DNA damage in haemocytes of Harpalus (Pseudophonus) rufipes (De Geer, 1774)(Coleoptera, Carabidae) as an indicator of sublethal effects of exposure to herbicides.

The carabid beetle Harpalus (Pseudophonus) rufipes is one the most common polyphagous species in the agroecosystem and plays an important role in the natural control of pests. The primary focus of the study was to examine whether exposure to herbicides, used for agricultural productivity, can have genotoxic sublethal effects on this epigean non-target species. The neutral comet assay was carried out to provide a quantitative measure of DNA double-strand breaks in haemocytes of adults. Beetles from a conventional potato field treated with herbicides such as metribuzin-, clomazone-, pendimethalin- and cycloxydim-based commercial formulates were compared with specimens from an organic potato field in which weeds were removed mechanically. Analyses showed that the level of DNA damage recorded as tail DNA percentage in adults from the conventional potato field (11.55 ± 0.47) was significantly higher (p = 9.5 × 10−5) than that in beetles from the organic control site (8.93 ± 0.22). Moreover, DNA damage reduction was recorded in beetles from the conventional field sampled about 12 weeks after the field treatment compared with that in beetles sampled about 8 weeks after the treatment. The genotoxic effect of herbicide commercial formulations used in the conventional potato field before and during sampling was determined. This report provides evidence that exposure to herbicides has a detrimental effect on H. rufipes and confirms that the Comet assay may be a useful tool in determining the potential genotoxicity of pollutants on soil arthropods.