Feeding by Japanese Beetle and Southern Masked Chafer Grubs on Lawn Weeds

Abstract

Root‐feeding white grubs (Coleoptera: Scarabaeidae) are among the most injurious insect pests of cool‐season turfgrasses; however, little is known about the influence of common lawn weeds on white grub populations. Greenhouse studies were conducted to evaluate the suitability of six weed species and one turfgrass including white clover (Trifolium repens L.), red clover (T. pratense L.), large crabgrass [Digitaria sanguinalis (L.) Scop.], annual bluegrass (Poa annua L.), buckhorn plantain (Plantago lanceolata L.), dandelion (Taraxacum officinale Weber), and Kentucky bluegrass (Poa pratensis L.) as food for grubs of the Japanese beetle (Popillia japonica Newman) and southern masked chafer (Cyclocephala lurida Bland). Third instars of both species fed upon and reduced root biomass of all weeds tested, and in some cases, reduced foliage yields as well. Survival of both grub species was as high, or higher, on most weeds as on Kentucky bluegrass. Dandelion and white clover appear to be particularly poor hosts for P. japonica and C. lurida, respectively.