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Toxicity of carbon dioxide at biologically producible levels to stored-product beetles

White, N.D.G., Jayas, D.S., Muir, W.E.
Environmental entomology 1995 v.24 no.3 pp. 640-647
Tribolium confusum, interspecific variation, carbon dioxide, oviposition, Tribolium castaneum, Cryptolestes pusillus, Cryptolestes ferrugineus, population growth, toxicity, insect control, storage pests, biological development, mortality
The effect of concentrations of carbon dioxide (CO2) that can be produced by biological respiration (7.5-19.2%) on oviposition of adult Tribolium castaneum (Herbst), Cryptolestes pusillus (Schonherr), or C. ferrugineus (Stephens) was determined. Relative to controls, T. castaneum, C. pusillus, and C. ferrugineus exposed to 7.5% CO2 for 1 wk, had numbers of offspring reduced by 43, 94, and 50%, respectively, and the total population at 6 wk was reduced 53, 84, and 19%, respectively. With levels of greater than or equal to 17.1% CO2 for 1 wk, no offspring were produced and exposed adults had high mortality. Eggs and subsequent immatures of Tribolium confusum J. du Val, T. castaneum, or C. ferrugineus were exposed for 3 wk to elevated levels of CO2 at 22 degrees C. Insect development was similar at 7.5 and 8.6% CO2 with mean mortality 43, 62, and 30% greater than controls for T. confusum, T. castaneum, and C. ferrugineus, respectively. Also, mean levels of 5.8-8.3% CO2 for 7 wk reduced, on all sampling dates, populations of T. confusum by 85%, T. castaneum by 99%, C. pusillus by 68% and C. ferrugineus by 54%. Although T. castaneum had a greater oviposition rate than C. pusillus at 7.5% CO2, immature mortality was greater for T. castaneum. Based on long-term exposure to levels of CO2 which can be produced by biological activity that affects oviposition and immature development, species in increasing order of sensitivity to CO2 are C. ferrugineus, C. pusillus, T. confusum, and T. castaneum.