Progress 07/01/07 to 06/30/12
Outputs
OUTPUTS: This project focuses on management of Banks grass mite in corn, with emphasis on the development of new miticidal treatments, as well as potential nonchemical alternatives. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Several experimental corn hybrids, containing one of two sources of resistance, were evaluated for resistance to Bank grass mite. Hybrids containing either source were less damaged than susceptible hybrids and a variety of available inbreds. However levels of resistance were not deemed to be sufficient for commercial use. Additionally, hybrids with soon to be commercialized drought traits were infested and evaluated for mite damage, with similar results. Also, for three years more mites were observed on plants in minimum till plots than on those in conventionally tilled plots, with intermediate densities noted on plants in strip-till plots. Twelve unregistered miticides, at various rates and with several adjuvants, were compared to commercial standards. Nine were applied preventively and three were applied reactively. One from each category performed as well or better than the corresponding commercial standard in the years in which mite abundance was adequate for treatment comparisons. Control studies on brown wheat mite, Petrobia latens, were conducted. Results from Russian wheat aphid insecticide trials co-infested with brown wheat mite suggested that the most effective Russian wheat aphid treatments also were effective against brown wheat mite. Early and late treatments with dimethoate at Lamar were equally effective in reducing mite abundance, however, yield benefit was observed only for the early treatment. Host range observations suggested that brown wheat mite is found only on cool season grasses. Exposing diapausing mite eggs to several photophases per day shortened time to hatch relative to eggs held under normal photoperiod conditions. PARTICIPANTS: F. Peairs, PI S. Hessler, Graduate student S. Merrill, Post Doctoral Associate T. Randolph, Research Associate J. Rudolph, Research Associate C. Walker, Research Associate C. Chaulk-Grace, Syngenta Seeds, Collaborator A. Wieland, Syngenta Seeds, Collaborator TARGET AUDIENCES: The primary target audience for this project is Colorado corn producers and those who advise them. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Mite-resistant hybrids would allow reduced pesticide use in corn production. The same could be true for drought tolerant corn hybrids, given the known association between drought stress and Banks grass mite abundance. Comite was the only registered preventive corn miticide for many years, until the registration of Oberon and more recently Onager. The registration of additional effective preventive miticides would further reduce the risk for resistance development. Currently, there is only one consistently effective reactive miticide treatment. The registration of additional reactive miticides would reduce the risk of resistance development for those producers who base treatment decisions on mite abundance. Brown wheat mite recently has emerged as a significant pest of winter wheat. Effective miticides are available, but growers need guidance regarding when treatment will be cost effective. Nothing is known about the effectiveness of other pest management approaches. Movement from winter wheat to noncultivated hosts is an important aspect of brown wheat mite field ecology and may provide insights into sampling strategies and management options. The ability to terminate egg diapause would eliminate one barrier to mass rearing this pest, which in turn would allow controlled infestations for plant resistance screening, as well as other management studies.
Publications
- Peairs, F. B., J. B. Rudolph, and T. L. Randolph. 2012. 2011 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR12-09, 37 pp.
|
Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: This project focuses on management of Banks grass mite in corn, with emphasis on the development of new miticidal treatments, as well as potential nonchemical alternatives. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. An experimental corn hybrid, containing a soon to be commercialized drought tolerance trait, and a conventional hybrid were infested with Banks grass mite. Infestations were not uniform enough to compare mite performance, and future comparisons likely will need to be made under more controlled conditions. Banks grass mite abundance was evaluated on corn plants under conventional, strip and minimum tillage. More mites were observed on minimum till plants than on conventionally tilled plants, with intermediate densities noted in the strip-till plots. Six unregistered miticides, at various rates and with several adjuvants, were compared to commercial standards. Four were applied preventively and two were applied reactively. Mite abundance was adequate for valid comparisons. One from each category performed as well or better than the corresponding commercial standard. Control studies on a second spider mite, Petrobia latens, the brown wheat mite were continued. Early and late treatments with dimethoate at Lamar were equally effective in reducing mite abundance. However, yield benefit was observed only for the early treatment. Host range observations suggested that brown wheat mite is found only on cool season grasses. Brown wheat mite infested an experiment designed to evaluate insecticides for Russian wheat aphid control. No statistical differences were observed, however, treatment rankings were similar to those observed in a similar study in 2009. Preliminary results suggested that exposing diapausing mite eggs to several photophases per day shortened time to hatch relative to eggs held under normal photoperiod conditions. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: The primary target audience for this project is Colorado corn producers and those who advise them. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Drought tolerant corn hybrids might be less prone to mite infestation, given the known association between drought stress and Banks grass mite abundance. Comite was the only registered preventive corn miticide for many years, until the registration of Oberon and more recently Onager. The registration of additional effective preventive miticides would further reduce the risk for resistance development. Currently, there is only one consistently effective reactive miticide treatment. The registration of additional reactive miticides would reduce the risk of resistance development for those producers who base treatment decisions on mite abundance. Brown wheat mite recently has emerged as a significant pest of winter wheat. Effective miticides are available, but growers need guidance regarding when treatment will be cost effective. Nothing is known about the effectiveness of other pest management approaches. The ability to terminate egg diapause would eliminate one barrier to mass rearing this pest, which in turn would allow controlled infestations for plant resistance screening, as well as other management studies.
Publications
- Merrill, S. C., S. M. Walter, F. B. Peairs, and J. A. Hoeting. 2011. Spatial variability of western bean cutworm (Lepidoptera: Noctuidae) pheromone trap captures in sprinkler irrigated corn in eastern Colorado. Environmental Entomology 40: 654-660
- Peairs, F. B., J. B. Rudolph, and T. L. Randolph. 2011. 2010 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR11-03, 31 pp.
|
Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: This project focuses on management of Banks grass mite in corn. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. 36 experimental corn hybrids and 72 inbreds, obtained from Syngenta were evaluated for Banks grass mite damage. Differences in mite damage among inbreds were noted, which were consistent with results from previous years. Logistical problems precluded yield measurements, so it is still unknown whether these differences would be sufficient to reduce mite yield effects. Banks grass mite abundance has been observed in corn under three irrigation regimes for the past six years. In the three years with measurable infestation, mite densities were inversely correlated with the amount of irrigation water applied. Twenty miticide treatments were evaluated for efficacy against Banks grass mite. Mite abundance was unusually severe, however, treatments containing hexythiazox or spiromesifen continued to provide good levels of control. A spiromesifen treatment and a fenpyroximate treatment outyielded the untreated control by 24 and 16%, respectively. Control studies on a second spider mite, Petrobia latens, the brown wheat mite were continued. However, mite abundance was too low to provide any useful results. The efficacy of several transgenic traits were evaluated for efficacy against western bean cutworm, Striacosta albicosta. Those traits expressing Cry 1F protein were effective, and no western bean cutworm larvae or damage were observed on hybrids with the SmartStax event. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: The primary target audience for this project is Colorado corn producers and those who advise them. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Banks grass mite management will be an important consideration for growers attempting to produce corn under limited or conservation irrigation regimes. Propargite was the only registered preventive corn miticide for many years, until the registration of spiromesifen and more recently hexythiazox. Both appear to be highly effective and have different modes of action, greatly reducing concerns regarding resistance development. The relative performance of propargite has declined in recent years, which may be an indication of resistance. Brown wheat mite recently has emerged as a significant pest of winter wheat. Effective miticides are available, but growers need guidance regarding when treatment will be cost effective. Nothing is known about the effectiveness of other pest management approaches, and progress in this area will be limited until suitable rearing methods are developed. Using corn hybrids with transgenic events effective against western bean cutworm allows growers to avoid the use of broad spectrum insecticides, which, in turn, may help avoid secondary Banks grass mite outbreaks.
