Agrilus prionurus (Coleoptera: Buprestidae): attack characteristics and known distribution of an invasive pest of western soapberry in Texas

Agrilus prionurus, a native of Mexico, was first reported in Texas in Travis County in 2003. It has infested only western soapberry (Sapindus saponaria var. drummondii) to date in Texas. As of 2010, A. prionurus has been detected in 33 counties in Texas, including near or within the cities of Fort Worth, Dallas, Waco, College Station, Austin, Houston and Corpus Christi. This buprestid is killing all sizes of soapberry trees over 2 inches DBH. It may threaten western soapberry throughout the tree’s range, which extends from northern Mexico to Missouri, and west to Arizona. Infested trees are easily recognized by the exposed sapwood that results when birds and squirrels chip off the bark to feed on larvae. A heavily-infested tree will be completely girdled by larval feeding. Adults are about one half inch long, shining black and distinctively marked with four small white spots on the wing covers. Larvae are flat-headed wood borers that may attain an inch or more in length. After feeding beneath the bark, larvae bore into the wood to pupate. Adults leave a D-shaped exit hole. Western soapberry exhibits little resistance to A. prionurus. The insect appears to be univoltine. Methods of prevention and control are under investigation.