Photographer: Joshua P. Basham Affiliation:Tennessee State University Source: www.bugguide.net Copyright: Joshua P. Basham (used with permission)
Adult Description: The adult Soapberry Borer (Agrilus prionurus) is about 1/2 to 1 inch long, shiny black, and distinctively marked with four small white spots on the wing covers. The adult leaves a D-shaped exit hole as it emerges from the soapberry tree.
Larva Description: Larvae are flat-headed wood borers that may attain an inch in length as they mature. After feeding beneath the bark, the larvae bore into the wood to complete development and pupate.
Host Plant: Western Soapberry (Sapindus saponaria var. drummondii)
As its populations rapidly expands across Texas, this wood-boring beetle is killing soapberry trees larger than two inches in diameter; and it may eventually threaten western soapberry populations throughout northern Mexico to Missouri, and west to Arizona.
The female Soapberry Borer lays her eggs under the bark of the soapberry tree so larvae can feed on the cambium layer.
The Soapberry Borer was first reported in eastern Travis County in 2003 infesting western soapberry trees.
U.S. Habitat: Western Soapberry trees in any setting.
U.S. Present: Texas
Methods of prevention and control are currently being investigated. Among the most promising is injection of a systemic insecticide into uninfested soapberry trees or those in early stages of attack. Dr. Donald Grosman, TFS entomologist in Lufkin, TX injected infested and uninfested soapberry trees in Fort Bend and Dallas counties with the active ingredient emamectin benzoate (registered for prevention of emerald ash borer) last summer. The trees are still being monitored and early results look promising.
Billings, R. and J. Pase. 2009. Soapberry Borer Infestations Found in 33 Counties in Texas. Texas Forest Service.
Haack, Robert A. 2006. Exotic bark-and Wood-boring Coleoptera in the United States: Recent Establishments and Interceptions. Canadian Journal of Forest Research. 36 (2): 269-288.