TOXICITY OF ALLYL ISOTHIOCYANATE-AMENDED SOIL TO LIMONIUS-CALIFORNICUS (MANN) (COLEOPTERA, ELATERIDAE) WIREWORMS

Acute toxicity of soil amended with allyl isothiocyanate (AITC) to thr ee size classes of Limonius californicus (Mann.) wireworms was determi ned in the laboratory. Wireworms were exposed to AITC at initial conce ntrations of 120-300 nmol/g soil for one day. During this time, extrac table AITC concentrations decreased by 66 to 93 %. Probit analysis est imated LC50 values of 238 and 226 nmol/g soil at one day posttreatment for medium and large wireworms, respectively. For small wireworms, LC 50 values decreased from 211 to 157 nmol/g soil during 1-137 days post treatment. Sublethal concentrations of AITC significantly reduced feed ing activity of treated wireworms at three posttreatment times and ove r the entire 137 days. Wireworm weight was not significantly affected by AITC. The potential exists to use glucosinolate-containing plant ti ssue as an isothiocyanate (ITC) source to reduce crop damage caused by L. californicus wireworms.