First records of invasive Vespa velutina nigrithorax Buysson, 1905 (Hymenoptera: Vespidae) and Megachile sculpturalis Smith, 1853 (Hymenoptera: Megachilidae) in Slovakia

Abstract

Biological invasions are an increasing threat to ecosystems; early identification of invasive species and rigorous monitoring are prerequisites to minimize environmental damage. Currently, two large hymenopterans of Asian origin are spreading across Europe: the yellow-legged hornet Vespa velutina nigrithorax Buysson, 1905 and the giant resin bee Megachile sculpturalis Smith, 1853, populations of which have been gradually being discovered across Europe since 2004 and 2008, respectively. Considering the current distribution of both species in Europe, further spread through Central Europe is expected in recent years. In July 2024, the first record of M. sculpturalis was documented in Slovakia, followed by more reports from 11 localities. Less than two months later, the second invasive hymenopteran, V. velutina nigrithorax, was also detected. Utilising multiple methods, their nest was discovered as well. On-site observations showed that the yellow-legged hornets (workers) were active almost two days after colony eradication. The finding of both species was accompanied by an intensive campaign using citizen science.