Progress 06/16/10 to 09/30/13
Outputs
Target Audience: Homeowners, landscape managers, groundskeepers, golfcourse superintendents, park and natural areas maintenance staff, school groundskeepers, Master Gardeners, extension staff, researchers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? This project supported the training of a PhD student in the fields of biological control and entomology. In addition, the lead investigator was able to participate in a number of research conferences and extension activities where the project results were disseminated. Examples of theseactivities are listed in the ‘Other Products’ section of this report and include participation in the UConn Turf Field Day for turf professionals, workshops on pest management for green industry workers, presentations to the public and to researchers at regional and national entomological meetings. How have the results been disseminated to communities of interest? Four publications have been submitted for peer-review, one fact sheet has been posted on the UConn IPM website,25 research reports and other publications have been developed and 18 presentations on Tiphia research andbiocontrol in turfhave been given. 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 important scarab beetle species, the Japanese beetle and oriental beetle are considered invasive species and have been reported as key pests of urban landscapes and of various other agricultural settings in the Northeast. The larvae of Japanese beetles (white grubs) primarily feed on the roots of a wide variety of plants, including all cool season grasses and most weeds that are commonly found in turfgrass sites. The root-feeding larvae of oriental beetles, are a major pest of blueberries, ornamental nurseries, and turfgrass. Tiphia vernalis (Spring Tiphia) and Tiphia popilliavora (summer Tiphia), were introduced as part of the biological control effort against Japanese beetle. This project has increased our knowledge on Tiphia parasitoids of white grubs which is necessary in order to develop more biologically-based pest management strategies against scarab pests. The data collected through this effort allowed target audiences to learn about: Tiphia parasitoids distribution and seasonal timing in CT, NH and MA; conservation biological control of Tiphia species (low risk IPM tactic) using landscape ornamental plants; and how to enhance Tiphia wasp activity and survival. Results from this project indicate that peonies are the best plants to attract and provide nectar to the spring Tiphia while wild carrot flowers are the only ones that significantly attract the summer Tiphia. These plants provide essential nectar to these wasps. In addition, the following key findings have been obtained on Tiphia host selection behaviors: a) Research for this project demonstrated for the first time that T. vernalis and T. popilliavora females are significantly attracted to volatiles emanating from grub infested Kentucky bluegrass and tall fescue over uninfested plants of the same species. The two Tiphia species do not show a preference for volatiles from either infested or uninfested perennial ryegrass. b) The study also showed that monoterpene levels emitted by grub-infested Kentucky bluegrass and tall fescue were significantly greater than that of control plants. Monoterpenes could not be identified from control and test perennial ryegrasses due to the extremely low concentrations measured. c) Behavioral studies of Tiphia and the host grubs demonstrated the importance of considering the host defensive responses and subsequent responses of the parasitoid. Overwintered, third instar oriental beetle grubs spent significantly longer time on defensive behaviors when they were attacked by T. vernalis which likely cause wasps to spend longer time trying to sting oriental beetle grubs. The active host resistance gained through behavioral defenses could make oriental beetle grubs less susceptible to T. vernalis attack than Japanese beetle grubs, especially under field conditions. Younger grubs attacked by T. popilliavora did not exhibit these differences. d) New information was produced on the cues used by T. popilliavora to find grubs once it is searching for hosts in the soil.
Publications
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Legrand, A. 2013. May is the time for Spring Tiphia. Accredited Organic Land Care Professionals Newsletter. May 2013. http://www.organiclandcare.net/education/olc-articles/may-time-spring-tiphia
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Legrand, A. 2012. Survey of Tiphia parasitoids of the Japanese and oriental beetles in Massachusetts and New Hampshire. 2012 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Obeysekara, P. and A. Legrand. 2012. Analysis of preovipositional behaviors of summer tiphia (Tiphia popilliavora) on larvae of Japanese and oriental beetles. 2012 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Obeysekara, P. and A.Legrand. 2012. Behavioral defenses of Japanese and oriental beetle larvae against tiphiid wasps. 2012 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Type:
Other
Status:
Published
Year Published:
2012
Citation:
Legrand, A. 2012. Ornamental plants that help the natural enemies of white grubs.
IPM Program Fact Sheet. University of Connecticut Cooperative Extension System.
