Wind Turbines as Overwintering Sites Attractive to an Invasive Lady Beetle,Harmonia axyridisPallas (Coleoptera: Coccinellidae)

Abstract

One of the most invasive species of insects in Europe is the Asian lady beetle, Harmonia axyridis (Pallas, 1773). This species is often observed in anthropogenic areas, especially during autumn and winter when the adults enter buildings and start the overwintering process in large aggregations. On wind farms in intensively used farmland in Poland, H. axyridis uses wind turbines as overwintering sites. We hypothesize that H. axyridis adults are attracted to wind turbines for heat and protection from the wind. We examined H. axyridis aggregations on 33 wind turbines and surrounding areas and measured temperatures on different parts of the turbines. Turbines had a higher temperature than the surrounding areas. The lady beetles mostly occupied the northwestern side of the turbines, which is the side protected from wind. A possible explanation for the beetle’s preference for turbines as overwintering sites is the lack of other anthropogenic structures available for overwintering in a homogenous farmland.