Survey and Rearing of Grape Berry Moth Larval Parasitoids in Northwest Pennsylvania

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Commodities

• Fruits: grapes

Practices

• Pest Management: integrated pest management

The grape berry moth (GBM), Paralobesia viteana is a destructive pest of grapes. The larvae of this insect feed on grape clusters causing direct damage and increased susceptibility to fungal pathogens. Management of GBM currently relies on applications of insecticides timed using a degree-day model. Although insecticides confer protection against this insect, their constant use poses human an environmental risk and can lead to the development of GBM resistance to these products. With the long-term goal of developing more sustainable strategies for GBM control, this project aims 1) to identify naturally occurring larval parasitoids of GBM in Northwest PA, 2) to develop a rearing protocol for at least one of the parasitoid species, and 3) to test the effectiveness of at least one species for controlling GBM in a commercial vineyard plot. During the growing season of 2022, parasitoids will be collected from the field, identified, and reared in laboratory conditions. In 2023, at least one of the reared parasitoid species will be released back to the field to test its efficacy in reducing GBM infestations. This study will provide new knowledge of the diversity of GBM larval parasitoids, their life cycle, and the effectiveness of GBM control in field conditions. Biological control using larval parasitoids is a sustainable practice that has not been previously addressed for GBM control in the Northeast of the US. The results of this project will be disseminated to growers in extension meetings and to the public through an extension article and a scientific publication.

This project seeks to 1) Identify larval parasitoids of grape berry moth in Northwestern Pennsylvania, 2) create a rearing protocol for at least one of the parasitic species identified, and 3) test the efficacy of at least one parasitic species in reducing grape berry moth infestations in a commercial vineyard plot. This project will be the baseline for future experiments of grape berry moth control using larval parasitoids. Our long-term goal is to include the release of parasitic wasps as part of an integrated pest management program to control grape berry moth in commercial vineyards. If successful, this project is likely to reduce production costs and increase farmers income by decreasing GBM infestations and by reducing the use of toxic insecticides.