2007 Annual Report 1a.Objectives (from AD-416) To determine the role of the imported biological control agent Peristenus digoneutis in reducing tarnished plant bug populations in apples and other crops, and measure the economic benefit this reduction provides to farmers. 1b.Approach (from AD-416) The tarnished plant bug (TPB) is a major pest of fruit, vegetable, seed, fiber, and nursery crops. This project focuses on apples, because they are grown in many states, are perennial, have a high value per acre, and are damaged by TPB in New York and other northeastern states. Since the establishment of P. digoneutis in the region, which has reduced populations of TPB in alfalfa, incidence of damage by TPB in apples has also fallen. Cooperator will conduct research to determine whether P. digoneutis is responsible for this reduction by. 1)measuring the impact of Peristenus digoneutis on TPB in apple orchards grown under different management practices;. 2)contrasting the rate of parasitism by P. digoneutis in apples with the rate in adjacent alfalfa, weeds, and other vegetation associated with apple orchards; and. 3)measuring the impact of biological control by P. digoneutis on native TPB parasitoids and associated mirids in apples. 3.Progress Report This report documents research under a specific cooperative agreement between ARS and Cornell University to determine the impact of an introduced European parasitoid of tarnished plant bugs (TPB). The project is a follow-on agreement to an SCA that terminated on 31 August 2005. Reported damage to commercial apples by TPB in the NE U.S. has declined over the past decade, coinciding with the establishment and spread of Peristenus digoneutis, a European parasitoid of TPB introduced in the region. The goal of this project was to determine the parasitoid’s impact and its role in the decline of TPB in apple crops and determine its compatibility with different pest management practices in apples. The research was completed in 2007. It showed that P. digoneutis successfully expanded into New York apple orchards, a new documented crop environment for this natural enemy. Peristenus was present in orchards that were actively sprayed with insecticides and in abandoned apple orchards that lacked such treatments. The parasitoids were able to attack TPB nymphs in the standard insecticide environment just as effectively as in the abandoned orchard environment where no insecticides were applied. To monitor project progress, the ADODR corresponded with the graduate student conducting the research regularly by electronic mail, met with the student at a national meeting where preliminary results were reported, and fully participated as a committee member in the student’s thesis defense at Cornell.