - 80% at 13
degree C, 61 - 68% at 20 degree C, and 14 - 44% at 27 degree C. Adult longevity was greatest at lower temperatures but was not significantly different between sexes. At 13 degree C longevity ranged between 4.5 to 8.5 days.
Impacts
(N/A)
Publications
- LITTLEFIELD, J.L. 1991. Biological control of RWA in Montana utilizing exotic parasitoids and predators - Project summary 1989-1990. Forth Annual RWA Conference, Oct. 10-12, 1990, Unpub. MSU, Bozeman, MT. pp. 170-172.
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Progress 01/01/90 to 12/30/90
Outputs
The purposes of the Insect Quarantine Laboratory are to: (1) contain and isolateimported arthropods and nematodes for use in biological control of weeds and insects programs and for other studies; (2) screen these organisms for parasites, pathogens and other contaminating organisms; and (3) facilitate the introduction, release, augmentation, and study of organisms used for biological control. Thirty one shipments, representing 26+ species, were received at the Insect Quarantine in 1990. Over 30 consignments/releases were made from these shipments. Activities included "pass through screening" of biological control agents for leafy spurge, Canada and musk thistles, knapweeds (spotted, diffuse and Russian), St Johnswort and of grasshopper parasitoids; host specificity testing of leafy spurge and musk thistle insects; and mass rearing and biological studies of insects attacking dalmatian and yellow toadflax and Russian wheat aphid.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 01/01/89 to 12/30/89
Outputs
In fall, 1988, 3 Aphidiid parasitoids (Aphidius matricariae, A. rhopalosiphi, and Ephedrus plagiator) were released against the Russian wheat aphid at an insectary site located in Bozeman, Montana. Although the wheat at the insectary did not survive the winter, parasitoids both native and introduced, were recovered from the plant debris in 1989. These have been tentatively identified as A. rhopalosiphi, Praon sp. and Aphelinus sp. Additional field releases of three parasitoid species were made in the fall of 1989. Sites will be revisited in 1990 to determine overwintering success. Also, releases of three Coccinellid species, Hippodamia variegata, Propylea quatuordecimpunctata, and Scymnus frontalis were made in Stillwater County in CRP land infested with Russian and western wheat aphids. Studies are currently underway to determine the effects of temperature on the rate of development, adult longevity and fecundity and survivorship of aphid parasitoids. Colonies of the
Russian wheat aphid (Diuraphis noxia), western wheat aphid (Diuraphis tritici), "oat bird-cherry aphid" (Rhopalosiphum padi), and corn leaf aphid (Rhopalosiphum maidis), as well as the parasitoids Aphidius matricariae, Aphidius rhopalosiphi and Diaeretiella rapae are being reared.
Impacts
(N/A)
Publications
- NOWIERSKI, R. M. and J. L. LITTLEFIELD. 1989. Exotic parasitoids of the Russian wheat aphid--Montana's Efforts. Proceedings of the Second Russian Wheat Aphid Workshop. Denver, CO, October, 1988. p. 36.
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