Annals of the Entomological Society of America

Over the past 30 yr, multiple species of predatory Coccinellidae, prominently Coccinella septempunctata L. and Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) have spread to new continents, influencing biodiversity and biological control. Here we review the mechanisms underlying these ecological interactions, focusing on multi-year field studies of native and non-native coccinellids and those using molecular and quantitative ecological methods. Field data from Asia show that H. axyridis, C. septempunctata, and Propylea japonica (Thunberg) (Coleoptera: Coccinellidae) are regularly among the most abundant predatory species but their rank varies by habitat. Studies of these species in their native Asian range, primarily related to their range in mainland China, document different patterns of seasonal abundance, species specific associations with prey, and habitat separation. Intraguild predation is well documented both in Asia and in newly invaded areas, and H. axyridis benefits most from this interaction. Harmonia axyridis also seems to rely more on cannibalism in times of prey scarcity than other species, and relatively sparse data indicate a lower predation pressure on it from natural enemies of coccinellids. Declines in the abundance of native coccinellids following the spread and increase of non-native species, documented in several multi-year studies on several continents, is a major concern for native biodiversity and the persistence of native coccinellid species. We suggest that future studies focus more attention on the community ecology of these invasive species in their native habitats. China Scholarship CouncilChina Scholarship Council; National Key R&D Program of China [2017YFE0104900]; National Institute of Food and Agriculture, United States Department of Agriculture, Hatch Program [1008480] Published version We thank the China Scholarship Council for a scholarship supporting H. Li's research in the Department of Entomology at the University of Kentucky. This work was supported by the National Key R&D Program of China (2017YFE0104900, to B. Li). J.J.O. was supported by the National Institute of Food and Agriculture, United States Department of Agriculture, Hatch Program under accession number 1008480.