Progress 07/01/03 to 12/31/07
Outputs
Progress Report Objectives (from AD-416) Determine the relative attractiveness of extrafloral nectar from different peach cultivars and the effects on natural enemy life history and biological control efficiency. Determine the effect of extrafloral nectary resources on natural enemy abundance and biological control on apple trees. Determine the spatial dynamics and distance at which extrafloral nectaries affect natural enemy effectiveness, and develop prototypical orchard designs for implementing natural enemy management practices in commercial orchards. Approach (from AD-416) Extrafloral nectar from peach leaves will be collected and tested for attractiveness to natural enemies with a gas-chromatography and electro- antennal detection system. Nectar will also be provided as diet to natural enemies to investigate nutritive qualities of the nectar. Field cage and orchard studies will be done to examine the effect of nectar sources on biological control of insect pests on apple. Both abundance of natural enemies and the number of pests killed will be used to evaluate the impact of nectar. Significant Activities that Support Special Target Populations The goal of this project was to evaluate the potential of incorporating peach trees into apple orchards to increase the level of biological control of insect pests on apple. Peach trees have extrafloral nectar glands that produce a sugary secretion that is an attractive food source for insect natural enemies. Laboratory trials using two model tree fruit pest systems (lady beetles and aphid pests; parasitoids and tufted apple budmoth) were conducted to examine the impact of providing nectar on the interaction between natural enemies and their hosts. Both lady beetles and the parasitoid lived longer and destroyed more pests when exposed to extrafloral nectar than without the nectar. In orchard tests we found that in the presence of peach trees more parasitoids were found than in an apple orchard without peach trees. Lady beetles also arrived a week earlier in apple orchards with peach trees thus allowing them to begin to control aphid populations earlier than in apple orchards without peach trees. Rates of biological control in orchards, reduced rates of aphid population growth and number of tufted apple budmoths parasitized, however, were not increased in the presence of peach trees. The most significant result of the 4 year experiment was that the addition of peach trees into apple orchards did produce an ecosystem-level response with significantly lower damage by San Jose scale and stink bugs to apple fruit for three consecutive years. This result demonstrates that in experiments that alter the structure of the orchard ecosystem, there can be implications for pest management beyond the target species. Suppression of pest damage can be achieved through other mechanisms rather than direct predator-prey or parasitoid host interactions. The ecosystem service of pest regulation can be achieved indirectly through subtle changes in ecosystem processes, such as host quality and competitive interactions. Work was monitored by site visits and calls.
Impacts
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) Determine the relative attractiveness of extrafloral nectar from different peach cultivars and the effects on natural enemy life history and biological control efficiency. Determine the effect of extrafloral nectary resources on natural enemy abundance and biological control on apple trees. Determine the spatial dynamics and distance at which extrafloral nectaries affect natural enemy effectiveness, and develop prototypical orchard designs for implementing natural enemy management practices in commercial orchards. Approach (from AD-416) Extrafloral nectar from peach leaves will be collected and tested for attractiveness to natural enemies with a gas-chromatography and electro- antennal detection system. Nectar will also be provided as diet to natural enemies to investigate nutritive qualities of the nectar. Field cage and orchard studies will be done to examine the effect of nectar sources on biological control of insect pests on apple. Both abundance of natural enemies and the number of pests killed will be used to evaluate the impact of nectar. Significant Activities that Support Special Target Populations This report serves to document research conducted under a reimbursable agreement between ARS and the USDA, CSREES, NRI. Additional details of research can be found in the report for the parent project 1931-21000-015- 00D Integrated Orchard Management and Automation for Deciduous Tree Fruit Crops. In collaboration with Dr. Clarissa R. Mathews, Shepherd Univ., Dr. Aijun Zhang, USDA, ARS, Chemicals Affecting Insect Behavior Laboratory, Beltsville and Dr. Greg Krawczyk, Penn State Univ., Tree Fruit Research and Extension Center, Biglerville, PA research continued on the effect of peach extrafloral nectar on the movement and effectiveness of natural enemies in apple orchards. Field and cage experiments are continuing to examine the impact of nectar on biological control. It has been shown that parasitic insects are attracted to sources of nectar and that there are higher levels of biological control of aphids in the immediate vicinity of the nectar source. Feeding trials of the lady beetle Harmonia axyridis in the presence of nectar and aphids showed that the beetles live longer and feed on more aphids in the presence of nectar. The methods used by the ADODR to monitor progress include phone calls, email, and site visits.
