Consumptive and non-consumptive effects of predatory arthropods on billbug (Coleoptera: Dryophthoridae) pests in turfgrass

Publication date: Available online 16 October 2018Source: Biological ControlAuthor(s): Madeleine M. Dupuy, Ricardo A. RamirezAbstractGeneralist predators affect pest populations through direct consumption or by non-consumptive effects, whereby predators induce changes in prey behavior which represent a cost to prey. A diverse community of predatory arthropods has been described in turfgrass, contributing to the direct mortality of pests including black cutworm, fall armyworm, and Japanese beetle. Billbugs are a major pest of turfgrass in the Intermountain West, but the composition of the local predatory arthropod community and whether predators aid in billbug suppression through consumptive or non-consumptive effects is unknown. First, we catalogued the predatory arthropod community on Utah and Idaho golf courses using linear pitfall traps. Then, we assessed adult billbug consumption by resident predators in the field. Using a series of lab assays, we assessed the most abundant predators’ consumption of billbug life stages, including adults, sentinel waxworm larvae at varied soil depths, and eggs in turf stems. Finally, we assessed the non-consumptive effects of these abundant predators on adult billbug activity (mating, oviposition, thanatosis). We found that the predatory arthropod community consisted primarily of carabids (Pterostichus melanarius, Harpalus sp., Amara aenea, and Anisodactylus sp.) and spiders (lycosids), representing 60% and 28% of all predators, respecti...

Source: Biological Control - October 16, 2018 Category: Biology Source Type: research