Abstract: Laboratory bioassay and field experiment were conducted to evaluate the toxicity and field control efficacy of pyriproxyfen and its mixture with organosilicon to B-biotype Bemisia tabaci. The laboratory bioassay indicated that pyriproxyfen had strong ovicidal activity against B. tabaci and high activity against B. tabaci nymphs, but had low toxicity to B. tabaci adults. After the adults were exposed to pyriproxyfen-treated eggplant leaves for 48 h, their oviposition on untreated eggplant leaves was not affected, but the egg hatching rate was sharply lowered, suggesting that pyriproxyfen had high transovarial activity. Organosilicon auxiliary agent did not show any synergistic effect when mixed with pyriproxyfen. Field trials showed that pyriproxyfen could effectively control the B. tabaci nymphs on eggplants, but could not effectively control the adults.

Key words: Bemisia tabaci B-biotype, pyriproxyfen, organosilicon auxiliary agent, transovarial activity, toxicity, control efficacy, anaerobic dechlorination, dechlorination enrichment culture, electron donor, DGGE, microbial community structure.