Progress 10/01/05 to 09/30/10
Outputs
OUTPUTS: 1.Alyokhin, A. 2010. Is there life beyond neonicotinoids Potato Pest Management Conference, Presque Isle, ME. 2.Alyokhin, A. 2010. Manure and compost in a potato cropping system - entomology. Agriculture Integration Conference, Presque Isle, ME. 3.Alyokhin, A. 2010. A systems approach to organic crop production: effects on insect pests. Maine Agricultural Trades Show, Augusta, Maine. 4.Alyokhin, A. 2009. Compost effects on insect pests of potatoes. Potato Pest Management Conference, Presque Isle, ME. 5.Gross, S., A. Alyokhin, R. Larkin, S. Erich, and S. Tavantzis. 2009. Effect of soil amendments on pest insects in potatoes. Maine Agricultural Trades Show, Augusta, Maine. 6.Gross, S., et al. 2009. Soil amendment effects on survivorship and development time of Colorado potato beetles. Entomological Society of America Meeting, Indianapolis, IN. 7.Alyokhin, A. 2010. Plant‐mediated effects of soil management on insect herbivores. Joint Seminar by the SDSU and the USDA-ARS, Brookings, SD. 8.Alyokhin, A. 2010. Refuse, treasure, and tree-hugging: response of insect herbivores to soil amendments. Michigan State University, East Lansing. 9.Alyokhin, A. 2009. Reduced Colorado potato beetle densities on manure-amended plots of the long-term Potato Ecosystem Project. Member Symposium at the Entomological Society of America Meeting, Indianapolis, IN. 10.Gross, S., et al. 2008. Reduced pest insect densities following compost application in organic and conventional potato systems. Northeast Potato Technology Forum, Bangor, Maine. 11.Gross, S., et al. 2008. Reducing pest insect densities in potato systems using compost applications. The Annual Earth Day, University of Maine, Orono. 12.Gross, S., et al. 2008. Reduced pest insect densities following compost application in potato systems. Entomological Society of America Meeting, Reno, NV. 13.Gross, S., et al. 2008. Reduced pest insect densities following compost application in organic and conventional systems. Northeast Potato Technology Forum, Fredericton, NB, Canada. 14.Alyokhin, A., et al. 2008. The effect of soil management on Colorado potato beetle populations. Potato Pest Management Conference, Presque Isle, ME. 15.Alyokhin, A. 2008. New strategies for managing Colorado potato beetle. Maine Potato Conference, Caribou, ME. 16.Alyokhin, A. and S. Gross. 2008. Compost effects on insect pests of potato. Maine Agricultural Trades Show, Augusta, ME. 17.Alyokhin, A. 2006. Colorado potato beetle control and philosophy of transcendental evil. University of Maine, Orono. 18.Alyokhin, A. 2006. It's all natural, man: explaining a few unexpected declines in pest populations. University of Maryland, College Park. 19.Alyokhin, A. 2006. Natural regulation in unnatural systems: ecological view on a potato field (and beyond). Queens College, New York. 20.Alyokhin, A. 2006. Colorado potato beetle control and harsh lessons in applied evolutionary biology. The Ohio State University, Wooster. PARTICIPANTS: PIs: Andrei Alyokhin, Peter Sexton Collaborators: Stellos Tavantzis, Susan Erich, Greg Porter, Robert Larkin, Gary Sewell, Eric Sideman, James Gerritsen Partner Organizations: Maine Organic Farmer and Gardener Association, Wood Prairie Organic Farm, USDA-ARS Graduate Student: Serena Gross TARGET AUDIENCES: Farmers, agricultural scientists, extension educators, crop consultants PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Our results provide a tangible incentive for commercial potato growers to use organic soil amendments. Potato plants grown on organically-amended soils are less favorable hosts to Colorado potato beetles compared to synthetically fertilized plants, as evidenced by slower beetle development, and, in some cases, increased larval mortality. Adult beetles do not avoid such plants. On the opposite, their recruitment and oviposition might be higher on amended plants early in the season because such plants emerge earlier and have a more vigorous stand. However, this puts subsequently hatching larvae at a disadvantage. As a result, larval populations are commonly lower on amended plots later in the season, while potato yields are higher. Although the observed effects are not sufficiently strong to ensure plant protection without additional insect control measures, they demonstrate an additional benefit of using organic soil amendments.
Publications
- 1. Alyokhin, A. 2009. Colorado potato beetle: What's been done and what may come. Potato Grower 38(3): 24-28.
- 2. Alyokhin, A. 2009. Colorado potato beetle management on potatoes: current challenges and future prospects. In: Tennant P, Benkeblia N (Eds) Potato II. Fruit, Vegetable and Cereal Science and Biotechnology 3 (Special Issue 1): 10-19.
