Relative and Seasonal Abundance of Beneficial Arthropods in Centipede grass as Influenced by Management Practices

Abstract

Pitfall traps were used to monitor the seasonal activity of arthropod predators, parasitoids, and decomposers in replicated plots of centipedegrass turf for 3 yr (1989-1991) at two locations. During 1990 and 1991, the influence of single or combined herbicide, insecticide, and fertilizer applications on these beneficials was assessed. In total, 21 species of carabids in 13 genera and 17 species of staphylinids in 14 genera were represented in pitfall-trap collections. Nonsminthurid collembolans, ants, spiders, and parasitic Hymenoptera were adversely affected in the short term by insecticide applications targeting the twolined spittlebug, Prosapia bicincta (Say). Other taxa, notably oribatid Acari, increased over time in response to pesticide or fertilizer applications. Although various taxa were reduced by pesticide application during three of four sample intervals, a lack of overall differences in season totals suggests that the disruptive influence of certain chemical management practices may be less severe than expected in the landscape.