Publications
- Peairs, F. B., J. B. Rudolph, and T. L. Randolph. 2010. 2009 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR10-03, 36 pp.
- Merrill, S. C., A. Gebre-Amlak, J. S. Armstrong, and F. B. Peairs. 2010. Nonlinear degree-day models for postdiapause development of the sunflower stem weevil (Coleoptera: Curculionidae). J. Econ. Entomol. 103: 302-307
|
Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: This project focuses on management of Banks grass mite in corn, with emphasis on the development of resistant inbreds and hybrids. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Thirty-six experimental corn hybrids, based on resistance evaluations in 2007, were obtained from Syngenta and planted at ARDEC and LaSalle with two levels of infestation. Three inbred nurseries, with a total of 1100 inbreds, also were established. One inbred set was observed at two locations, while the other was replicated twice. Differences in mite damage among inbreds were noted, which were consistent between locations or reps. It is still unknown whether these differences would be sufficient to reduce mite yield effects. Twenty miticide treatments were evaluated for efficacy against Banks grass mite. Mite abundance was unusually low, precluding any useful comparisons. Control studies on a second spider mite, Petrobia latens, the brown wheat mite were initiated. Five varieties of winter wheat infested with brown wheat mite were treated with dimethoate at two growth stages. Only miticide treatment affected mite abundance, and earlier treatments were more effective at reducing total mite days in the crop. In a second study, brown wheat mite was sampled following overhead irrigation, fertilizer topdressing and treatment with either chlorpyrifos or dimethoate. Only the insecticide treatments had a lasting effect on mite density, and the two insecticides were equally effective. Mite observations in a planting date by seeding rate study suggested that mite abundance was affected by planting date, but not seeding rate. Finally, mite abundance was determined in treated and untreated areas of a commercial winter wheat field. Dimethoate was effective against brown wheat mite, and the untreated area yielded 45% less than the treated area. PARTICIPANTS: F. B. Peairs, PI S. Merrill, Post Doctoral Associate T. Randolph, Research Associate J. Rudolph, Research Associate C. Walker, Research Associate C. Chaulk-Grace, Collaborator A. Wieland, Collaborator TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Brown wheat mite was added as a second mite of interest.
Impacts
Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Comite was the only registered preventive corn miticide for many years, until the registration of Oberon and more recently Onager. Both appear to be highly effective and have different modes of action, greatly reducing concerns regarding resistance development. Brown wheat mite recently has emerged as a significant pest of winter wheat. Effective miticides are available, but growers need guidance regarding when treatment will be cost effective. Nothing is known about the effectiveness of other pest management approaches.
Publications
- Peairs, F. B., J. B. Rudolph, and T. L. Randolph. 2009. 2008 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR09-11, 27 pp.
|
Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: This project focuses on management of Banks grass mite in corn, with emphasis on the development of resistant inbreds and hybrids. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Thirty-six experimental corn hybrids, based on resistance evaluations in 2007, were obtained from Syngenta Seeds and planted at ARDEC with two levels of infestation. No hybrid effects on mite abundance or mite effects on grain yield were noted, however, 50% hail damage followed by several heavy rain events was experienced starting on August 14. These events terminated mite activity about a month earlier than normal, making any results obtained inconclusive. Two inbred nurseries, with a total of 1100 inbreds from Syngenta Seeds and Dow Mycogen, also were established with similar outcomes. Twenty-four miticide treatments were evaluated for efficacy against Banks grass mite. This trial experienced problems similar to those noted above, although some abundance data were obtained. Acramite, Onager and Zeal again showed potential as alternatives to Oberon, the current commercial standard. Several experimental treatments should be retested under better conditions. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: The primary target audience for this project is Colorado corn producers and those who advise them. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Propargite had been the only registered preventive corn miticide for many years, until the registration of spiromesifen and hexythiazox in 2006 and 2008, respectively. Corn growers facing spider mite outbreaks in corn now have unbiased, research-based information on which to base their choice of preventive treatments, as well as available reactive options.
Publications
- Peairs, F. B., J. B. Rudolph, T. L. Randolph, and S. Merrill. 2008. 2007 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR08-06, 34 pp.
|
Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: This project focuses on management of Banks grass mite in corn, with emphasis on the development of resistant inbreds and hybrids. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. An experimental corn hybrid containing a Syngenta inbred identified as being resistant to Banks grass mite was tested for a second year at ARDEC under three levels of infestation. Abundance of both Banks grass mite and twospotted spider mite was generally lower on the resistant hybrid. However, yield differences between the susceptible and resistant hybrids were not detected. Possible explanations include insufficient level of resistance, extremely high late season mite activity, lack of control in the zero infestation level, or a combination of these problems. Approximately 900 inbreds were assessed for
Banks grass mite resistance. While most were susceptible, approximately ten showed sufficient promise to be retained and reassessed in 2008. One recently registered miticide and two unregistered miticides with new active ingredients were tested for efficacy against Banks grass mite. Oberon, which is now registered on corn, performed comparably or better than Comite, and Acramite and Onager showed promise as new alternatives to Comite.
PARTICIPANTS: F. B. Peairs, PI S. Merrill, Post Doctoral Associate T. Randolph, Research Associate J. Rudolph, Research Associate C. Chaulk-Grace, Collaborator
TARGET AUDIENCES: The primary target audience for this project is Colorado corn producers and those who advise them.
PROJECT MODIFICATIONS: None
Impacts
Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Comite was the only registered preventive corn miticide for many years, until the registration of Oberon. The latter appears to be highly effective, greatly reducing concerns regarding resistance development. The addition of Acramite and Onager to the market place would further improve the situation.
Publications
- Davidson, S. A., F. B. Peairs, R. Khosla. 2007. Insect pest densities across site-specific management zones of irrigated corn in northeastern Colorado. J. Econ. Entomol. 100: 781-789.
- Peairs, F. B., J. B. Rudolph, and T. L. Randolph. 2007. 2006 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR07-07, 26 pp.
|
Progress 01/01/06 to 12/31/06
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn, and on the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were much more abundant in 2006 than in the 2005 crop year, due to extremely dry spring weather. Limitations to useful pest management research remain (1) inability to mass rear brown wheat mite; (2)
inability to establish controlled infestation in field plots; and (3) lack of practical and efficient sampling and monitoring techniques. An experimental corn hybrid containing a Syngenta inbred identified as being resistant to Banks grass mite was tested at ARDEC under several levels of infestation. Yield differences between the susceptible and resistant hybrids were not detected due perhaps to lack of late season mite activity, predation, insufficient control in the zero infestation level, or a combination of these problems. One recently registered miticide and two unregistered miticides with new active ingredients were tested for efficacy against Banks grass mite. Oberon, which is now registered on corn, performed comparably to Comite, and Acramite and Zeal showed promise as new alternatives to Comite. Plants in three productivity-defined management zones at ARDEC were infested again with three levels of Banks grass mite, European corn borer, and western bean cutworm to determine
if yield loss relationships differ across zones. Extremely dry conditions and irrigation problems have made it difficult to obtain clear results from these studies. Previous studies indicated that corn pest abundance differed across management zones. If yield loss relationships differ as well, then separate economic injury levels for each management zone would be required for pest management decisions.
