Effect of Plastic Mulch Colors on Anasa tristis (Hemiptera: Coreidae) Population Dynamics in Summer Squash, Cucurbita pepo (Cucurbitales: Cucurbitaceae)

The squash bug, Anasa tristis (De Geer), is a serious pest of cucurbit crops across the United States, especially within summer squash (Cucurbita pepo L.) systems. Using their piercing sucking mouthparts, squash bugs feed on both leaf tissue and fruits, often leading to leaf necrosis, marketable fruit loss, and even plant death. To date, the relationship between squash bug presence and plasticulture has not been adequately investigated. This 2-yr study evaluated the effects of white, black, and reflective plastic mulch colors on the occurrence of all squash bug life stages and marketable zucchini yield in Virginia. In both years, A. tristis adults and egg masses were more numerous on zucchini plants grown in white and reflective plastic mulch compared to bare ground plants. Greater nymphal densities and marketable fruit yield were observed in certain plastic mulch treatments versus the bare ground treatment, yet these differences were not consistent in both years. Contrary to the repellency effects reflective mulches have on other cucurbit insect pests, our research suggests that reflective and other plastic mulch colors can negatively impact squash bug management, especially in regions with high A. tristis pressure. Our study offers new insights for cucurbit growers to use when considering whether they should implement plasticulture in their growing systems.