DETECTION OF INSECTICIDES BY BIOASSAY WITH DROSOPHILA MELANOGASTER.

ABSTRACT

The sensitivity of Drosophila melanogaster to insecticides has been evaluated for the organophosphorus dimethoate and omethoate, the carbamates carbofuran and carbaryl, and the pyrethroids permetrine, deltametrine and alpha-cypermetrine. This work was aimed at determining the fly's efficiency as a trial method for the detection of insecticide residues. Median lethal concentration, LC₅₀, calculated by percent mortality of the drosophilas exposed for 24 hours to several insecticide concentrations was used as the toxicity parameter. The LC₅₀ (µg.mL^-1) values found: carbofuran 9.70; carbaryl > 5,000; dimethoate 19.9; omethoate 67.8; permetrine 581; deltametrine 1.28; alphacypermetrine 2.16, indicate that bioassay utilizing Drosophila melanogaster is useful as a trial method for the detection of insecticides, despite its insensitivity for carbaryl.

KEY WORDS:
Drosophila melanogaster, insecticide; median lethal concentration; structure-activity relationships.