Intraguild predation and successful invasion by introduced ladybird beetles

• Published in: Oecologia Vol. 140; no. 4; pp. 559 - 565
• Main Authors: Snyder, William E, Clevenger, Garrett M, Eigenbrode, Sanford D
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01-08-2004; Springer; Springer Nature B.V
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Aphididae; Aphidoidea; Beetles; Biological and medical sciences; Biological control; Body Constitution; Coccinella septempunctata; Coccinella transversoguttata; Coccinellidae; Coleoptera; Coleoptera - physiology; Competitive Behavior - physiology; Ecological invasion; Environment; Fundamental and applied biological sciences. Psychology; General aspects; Harmonia axyridis; Hippodamia convergens; Idaho; Indigenous species; Instars; Introduced species; Invasive species; Larva - physiology; Larvae; Microcosms; Native species; Observation; peas; Pisum sativum; Population Dynamics; Population Ecology; Predation; Predators; Predatory Behavior - physiology; Species Specificity; Washington; North America; Aphidoidea; Introduced species; Coleoptera; Insecta; Biological control; Invasion; Classical biological control; Generalist predators; Invasive species; Homoptera; Arthropoda; Aphididae; Aphids; Predator; Predation; Invertebrata
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-004-1612-5

Introductions of two ladybird beetle (Coleoptera: Coccinellidae) species, Coccinella septempunctata and Harmonia axyridis, into North America for aphid biocontrol have been followed by declines in native species. We examined intraguild predation (IGP) between larvae of these two exotic species and larvae of the two most abundant native coccinellids in eastern Washington State, C. transversoguttata and Hippodamia convergens. In pairings between the two native species in laboratory microcosms containing pea (Pisum sativum) plants, neither native had a clear advantage over the other in IGP. When the natives were paired with either Harmonia axyridis or C. septempunctata, the natives were more frequently the victims than perpetrators of IGP. In contrast, in pairings between the exotic species, neither had an IGP advantage, although overall rates of IGP between these two species were very high. Adding alternative prey (aphids) to microcosms did not alter the frequency and patterns of relative IGP among the coccinellid species. In observations of encounters between larvae, the introduced H. axyridis frequently survived multiple encounters with the native C. transversoguttata, whereas the native rarely survived a single encounter with H. axyridis. Our results suggest that larvae of the native species face increased IGP following invasion by C. septempunctata and H. axyridis, which may be contributing to the speed with which these exotic ladybird beetles displace the natives following invasion.