Exclusion and Repulsion of Popillia japonica (Coleoptera: Scarabaeidae) Using Selected Coverings on High Tunnel Structures for Primocane Red Raspberry.

Abstract

Simple SummaryThe Japanese beetle, Popillia japonica Newman, has become an invasive pest of increasing concern for several high-value berry crops in the Midwest region of the U.S. since 2010. Due to the feeding injury caused by adult beetles, many producers have increased their use of foliar insecticides to manage P. japonica. With a goal to develop sustainable Integrated Pest Management (IPM) systems for raspberry production, we initiated a 3-year study to examine the potential for various high-tunnel production systems to suppress P. japonica populations, and thus minimize insecticide use in primocane (autumn maturing) raspberry. During each year of the study, we observed significant reductions in P. japonica beetle infestations (p < 0.05), under the high-tunnel, covered systems, compared to nearby open plots of raspberry.In temperate climates, there has been an increasing interest by fruit growers to implement the use of high tunnels, using a variety of coverings, to extend the season for fruit production. High tunnels also provide an opportunity to enhance insect pest management, via physical exclusion, and thus support reductions in insecticide use. Due to increasing pest pressure by the Japanese beetle, Popillia japonica Newman, in Midwest U.S. raspberry, a 3-year study (2017–2019) was conducted to evaluate the efficacy of selected high tunnel coverings to suppress adult beetle populations and minimize adult feeding injury. During each year of the study, P. japonica adult beetles were significantly reduced under poly-based coverings, with the ends open, and when a fine, nylon-mesh was used to cover the ends (p < 0.05). The poly-based covering also resulted in moderately higher ambient temperatures, which may have influenced beetle movement, including a “repellency effect” that encouraged beetles to exit the high tunnel structures. Although P. japonica adults are known to feed on raspberry flower clusters, including fruit, the majority (73–92%) of beetle feeding in this study was observed on the foliage. The impact of high tunnels on P. japonica are discussed within the context of developing sustainable Integrated Pest Management (IPM) programs for raspberry production.