Actualisation des connaissances sur l’abeille Megachile sculpturalis SMITH, 1853 en France et en Europe (Hymenoptera : Megachilidae)

Abstract

Update of knowledge on the bee Megachile sculpturalis SMITH, 1853 in France and Europe (Hymenoptera: Megachilidae). - Megachile sculpturalis is a bee native to eastern Asia that is now also present in North America and Europe. This article follows the first synthesis on the ecology and geographical distribution in Europe of this species published in this same journal in 2018 and updates their knowledge. Megachile sculpturalis has been observed in 13 European countries. Its range now extends from the French Atlantic coast in the west to the Crimean Peninsula in the east. It has also been recorded on two Mediterranean islands, Elba (Italy) and Mallorca (Spain). In France, between 2008 and 2020, it was observed in 259 communes in 46 departments. The most northerly French observation was made in 2020 near Reims in the Marne department. Concerning feeding behaviour, new pollen analyses corroborate the results of previous ones which suggested a polylectic diet with a marked preference for shrubs of Asian origin (especially Sophora japonica and Ligustrum sp.). Regarding nesting behaviour, M. sculpturalis makes extensive use of bee hotels. However, a range of diameters (holes in logs or sections of plant stems) between 4 and 8 mm is suitable for the main native species likely to nest in the hotels, while limiting the establishment of M. sculpturalis. New observations have confirmed the tendency of M. sculpturalis to empty the nests of other species in order to establish its own larval cells. In addition, in Switzerland, a female was observed killing a bee of the genus Heriades. Such events, if frequent, could have negative impacts on native bees, but data are currently insufficient to quantify these impacts on populations.