|HODDLE, MARK - University Of California|
|VAN DRIESCHE, ROY - University Of Massachusetts|
Submitted to: USDA Interagency Research Forum on Invasive Species
Publication Type: Proceedings
Publication Acceptance Date: 3/30/2011
Publication Date: 1/13/2012
Citation: Duan, J.J., Taylor, P.B., Fuester, R.W., Hoddle, M., Van Driesche, R. 2012. Worldwide diversity of parasitoid guilds of Agrilus woodborers (Coleoptera: Buprestidae). USDA Interagency Research Forum on Invasive Species. p. 14; p. 24; p. 70.
Technical Abstract: Agrilus is the largest genus within the family Buprestidae (Coleoptera), with nearly 3,000 described species worldwide. Agrilus adults normally lay eggs under the loose bark or in crevices of host plant tissues, and larvae bore into the living tissue of their host plants. While a few species feed on herbaceous plants, generally attacking root or stem tissue, most Agrilus species attack the cambial tissue of woody trees or shrubs. In their native habitats, Agrilus populations are generally suppressed by a diverse group of natural enemies and/or host tree resistance, and rarely become serious pests. However, when introduced into ecosystems where host plants lack co-evolutionary resistance, or where appropriate specialized natural predators and parasites are absent, they can become severe pests. The recent invasion of North America by the emerald ash borer, Agrilus planipennis, from northeast Asia is an excellent example of this. In the present study, we reviewed literature studies in North America (U.S. and Canada), Europe and Asia (particular Russia, China, Japan, and the Korean peninsula) to identify parasitoid guilds associated with Agrilus woodborers. There are at least 10 species of hymenopteran parasitoids attacking eggs of Agrilus beetles and 38 species attacking Agrilus larvae infesting various host plants (trees) in North America, Asia and Europe. While most of the egg parasitoids (8 species) belong to the family Encyrtidae, a majority of the larval parasitoids are members of three families: Braconidae (18 species/5 genera), Ichneumonidae (9 species/8 genera), and Eulophidae (4 species/one genus). The highest rate of Agrilus egg parasitism (>50%) was recorded for with four species of encyrtid wasps reported in North America, Asia, and Europe. In contrast, the highest rate of Agrilus larval parasitism (>50%) caused by species in two genera of braconid wasps: Atanycolus (in North America) and Spathius (in Asia), and one of Eulophidae, Tetrastichus (in Asia and Europe). Although ichneumonid wasps were frequently reported attacking Agrilus wood borers, primarily in North America, the reported rate of Agrilus larval parasitism by this group of parasitoids has been generally low (<1%). Potential for success in biological control of emerald ash borer (A. planipennis) in the US with North American native parasitoids and old-associations Asian parasitoids is discussed.