Cucurbit production systems and their impact on beneficial insect conservation

Monday, November 17, 2014: 10:36 AM
D136 (Oregon Convention Center)
Margaret Lewis , Department of Entomology, Pennsylvania State University, University Park, PA
Striped cucumber beetle, Acalymma vittatum, is a key pest of cucurbit crops in the Northeastern United States and a competent vector of the pathogen Erwinia tracheiphila, the causal agent of bacterial wilt. Disease management happens only through vector control, resulting in increased use of insecticides to manage beetle populations. Beyond concerns about the development of insecticide resistance in A. vittatum, insecticides contribute to natural enemy and pollinator decline. These cucurbit production systems also rely on plastic mulch, which requires conventional soil tillage, a practice linked to erosion, increased pesticide runoff, and potential disturbance to ground-dwelling arthropods. Two potential alternative management tactics are strip tillage, a type of conservation tillage, and use of polyprene row covers. However, little is known about how these practices affect beneficial arthropods and ecosystem services within cucurbit cropping systems. During a two year field study, we evaluated the impact of strip tillage versus plastic mulch with row covers on beneficial ground-dwelling arthropod assemblages. Using a split-plot design, we assessed ground beetle (Coleoptera: Carabidae) activity-density with pitfall trapping. Data suggests that Carabid response to tillage is species-specific, with Cicindela punctulata demonstrating sensitivity to soil disturbance. An understanding of how different cucurbit production practices affect beneficial arthropod populations will allow growers to implement cucurbit management programs that effectively manage A. vittatum while maintaining valuable ecosystem services.