FLUORIDE LOADING OF A LEPIDOPTERAN LARVA (PIERIS-BRASSICAE) FED ON TREATED DIETS

Experiments to assess the impact of dietary fluoride on larvae of Pier is brassicae were designed to substantiate field observations that at polluted sites little fluoride is absorbed by insect larvae and that m ost of the body load is caused by surface contamination. Treatment wit h fluoride as HF or AlF3 had no effect on pupal weight of Pieris and w e conclude that fluoride, at concentrations likely to be found on vege tation at polluted sites, is unlikely to have a direct impact on the g rowth of chewing herbivores. Fluoride in the gut formed the biggest co mponent of the total body load. A significant amount of fluoride was d etected in exuviae, but resulted from surface contamination. When larv ae from polluted food were transferred to untreated food it took sever al days for the fluoride content of the faeces to return to background levels. (C) 1998 Elsevier Science Ltd. All rights reserved.