Translator Disclaimer
1 October 2004 Feeding Preference of Three Lady Beetle Predators of the Hemlock Woolly Adelgid (Homoptera: Adelgidae)
Elizabeth E. Butin, Nathan P. Havill, Joseph S. Elkinton, Michael E. Montgomery
Author Affiliations +

In a laboratory study, we tested the feeding preferences of three coccinellid predators of hemlock woolly adelgid, Adelges tsugae Annand, an introduced pest of hemlock in the eastern United States. The species tested were Sasajiscymnus tsugae Sasaji & McClure (formerly Pseudoscymnus tsugae) from Japan, Scymnus ningshanensis Yu & Yao from China, and Harmonia axyridis (Pallas), a generalist species introduced from Asia that is currently widespread in eastern hemlock, Tsuga canadensis Carriere, forests. We measured the feeding preference of each beetle species when given the choice of A. tsugae and either 1) Pineus strobi (Hartig) on Pinus strobus L.; 2) Adelges laricis Vallot on Larix decidua Mill.; 3) Adelges cooleyi (Gillette) on Pseudotsuga menziesii (Mirb.) Franco; or 3) Paraprociphilus tessellatus (Fitch) on Alnus serrulata (Ait.) Willd. We evaluated beetle preference for adults, nymphs, and eggs of each prey species. Generally, when adult or nymphal prey stages were compared, S. tsugae preferred A. tsugae adults to P. strobi, A. cooleyi, A. laricis, and P. tessellatus. S. ningshanensis showed less preference between adelgid species, but it did not prefer P. tessellatus nymphs. When preferences for adelgid eggs were assayed, S. tsugae and S. ningshanensis showed no preference between A. tsugae and A. cooleyi or P. strobi, but S. tsugae did prefer A. tsugae to A. laricis. Larvae of S. tsugae were unable to survive on P. tessellatus nymphs. H. axyridis adults readily consumed both A. tsugae and P. tessellatus, but H. axyridis larvae did not complete their life cycle on A. tsugae. Our host range tests suggest that S. ningshanensis and S. tsugae may feed on several species of Adelgidae and that A. tsugae is often preferred.

Elizabeth E. Butin, Nathan P. Havill, Joseph S. Elkinton, and Michael E. Montgomery "Feeding Preference of Three Lady Beetle Predators of the Hemlock Woolly Adelgid (Homoptera: Adelgidae)," Journal of Economic Entomology 97(5), 1635-1641, (1 October 2004).
Received: 24 March 2004; Accepted: 1 June 2004; Published: 1 October 2004

This article is only available to subscribers.
It is not available for individual sale.

hemlock woolly adelgid
preference testing
Pseudoscymnus tsugae
woolly alder aphid
Get copyright permission
Back to Top