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Tiphia popilliavora was introduced as part of the biological control effort against the Japanese beetle. The objective of this study was to determine if the sequence, duration, and frequency of preovipositional behaviors vary when the wasp attacks Japanese vs. oriental beetle grubs. An observation chamber was used to simulate below-ground conditions and a video camera was used to record each oviposition event. The sequence of preovipositional behaviors on Japanese and oriental beetles was developed using lag sequential analysis. Female wasps of T. popilliavora performed six distinct behaviors when they attack grubs. These pre-ovipositional behaviors are: stinging, examining, moving soil, kneading, host-feeding, and host scraping. The sequence of pre-ovipositional behaviors by T. popilliavora did not show a difference between Japanese and oriental beetles hosts. There was also no significant difference between the two host species in total number of occurrences for each wasp behavior. However, of the six behaviors leading to oviposition, T. popilliavora spent significantly longer time stinging oriental beetles compared to Japanese beetles. In contrast, the wasp spent significantly more time scraping Japanese beetles than oriental beetles. Oriental beetle grubs showed a higher frequency of vigorous movements with initial contact with the wasps' antennae than did Japanese beetle grubs. This could explain the longer time the wasp spent on stinging to paralyze oriental beetles. Scraping using the ovipositor sheath and abdominal rasping may enlarge and roughen the crease between fifth and sixth abdominal segments by wearing away the integument. If the integuments of Japanese and oriental beetle grubs are texturally different, then it might explain why the duration of host scraping by T. popilliavora varies between two host species. A second study focused on the defensive behaviors of Japanese and oriental beetle grubs in response to Tiphia parasitoid attack. The sequence, duration, and frequency of defensive behaviors were analyzed when grubs were attacked by Tiphia vernalis and T. popilliavora. The grub defensive behaviors were broadly divided into three categories: vigorous movements, rubbing their abdomen or head against the wasp's abdomen, and biting at the attacking wasp. Of the three defensive behaviors, both grub species spent longer time on vigorous movements and these movements lasted up to ~ 6 min. Grubs were observed to twist and turn with quick writhing movements. As soon as the wasp advanced onto the grub, the grub crawled rapidly and burrowed away from the wasp. When the grubs were attacked by T. vernalis, vigorous movements were performed more often by oriental than Japanese beetles. There was no difference in the number of biting acts and number of times grubs rubbed their head or abdomen against wasp's abdomen. There was no difference in the number of vigorous movements, number of biting events, or number of rubbing acts between the grub species when under attack by T. popilliavora. There was also no significant difference between the two grub species in their total duration of vigorous movements and rubbing acts. PARTICIPANTS: Ana Legrand, Project Director and Piyumi Obeysekara, Ph.D student. TARGET AUDIENCES: Homeowners, landscape managers, groundskeepers, golfcourse superintendents, park and natural areas maintenance staff, school groundskeepers, Master Gardeners, extension staff. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Two important scarab beetle species, the Japanese beetle and oriental beetle are considered invasive species and have been reported as key pests of urban landscapes and of various other agricultural settings in the Northeast. The larvae of Japanese beetles primarily feed on the roots of a wide variety of plants, including all cool season grasses and most weeds that are commonly found in turfgrass sites. The root-feeding larvae of oriental beetles, are a major pest of blueberries, ornamental nurseries, and turfgrass. Tiphia vernalis (Spring Tiphia) and Tiphia popilliavora (summer Tiphia), were introduced as part of the biological control effort against Japanese beetle. This project has increased our knowledge about Tiphia parasitoids that attack pest scarab beetles. We now have a better understanding of pre-ovipositional wasp behaviors and of grub defensive behaviors that could potentially explain in part parasitism levels observed in the field. Results from this project show that the occurrence and duration of Tiphia behaviors can differ depending on the scarab host species and host age. In general, the data collected through this effort will allow target audiences to learn about: Tiphia parasitoids distribution, seasonal timing and impact; conservation biological control involving Tiphia species (low risk IPM tactic); how to enhance Tiphia wasp activity and survival and to know how to integrate this biocontrol tactic into pest management plans for turfgrass or other settings. The goals for the intermediate impacts of this project are to promote the use of conservation biocontrol and to reduce the use of insecticides against selected scarab beetles. The long term impacts of this work would be to reduce human exposure to pesticides applied in public/private outdoor areas (general public, staff), reduce non-target impacts and to reduce costs of pest management efforts against target pests. In addition to change in knowledge impacts, this project is also providing training to a PhD student in the fields of biological control and entomology increasing research capacity in these fields.
