2007 Annual Report 1a.Objectives (from AD-416) The objectives of the research are to identify antifeedant, antibiosis, or other responses from specific pest species to wild Malus sp. and identify underlying mechanisms responsible for these responses. 1b.Approach (from AD-416) ARS will survey and characterize feeding and/or oviposition activity of arthropod pests of tree fruit to Malus sp. germplasm in USDA apple germplasm repository, Geneva, NY. Verify field observations by conducting laboratory- and field-based assessments of feeding and/or oviposition activity of targeted arthropod pests using the wild Malus sp. germplasm collection in Geneva, NY. Identify biochemical differences in various Malus germplasm and relate them to specific pest responses to wild Malus germplasm. Cornell will provide laboratory space for post-doctoral personnel, needed equipment and arthropods from laboratory-reared colonies required for experiments and provide services and general support to ARS personnel for insect surveys of germplasm resources, maintenance of laboratory orithropod colonies, characterize feeding and/or oviposition activity, and data management. 3.Progress Report This report serves to document research conducted under a reimbursable agreement between ARS and the Cornell University. 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. Harvey Reissig, Cornell University, and Phil Forsline, USDA-ARS Plant Germplasm Repository in Geneva, NY, bioassays and field observations were conducted in the Malus germplasm repository collection. Results confirm that:. 1)There is little potential for resistance in Malus to attack from plum curculio, despite prior published claims. 2)'E26-7' is resistant to feeding by apple maggot larvae for much of the growing season. . 3) Malus x soulardii, and Malus tschonoskii are significantly resistant to attack from larvae of key internal fruit feeding pests, including codling moth and oriental fruit moth. The resistance mechanisms are tentatively elucidated, and appear to be based in high levels of larval mortality after feeding on fruit tissue. An understanding of the resistance levels and mechanisms in Malus germplasm will contribute to development of pest resistant cultivars requiring less pesticide usage. The methods used by the ADODR to monitor progress include phone calls, email, and site visits.