Management of pest mole crickets using the insect parasitic nematode Steinernema scapterisci.

摘要

Steinernema scapterisci Nguyen and Smart nematodes became established on two golf courses in Gainesville, FL, when applied as an augmentative application, and moved to untreated areas. It took about 4--8 wk post application for infection of mole crickets ( Scapteriscus spp.) to equal or exceed pretreatment levels. Infection levels in untreated areas at least 80 m away from treated areas reached infection levels similar to the treated areas in approximately 20 wk post application.; After a nematode application, mole crickets are frequently assayed to confirm nematode establishment. However, the standard soap flush was suspected of providing false negatives under field conditions. Thus, we examined the effect of several potential flushing solutions on the survival and infectivity of S. scapterisci as well as flushing ability under field conditions. Seventy percent of S. scapterisci died in the lemon dish detergent solution, confirming that assays for nematode infection of soap-flushed mole crickets are likely to be inaccurate. When sampling for mole crickets in areas where S. scapterisci has been applied, a potential alternative to the standard soap drench is a dilute permethrin drench.; Aqueous solutions of pesticides (acephate, bifenthrin, deltamethrin, fipronil and imidacloprid) used in turfgrass to control mole crickets were tested for compatibility with S. scapterisci in the laboratory. Survival of S. scapterisci was >95% in solutions of acephate, bifenthrin and imidacloprid. Infectivity of S. scapterisci previously exposed to insecticides was >60% in acephate and bifenthrin; however, infectivity was 40% in imidacloprid. The entomopathogenic nematode was compatible with all insecticides tested.; Both healthy and nematode-infected mole crickets had similar tunneling behavior. Although not significant, crickets treated with 500 or 10,000 nematodes tunneled less than uninfected crickets. Mole crickets did not appear to differentiate between untreated and nematode-treated sand. Female crickets infected with nematodes were able to lay eggs, and clutch size and egg chamber size were not significantly different than healthy crickets. Crickets also laid eggs in sand treated with nematodes, suggesting that the nematode treated sand was not a deterrent. Mole crickets in Y-tube tests did not significantly choose untreated sand over sand treated with 500 or 10,000 nematodes. When given a choice between field rates of S. scapterisci and acephate, bifenthrin, deltamethrin, fipronil, or imidacloprid, crickets significantly chose nematodes over insecticides.