BIOLOGICAL CONTROL Influence of Commercially Available Wildflower Mixes on Beneficial Arthropod Abundance and Predation in Turfgrass

Conservation and augmentation of indigenous natural enemies are promising strategies for biologically based pest management in outdoor urban environments. This research sought to determine whether the addition of wildßower plantings would enhance the occurrence, abundance and impact of beneÞcial arthropods in the landscape, and to determine the potential compatibility of pest-resistant turfgrass and natural control of Japanese beetle, Popillia japonica Newman, and fall armyworm, Spodoptera frugiperda (J.E. Smith). A bermudagrass cultivar (susceptible to fall armyworm), a zoysiagrass cultivar (resistant to fall armyworm), and two different commercially available wildßower mixes all harbored a diverse array of beneÞcial arthropods in both large and small plot evaluations. A wildßower mix containing 15 species of ßowers provided signiÞcant, season-long increases in foliar-dwelling spiders and bigeyed bugs during 1-yr of a 2-yr study in large (1,512 m) plots. Ground-dwelling spiders were more abundant in bermudagrass turfgrass than in wildßowers both years, whereas ants were not signiÞcantly affected by cover type. Eachwildßowermix evaluated in a separate 2-yr small plot study increased the abundance of some, but not all beneÞcial arthropod taxa sampled. This increased abundance was only occasionally also observed in adjacent turfgrass areas.However, fall armywormeggsand larvae, and Japanesebeetleeggswereconsistently andheavily preyed upon in small plots regardless of turfgrass species in the plot or surrounding border of ßowers or mulch. Most beneÞcial taxa, even Geocoris uliginosus, which was more common in turfgrass, were represented in ßowers, suggesting that these ßoral plantings may be useful in providing refugia for beneÞcials when insecticide applications are required to suppress turfgrass pests.