Host range and selected factors influencing the mosquito larvicidal activity of the PG-14 isolate of Bacillus thuringiensis var. morrisoni.
Laboratory bioassay of the PG-14 isolate of Bacillus thuringiensis var. morrisoni (serotype 8a:8b) against early fourth instar larvae of 8 species of mosquitoes revealed a range of susceptibilities similar to the susceptibilities of these species to Bacillus thuringiensis var. israelensis (serotype 14). The most susceptible species were: Culex quinquefasciatus, Cx. salinarius, Anopheles albimanus and Aedes aegypti. The least susceptible species tested was An. quadrimaculatus. Separate bioassays of PG-14 against the four instars of Ae. aegypti demonstrated a strong negative correlation (R = -0.97) between larval age and susceptibility. Temperature significantly affected the stability of larvicidal toxin in aqueous suspensions of PG-14. Larvicidal activity of a bacterial suspension was nearly completely eliminated after 132 days of storage at 31 degrees C, but was essentially unchanged for those suspensions stored at 4 degrees C.
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Insects Affecting Man and Animals Research Lab, USDA, ARS, Gainesville, FL 32604.
Lacey
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Padua
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D000330:Aedes; D000818:Animals; D000852:Anopheles; D001413:Bacillus thuringiensis; D003465:Culex; D006702:Homing Behavior; D007814:Larva; D009032:Mosquito Control; D013997:Time Factors