01562nas a2200157 4500008004100000245015700041210006900198300001000267490000800277520095000285653001201235100002001247700001901267700001401286856010401300 1982 eng d00aA Comparison of Laboratory and Field Tests of Bacillus sphaericus Strain 1593 and Bacillus thuringiensis var. israelensis Against Aedes stimulans Larvae0 aComparison of Laboratory and Field Tests of Bacillus sphaericus  a55-610 v1143 a

Bacillus thuringiensis var. israelensis (serotype H-14) and B. sphaericus strain 1593 were tested against Aedes stimulons larvae in the laboratory and in 38-cm-diam, open-ended cylinders embedded in the bottom detritus of a woodland pool. Estimates of LC50 were lower against fourth instars in the field at a mean temperature of 15.9 °C than in the laboratory at 21.1 °C. The greater efficacy in the field was attributed to high daytime water temperatures (mean 20.5 °C) following treatment and exposure of the larvae to substantially greater amounts of toxic material in a larger volume of water than in the laboratory. The regression of probit on log10 concentration was not linear over the entire range of mortality caused by B. sphaericus, increasing the difficulty of estimation of LC values. Bacillus sphaericus was significantly less active than B. thuringiensis.

10abiology1 aWraight, S., P.1 aMolloy, D., P.1 aMcCoy, P. uhttps://nysm.nysed.gov/staff-publications/comparison-laboratory-and-field-tests-bacillus-sphaericus