Effects of abamectin and milbemycin D on gypsy moth, Lymantria dispar L., were determined. Fifty percent of third instars exposed for 2 h to 5.2 ppm milbemycin D on artificial diet were flaccid and paralyzed, whereas larvae exposed to 5.0 ppm abamectin were unaffected. When larvae were exposed to abamectin on artificial diet for 24 or 48 h, 50% of third instars died. Larvae exposed for 24 h to milbemycin D were not affected, but at 48 h 165 ppm caused 50% mortality of third instars. When larvae were exposed to milbemycin D residues for 48 h and observed 5·d later, the LC50was 92 ppm. LC50's(ppm) when larvae were exposed for 72 h to residues on poplar foliage were 4 for abamectin, 1,454 for milbemycin D, and 125 for carbaryl. Five days after exposure to foliage residues, LC50's (ppm) were 1 for abamectin, 244 for milbemycin D and 106 for carbaryl. On both substrates, abamectin was most toxic to third instars. Larvae exposed for 2 h to milbemycin D residues were flaccid and paralyzed but the effect was reversible.
Document Type: Research Article
Publication date: October 1, 1989
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.