- 3. Alyokhin, A. 2008. www.potatobeetle.org
- 4. Hoy, C. W., G. Boiteau, A. Alyokhin, G. Dively, and J. M. Alvarez. 2007. Managing insect and mite pests. In: Potato Health Management, D.A. Johnson ed. The American Phytopathological Society Press, St. Paul, MN.
- 5. Alyokhin, A. and R. Atlihan. 2005. Reduced fitness of the Colorado potato beetle (Coleoptera: Chrysomelidae) on potato plants grown in manure-amended soil. Environmental Entomology 34: 963-968.
- 6. Alyokhin, A., G. Porter, E. Groden, and F. Drummond. 2005. Colorado potato beetle response to soil amendments: a case in support of the mineral balance hypothesis Agriculture, Ecosystems, and Environment 109: 234-244.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Main outputs of the project during the reported period came in the form of presentations to target constituencies. The following extension presentations were delivered to potato growers: 1. Gross, S., A. Alyokhin, R. Larkin, S. Erich, and S. Tavantzis. 2009. Effect of soil amendments on pest insects in potatoes. 68th Maine Agricultural Trades Show, Augusta, Maine. 2. Alyokhin, A., S. Gross, S. Tavantzis, R. Larkin, and S. Erich. 2008. The effect of soil management on Colorado potato beetle populations. 2008 Potato Pest Management Conference, Presque Isle, ME. 3. Alyokhin, A. 2008. New strategies for managing Colorado potato beetle. 23d Annual Maine Potato Conference, Caribou, ME. 4. Alyokhin, A. and S. Gross. 2008. Compost effects on insect pests of potato. 67th Annual Maine Agricultural Trades Show, Augusta, ME. In addition, the following presentations were made to other scientists involved in agricultural pest management: 1. Gross, S., A. Alyokhin, R. Larkin, S. Erich and S. Tavantzis. 2008. Reduced pest insect densities following compost application in organic and conventional potato systems. Northeast Potato Technology Forum, Bangor, Maine. 2. Gross, S., A. Alyokhin, R. Larkin, S. Erich and S. Tavantzis. 2008. Reducing pest insect densities in potato systems using compost applications. The Annual Earth Day Celebration of the Life and Legacy of Dr. Edith Marion Patch, University of Maine at Orono. 3. Gross, S., A. Alyokhin, R. Larkin, S. Erich and S. Tavantzis. 2008. Reduced pest insect densities following compost application in potato systems. Entomological Society of America Annual Meeting, Reno, NV. 4. Erich, M.S., S. Tavantzis, R. Larkin, A. Alyokhin, and S. Gross. 2008. Compost and biological amendments in potato systems: Effects on soil properties and fertility. Northeast Potato Technology Forum, Fredericton, New Brunswick, Canada. 5. Bernard, E., R. Larkin, S. Tavantzis, S. Erich, A. Alyokhin, and S. Gross. 2008. Compost and biological amendments in potato systems: Effects on soil microbial communities. Northeast Potato Technology Forum, Fredericton, New Brunswick, Canada. 6. Tavantzis, S., R. Larkin, A. Alyokhin, S. Erich, E. Bernard and S. Gross. 2008. Compost and biological amendments in potato systems: Effects on soil-borne diseases and yield. Northeast Potato Technology Forum, Fredericton, New Brunswick, Canada. 7. Gross, S., A. Alyokhin, R. Larkin, S. Erich and S. Tavantzis. 2008. Reduced pest insect densities following compost application in organic and conventional systems. Northeast Potato Technology Forum, Fredericton, New Brunswick, Canada. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Changes in knowledge: Populations of Colorado potato beetles, and potato-colonizing aphids were scouted weekly on field plots set up on a commercial organic farm and conventional Aroostook Research Farm. More egg masses were found on potato plants grown in soils amended with compost on Aroostook Farm early in the season. However, there was little difference in larval populations later in the season, possibly because plants grown in amended soils were not as suitable for larval development as the plants grown in non-amended soils. On the organic farm, egg populations were similar between the treatments, while larval populations were reduced on the amended plots. Populations of the potato aphid and the green peach aphid were lower on the amended plots on both farms. First instars were released on caged potted potato plants grown in greenhouse in soilless peat moss-based mix with or without compost, fertilizer, and hypovirulent Rhyzoctonia solani. This experiment followed a factorial randomized block design. The larvae were counted on each plant every other day. Feeding on plants grown without fertilizer increased development time for larvae, as did feeding on plants grown with eight grams of hypovirulent Rhyzoctonia solani. Compost had no effect on larval development. Larval survivorship was similar among treatments.
