Studies on the toxicity of some carbamate fungicides in Drosophila melanogaster Meig. (Insecta, Diptera).

This paper reports the effects of three commercial powders mixed into the diet, Dithane M-45 (mancozeb 80%), Pomarsol (thiram 80%) and Peltar (maneb 50% and methyltiophanate 25%) on survivorship of adults Drosophila and on the progeny. With wild-type adults (Oregon), fungicides were added to the diet at the rate recommended on the label. The mean lifespan was reduced by 42.5% (Pomarsol), 50% (Dithane M-45), and 83% (Peltar). For larvae of two strains (Oregon and triploid) intoxicated with Dithane M-45 and Peltar, a linear relationship was demonstrated between the doses and the percentage of the progeny reduction. The calculated doses inducing a 50% reduced progeny (PR50) are in the range of 400 to 700 ppm. With Pomarsol in the range of 500 to 1500 ppm and for the both strains, the progeny was decreased by about 60%. A very reduced size and a leg paralysis was observed with each toxic powder for Oregon and triploid flies. It appears that a triploid stock of chromosomes does not significantly modify the reaction of the flies.