Potential impact of genetically modified Lepidoptera‐resistant Brassica napus in biodiversity hotspots: Sicily as a theoretical model

Abstract

The general increase of the cultivation and trade of Bt transgenic plants resistant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased the cultivation and importation of oilseed rape (Brassica napus L.), including transgenic lines. In environmental risk assessments (ERAs) for its potential future cultivation as well as for food and feed uses, the impact on wild Brassicaeae relatives and on non-target Lepidoptera should be assessed. Here we consider the potential exposure of butterflies as results of possible cultivation or naturalization of spilled seed in Sicily (Italy). Diurnal Lepidoptera, which are pollinators, can be exposed directly to the insecticidal proteins as larvae (mainly of Pieridae) through the host and through the pollen that can deposit on other host plants. Adults can be exposed via pollen and nectar. The flight periods of butterflies were recorded, and they were found to overlap for about 90% of the flowering period of B. napus for the majority of the species. In addition, B. napus has a high potential to hybridise with endemic taxa belonging to the B. oleracea group. This could lead to an exposure of non-target Lepidoptera if introgression of the Bt gene into a wild population happens. A rank of the risk for butterflies and wild relatives of oilseed rape is given. We conclude that, in environmental risk assessments, attention should be paid to plant-insect interaction especially in a biodiversity hotspot such as Sicily.

A 12-Year Experimental Design to Test the Recovery of Butterfly Biodiversity in an Urban Ecosystem: Lessons from the Parc Urbain des Papillons

“…This period is then followed by a decrease both in abundance and specific richness of the communities, as observed in [52]. This peak in butterfly diversity also coincided with food availability due to the Mediterranean vegetation phenology [53][54][55][56]. The WAS and BUP after were mostly composed of early blooming Mediterranean species or nectariferous horticultural species that are very sensitive to summer drought leading to a drop in nectar availability after May.…”

Limits of Concern: suggestions for the operationalisation of a concept to determine the relevance of adverse effects in the ERA of GMOs

“…Against this background and to harmonise protection goals for ERA purposes as required by EFSA, effects by GM crops on non-target lepidopteran species in off-field areas need to be small to negligible. Clearly, for endangered or protected Lepidoptera occurring in protected sites or biodiversity hotspots within the agro-environment [133–135], no additional adverse effects due to Bt maize cultivation should be tolerated at all (see also [22]).…”

Development of Transgenic Brassica Crops against Biotic Stresses Caused by Pathogens and Arthropod Pests

“…In rapeseed Bt transgenic lines, it has been reported that there could be an exposure to the insecticidal protein of transgenic lines by diurnal pollinators Lepidoptera, as larvae (mainly of Pieridae) through the host and through pollen, and as adults via pollen and nectar. This could lead to a localized loss of biodiversity that requires exhaustive environmental risk assessments [158]. Similarly, the effects of silkworm (Bombyx mori) larvae with pollen from Bt Chinese cabbage have been studied.…”