Macro-moths as possible assessment endpoints for non-target effects of Bt-maize pollen: a faunistic study in three Italian protected areas

Lepidoptera are the phytophagous group most at risk of impact by insect-resistant genetically modified (GM) plants since most of these crops have been developed to express toxins to specifically target lepidopteran pests. In the case of Bt-maize cultivation, pollen grains released by GM plants could dust larval host plants growing inside or nearby maize fields, thus leading to the exposure of caterpillars to the Cry toxins. This way of exposure has been studied mainly for butterflies, whereas moths, in spite of their great diversity and abundance, were rarely considered. To evaluate the potential exposure of moth species to maize pollen in absence of Cry-expressing plants, macro-moths were sampled by means of light traps in three protected areas of Northern, Central and Southern Italy where conventional maize is among the main crops. Light traps were activated in two consecutive years (2010- 11) from the beginning of June to the end of July, a period that encompasses the anthesis of most maize cultivars grown in Italy. Overall, 11446 individuals belonging to 201 species and nine families were collected. Given that larvae of several sampled species are likely to match the criteria of potential exposure to maize pollen and susceptibility to Cry toxins, macro-moths might be considered among the potential assessment endpoints for environmental risk assessment of GM plants, especially in the vicinity of protected areas.