Impacts
We need to raise brown wheat mites in large quantities if we are to measure yield effects and screen wheat for resistance. Proper brown wheat mite management decisions also depend on simple, accurate sampling methods, which may be developed from the wooden stake method or from a newly developed suction sampler which is much less expensive that the one used to date. Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Comite was the only registered preventive corn miticide for many years, until the registration of Oberon. The latter appears to be highly effective, greatly reducing concerns regarding resistance development. Pest management decisions made on a management zone basis, as defined through precision agriculture technology, rather than the entire field can lead to cost savings through reduced or more efficient pesticide use.
Publications
- Peairs, F. B., J. B. Rudolph, J. B., T. L. Randolph, S. M. Walters, and A. Gebre-Amlak. 2006. 2005 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR06-05, 30 pp.
- Anderson, R. L., K. L. Bailey, and F. B. Peairs. 2006. Guidelines for integrating ecological principles of pest management with rotation design. Pp. 195-225 in, Peterson, G.A., P. W. Unger, and W. A. Payne, eds. Dryland Agriculture, Agronomy Monograph No. 23. 2nd Ed. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Madison, WI.
- Lanier, W. T., M. J. Brewer, F. B. Peairs, G. L. Hein, H. F. Schwartz, J. B. Campbell, and S. Blodgett. 2006. Development and assessment of an on-line High Plains Integrated Pest Management Guide for a regional audience. American Entomologist 52: 30 - 35.
|
Progress 01/01/05 to 12/31/05
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn, and on the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were less abundant than in the 2004 crop year, due to moist spring weather. Limitations to useful pest management research remain (1) inability to mass rear brown wheat mite; (2) inability to
establish controlled infestation in field plots; and (3) lack of practical and efficient sampling and monitoring techniques. Thirty inbreds resulting from crosses of A554 and CM105 with two sources of mite resistance (TAM Mite 1 and TAM Mite 3), as well as 13 lines from Texas were evaluated at two locations for resistance to Banks grass mite. Mite abundance LaSalle was much greater than either 2004 location. Only of the 30 Colorado lines, both with S3xCM105 backgrounds appeared resistant under the conditions. Several of the Texas lines were rated as resistant, although resistance and maturity may be confounded. The Syngenta inbred identified as resistant in 2004 again was as resistant as any of the experimental lines. Resistant experimental hybrids will be available for testing in 2006. Plants in three productivity-defined management zones at ARDEC were infested with three levels of Banks grass mite, European corn borer, and western bean cutworm to determine if yield loss
relationships differ across zones. Previous studies indicated that corn pest abundance differed across management zones. If yield loss relationships differ as well, then separate economic injury levels for each management zone would be required for pest management decisions.
Impacts
We need to raise brown wheat mites in large quantities if we are to measure yield effects and screen wheat for resistance. Proper brown wheat mite management decisions also depend on simple, accurate sampling methods, which may be developed from the wooden stake method. Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Pest management decisions made on a management zone basis, as defined through precision agriculture technology, rather than the entire field can lead to cost savings through reduced or more efficient pesticide use.
Publications
- Gebre-Amlak, A., Michaud, J.P., Peairs, F.B., Hein, G.L., Sloderbeck, P.E., and Higgins, R.A. 2005. Insect pest identification and control. Pp. 16 - 23 in R. Meyer et al., eds. High Plains Sunflower Production Handbook. Kansas State University, Manhattan, KS.
- Peairs, F.B., Bean, B., and Gossen, B.D. 2005. Pest management implications of reduced fallow periods in dryland cropping systems in the Great Plains. Agron. J. 97:373-377.
- Rudolph, J.B., Randolph, T.L., Walters, S.M., Peairs, F.B., and Gebre-Amlak, A. 2005. 2004 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR03-01, 43 pp.
|
Progress 01/01/04 to 12/31/04
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn, and on the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were more active in 2003 - 2004 than in several previous years, which allowed one yield loss assessment. Averaged over cultivars and cropping system, yields were reduced 43% by brown wheat mite.
While yields were extremely low in this experiment (10.2 bu/acre), miticide treatment was cost-effective. Limitations to useful pest management research remain (1) inability to mass rear brown wheat mite; (2) inability to establish controlled infestation in field plots; and (3) lack of practical and efficient sampling and monitoring techniques. Fifty eight inbreds resulting from crosses of A554 and CM105 with two sources of mite resistance (TAM Mite 1 and TAM Mite 3), as well as 17 lines from Texas were evaluated at two locations for resistance to Banks grass mite. Sixteen lines were retained, mostly from the S1 x A554 group. In addition, a Syngenta inbred, appearing to have a unique source of resistance, was identified as a potential new recurrent parent. Plants with varying levels of N and water within in three productivity-defined management zones at ARDEC were infested with Banks grass mite, European corn borer, western bean cutworm, and western corn rootworm. All four pests
tended to be more abundant in the higher productivity zones. Interactions with N and water have yet to be analyzed. This further strengthens our evidence of corn pest abundance differing by management zone and that pest management decisions might vary by zone.
Impacts
Practical and efficient sampling of brown wheat mite would greatly facilitate effective management. Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Pest management decisions made on a management zone basis, as defined through precision agriculture technology, rather than the entire field can lead to cost savings through reduced or more efficient pesticide use.
Publications
- Davidson, S. 2003. Influence of site-specific management zones on arthropod pests of irrigated corn in northeastern Colorado. M. S. Thesis, Colorado State University.
- Hein, G. L. and Peairs,F. B. 2004. Insect management. Pp. 93 - 108 in Schwartz,H., Brick,M., Harveson,R. and Franc,G. Dry bean production and integrated pest management. 2nd Ed. Colorado State University, University of Nebraska, University of Wyoming Regional Publication. Fort Collins, CO.
|
Progress 01/01/03 to 12/31/03
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn, and on the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were less active in 2001 and 2002 than in several previous years. No research progress was made because of the drought. Limitations to useful pest management research remain (1) inability to mass rear
brown wheat mite; (2) inability to establish controlled infestation in field plots; and (3) lack of practical and efficient sampling and monitoring techniques. Backcrosses of the parent corn inbreds (A554 and CM105) with two sources of mite resistance (TAM Mite 1 and TAM Mite 3), were selfed and selected for maturity and mite resistance. 340 inbreds representing the four parent line/resistance source combinations were evaluated for mite resistance at two locations. Of these, 59 were saved for further selfing as well as topcrossing for initial yield evaluations this winter. Plant infesting stages of Banks grass mite, European corn borer, western bean cutworm and western corn rootworm were sampled weekly during the growing season in three productivity-defined management zones at one location. In addition, plants in three management zones at ARDEC were infested with Banks grass mite, European corn borer and western corn rootworm. Banks grass mite, European corn borer and western corn
rootworm larvae were more abundant and damaging in the high productivity zone at ARDEC, as was observed in 2002 in all situations in which there was sufficient pest abundance to assess. This further strengthens our evidence of corn pest abundance differing by management zone and that pest management decisions might vary by zone.
Impacts
We need to raise brown wheat mites in large quantities if we are to measure yield effects and screen wheat for resistance. Proper mite management decisions also depend on simple, accurate sampling methods, which may be developed from the wooden stake method. Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Pest management decisions made on a management zone basis, as defined through precision agriculture technology, rather than the entire field can lead to cost savings through reduced or more efficient pesticide use.
