mancozeb and dichlofluanid

Four day old Drosophila pairs were maintained on nutritive media surface treated with fungicide doses according to the standard level recommended by the manufacturers. The flies were treated for 1 to 6 weeks and the eggs laid in 3 hours were counted each week during and after treatment. The capacity of treated flies egg laying was determined on treated media and then on untreated one. For the benomyl preparation (Benlate) and the mancozebe preparation (Dithane M45), there was an overall reduction of the egg mass on treated media but not on untreated media. There appears to be an essential repulsive effect which perturbs egg laying and causes a retention of eggs. However, after 3 to 4 weeks the quantity of egg mass also diminished on untreated media. Once the treatment was terminated the capacity to lay eggs partially returned. The copper sulfate preparation (Bouillie bordelaise) also exhibited a repulsive effect as exhibited by a retention of a certain number of eggs, but there was a more direct and fast effect on fecundity. Effect was more brutal with the dichlofluanide preparation (Euparène), and rapidly irreversible: the egg masses were very reduced after only one week of treatment on both treated and untreated media, and after termination of treatment there was an incomplete and temporary recuperation of the capacity to lay eggs. The results presented here are in agreement with those obtained previously concerning longevity. At the doses recommended for agricultural treatments, Benlate and Dithane M45 showed low toxicity for Drosophila adults in comparison with Bouillie bordelaise and Euparène which revealed a high toxicity in agreement with the fecundity and longevity data.

Topics: Aniline Compounds; Animals; Benomyl; Copper; Copper Sulfate; Drosophila melanogaster; Female; Fertility; Fungicides, Industrial; Male; Maneb; Oviposition; Zineb