The Use of Folsomia fimetaria and Drosophila melanogaster as Test Insects for the Detection of Insecticide Residues1

Abstract

The use of Folsomia fimetaria (L.) as an additional test insect for the detection of toxic insecticidal residues was of advantage when Drosophila melanogaster Meigen was relatively resistant to some insecticides. A rearing method for, and bioassay method with F. fimetaria is described. It was found that F. fimetaria was more susceptible to the organophosphorus and carbamate insecticides, and D. melanogaster was more susceptible to the chlorinated hydrocarbon insecticides tested. With parathion and diazinon, 1.2 to 2.7 times larger amounts had to be used with D. melanogaster to obtain the same toxicity effects as with F. fimetaria. With Temik® (2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime) a 9 times higher dosage had to be used, while with carbaryl almost no mortalities of D. melanogaster could be obtained. However, with the chlorinated hydrocarbon insecticides, F. fimetaria was more resistant and it took a 33 times higher dosage of aldrin to obtain the same LD50 as observed with D. melanogaster. These differences were considerably reduced with lindane, and only a double dosage of this insecticide was necessary to obtain the same LD50 value with F. fimetaria. Both species were rather resistant to DDT.