Publications
- Walters, S. M., F. B. Peairs & A. Gebre-Amlak. 2003. 2002 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Bull. LTB03-2, 45 pp.
|
Progress 01/01/02 to 12/31/02
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn, and on the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were less active in 2001 and 2002 than in several previous years. No research progress was made because of the drought. Limitations to useful pest management research remain (1) inability to mass
rear brown wheat mite; (2) inability to establish controlled infestation in field plots; and (3) lack of practical and efficient sampling and monitoring techniques. Backcrosses of the parent corn inbreds (A554 and CM105) with two sources of mite resistance (TAM Mite 1 and TAM Mite 3), were selfed and selected for maturity and mite resistance. We were unable to establish damaging mite in the breeding nursery, likely because of the drought. Selfs were made but not selected for mite resistance and will be selfed again this winter. Plant infesting stages of Banks grass mite, European corn borer, western bean cutworm and western corn rootworm were sampled weekly during the growing season in three productivity-defined management zones at two locations. In addition, management zones were established at ARDEC. Western corn rootworm larvae were more abundant and damaging in the high productivity zone at all three locations. Survival of artificially infested European corn borer larvae was
better in the high productivity zone. This is our first evidence of corn pest abundance differing by management zone and that pest management decisions might vary by zone.
Impacts
Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Pest management decisions made on a management zone basis, as defined through precision agriculture technology, rather than the entire field can lead to cost savings through reduced or more efficient pesticide use.
Publications
- Guse, C. A., D. W. Onstad, L. L. Buschman, P. Porter, R. A. Higgins, P. E. Sloderbeck, G. B. Cronholm, and F. B. Peairs. 2002. Modeling the development of resistance by stalk-boring Lepidoptera (Crambidae) in areas with irrigated transgenic corn. Environ. Entomol. 31: 676 - 85.
- Heermann, D. F., J. Hoeting, S. E. Thompson, H. R. Duke, D. G. Westfall, G. W. Buchleiter, P. Westra, F. B. Peairs & K. Fleming. 2002. Interdisciplinary irrigated precision farming research. Precision Agriculture 3: 47 - 61.
- Onstad, D. W., C. A. Guse, P. Porter, L. L. Buschman, R. A. Higgins, P. E. Sloderbeck, F. B. Peairs and G. B. Cronholm. 2002. Modeling the development of resistance by stalk-boring lepidopteran insects (Crambidae) in areas with transgenic corn and frequent insecticide use. J. Econ. Entomol. 95: 1033 - 43.
|
Progress 01/01/01 to 12/31/01
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn. In addition, some effort is devoted to the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were less active in 2001 than in the previous year. Yield effects were not noted because of our inadequate ability to control infestation densities. Mite showed a
propensity to congregate and to lay eggs on vertical wooden stakes in the field. It may be possible to develop sampling and monitoring methods that take advantage of this behavior. Production of diapausing (white) eggs terminated a thriving growth chamber colony for no apparent reason. The inability to mass rear this mite remains the most significant obstacle to developing an effective field research program. Backcrosses of the parent corn inbreds (A554 and CM105) with two sources of mite resistance (TAM Mite 1 and TAM Mite 3), were selfed and selected for maturity and mite resistance. TAM Mite 1 x CM105 and TAM Mite 3 x A554 will undergo the 4th backcross this winter, while TAM Mite 3 x CM105 and TAM Mite 1 x A554 will undergo their 2nd and 3rd backcross, respectively. Families selected this summer averaged resistance scores of 2 or 3, while the local hybrid scored an 8 or 9, on a 1-10 scale. Plant infesting stages of Banks grass mite, European corn borer, western bean cutworm and
western corn rootworm were sampled weekly during the growing season in three productivity-defined management zones at two locations. Yields were taken from insecticide-protected and unprotected plants to determine treatment benefit by management zone. Since pest densities were generally low it is unlikely that insecticide treatment benefits will be of much significance for the 2001 growing season.
Impacts
We need to raise brown wheat mites in large quantities if we are to measure yield effects and screen wheat for resistance. Proper mite management decisions also depend on simple, accurate sampling methods, which may be developed from the wooden stake method. Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Pest management decisions made on a management zone basis, as defined through precision agriculture technology, rather than the entire field can lead to cost savings through reduced or more efficient pesticide use.
Publications
- Peairs, F. B. 2001. Three mites that affect Colorado wheat. Pp. 18 in, J. Johnson, ed. Making better decisions: 2000 Colorado wheat variety performance trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR01-4, 19 pp.
- Walter, S. 2001. Sampling patterns and spatial variability of three insect pests in sprinkler irrigated corn in eastern Colorado. M. S. Thesis, Colorado State University.
- Walters, S. M., F. B. Peairs & A. Gebre-Amlak. 2001. 2001 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Bull. LTB01-2, 38 pp.
- Walters, S. M., F. B. Peairs & A. Gebre-Amlak. 2001. 2000 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Bull. LTB01-1, 46 pp.
|
Progress 01/01/00 to 12/31/00
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn. In addition, some effort is devoted to the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were active in 2000. Yield effects were difficult to document because of associated drought and Russian wheat aphid infestations. Dimethoate provided effective control
for a second year, although timing and frequency of applications to maximize yield benefits are not yet clear. Brown wheat mites were successfully reared on wheat plants in a growth chamber. Enough mites were produced to make controlled infestations in a field study. Production of diapausing (white) eggs has not been a problem in the laboratory colony to date. Backcrosses of the parent corn inbreds (A554 and CM105) with two sources of mite resistance (TAM Mite 1 and TAM Mite 3), excluding TAM Mite 1 x A554, were selfed and selected for maturity and mite resistance. The second backcross of these and a second attempt at the initial TAM Mite 1 x A554 cross will be made this winter. Selfing and evaluation will continue this summer. This process will result eventually in adapted mite-resistant corn hybrids that can be used to develop nonchemical management approaches. European corn borer and western bean cutworm adult trap catch, egg masses per plant and larvae per plant were determined
for a second season. Insect activity was again too low to draw any meaningful conclusions. Analysis of two earlier data sets indicated that trap catch was related to distance from field edge and, in the case of European corn borer, the proximity of neighboring corn fields.
Impacts
We need to raise brown wheat mites in large quantities if we are to develop resistant wheats. Improved mite management also depends on knowing its impact on wheat yield. Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Cheaper sampling methods would allow growers to reduce pesticide use through precision agriculture technology.
Publications
- D. F. Heermann, J. Hoeting, H. R. Duke, D. G. Westfall, G. W. Buchleiter, P. Westra, F. B. Peairs & K. Fleming. 2000. Irrigated precision farming for corn production. Proceedings, Second International Geospatial Information in Agriculture and Forestry Conference. Lake Buena Vista, FL, 10 - 12 January.
- Walters, S. M. F. B. Peairs & S. D. Pilcher. 2000. 1999 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Bull. LTB00-1, 55 pp.
