Larvae of
Galleria 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 of
G. mellonella and also to the pupal parasitoid
Pimpla 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 in
P. 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, whereas
P. turionellae is apparently a ‘macroconcentrator’ (CF>2).
Key words insects - metals - metal transfer - cadmium - lead - food chain - concentration factor