ABSTRACT
An oxidative metabolism of Collembolan Proisotoma minuta was determined with a model compound of aldrin and dieldrin in this paper. The seven-day LD(50) values for aldrin, dieldrin, and piperonyl butoxide in salt solution were 0.496, 0.367, and 8.346 mg L(-1), respectively. When P. minuta were exposed to aldrin, dieldrin was the sole metabolite. The conversion of aldrin to dieldrin was known to be catalyzed by P450 monooxygenases system. It has been shown that the synergist piperonyl butoxide inhibited the metabolism of aldrin in P. minuta.
Subject(s)
Insecta/drug effects , Insecta/metabolism , Insecticides/metabolism , Insecticides/toxicity , Aldrin/metabolism , Aldrin/toxicity , Animals , Dieldrin/metabolism , Dieldrin/toxicity , Insecta/growth & development , Lethal Dose 50 , Oxidation-Reduction , Piperonyl Butoxide/metabolism , Piperonyl Butoxide/toxicity , Time FactorsABSTRACT
The acute toxicity test is described in this experiment where the Collembola species Proisotoma minuta was exposed to herbicides in an artificial sea salt solution for seven days. The salt solution did not prohibit the insects' reproduction system. The seven day LD50 values for trifluralin, pendimethalin, metolachlor, prometryn, paraquat, atrazine, fluometuron, and diuron were 3.48, 10.4, 12.4, 13.0, 23.1, 33.4, 250, and 711 mg L(-1), respectively. A good correlation between toxicity of the compounds and their lipophilicity and vapor pressure was recorded in this study.
Subject(s)
Herbicides/toxicity , Insecta/drug effects , Sodium Chloride/toxicity , Soil Pollutants/toxicity , Animals , Dose-Response Relationship, Drug , Female , Insecta/physiology , Lethal Dose 50 , Male , Oviposition/drug effects , Reproduction/drug effects , Reproduction/physiology , Solutions , Toxicity Tests, AcuteABSTRACT
An increased level of the Collembolan, Proisotoma minuta Tullberg was found in the cotton-growing areas of New South Wales, Australia. They were regularly exposed to endosulfan, a highly insecticidal compound. Toxicity, sub-lethal effects and metabolism of endosulfan were studied in P minuta that had been successfully maintained in a plaster of Paris and charcoal mixture substrate with freeze-dried yeast as a food. The 168-h LD50 values were 0.011, 0.049 and 0.055 mg liter(-1) for alpha- and beta-endosulfan and endosulfan sulfate, respectively. When P minuta were exposed to non-lethal concentrations of the endosulfans, egg production was inhibited. On recovery from the toxic effects of the endosulfans they resumed production of viable eggs. Conversion of alpha- and beta-endosulfan to endosulfan sulfate was found and the endosulfan sulfate could be further metabolized. The rate of metabolism of alpha-endosulfan was greater than that of beta-endosulfan and the product of endosulfan sulfate metabolism was not identified.
