Author
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Castle, Steven |
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Henneberry, Thomas |
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Submitted to: Sweetpotato Whitefly Progress Review Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 8/1/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Three years of continuous resistance monitoring of Bemisia tabaci populations in the Imperial Valley, CA have revealed a pattern of LC50s that vary according to crop and insecticide. Comparisons of mean LC50s between host crops within a single year also reveal significant differences that are consistent from one Year to the next. Fluctuations in mean LC50S generated by the resistance monitoring program have been most apparent for bifenthrin. In spring 1995, adjacent plantings of kale and cantaloupe, each with their resident whiteflies, permitted comparison of responses to four insecticide treatments using the yellow sticky card bioassay technique. Adult whiteflies collected directly from each crop were bioassayed, and then greenhouse colonies were established on both cantaloupe and broccoli plants with whiteflies from both crop sources. After one week in the greenhouse, these whiteflies were tested, and subsequently the Fl generation was tested. Whiteflies collected on kale in the field were significantly (non-overlap of 95 p C.I.s) less sensitive to bifenthrin than those collected on cantaloupe. When reciprocal transplants were made, whiteflies that continued to be cultured on kale remained less susceptible than those that remained on cantaloupe, whereas ones that originated on kale but were transplanted to cantaloupe became more susceptible to bifenthrin. |
