GABA-gated chloride channel blocker. Prototype of the phenylpyrazole insecticides known as fiproles. Prepn: I. G. Buntain et al., EP 295117 (1988 to May & Baker); L. R. Hatton et al., US 5232940 (1993). Mechanism of action study: L. M. Cole et al., Pestic. Biochem. Physiol. 46, 47 (1993). Comprehensive description: F. Colliot et al., Brighton Crop Prot. Conf. - Pests Dis. 1992, 29-34.