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Kevin M. Spollen, Murray B. Isman, Acute and Sublethal Effects of a Neem Insecticide on the Commercial Biological Control Agents Phytoseiulus persimilis and Amblyseius cucumeris (Acari: Phytoseiidae) and Aphidoletes aphidimyza (Diptera: Cecidomyiidae), Journal of Economic Entomology, Volume 89, Issue 6, 1 December 1996, Pages 1379–1386, https://doi.org/10.1093/jee/89.6.1379
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Abstract
We tested the effects of a neem insecticide, containing azadirachtin (AZA) as the active ingredient, on fecundity, adult and egg mortality, and preference for neem-treated or untreated foliage on 2 predacious mite species, Phytoseiulus persimilis Athias-Henriot, and Amblyseius cucumeris (Oudemans). We also tested the effects of neem on egg, larval, and adult survival,, and on ovipositional preference for neem treated or untreated foliage, on the aphid predator Aphidoletes aphidimyza (Rondani). We found no significant differences in egg or adult mortality between treated and untreated mites for either species. For A. cucumeris, untreated females that contacted leaf disks and prey treated with 60 ppm AZA laid fewer egg after 48 h than females on untreated disks. In leaf-disk choice tests, significantly more P persimilis were found on untreated disks than those treated with 60 ppm after 24 h, and significantly more A. cucumeris were found on untreated disks than those treated with 60 ppm after 48 h. However, the number of eggs laid on treated versus untreated disks in these choice tests were not significantly different. For A. aphidimyza we found no significant differences in the percentage eclosion between neem-treated and untreated eggs. However, larval mortality ranged from 30 to 100% for 1st instars treated with neem, and adult emergence of treated larvae was significantly lower for 1st- and 3rd-instar A. aphidimyza compared with untreated controls. First and 3rd instars that acquired neem from contact with treated foliage or ingestion of treated aphids had greater mortality than larvae that were sprayed directly with neem solutions. No significant differences in the sex ratio of adults of the surviving neem treated and control larvae occurred. Adult A. aphidimyza exposed to 60 ppm AZA residues for 48 h in residual contact tests had significantly greater mortality (13%) compared with controls (5%). No significant differences in the number of eggs laid on treated and untreated mustard cabbage plants were apparent. We compared our results with previously published data on the effect of neem on beneficial arthropods.