Publications
- Legrand, A. Ornamental plants that attract Tiphia parasitic wasps of Japanese & oriental beetles. 2012. IPM Program Fact Sheet. University of Connecticut Cooperative Extension System. June 30, 2012.
- Legrand, A. 2012. Use of peonies to increase Tiphia vernalis parasitism on white grubs. Turfgrass Field Day Research Summaries. July 17 2012. College of Agriculture and Natural Resources, University of Connecticut.
- Obeysekara, P., Legrand, A.. Do Tiphiid wasps use herbivore-induced plant volatiles for finding white grubs 2012. Connecticut Conference on Natural Resources Proceedings. Storrs, CT. March 2012.
- Obeysekara, P. and A. Legrand. 2011. Systemic release of herbivore-induced plant volatiles by cool season turfgrasses infested by root feeding larvae of Japanese beetle (Popillia japonica Newman) and Oriental beetle (Anomala orientalis). 2011 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Obeysekara, P. and A. Legrand. 2011. The ability of tiphiid wasps to detect kairomones and frass from scarabaeid grubs at some distance in the soil. 2011 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Obeysekara, P. and A. Legrand. 2012. Systemic release of herbivore-induced plant volatiles by cool season turfgrasses infested by root feeding larvae of Japanese beetle (Popillia japonica Newman) and Oriental beetle (Anomala orientalis).Turfgrass Field Day Research Summaries. July 17 2012. College of Agriculture and Natural Resources, University of Connecticut.
- Obeysekara, P. and A. Legrand. 2012. The ability of tiphiid wasps to detect kairomones and frass from scarabaeid grubs at some distance in the soil. Turfgrass Field Day Research Summaries. July 17 2012. College of Agriculture and Natural Resources, University of Connecticut.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Experiments were conducted to better understand the nature of turfgrass plant volatiles produced as a result of root herbivory. This information is key to elucidating the host location mechanisms employed by Tiphiid wasps. Plant volatiles were collected from Kentucky bluegrass, tall fescue, and perennial ryegrass . These plants were grown in separate pots and grown in a plant growth chamber for 8 weeks. Third instar Japanese and Oriental beetle larvae were introduced to half of the plants and allowed to feed on the roots for a week. The other plants were kept without grubs to serve as controls. Plant volatiles were collected by dynamic headspace sampling from the upper part of the plant. For each grass species volatiles were collected simultaneously from a grub infested and a healthy plant. Plants were placed individually in glass volatile collection chambers. Clean air was passed through each chamber at 200 mL/min and was pulled at 100 mL/min through a collection trap. The collection traps contained Tenax-GR absorbent. The volatiles were collected for 24-h period (including 12-h-photoperiod). Volatile analysis was done by GC-MS and the compounds were tentatively identified using NIST MS 2011 mass spectrum database search. The area under an identified peak was integrated using a single m/z fragment from the total-ion spectrum for each compound. The study showed that monoterpene levels emitted by grub-infested Kentucky bluegrass and tall fescue were greater than that of control plants. Low levels of monoterpenes were observed for both test and control of perennial ryegrass. In addition to the analysis of turfgrass volatiles, experiments were conducted on Tiphia wasp search behavior. Dual-choice tests were conducted to test whether or not T. vernalis and T. popilliavora can respond to cues at varying distances in the soil. Host frass and other cues were buried in a soil column at a depth of 0, 2, or 5 cm from the junction of a Y-tube, and wasps were tested for successful