Publications
- No publications reported this period
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Populations of Colorado potato beetles, and potato-colonizing aphids were scouted weekly on field plots set up on a commercial organic farm and conventional Aroostook Research Farm. More adults colonized potato plants grown in soils amended with compost, which also led to a higher numbers of egg masses on one of the farms. However, there was little difference in larval populations later in the season, possibly because plants grown in amended soils were not as suitable for larval development as the plants grown in non-amended soils. A follow-up greenhouse experiment was conducted to determine which life stages of the Colorado potato beetle are affected by the soil amendments and if certain amendments cause a higher fatality in Colorado potato beetles. First instars were released on caged potted potato plants grown in soilless peat moss-based mix with or without compost and natural enemies used to suppress soilborne disease: hypovirulent Rhyzoctonia solani, Bacillus subtilis, Trichoderma virens, a combined application of B. subtilis and T. virens, and a control with no added biocontrol agent. The treatments were arranged in a fully factorial design. The larvae were counted on each plant every other day. Feeding on plants treated with B. subtilis alone or in combination with T. virens delayed development of the Colorado potato beetle larvae when compared with larvae feeding on plants grown in any of the other biocontrol treatments and the control plants with no biocontrol agents added. Compost had no effect on larval development. Larval survivorship was similar among the treatments. The greenhouse experiment described above was repeated using potato aphids and green peach aphids instead of the Colorado potato beetles. Five adult aphids be were released onto each plant. Plants were left undisturbed for ten days. After that, the number of aphids infesting each plant was recorded. Aphid populations at the end of the experiment were similar among the plants regardless of the treatment. Beetle recruitment to plants grown in soilless potting mix amended with compost or B. subtilis was quantified in greenhouse experimental arenas consisting of a wooden box (240 by 107 by 30 cm) filled with field-collected soil and enclosed in a Saran screen cage with a transparent plastic roof. One potted potato plant grown in manure-amended soil, and one potted potato plant grown in synthetically fertilized soil were placed into each arena. Ten field-collected beetles (five males and five females) were released in the center of the arena. Number of beetles of each sex and the number of eggs was recorded on each plant 48 hours after beetle release. The experiment was repeated nine times. Neither treatment affected the number of beetles or egg masses recruited to the experimental plants. PARTICIPANTS: Because of the interdisciplinary implications of our findings, activities are closely coordinated with Stellos Tavantzis (plant pathologist, UMaine), Robert Larkin (soil microbiologist, USDA-ARS), and Susan Erich (soil scientist, UMaine). Serena Gross is receiving training as a M.S. student working on this project. TARGET AUDIENCES: Potato growers, extension personnel, agricultural scientists PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The decrease in pest populations on plants grown in amended soil suggests that soil amendments are not only improving plant nutrition, but also contribute to better plant protection from insect herbivory. This potentially allows for a reduced use of harmful insecticides.
Publications
- No publications reported this period
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Progress 10/01/05 to 09/30/06
Outputs
We conducted a series of no-choice assays comparing Colorado potato beetle reproduction and development on potato plants grown in manure-amended and synthetically fertilized soils. Manure-amended soil received annual applications of raw cow manure since 1991, and additional applications of cull potato compost and green manure between 1991-1998. Plants grown in manure-amended soil were inferior Colorado potato beetle hosts compared to plants grown in synthetically fertilized soil. The observed negative effects were broad in scope. Female fecundity was lower in field cages set up on manure-amended plots early in the season, although it later became comparable between the treatments. Fewer larvae survived past the first instar, and development of immature stages was slowed down on manure-amended plots. In the laboratory, first instars consumed less foliage from plants grown in manure-amended soils. Densities of Colorado potato beetles, flea beetles, European corn borers,
potato-colonizing aphids, and their natural enemies were estimated weekly on field plots. Manure soil amendment resulted in lower populations of all Colorado potato beetle stages. The difference was not statistically significant at alpha=0.05. However, its considerable numerical value and consistency with other years of the project suggest that it was biologically meaningful. We detected significantly higher European corn borer damage on manure-amended plots while scouting during the season. However, survey of potato stalks at the end of the season failed to confirm this finding. Soil amendment did not appear to have an effect on other insects. We started testing if elevated boron concentrations detected in plants grown on manure-amended plots were responsible for the observed negative effects on the Colorado potato beetles. We created a range of boron concentrations in potato tissues by growing plants in hydroponic solutions with incrementing amounts of boron. The plants were then
enclosed in ventilated plastic cages. Ten first-instar Colorado potato beetles were released on each plant. We did not detect increase in larval mortality with the increase in boron concentration. However, only two replications per concentration were completed by the time of this report. Therefore, definite conclusions are still premature at this point.
Impacts
The decrease in female fecundity and larval survivorship might complement other mortality sources, thus decreasing the amount of chemicals necessary to suppress beetle populations. In addition, development slowdown may allow plants more opportunity to compensate for damage, especially in combination with lower leaf consumption by the beetles. Also, it may extend a window of opportunity for using Bacillus thuringiensis-based insecticides, which are most efficient against early instars. Furthermore, slower rate of development may allow more predation and parasitism in areas with significant natural enemies.
Publications
- No publications reported this period
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