Smokey-winged Beetle Bandit Wasp

Appearance

''Cerceris fumipennis'' is distinguished by five conspicuous characteristics:
⤷ It is large, about the size of common yellow jacket wasps.
⤷ It has dark smoky, blue/black wings.
⤷ The wasp's body is predominantly black except for a few yellow markings.
⤷ It has a conspicuous, single broad creamy yellow abdominal band.
⤷ Females have three creamy patches between the eyes; while males are marked with two yellow triangles abutting their eyes.

Behavior

''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 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 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 eclosion, which equals 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.