discrimination of the arm containing cues. The ability of T.vernalis to detect cues at 2 and 5cm were examined whereas for T. popilliavora, cues at depth 0, 2, and 5 cm were examined. Third-instar Japanese and Oriental beetle larvae were reared in separate cups for 2-7 days and the soil from those cups was used as the source of cues. The amount of soil packed at each depth was 12.5g and the soil containing cues was then covered with moist autoclaved soil up to the junction. Only moist autoclaved soil was used to pack the other arm of the tube. Each parasitoid was tested by placing it on the Y-tube stem entrance and scoring its choice between two arms. A total of 250 female Tiphiid parasitoids were tested. The study showed that at a depth of 2 cm both T. vernalis and T. popilliavora chose the arm filled with cues more often than the than the opposite arm. When the cues were buried at 5cm, the two Tiphia species did not show a preference for arm with cues or without cues. At a depth of 0 cm, T.popilliavora chose the arm containing cues significantly more often than the opposite arm. PARTICIPANTS: Ana Legrand, Project Director and Piyumi Obeysekara, Ph.D. student. TARGET AUDIENCES: Homeowners, landscape managers, groundskeepers, golfcourse superintendents, park and natural areas maintenance staff, school groundskeepers, Master Gardeners, extension staff. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This project will increase our knowledge about Tiphia parasitoids that attack pest scarab beetles. The data collected through this effort will allow target audiences to learn about: Tiphia parasitoids distribution, seasonal timing and impact; conservation biological control involving Tiphia species (low risk IPM tactic); how to enhance Tiphia wasp activity and survival and to know how to integrate this biocontrol tactic into pest management plans for turfgrass or other settings. The goals for the intermediate impacts of this project are to promote the use of conservation biocontrol and to reduce the use of insecticides against selected scarab beetles. The long term impacts of this work would be to reduce human exposure to pesticides applied in public/private outdoor areas (general public, staff), reduce non-target impacts and to reduce costs of pest management efforts against target pests. In addition to change in knowledge impacts, this project is also providing training to a PhD student in the fields of biological control and entomology.
Publications
- Legrand, A. 2011. Tiphia parasitic wasps take on Japanese and Oriental beetle grubs. Home & Garden News, May/June 2011. Home and Garden Education Center. College of Agriculture and Natural Resources, University of Connecticut.
- Obeysekara, P. and A. Legrand. 2011. Do tiphiid wasps use herbivore induced plant volatiles for finding white grubs p. 81- 83. In K. Guillard (ed), 2010 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Obeysekara, P. and A. Legrand 2011. Do Tiphiid Wasps Use Herbivore-Induced Plant Volatiles for Finding White Grubs Connecticut Conference on Natural Resources Proceedings, Storrs, CT. March 2011.
- Ramoutar, D., A. Legrand and S. Alm. 2010. Field effectiveness of Metarhizium anisopliae F52 (Deuteromycota: Hyphomycetes) against larvae of Popillia japonica (Coleoptera: Scarabaeidae) and Listronotus maculicollis (Coleoptera: Curculionidae) in turfgrass. Journal of Entomological Science 45:1-7.
- Legrand, A. 2010. Parasitism rates of Tiphia vernalis in Connecticut. IPM Program. Biocontrol of White Grubs Fact Sheets. August 2010.
- Legrand, A. 2010. Evaluation of ornamental plants as nectar sources for Tiphia parasitoids. Connecticut Conference on Natural Resources Proceedings, Storrs, CT. March 2011.
- Legrand. A. 2011. May is the time for the Spring Tiphia. UConn Turfgrass Update. May 2011.