- Heermann, D. F., H. R. Duke, G. W. Buchleiter, D. G. Westfall, K. Fleming, D. B. Bosley, P. Westra and F. B. Peairs. 2000. Multidisciplinary study of irrigated precision farming. In P. C. Roberts, R. H. Rust, & W. E. Larson, eds. Proc. 5th International Conference On Precision Agriculture. Amer. Soc. Agron., Madison, WI.
|
Progress 01/01/99 to 12/31/99
Outputs
This project focuses on management of brown wheat mite in winter wheat and Banks grass mite in corn. In addition, some effort is devoted to the emerging issue of precision agriculture through research on the spatial and temporal distribution of corn pest damage. Producers are interested in the potential efficiencies offered by precision agriculture, but need more information on pest sampling efficiency, costs and site-specific management options. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Brown wheat mites were active in 1999. Unexpectedly good survival was noted during a very wet (6" of rain) April. In spite of high mite densities (8 per cm2) yield effects were not
observed. Dimethoate provided effective control, although optimal timing and frequency of applications are not yet clear. Several ovipositional substrates were tested as part of the development of mass rearing methods. Sponge and lava rock were preferred substrates and could be used both in mass rearing and infestation. Three candidate hybrids were tested for adaptation to northern Colorado. One was selected for development of spider mite resistance. Crosses of the parent inbreds with two sources of mite resistance were selfed and selected for maturity and mite resistance. Progeny of these will be crossed again with parent inbreds this winter. Progeny will be reselected this summer. This process will result eventually in mite-resistant corn hybrids that can be used to develop nonchemical management approaches. European corn borer and western bean cutworm adult trap catch, egg masses per plant and larvae per plant were determined. Twenty-five pairs of samples per field were collected
in Fields 6 and 7 at Wiggins, with one member of each sample pair having European corn borer and western bean cutworm pheromone traps operated in a manner similar to previous seasons. Pheromone trap catches were counted weekly to assess adult populations. Egg mass and larval data were collected from 10 consecutive plants in each of four directions from the trap or from a fixed point in the trapless sample of each pair. Each of the following was recorded once during the season: western bean cutworm egg masses per plant; plants with European corn borer "shot hole" damage; European corn borer egg masses per plant; and number and location of European corn borer larvae and pupae per plant. European corn borer and western bean cutworm counts were too low for accurate comparisons between adult pheromone trap catches and egg mass and larval counts
Impacts
We need to raise brown wheat mites in large quantities if we are to develop resistant wheats. Improved mite management also depends on knowing its impact on wheat yield. Corn hybrids resistant to Banks grass mite would provide growers a long-term, less costly solution to this perennial pest problem. Cheaper sampling methods would allow growers to reduce pesticide use through precision agriculture technology.
Publications
- D. F. Heermann, J. Hoeting, H. R. Duke, D. G. Westfall, G. W. Buchleiter, P. Westra, F. B. Peairs & K. Fleming. 1999. Interdisciplinary irrigated precision farming research. P. 121 - 130 in, J. V. Stafford, ed. Precision Agriculture `99. Sheffield Academic Press.
- Peairs, F. B. & T. L. Archer. 1999. Spider mites. P. 104 - 106 in, Steffey, K. L., M. E. Rice, J. All, D. A. Andow, M. E. Gray & J. W. Van Duyn, eds. Handbook of Corn Insects. Entomological Society of America, Lanham, MD.
- Schwartz, H. F. & F. B. Peairs. 1999. Integrated pest management. P. 371 - 388 in, Singh, S. P., ed. Common Bean Improvement in the Twenty-First Century. Kluwer Academic Publishers, Dordrecht, The Netherlands.
- Walters, S. M. & F. B. Peairs. 1999. Spatial variability of trap catches of three insect pests in sprinkler irrigated maize in eastern Colorado, USA. P. 229 - 238 in, J. V. Stafford, ed. Precision Agriculture `99. Sheffield Academic Press.
- Walters, S. M. F. B. Peairs & S. D. Pilcher. 1999. Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Bull. LTB99-4, 57 pp.
|
Progress 01/01/98 to 12/31/98
Outputs
This project focuses on management of brown wheat mite in winter wheat and corn spider mites. Wheat producers in the southeastern Colorado consider brown wheat mite to be an emerging pest problem. In the 1996-1997 crop year several growers had to treat their `Halt' wheat (resistant to Russian wheat aphid) for brown wheat mite, so there is a possibility that this pest will become an impediment to the adoption of aphid-resistant cultivars. Banks grass mite is the most widespread and difficult to manage of the arthropod pests attacking corn in Colorado. In spite of its long history of developing resistance to miticides, chemical control remains the only viable management tactic. Two effective miticides are labeled but alternatives need to be developed if long-term IPM approaches are to be implemented. No progress was made toward brown wheat mite objectives due to lack of pest activity. Seeds of several inbreds of appropriate maturity for northern Colorado were obtained.
These inbreds will be crossed during the 1998 - 1999 winter with two sources of spider mite resistance. Additionally the possible hybrid combinations will be generated. Inbreds will be selfed and screened for mite resistance and maturity at Fort Collins. Hybrids will be evaluated for yield and adaptation at the same time. This process will result eventually in mite-resistant corn hybrids that can be used to develop nonchemical management approaches. Emerging issues Bt corn hybrids again were compared to non-Bt hybrids with and without insecticide treatment, at two eastern Colorado locations, with results similar to previous studies. The use of Bt corn was as effective as properly scouted and timed insecticide applications for corn borer management. Western bean cutworm and Banks grass mite were not affected by the use of Bt corn. European corn borer and western bean cutworm adults again were monitored with pheromone traps at 365 locations over two center-pivot corn fields at Wiggins,
CO as part of a larger precision farming project that attempts to describe the entire production system. Trap catches were spatially variable, with European corn borer distribution seemingly influenced by the types of vegetation adjacent to the study fields. These studies may lead to site-specific management of these pests with fewer chemical inputs.
Impacts
(N/A)
Publications
- Peairs, F.B. & S. D. Pilcher. 1998. 1997 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Bull. TB98-1, 38 pp.
- Archer, T. L., F. B. Peairs, & J. A. Mihm. 1997. Mechanisms and bases of resistance in maize to mites. In J. A. Mihm (ed.) Insect Resistant Maize: Recent Advances and Utilization; Proceedings of an International Symposium held at the International Maize and Wheat Improvement Center (CIMMYT) 27 Nov.-3 Dec. 1994. Mexico D.F.: CIMMYT pp. 101-105.
- Donohue, J. D., M. J. Brewer, F. B. Peairs, & G. L. Hein (eds). 1998. High Plains Integrated Pest Management Guide for Colorado-Western Nebraska-Wyoming. Bull. No. 564A. Colorado State University, Fort Collins.
