You may have already heard about the invasive emerald ash borer (EAB) and the havoc it is wreaking throughout the Midwest, Eastern U.S. and Canada. It is a beetle belonging to the family Buprestidae (metallic-wood-boring beetles), which contains a number of tree pests. Unfortunately, new infestations of EAB are often not detected until they are well-established and trees begin to decline and/or die. However, recent work by researchers in Guelph, Ontario, has shown that we may get some help finding EAB from a native wasp, Cerceris fumipennis. This wasp provisions its nests with beetles in the family Buprestidae, including EAB when present. The wasp is much more effective than humans at finding EAB, and is proving to be a reliable way to monitor for this pest. We are now using this wasp in a biosurveillance program.
What is biosurveillance? When applied to insects, it is using one insect species to survey for a pest species.
Cerceris fumipennis is a beneficial insect found throughout North Carolina. It is a solitary, ground-nesting wasp that lives in diffuse colonies in sparsely vegetated, open spaces with hard-packed sandy soil. Colonies are almost always found in full sunshine near wooded areas in places of human disturbance (fire pits, campsites, road and trail edges, informal parking lots, playgrounds and baseball diamonds). Coincidentally, many of these areas are at high risk for firewood-borne EAB infestation. For the past few years, the NCDA&CS has been making a concerted effort to find colonies of the wasp so that we can begin using them to monitor for EAB and other pest Buprestidae.
In order to find colonies of the wasp (which incidentally does NOT sting, even when handled by humans), we use Google Earth images to search for baseball diamonds throughout the state. Most ball diamonds provide the ideal habitat for the wasp and are easy to locate using satellite imagery. Since 2008, we have surveyed about half of North Carolina for the wasp. When C. fumipennis are found in sufficient numbers, beetle prey are collected from the wasps as they return to their nests. As a result of the survey, we have collected 1,765 buprestid beetles. Included among the beetles collected are nine native pests: Agrilus anxius (bronze birch borer), A. bilineatus (two-lined chestnut borer), A. acutipennis (spotworm borer), A. arcuatus (a pest of hickory), A. ruficollis (rednecked cane borer), A. torquatus (hickory spiral borer), Chrysobothris femorata (flatheaded appletree borer), Phaenops fulvoguttata (hemlock borer) and Poecilonota cyanipes (a pest of eastern poplar). With the recent discovery of EAB in North Carolina, surveys for the wasp are being used to monitor its spread and to detect other Agrilus species of concern including: A. biguttatus (oaksplendor beetle), A. coxalis auroguttatus (gold-spotted oak borer) and A. sulcicollis (European oak borer).
In addition to C. fumipennis‘ use as a biosurveillance tool to detect pest species, the wasp has also proven useful as a tool to learn more about the diversity of Buprestidae in North Carolina. To date we have collected and identified 12 new state records for North Carolina: Actenodes simi, Agrilus anxius, A. carpini, A. fulgens, A. lecontei, A. pseudocoryli, A. quadriimpressus, Buprestis consularis, Chrysobothris azurea, C. hubbardi, Phaenops obtusa and Poecilonota cyanipes.
Contributed by Whitney Swink, research specialist, NCDA&CS Plant Industry Division.
If you wish to learn more about the Cerceris biosurveillance program, please contact Whitney Swink (firstname.lastname@example.org).