Eastern Poplar Buprestid
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Hosts
Poplar, willow. Has been reared from eastern cottonwood, black cottonwood, quaking aspen, bigtooth aspen, and willow (Chamberlin 1926, Evans 1957, Wellso and others 1976). Beetles have been collected from ash, sycamore, and pine, but it is unlikely that these serve as larval hosts.
Range
The most common and widely distributed member of Descarpentriesina in North America. Recorded from southern Arizona northward along the Rocky Mountains to the Yukon, eastward to New Brunswick, and southward to the Gulf Coast; it does not occur along the Pacific Coast (Chamberlin 1926, Evans 1957).
Description
Adult
Elongate to moderately slender, somewhat oval, dark bronze beetle (Chamberlin 1922, Evans 1957). Head sparsely covered with fine pubescence and slightly flattened along with pronotum. Elytra with dark bluish bronze, abbreviated, elevated, irregular lines tinged with coppery bronze. Females slightly broader and darker than males. Beetles 9.3 to 18.0 mm long and 3.25 to 7.00 mm wide.
Larva
Clublike or pest like in shape with thoracic segments and head moderately flattened (Burke 1917a). Thoracic plates smooth and marked dorsally with inverted V, and ventrally with one groove (USDA FA 1985). Larvae yellowish white with dark brown heads, measuring 17.8 to 25.4 mm long.
Biology
Adults emerge late April through June in its southern range but have been taken in flight as late as August and September in its northern range (Essig 1929). On sunny days, adults are frequently found resting, crawling, and ovipositing on host trees. Females prefer weakened stems for oviposition. It has also been reared from galls of Saperda concolor LeConte in aspen and from galls of Agrilus criddlei in willows (Chamberlin 1922, Wellso and others 1976). Larvae initially excavate small cavities just under the bark, then extend their galleries into the wood usually to the pith of stems up to 25 mm in diameter. In large stems, most larvae burrow to about 12 mm then continue longitudinally. Larvae overwinter within their galleries. Mature larvae prepare chambers typically at one end of the galleries and pupate. New adults gnaw exit holes directly through the bark to emerge. A generation is completed in 1 to 2 years (USDA FS 1985).
Injury and Damage
This beetle commonly attacks stems 12 to 32 mm in diameter, but it is occasionally found in stems up to 75 mm in diameter. The earliest evidence of injury is small wet or stained spots on the bark. Little or no frass is ejected from the sites. The bark sometimes cracks open, exposing a frass-packed cavity just beneath. Galleries are oval to irregular in cross section and 6.4 mm in diameter, extend 6.4 to 12.7 mm into the wood, and run 5 to 30 cm longitudinally within the stem. Galleries are almost entirely filled and packed tightly with a frass mixture of fine particles and short fibers. Oval-elongate exit holes 2.3 to 4.8 mm across can be found in the bark after beetles emerge. Healed wounds leave irregularly shaped scars over the entrances and small oval to round scars over the exit sites. Beetles usually attack wild and ornamental trees that are weakened, injured, or decadent. In its southern range, this buprestid prefers the lower branches of cottonwoods that are weakened, dying, or being shaded out and self-pruned (Solomon and Wellso 1983). This borer rarely attacks boles of healthy trees and is found largely in weakened branches, so it might even be considered beneficial in helping the tree to self-prune its lower branches, thereby improving the quality of the wood.
Control
Light incidence of woodpecker predation had been observed, but no parasites have been found. Maintenance of high vigor in ornamental and other high-value trees can prevent infestation. Direct controls have not been needed.
Gallery
 Photo by James Solomon, USDA Forest Service, Bugwood.org |  Photo by James Solomon, USDA Forest Service, Bugwood.org |
References
Solomon, J.D. 1995. Guide to insect borers of North American broadleaf trees and shrubs. Argic. Handbk. 706. Washington, DC: U.S. Department of Agriculture, Forest Service. 735 p.