- Peairs, F. B. 1998. Common fall pests in Colorado winter wheat. Pp. 13 in, J. Johnson, ed. Making better decisions: 1997 Colorado wheat variety performance trials. Colorado State Univ. Agric. Exp. Sta. Tech. Rep. TR98-5, 24 pp.
|
Progress 01/01/97 to 12/31/97
Outputs
This project has focused on management of alfalfa weevil and corn spider mites. Some progress has been made towards finding nonchemical management alternatives for corn spider mites, but chemical control remains the only viable alternative for alfalfa weevil. Two emerging corn pest management issues need to be addressed. The use of genetically modified corn hybrids to control insects is now a reality. Growers need local research information on whether this is a viable approach for our conditions. They also need information on the role that insect management decisions have in precision farming (site-specific agriculture). Objective 1. No progress was made towards this objective. Objective 2. No progress was made towards this objective. Objective 3. Promising lines from the Crumpacker collection of dryland corn varieties were rescreened for mite resistance, in cooperation with Texas A&M University. Several experimental mite-resistant hybrids were also screened. The
maturity range of the currently available resistant materials is unacceptable for northern Colorado. It may be necessary to select for earlier resistant types before work can continue in this area. A new miticide, hexythiazox, was tested in both small and commercial corn plots. This is the first potential alternative to propargite and bifenthrin to be tested in several years. Objective 4. Crop losses were measured for alfalfa weevil, western corn rootworm, Russian wheat aphid, and European corn borer. These data are used to help Colorado growers make economically sound pest management decisions and to prioritize pest research. Emerging issues: Fifteen Bt corn hybrids were compared to 15 non-Bt hybrids with and without insecticide treatment, at two eastern Colorado locations. European corn borer activity was greater than normal. Under these pest conditions, the use of Bt corn was as effective as properly scouted and timed insecticide applications for corn borer management. Western bean
cutworm and Banks grass mite were not affected by the use of Bt corn. European corn borer, western bean cutworm and western corn rootworm adults were monitored at 365 locations over two center-pivot corn fields at Wiggins, CO. These results are part of a larger precision farming project that attempts to describe the entire production system. Data have been entered into Arcview for GIS analysis and comparison with other data layers collected in the project. These analyses will be used to provide a better understanding of how insect pest data can be incorporated into precision farming decisions.
Impacts
(N/A)
Publications
- Peairs, F.B. 1997. Western corn rootworm management. P. 148 - 154. In Bohmont, B. ed. Proceedings 27th Annual Colorado Crop Protection Institute, 13-14 Nov. 1997. Colorado State University, Fort Collins, CO. 201 pp.
- Peairs, F.B. & S. D. Pilcher. 1997. 1996 Colorado field crop insect management research and demonstration trials. Colorado State Univ. Agric. Exp. Sta. Tech. Bull. TB97-5, 57 pp.
|
Progress 01/01/96 to 12/30/96
Outputs
Obj.1 Summer alfalfa weevil infestations were found in 7 of 7 Weld County fieldsbut were all subeconomic. Beauvaria bassiana was tested against adult and larval alfalfa weevil and pea aphid under several temperature regimes. Colorado hay producers, especially those in urbanized areas still lack effective nonchemical means of alfalfa weevil management. Obj. 2. Dimethoate LC50s for Banks grass mite on corn in Weld County were similar to those recorded in 1987 and about half as high as those of Prowers County mites, indicating that the pattern of resistance to dimethoate has not changed appreciably in the last decade. Four applications of lambda cyhalothrin did not affect bifenthrin LC50s for Banks grass mite. Obj 3. Crumpacker corn collection was screened unsuccessfully for spider mite resistance. A comparison of three cycles of selection in Maiz Amargo and in a Nebraska heat tolerant population indicated selection progress at a Texas location, but results were
inconclusive at the Colorado location due to insufficient mite damage. Obj 4. Crop losses were measure for alfalfa weevil (2.3%), western corn rootworm (9.1%), Russian wheat aphid in spring wheat (10.4 and 22.6%), European corn borer and spider mites (39%), spider mites in winter wheat (15.6%), spider mites in corn (15.8, 12.4, and 6.0%), the combination of Banks grass mite and European corn borer (19.6 and 16.5%), the combination of Banks grass mite, European corn borer and western bean cutworm (9.1%), and sunflower stem weevil (60.5%).
Impacts
(N/A)
Publications
|
Progress 01/01/95 to 12/30/95
Outputs
Objective 1. Generalist predator densities increased temporarily after sucrose sprays, but alfalfa weevil densities and crop yield were not affected. A microbial insecticide containing Beauvaria bassiana did show promising activity against alfalfa weevil. The alternatives tested this year, other than conventional insecticides, do not have the potential to replace carbofuran. Colorado hay producers still lack effective nonchemical alfalfa weevil controls. This need is particularly critical for producers in urbanized area. Objective 2. Spider mite pesticide resistance was measured to better understand the potential for spider mite outbreaks resulting from adult rootworm treatments. Such outbreaks could make the adult management strategy (an approach receiving renewed interest) impractical for some Colorado growers. Objective 3. A experimental corn inbred resistant to spider mites was released in cooperation with Texas A&M. Colorado corn growers rely on 3 miticides that
could easily be lost to resistance or regulation in the near future. Objective 4. Crop losses were measure for alfalfa weevil (6.5%), western corn rootworm (28%), Russian wheat aphid (67%), European corn borer and spider mites (39%), spider mites (26%), and the combination of western bean cutworm and European corn borer (22% and 18%). These data are used to help Colorado growers make economically sound pest management decisions and to prioritize pest research.
Impacts
(N/A)
Publications
|
Progress 01/01/94 to 12/30/94
Outputs
Experimental corn hybrids were again resistant to heavy mite infestations. An experimental inbred developed in this project, 'TAM Mite 1', has been submitted for release by Texas A&M University. Such resistance could save Colorado corn producers ca. $20/ acre miticide costs in outbreak years. Pale western cutworm and army cutworm were identified as limiting factors in dry edible beans produced in conservation tillage, dryland systems in SW CO. Conventional chemical control approaches are inadequate. Sampling and modified insecticide placement studies are planned so growers can comply with soil conservation requirements and still include this crop in their rotations. Methods for rearing western bean cutworm were refined, making it feasible to produce large numbers of this pest for host plant resistance and other studies. Studies of pheromone catches of this pest showed that surrounding crops affect trap catch. This and other information will allow pheromone trap catches
to replace in-field scouting of dry edible beans for western bean cutworm. Measurements were made of yield losses caused by European corn borer, western corn rootworm, western bean cutworm and spider mites in corn, alfaflfa weevil, and Russian wheat aphid in wheat and barley. This helps Colorado producers make more informed decisions about insecticide use.
Impacts
(N/A)
Publications
|
Progress 01/01/93 to 12/30/93
Outputs
First and second generation European corn borer from eastern Colorado were less susceptible to Bacillus thuringiensis than those from an Iowa lab colony for a second year. This is evidence that this insect can develop resistance to this very safe insecticide and to transgenic corn hybrids. Experimental corn hybrids were resistant to Banks grass mite. This resistance, once incorporated into commercial hybrids, could result in $20/acre savings to Colorado corn producers in areas where preventive miticide treatments are necessary. Western bean cutworm pheromone trap catches can now be used to time insecticide treatment in dry beans and corn, and to decide on the need to use insecticides in dry beans. This allows more cost-effective and environmentally sound insecticide use in these crops. Studies are underway to develop similar methods for head-infesting caterpillars in sunflower and for pale western cutworm in dry bean. Data on control of flea beetles in crambe allowed
an insecticide label expansion so Colorado producers can control this pest. Similar data were used to support emergency registrations of an insecticide for control of pale western cutworm in small grains and of a miticide for control of spider mites in corn. Measurements were made of yield losses caused by alfalfa weevil, western bean cutworm, European corn borer, western corn rootworm, and Russian wheat aphid. These are use to help Colorado producers make more informed decisions about insecticide use.
