Cultural Control of Drosophila suzukii in Small Fruit—Current and Pending Tactics in the U.S.

SIMPLE SUMMARY: Integrated Pest Management (IPM) is a science-based decision-making process that uses a variety of management approaches to increase farm profitability while protecting human health and the environment, with pesticides used only as a last resort. An important alternative to pesticides, cultural controls modify production practices and/or the crop environment to reduce pest populations and damage. This review presents the current state of knowledge and implementation of cultural controls to manage the invasive vinegar fly, spotted-wing drosophila, in U.S. small fruit crops. Spotted-wing drosophila causes direct damage by laying its eggs into ripening fruit. Because it reproduces quickly, uses a variety of cultivated and wild fruits, and is highly mobile, spotted-wing drosophila is difficult to manage. Developing effective and economic cultural controls to manage spotted-wing drosophila will help improve IPM programs. ABSTRACT: Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), a vinegar fly of Asian origin, has emerged as a devastating pest of small and stone fruits throughout the United States. Tolerance for larvae is extremely low in fresh market fruit, and management is primarily achieved through repeated applications of broad-spectrum insecticides. These applications are neither economically nor environmentally sustainable, and can limit markets due to insecticide residue restrictions, cause outbreaks of secondary pests, and select for insecticide resistance. Sustainable integrated pest management programs include cultural control tactics and various nonchemical approaches for reducing pest populations that may be useful for managing D. suzukii. This review describes the current state of knowledge and implementation for different cultural controls including preventative tactics such as crop selection and exclusion as well as strategies to reduce habitat favorability (pruning; mulching; irrigation), alter resource availability (harvest frequency; sanitation), and lower suitability of fruit postharvest (cooling; irradiation). Because climate, horticultural practices, crop, and market underlie the efficacy, feasibility, and affordability of cultural control tactics, the potential of these tactics for D. suzukii management is discussed across different production systems.