Decline in relative abundance of hippodamia convergens (Coleoptera: Coccinellidae) in fall shoreline aggregations on western lake superior

Abstract

In the 1970s, migratory coccinellid aggregations on western Lake Superior shorelines consisted of over 90% Hippodamia convergens Guérin-Méneville. In 2014, the alien Harmonia axyridis (Pallas) accounted for over 80% of shoreline coccinellid aggregations and H. convergens declined to less than 10% of the total. Additional work is needed to elucidate the extent and cause of the decline of H. convergens in western Lake Superior shoreline aggregations.