Abstract
Several groups of Gammarus lacustris adults were exposed to solutions containing 0.5 and 5.0 mg of Bacillus thuringiensis subsp. israelensis per liter for 1- or 24-h periods by using traditional static bioassay exposure procedures. During a postexposure holding period, fecal pellets were removed and plated on tryptic soy agar to determine B. thuringiensis subsp. israelensis spore content. The experiments verified that traditional exposure procedures assure ingestion of B. thuringiensis subsp. israelensis spores and provided a mean dose estimate of 1,948 spores ingested per test animal with a 95% confidence interval ranging from 891 to 4,296 (1-h exposure, 5.0 mg/liter). It was also found that dose level is highly dependent upon both exposure duration and concentration and that relatively short exposures can result in a relatively long-term retention of spores postexposure (≥30 days). Body burden experiments established that large numbers of spores adsorb to the bodies of test animals during exposure and may in part explain the long-term retention of spores in the test system postexposure. These results imply that in field applications of microbial control agents, toxicologically unaffected but exposed organisms might transport the agent to untreated sites, expanding the effective treatment area and the number of organisms exposed.
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- Aly C. Germination of Bacillus thuringiensis var. israelensis spores in the gut of Aedes larvae (Diptera: Culicidae). J Invertebr Pathol. 1985 Jan;45(1):1–8. doi: 10.1016/0022-2011(85)90041-2. [DOI] [PubMed] [Google Scholar]
- Barjac H. Etude cytologique de l'action de Bacillus thuringiensis var. israelensis sur larves de Moustiques. C R Acad Sci Hebd Seances Acad Sci D. 1978 Jun;286(22):1629–1632. [PubMed] [Google Scholar]
- Margalit J., Dean D. The story of Bacillus thuringiensis var. israelensis (B.t.i.). J Am Mosq Control Assoc. 1985 Mar;1(1):1–7. [PubMed] [Google Scholar]
- Miller L. K., Lingg A. J., Bulla L. A., Jr Bacterial, viral, and fungal insecticides. Science. 1983 Feb 11;219(4585):715–721. doi: 10.1126/science.219.4585.715. [DOI] [PubMed] [Google Scholar]
- Mulla M. S., Federici B. A., Darwazeh H. A., Ede L. Field evaluation of the microbial insecticide Bacillus thuringiensis serotype H-14 against floodwater mosquitoes. Appl Environ Microbiol. 1982 Jun;43(6):1288–1293. doi: 10.1128/aem.43.6.1288-1293.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Petras S. F., Casida L. E. Survival of Bacillus thuringiensis Spores in Soil. Appl Environ Microbiol. 1985 Dec;50(6):1496–1501. doi: 10.1128/aem.50.6.1496-1501.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thomas W. E., Ellar D. J. Bacillus thuringiensis var israelensis crystal delta-endotoxin: effects on insect and mammalian cells in vitro and in vivo. J Cell Sci. 1983 Mar;60:181–197. doi: 10.1242/jcs.60.1.181. [DOI] [PubMed] [Google Scholar]
- Tyrell D. J., Davidson L. I., Bulla L. A., Jr, Ramoska W. A. Toxicity of parasporal crystals of Bacillus thuringiensis subsp. israelensis to mosquitoes. Appl Environ Microbiol. 1979 Oct;38(4):656–658. doi: 10.1128/aem.38.4.656-658.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]