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Progress 10/01/05 to 09/30/06
Outputs
Progress Report 4d Progress report. This report serves to document research conducted under a reimbursable agreement between ARS and the USDA, CSREES, NRI. Additional details of research can be found in the report for the parent 1931-21000-015-00D Integrated Orchard Management and Automation for Deciduous Tree Fruit Crops. In collaboration with Dr. Clarissa R. Mathews, Shepherd Univ., and Dr. Aijun Zhang, USDA, ARS, Chemicals Affecting Insect Behavior Laboratory, Beltsville, it was shown that the multicolored Asian Lady beetle did not respond to odors of extrafloral nectar from peach. The attraction to these food sources was concluded to be due to feeding on the nectar once encountered while searching for food, whether it is for aphids or other sources. Studies have been initiated to evaluate the tufted apple budmoth parasitoid, Goniozus flavadana, to nectar. Further field studies on predator and parasitoid reaction to peach extrafloral nectar have continued. Field
data showed that peach extrafloral nectar in apple orchards does enhance biological control of spirea aphid on apple. It was also shown that if too many sources of nectar are provided there can be a reduction in biological control. Apple orchards with 9% of the trees being peach trees showed greater biological control by the multicolored lady beetle than orchards with no peach trees or orchards with 50% of the trees being peach. It is concluded that to optimize biological control of spirea aphid in apple orchards, no more than 20% of the trees should be producing extrafloral nectar, otherwise the nectar would compete with aphids for the searching lady beetles.
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Progress 10/01/04 to 09/30/05
Outputs
4d Progress report. This report serves to document research conducted under a reimbursable cooperative agreement between ARS and NRI. Additional details of research can be found in the report for the parent CRIS 1931-21000-015- 00D, Integrated Orchard Management for Deciduous Tree Fruit Crops. In a 4-hour cage study the presence of peach extrafloral nectaries decreased the number of aphids eaten by lady beetles; the presence of buckwheat flowers had no effect on number of aphids eaten. These results indicate the possibility that providing alternative food sources for natural enemies may not increase biological control as has been expected. This research was done in cooperation with Shepherd University. This accomplishment addresses the use of flowers and extrafloral nectaries in crop systems in an attempt to increase naturally occurring biological control and the results are a reminder to other researchers that experiments need to be conducted to verify the
assumptions regarding alternate food sources and biological control rates. Field studies are continuing to evaluate the effect of peach extrafloral nectar on biological control of tufted apple budmoth and aphids. This project supplements the parent CRIS by providing detailed information on the interaction between biological control and extrafloral nectar, contributing to objective 2a, enhancing natural biological control of insect pests of apple.
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Progress 10/01/03 to 09/30/04
Outputs
4. What were the most significant accomplishments this past year? D. Progress Report: This report serves to document research conducted under a Reimbursable Agreement between ARS and NRI. Additional details of research can be found in the report for the parent CRIS 1931-21220-011-00D, Integrated Orchard Management for Deciduous Tree Fruit Crops. Field experimentation related to the objective of determining the spatial influences of peach extrafloral nectaries on biological control in apple orchards has been initiated. Colonies of the predator beetle and parasitoid are being established for laboratory studies. A new peach orchard has been planted for studies comparing extrafloral nectar production among peach cultivars. The parent CRIS has the objective of enhancing native biological control of insect pests of apple, this project supplements this objective by providing detailed information on the interaction of peach extrafloral nectaries with pest and beneficial
insects.
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