- Legrand, A. 2011. Evaluation of landscape ornamental and herb plants as nectar sources for Tiphia parasitoid wasps. p. 84 - 87. In K. Guillard (ed), 2010 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Legrand, A. 2011. Color preference of the Japanese beetle parasitoid Tiphia vernalis. p. 88. In K. Guillard (ed), 2010 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Two important white grub species, the Japanese beetle (Popillia japonica) and Oriental beetle (Anomala orientalis) have been reported as key pests of urban landscapes in the Northeast. Two parasitoid species, Tiphia vernalis and Tiphia popilliavora, were introduced as biocontrol agents against these beetle pests. It is still unclear whether these parasitoids can locate host patches at some distance above ground and little is known about the role of herbivore-induced plant volatiles in their host habitat location. One component of this project conducted by a Ph.D. student seeks to increase our understanding of how T. vernalis and T. popilliavora locate their hosts. To this end, two-choice bioassays were conducted in a Y-tube olfactometer to test whether wasps are attracted to herbivore-induced plant volatiles. Plants for these tests included Kentucky bluegrass Poa pratensis L., tall fescue Festuca arundinacea Schreb., and perennial ryegrass Lolium perenne L. These plants were grown in separate pots and grown in a plant growth chamber for 6 weeks. Third instar grubs of P. japonica and A. orientalis were introduced to half of the plants and allowed to feed on the roots for a week. The other plants were kept without grubs to serve as controls. For the bioassays, air was filtered through activated charcoal, humidified, and split into two air streams that were fed each through a glass chamber and then to one of the Y-tube olfactometer arms at a flow of 1 l min-1 in each arm. At the end of the stem, air was drawn out at a rate of 2 l min-1. A small pot with a given turfgrass species was placed in each of the glass chambers so that air could pass above the plants and be directed to the Y-tube olfactometer. Experiments were performed between 0900 and 1700 hours at 20-25 C and 50-60% RH, using a light bulb (50W) positioned above the olfactometer. The pots were sealed using Teflon bags in order to prevent odor contamination from the pots or soil before placing the plants in the glass chambers. Each parasitoid was tested by placing it on the Y-tube stem entrance and scoring its choice between a plant that had been exposed to grub feeding vs. a control uninfested plant. A total of 255 female Tiphiid parasitoids were tested. For these experiments, T. vernalis were collected during early May to mid June while T. popilliavora were collected during August to early September. The study demonstrated that T. vernalis and T. popilliavora females were significantly attracted to volatiles emanating from grub infested Kentucky bluegrass and tall fescue over uninfested plants of the same species. The two Tiphia species did not show a preference for volatiles from either infested or uninfested perennial ryegrass. The next step in this research will be to elucidate the volatile profiles of infested vs. uninfested turfgrass species used for this study. Other outputs include: digital public display presentation on natural enemies, IPM Bug Bingo to teach about insect natural enemies including Tiphia parasitoids, and a poster presentation titled: Do Tiphiid wasps use herbivore-induced plant volatiles for finding white grubs PARTICIPANTS: Ana Legrand, Project Director Piyumi Obeysekara, Ph.D. student TARGET AUDIENCES: Homeowners, landscape managers, groundskeepers, golfcourse superintendents, park and natural areas maintenance staff, school groundskeepers, Master Gardeners, extension staff. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This project will increase our knowledge about Tiphia parasitoids that attack pest scarab beetles. The data collected through this effort will allow target audiences to learn about: Tiphia parasitoids distribution, seasonal timing and impact; conservation biological control involving Tiphia species (low risk IPM tactic); how to enhance Tiphia wasp activity and survival and to know how to integrate this biocontrol tactic into pest management plans for turfgrass or other settings. The goals for the intermediate impacts of this project are to promote the use of conservation biocontrol and to reduce the use of insecticides against selected scarab beetles. The long term impacts of this work would be to reduce human exposure to pesticides applied in public/private outdoor areas (general public, staff), reduce non-target impacts and to reduce costs of pest management efforts against target pests. To date information has been generated about suitable plants that attract Tiphia wasps and could be used in conservation efforts and about factors relevant to the host searching behavior of these parasitoids.
Publications
- Legrand. A. 2010. Evaluation of landscape ornamental plants as nectar plants for Tiphia vernalis. UConn Turfgrass Field Day Research Summaries. College of Agriculture and Natural Resources, University of Connecticut.
- Legrand. A. 2010. Evaluation of landscape ornamental plants as host plants for pest scarab beetles. UConn Turfgrass Field Day Research Summaries. College of Agriculture and Natural Resources, University of Connecticut.
- Legrand. A. 2010. Evaluation of ornamental plants as nectar sources for summer Tiphia parasitoid wasps. UConn Turfgrass Field Day Research Summaries. College of Agriculture and Natural Resources, University of Connecticut.
- Legrand, 2009. Evaluation of landscape ornamental plants as nectar plants for Tiphia vernalis and as host plants for pest scarab beetles. p. 73-76. In K. Guillard (ed). Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Legrand, 2009. Evaluation of ornamental plants as nectar sources for summer Tiphia. p. 77-79. In K. Guillard. 2009 Annual Turfgrass Research Report, College of Agriculture and Natural Resources, University of Connecticut.
- Legrand, A. 2009. Drubbing Grubs Naturally. TurfGrass Trends September 1. Pg. 49-52. On-line:http://www.turfgrasstrends.com/turfgrasstrends/Turf+maintenan ce/Drubbing-Grubs-Naturally/ArticleStandard/Article/detail/630612
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