Tolerance of Western Corn Rootworm Larvae (Coleoptera: Chrysomelidae) to 6-Methoxy-2-benzoxazolinone, a Corn Semiochemical for Larval Host Location

6-Methoxy-2-benzoxazolinone (MBOA) and 2,4-dihydroxy-7-methoxy-l,4-benzoxazin-3-one (DIMBOA), its natural precursor, are toxic to many insect species. We studied the possible toxicity of MBOA, a host-location semiochemical for western corn rootworm larvae, to larvae of this species. DIMBOA previously was shown by other workers to be toxic to frst-instar western corn rootworm, Diabrotica virgifera virgifera LeConte. Using methods that previously showed DIMBOA to be toxic, we found that MBOA had no toxic effects on larvae of the western corn rootworm. The tolerance of western corn rootworm larvae to MBOA is consistent with the putative role of this benzoxazolinone as a semiochemical for the species.