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Cerceris fumipennis is a ground-nesting solitary wasp native to eastern North America. It is mainly black, with smoky blue/brown wings and a single yellow/cream colored band across the distinctively shaped abdomen. Nests of different females are constructed in loose aggregations. The female hunts buprestid wood-boring beetles, paralyzes them with her stinger, and brings them back to provision her nest. As the last beetle is placed into each cell within the nest, she lays an egg on it and closes off the cell. When the egg hatches, the emerged wasp grub consumes the living beetles. Cerceris fumipennis has received considerable attention as a potentially invaluable "biosurveillance" tool to detect early invasions by the Emerald Ash Borer (Agrilus planipennis), an Asian buprestid first detected in North America in 2002 that has caused severe damage to native ashes in several areas. Although host preferences of C. fumipennis are too broad to make it a practical biocontrol agent, it has proved to be very effective in detecting the presence of A. planipennis in an area well before it might otherwise be detected. Monitoring programs involving batteries of mobile colonies which can be deployed wherever they are needed, in which incoming prey items are documented (and sometimes sampled) by human volunteers, are now operating in numerous U.S. states and Canadian provinces. (Careless and Marshall 2010; http://www.cerceris.info)
Cerceris fumipennis, the only species of buprestid-hunting Crabronidae occurring in eastern North America, is found throughout the continental United States east of the Rockies: from Texas and Florida north to Maine, Wyoming, and into Canada. The wasps most often nest in open areas of hard-packed sandy soil surrounded by woody habitat suitable for their buprestid beetle prey.
Cerceris fumipennis is distinguished by five conspicuous characteristics:
Cerceris fumipennis is a solitary ground-nesting wasp. Each lone female constructs and attempts to maintain a single subterranean nest for the duration of the flight season. Her solitary nest is in close proximity to others, forming a neighborhood or informal colony of nests. The nest's entrance is easily visible, marked by a small circular mound of earth. Each nest is composed of a single entrance hole which leads to subterranean cells. Like many crabronid and sphecid wasps, C. fumipennis females mass provision for their cells before laying an egg in them. Adult females provision their cells with beetles of the family Buprestidae.
When hunting for buprestid prey, the maximum foraging range of the wasp is estimated at 2 km with an estimated average flight distance of 750 meters from the nest. Once prey has been found, a female wasp will typically attack a target beetle by alighting on it, climbing over it, and grabbing it by the thorax with her mandibles before inserting her stinger into the base of the beetle's leg (in the membrane of the coxal joint, a gap in the buprestid's armour) and injecting a paralytic venom. Once at the nest entrance or in the burrow, the female wasp will sometimes re-sting poorly paralyzed prey in the same joint.
Within minutes of placing the final paralyzed beetle into its subterranean cell the adult wasp lays a single hotdog-shaped egg along the beetle's mesosternum. Prey beetles are paralyzed, not killed, ensuring that each beetle will remain fresh until the wasp larva can begin feeding upon it. After the egg is laid, the completed cell is detached from the burrow as the female wasp backfills the access with 3 – 6 cm of soil.
Once one cell is completed the wasp begins work on the next cell by excavating in a new direction off the main burrow. Most cells (approximately 5 – 12, but up to 24) are constructed 7 – 20 cm below grade with the egg, larva and pupal stages all developing within the confines of the single nest. In Ontario, the duration of time spent in the brood cell is about 10 months.
Emergence dates and speed of the life cycle vary across the wasp's broad distribution. In Ontario, the flight season typically begins the last week of June and continues until early September. Emergence dates and duration of flight season can be influenced by droughts, which could postpone emergence or shorten the flight season. Ontario colonies are associated with somewhat disturbed sites compacted by human activity such as baseball diamonds, parking areas, infrequently used roads, roadsides, footpaths and the soil around campfire pits.
In collecting buprestid prey, C. fumipennis has also been recorded collecting Emerald Ash Borer (EAB; Agrilus planipennis), a pest insect known for killing North American species of ash trees. EAB has proven difficult to detect using traditional methods of ground/visual surveys and sticky traps, both of which are costly, labour-intensive and at times destructive or impractical. Biosurveillance, using another species to survey for a pest species, offers an alternative approach for the detection and survey of EAB populations. Preliminary studies have shown that the wasp's EAB detection skills far surpass any comparable human technology. C. fumipennis has become a novel ally in efforts to monitor for EAB in Canada and the United States.
Researchers have unofficially nicknamed C. fumipennis the "Smokey Winged Beetle Bandit”. This name has now been submitted to the Entomological Society of America's committee on common names. By transporting mobile populations of this wasp, biosurveillance could facilitate an early warning system for the Emerald Ash Borer across the United States & Canada. By using trained wasp watchers to look for what C. fumipennis brings back to its ground nest entrance, this could augment an early warning system that currently only utilizes "Purple Barney traps" that mimic the same color spectrum as Fraxinus ash tree leaves, to attract the EAB bug.
Cerceris fumipennis, the only species of buprestid-hunting Crabronidae occurring in eastern North America, is found throughout the continental United States east of the Rockies: from Texas and Florida north to Maine, Wyoming, and into Canada. The wasps most often nest in open areas of hard-packed sandy soil surrounded by woody habitat suitable for their buprestid beetle prey.
Known C. fumipennis colonies in Ontario, Canada
