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ARS Home » Research » Publications at this Location » Publication #114714
Title: TOXICOLOGICAL STUDIES OF TWO INSECT GROWTH REGULATORS ON THE PREDATOR GEOCORIS PUNCTIPES

Author
item Naranjo, Steven
item PRABHAKER, NILIMA - U CA, RIVERSIDE, CA

Submitted to: Sweetpotato Whitefly Progress Review Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Laboratory experiments were conducted to evaluate the direct effects of two insect growth regulators (IGR), buprofezin and pyriproxyfen, on survival an reproduction of Geocoris punctipes. Topical and contact residue assays were performed on both 5th instar nymphs and on 5-10 day old adults. Over a wide range of doses buprofezin had no effect on survival or reproduction of 5th instar nymphs or adults based on topical or contact residue assays. Topical assays with pyriproxyfen on 5th instar nymphs yielded an LD50 and LD90 of 3520 and 47,186 ppm, respectively. Concentrations of field applications are ca. 2700 ppm. At doses greater than 2700 ppm most nymphs molted to the adult stage but many had wing deformities that prevented successful mating and reproduction. Contact residue assays on 5th instar nymphs yield an LD50 and LD90 of 706 and 2307 ppm, respectively. Most of the affected nymphs molted to the adult stage but had wing deformities. Pyriproxyfen did not affect adult survival in either topical or contact residue assays over wide range of doses. Reproduction also was unaffected at doses up to field application rates. Egg viability, but not rate of oviposition, declined slightly at doses greater than or equal to times higher than field application rates. Results suggest that buprofezin is benign to G. punctipes but that pyriproxyfen may be slightly to moderately detrimental under ideal exposure.