Effect of a continuous treatment by HgCl2 simulated in the environment on the development of two generations of the acridide, Acrotylus patruelis (H.-S.) (Orth., Acrididae)

A continuous treatment of the environment was investigated under simulated conditions using mercury and the acridide Acrotylus patruelis (H.-S.) as test animal. The insects were fed by wheat germs in hydroculture and rolled oats, both treated with mercury. The females layed their eggs in glass pots filled with sand treated with various amounts of HgCl2. Two generations were bred under continuous treatment. By feeding treated food the oviposition increased significantly reaching the threefold number of eggs in the P-generation. In the F1 even more eggs were produced. Mercury stimulated the1777function of the ovaries. In this way the females have the possibility to prevent a toxic accumulation of Hg in their bodies. The increase of oviposition can be considered as a mechanism of decontamination. The females of both generations were not able to measure the content of mercury in the soil. At all investigated concentrations larvae hatched but in those higher than 6.05 mg HgCl2/kg a significant reduction of hatching could be found. The hatching of the larvae of the F2 generation was much less than that of the F1. Larval development depended highly on the concentration of mercury. The larval period was prolonged up to 40 per cent by feeding of contaminated wheat germs. By continuous contamination of the soil and of the food the larval period was increased up to twofold compared with the control. The imaginal rate was reduced by increasing mercury content in the soil. At least only 30 per cent reached the adult stage. The imaginal life span also depended on the Hg amount of the soil in which the eggs developed and on the contamination of the food. At least only 20 days were reached (normally 3-4 months). The body weight of the treated adults did not differ from that of the control. During the larval period the accumulation of mercury in the body was threefold compared with the control insects. The mercury content was reduced at the beginning of oviposit