Impacts
(N/A)
Publications
|
Progress 01/01/92 to 12/30/92
Outputs
Alfalfa weevil was confirmed to have a second generation in two regions of Colorado. First and second generation European corn borers from eastern Colorado differed in susceptibility to Bacillus thuringiensis. Both generations differed from an Iowa laboratory strain. Yield losses were observed in replicated small plot trials to alfalfa weevil, European corn borer, western bean cutworm, western corn rootworm, and wheat curl mite. Observations on chemical control of wheat curl mite were made for the first time in Colorado, with carbofuran providing control superior to other registered products. Control of pale western cutworm with rates of chlorpyrifos effective against Russian wheat aphid was inferior to that achieved with low rates of several pyrethroid insecticides. Long term control of western corn rootworm adults with carbaryl/curcurbitacin combination (Slam) was inferior to that achieved with several rates of microencapsulated methyl parathion.
Impacts
(N/A)
Publications
|
Progress 01/01/91 to 12/30/91
Outputs
Amidicloprid, an experimental insecticide, provided significant control of a natural Russian wheat aphid when applied as a seed treatment to spring barley. Certain formulations of chemigated Bacillus thuringiensis performed as well as conventional insecticides in 4 tests against second European corn borer. No difference in control of western bean cutworm was observed when comparing chemigated and aerially-applied permethrin. In cooperation with Texas A&M University, 20 S1 lines of a temperate corn population were selected for corn spider mite resistance, while selfs were performed in two other populations for selection in 1992. Two hundred S3 ears from a tropical x temperate nursery were selected for further testing and selection this winter in cooperation with CIMMYT. Yield losses were observed for western corn rootworm (29.9% and 8.8% at separate sites); western bean cutworm in corn (10.3%); European corn borer (9.6%); and corn spider mites (14.7%). Survival of
European corn borer in a relatively hot, dry environment was 20% of that in a relatively cool, moist environment. This information was generated to support a Colorado Department of Agriculture quarantine decision.
Impacts
(N/A)
Publications
|
Progress 01/01/90 to 12/30/90
Outputs
An 11.2% grain yield loss to western corn rootworm larvae was measured in commercial continuous field corn. A 100% infestation of western bean cutworm reduced grain corn yields 9.5%. Losses at the currently accepted economic threshold would not have economically justified an insecticide treatment if such treatment had also provoked a secondary outbreak of spider mites. For a third year, chemigated Bacillus thuringiensis was as effective as chlorpyrifos or biphenthrin in controlling second generation European corn borer. In-furrow treatments with aldicarb at 2 rates did not affect pinto bean yields or test weights. For a second year, in-furrow treatments with registered insecticides signifcantly reduced Russian wheat aphid numbers in bioassays conducted in April of the year following September treatment.
Impacts
(N/A)
Publications
|
Progress 01/01/89 to 12/30/89
Outputs
Low rates of aerially-applied Lorsban 4E reduced RWA populations as well as higher rates, but yields were significantly higher with higher rates. Lorsban 4E remains the most promising of the unregistered insecticides. The addition of crop oils may improve control achieved with several insecticides. Chemigated Bacillus thuringiensis controlled second generation European corn borer as well as chemigated chlorpyrifos or permethrin. Biphenthrin controlled corn spider mites and protected yields as well as propargite, the registered standard, in both small scale and large scale experiments. Treatments for control of western bean cutworm in pinto beans were timed using pheromone trap counts. 95% control was achieved which avoided 8-10% yield losses. Losses to western corn rootworm in commercial continuous field corn were 9.2% based on comparisons of yields of plots with and without soil insecticides.
Impacts
(N/A)
Publications
|
Progress 01/01/88 to 12/30/88
Outputs
1. Control of Russian wheat aphid with planting-time treatments was accomplishedwith seed treatments (greenhouse), granular systemics, and in-furrow injections of liquid systemic insecticides. Disulfoton 8E gave significant RWA control at 18 weeks after planting under producer conditions. Chlorpyrifos was equal to or better than other foliar insecticides for RWA control in 7 experiments. 2. Chemigated Bacillus thuringiensis was as effective in controlling first and second generation European corn borer as chemigated conventional insecticides, presenting a nongroundwater-contaminating alternative for this serious corn pest. Chemigated chlorpyrifos was effective for the second year as a rescue treatment for corn rootworms. Chemigated biphenthrin was effective against Banks grass mite in corn. 3. Dimethoate resistance in Banks grass mite was measured throughout the state and was found to be well correlated with years of consistent corn miticide applications. Resistance
also varied from field to field within a county, but not within a field at a single sample date. Within field measurements of resistance also varied with plant growth stage. Reactive propargite treatments were again effective against both Banks grass mite and two-spotted spider mite, providing the producer an alternative where dimethoate is no longer effective. 4. The 1987 economic impact of the Russian wheat aphid in Colorado was estimated to be ca. 27 million dollars based on a 7 million bushel loss and 1.2 million acres sprayed.
Impacts
(N/A)
Publications
|
Progress 01/01/87 to 12/30/87
Outputs
Russian wheat aphids were observed in the field on 8 non-wheat alternate hosts. Greenhouse studies identified 22 grasses as good Russian wheat aphid hosts, 26 grasses as poor hosts, and 21 grasses as nonhosts. Allison-Pike suction traps were established at seven sites to monitor Russian wheat aphid flight activity. First catch ranged from April 21 to July 29. Peak catch ranged from June 3 to August 26. Total catch ranged from 10 to 2774 aphids from April to August, 1987. Four soil insecticides applied at planting and at cultivation for control of western corn rootworm larvae demonstrated that control at the later timing is superior. Aerially-applied carbofuran 15G and chemigated chlorpyrifos 4E as "rescue" treatments were also effective. Chemigated Bacillus thuringiensis (Dipel ES) provided control of first and generation European corn borer equivalent to that achieved with organic insecticides.
Impacts
(N/A)
Publications
|
Progress 01/01/86 to 12/30/86
Outputs
The Russian wheat aphid (RWA), Diuraphis noxia, was first reported from Colorado on March 28, 1986, and has since been confirmed from 25 counties. Control with registered insecticides has been in the 70-75% range with both small- and large-scale replicated tests. 13 potential noncrop host species were identified in 2-week, no choice tests. 5 of 14 grasses recommended for the Conservation Reserve Program were also identified as potential hosts. Agropyron spp predominated in both tests. RWA was able to infest wheat seedlings as young as 5 days. Movement from volunteer wheat to adjacent fall plantings has been demonstrated. The currently accepted threshold of 20 alfalfa weevil larvae/180 sweep was tested on a commercial scale for a second year. All treatments made at infestations above this level were profitable. Gains were made in dry matter production on first and second cutting. No changes in hay quality were observed. First generation European corn borer was
successfully controlled with Bacillus thuringiensis applied through centerpivot irrigation systems. Control of second generation larvae was not satisfactory, but was equal to that achieved with conventional insecticides. Control of western bean cutworm with chemigated B.t. remains unfeasible, but several treatments were promising. Significant differences in dimethoate resistance, consistent with local miticide use patterns, were found among Colorado Bank grass mite populations.
