An insecticide; a semisynthetic derivative of avermectin B1a; binds to GABAA receptors (Ki = 17.6 nM in rat brain membranes), including those containing β1, β2, or β3 subunits (IC50s = 57, 210, and 49.8 nM for α1β1γ2, α1β2γ2, and α1β3γ2 subunits, respectively); potentiates the GABA response; binds to and inhibits glycine receptors (IC50 = 218 nM in rat spinal cord); induces mortality in 90% of S. exigua larvae in a diet incorporation assay at a dose of 1.067 ng/ml