Accumulation of Cd and Pb in successive stages ofGalleria mellonella and metal transfer to the pupal parasitoidPimpla turionellae

Larvae ofGalleria mellonella L. (Lepidoptera, Pyralidae) were exposed to Pb (4, 43, 430 μg Pb/g food dw) and Cd (4, 20, 40 μg Cd/g food dw) applied singly and in combination. Metal transfer of Pb and Cd was investigated from food to larvae and successive stages ofG. mellonella and also to the pupal parasitoidPimpla turionellae L. (Hymenoptera, Ichneumonidae). Larvae/food concentration factors (CFs) were highest in controls (Cd 5.25, Pb 3.07) and ranged from 0.19 to 0.92 for Cd and from 0.18 to 0.83 for Pb in contaminated groups; in general, the CFs decreased with an increasing contamination level in food.G. mellonella eliminated most of its larval metal load before pupation (metal concentration in larvae ς> pupae). Although pupae were only moderately contaminated (0.11–1.61 μg Cd/g dw), concentrations inP. turionellae ranged from 0.5 to 6.8 μg Cd/g dw. Again, CFs (parasitoid/pupa) decreased with enhanced levels of metal in the host pupae (Cd 3.07–14.05, Pb 0.0–2.47). The CFs calculated for both species were lower at combined contamination compared to single application.G. mellonella can be classified as a ‘deconcentrator’ (CF<1) along with other lepidopteran species, whereasP. turionellae is apparently a ‘macroconcentrator’ (CF>2).