Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region
Matthias Buck, Stephen A. Marshall, and David K.B. Cheung
Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
Species recognition. The very common aerial yellowjacket differs from D. norvegicoides, the only other yellow-marked Dolichovespula of the east, by the medially interrupted or incised apical fasciae of terga 1 and 2 (not narrowed medially in D. norvegicoides). The very rare, mainly western, yellow-marked colour form of D. adulterina can be separated from D. arenaria by the more extensive black markings in the ocular sinus (see key).
Variation. Fore wing length 9.0–12.0 mm (workers), 12.5–13.5 mm (♀♀), 9.5–12.0 mm (♂♂). Black clypeal spot usually elongate (often with a pair of small spots on each side), rarely small and round or anchor-shaped (females), or absent (male), rarely narrowly extending to ventral margin of clypeus (females). Black medial subantennal mark rarely with yellow spots in male (usually connected to corona). Ocular sinus predominantly yellow except in melanic males from northern localities, in which black area broadly reaches lower margin of sinus. Yellow postocular band wide throughout or narrowed (rarely in male) or with enclosed black spot near middle. Pronotal carina almost always more or less marked with yellow. Scutum rarely with a pair of yellow spots in posterior half. Metapleuron and propodeum rarely with small yellow spots in female; spots exceptionally present on propodeum in male (1 ♂, ON, Guelph, DEBU). Males from subarctic localities may have the mesosoma entirely black (e.g., 1 ♂, MB, Churchill, Akudlik, EDUM). Pairs of black discal spots often absent in worker, sometimes present on tergum 5 rarely on 4; spots better developed in queen and always present on terga 4 and 5, usually on 3 and sometimes on 2; spots usually attached to basal band in male and then most frequently so on terga 4 and 5, more rarely on terga 2, 3 or 6.
Distribution. Canada: all provinces and territories except NU. Northern and western U.S.: AK, south to GA, KY, IL, IA, NE, NM, AZ and CA (Carpenter and Kojima 1997). This is one of the most common yellowjacket species in eastern North America.
Biology. Nests are usually aerial and attached to herbage, shrubs or trees from near the ground to canopy level. In urban situations they are often found on manmade structures. More rarely nests are constructed under rocks or even in ground burrows where workers may excavate soil to allow for nest expansion, as in Vespula species. Females usually forage for live arthropods and rarely visit carrion. Because of its tendency to use manmade structures as nest locations and because of its abundance this species can be a nuisance. Individuals from smaller colonies are usually not very aggressive but large colonies (which are relatively rare) can react strongly and very aggressively to disturbance (Akre et al. 1981).