Impacts
(N/A)
Publications
|
Progress 01/01/85 to 12/30/85
Outputs
Aerially-applied and chemigated chlorpyrifos and fenvalerate were compared for asecond season for control of European corn borer in field corn. Pest pressure was low so significant differences were few. For the second year, chemigated insecticides were numerically superior to aerially applied insecticides in terms of control of both generations of corn borer and dry grain yield. In contrast to the first year there was no apparent advantage to the addition of crop oils to chemigated insecticides. In cooperation with Nebraska, Kansas, and Texas, Banks grass mite and two-spotted spider mite from corn were tested for resistance to biphenthrin, dimethoate, and methidathion. Banks grass mite was more susceptible to the 3 chemicals in all 4 states. Methidathion was the most toxic to both species in Colorado. Considerable variation in resistance to biphenthrin was encountered in the Texas and Colorado populations, even though this chemical has yet to be registered. The
use of crop oil to improve the efficacy of propargite against Banks grass mite and two-spotted spider mite on corn was tested. For the second year the use of oil resulted in significantly less efficacy. Several insecticides were tested against a severe (1920/plant) onion thrips infestation in preblossom dry beans. All materials performed well and averaged a 78% yield increase.
Impacts
(N/A)
Publications
|
Progress 01/01/83 to 09/30/84
Outputs
Aerial applications and center pivot injections of chlorpyrifos and fenvalerate emulsifiable concentrates were compared for control of corn pests in northeast Colorado. Comparisons were made in terms of control of first and second generation European corn borer (ECB), changes in beneficial insect counts after applications, and yield. Center pivot injections (chemigation) were carried out with and without the addition of nonemulsifiable crop oil. Oil treatments were numerically, but not statistically, superior to conventional treatments for control of both ECB generations, impact on beneficial insects, and grain yield. When chemigation with oil was compared to aerial application, chemigation was numerically, but not statistically, superior to aerial application for impact on beneficial insects and grain yield. Chemigation with oil was statistically superior to aerial application for control of first and second generation ECB. 94 grain samples from farm-stored wheat
were examined for insects. 75.5% were infested with an average of 16.5 insects/sample. 34% exceeded the economic threshold for lesser grain borers, averaging 13.3 borers/sample. 30.8% of the samples exceeded the economic threshold for secondary grain pests, averaging 36.2 insects/sample. In total, 46.8% of the samples surpassed the currently accepted economic thresholds for lesser grain borers or secondary pests or both.
Impacts
(N/A)
Publications
|
Progress 11/01/82 to 11/30/83
Outputs
Research was initiated during the past year on corn pests, with particular emphasis on chemigation system efficacy relative to aerial application. Assessment of european corn borer and western bean cutworm impact in eastern Colorado was accomplished, and spider mite treatments were evaluated.
Impacts
(N/A)
Publications
|
Progress 01/01/82 to 12/30/82
Outputs
Research conducted during the past year with respect to spider mite problems on corn were: Studies designed to assess the synergictic effect of spider mite feeding and water stress of grain production. Evaluation of late season application of COMITE for control of two spotted spider mite. Analysis of data is in progress. Grasshopper research has involved completion of a life systems model for Melanoplus sanquinipes (see Publications (2) and (6)).
Impacts
(N/A)
Publications
|
Progress 01/01/81 to 12/30/81
Outputs
The major research effort of FY 81/82 was a field study designed to test efficacy of various acaricides for control of spider mites on corn. A further objective of this study was to gain an understanding of the basic community structure associated with mites in commercial corn fields. Results from this study are summarized as follows: Twospotted spider mite comprises an important component of the mite complex associated with corn in Northeastern Colorado. Important ecological and behavioral differences exist between twospotted spider mite and the other major mite pest (Banks grass mite). Results indicate significant resistant of twospotted spider mite populations to all materials tested. Two natural enemies (Amblyseuis fallacis and Stethorus sp.) were found to be in close association with spider mite populations. Ecologically, these two predators appear to be highly compatible and under favorable circumstances provide effective biological control. It, therefore,
appears promising that further research will result in successful integrated control of spider mites on corn utilizing acaricide applications and naturally occurring biological control agents. In order to facilitate the goal of a successful IPM program, laboratory colonies have been established for Bank's grass mite, the resistant strain of twospotted spider mite, the local strain of A. fallacis and an O-P resistant strain of A. fallacis. These colonies are being used in laboratory studies designed to compliment our field studies.
Impacts
(N/A)
Publications
|
Progress 01/01/80 to 12/30/80
Outputs
Experiment Station Project #53 has a major goal the development of IPM systems for Banks grass mite, and rangeland grasshopper pests. The research approach involves studies to: (1) Understand basic ecological relationships of targeted pest populations, (2) Develop population models of targeted pest/resource complexes, (3) Systems level evaluation of IPM programs. Good progress has been made in laboratory studies involving basic population dynamics of Banks grass mite feeding on a native host (blue grama grass). This information, which should be submitted for publication this year, will be used to develop a computer simulation model describing the life history of Banks grass mite on blue grama. Similar information for Banks grass mite feeding on corn (which is being collected by Dr. T. Holtzer, University of Nebraska, Lincoln) will be used to build a model comparing Banks grass mite feeding on a native host and corn. Such a model may provide insight to basic
ecological relationships for colonization of cultivated crops from native sources. The developed model will also provide a basis for biological control model involving Banks grass mite and the phytoseiid predator Amblyseus fallacis. A study of the relationship between foliar Nitrogen and population success of the bigheaded grasshopper (Aulocara elliotti (Thomas) has recently been completed. Results from this study indicate that availability of adequate organic Nitrogen may play a role in both population limitation and outbreaks of this important grasshopper pest.
Impacts
(N/A)
Publications
|
Progress 01/01/79 to 12/30/79
Outputs
Principal accomplishments during FY79-80 involved conceptual advances in modeling arthropod population processes. A significant theoretical contribution was made by deliniation of the effect that nonlinearity and variable temperature regimes have on representation of temperature dependent life history parameters (Tanigoshi and Logan, 1979). Advances in methodologies for modeling variation in developmental rates and the spatio/temporal distribution of microhabitat temperatures were developed ad discussed in Logan, et al. 1979. Modeling arthropod population dynamics for applications in pest management programs often requires accurate portrayal of microhabitat driving variables. In fact, for development of pest management strategies in systems of marginal productivity, interpretative meterorological modesl are of equal importance to the models which describe pest population dynamics. Development of an improved model for projecting microhabitat temperature curves based
on minimal information is given in Parton and Logan, 1980. Representation of spatial dynamics is of critical importance for developement of truly useful grasshopper IPM models. Inclusion of spatial dynamics in population models poses isgnificant conceptual and technological problems.
Impacts
(N/A)
Publications
|
Progress 01/01/78 to 12/30/78
Outputs
The title of this research project is indicative of the general nature and broadscope of the project. The primary target pests to date are: McDaniel spider mite, a pest of tree fruits; Bank's grass mite, a pest associated with range and corn production; and a grasshopper complex associated primarily with range and dryland or well irrigation agro-ecosystems. Each subproject and the general problem of environmental monitoring and biological interpretation of climatic driving variables will be discussed separately. Monitoring and interpretation of microhabitat: Significant conceptual advances have been made in regard to an improved biological interpretation of microclimatological driving variables. These advances are discussed in detail in publications (1), (2), and (4). Techniques discussed in these publications will provide the mechanism for inclusion of an improve microhabitat representation for all target biological systems. Spider mite research: Bank's grass
mite population were isolated from corn in the Fort Collins area. A colony from this source material is currently maintained on blue gramma grass. Investigations are currently underway to relate spider mite feeding damage as it affects photosynthetic properties of the host plant (Blue Gramma). It has recently been determined that the primary phytophagous mite pest of tree fruit in Colorado is the McDaniel spider mite (personal communication, W.C. Batiste, Grand Junction, CO).
Impacts
(N/A)
Publications
|
|