LAUSR

With their high persistence in the environment and their potential for long-range atmospheric transport, persistent, bioaccumulative, and toxic chemicals (PBTs) may be among the numerous anthropogenic threats to insect populations worldwide. The effects of PBTs on insects have been investigated in the laboratory, but topical field studies are scarce. A reason might be the multiple challenges that PBT-related field studies on wild insects face. Here, two species of bumblebees (Bombus spp.) and of ants (Formica spp.) were studied in two high-elevation locations in the Austrian and German Alps to tackle two of these challenges. First, PBTs occur in minuscule concentrations compared with other substances in the environment. Therefore, the practicability of body burden data from pooled individuals was tested. Second, fitness proxies, like fecundity, which typically are endpoints for chemical toxicity, are difficult to quantify in the field. Hence, fluctuating asymmetry (FA) of bumblebee wings and ant heads was tested as an alternative endpoint. To exclude that FA was caused by genetic stressors, inbreeding-levels were estimated using population-genetic markers, and their relations to FA in the same individuals were assessed. We successfully quantified PCBs and Hg as PBTs using the pooled samples and found PBT data from pooled individuals useful, in that significant correlations to FA were identified in bumblebees and ants. This confirmed the potential of FA to indicate PBT effects in wild insects. Inbreeding did not interfere with PBT links to FA in any instance. Our findings contribute to developing a quantitative methodological framework for investigating effects of persistent environmental chemicals on wild insects. This article is protected by copyright. All rights reserved. © 2022 SETAC.