Eumenes fraternus

Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region
CJAI 05, February 19, 2008
doi: 10.3752/cjai.2008.05

Matthias Buck, Stephen A. Marshall, and David K.B. Cheung

Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1

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17. Eumenes fraternus Say, 1824
Figs B2.1, 30; B4.4, 7, 9, 17; C17.1–5.

Species recognition. Besides characters provided in the key E. fraternus can be distinguished from E. crucifera and E. verticalis by the shorter pubescence of the scape (hair length less than 0.8x mid ocellar diameter). In E. crucifera and especially E. verticalis at least some hairs are as longs as mid ocellar diameter.

Variation. Fore wing length 8–10.5 mm (♂♂), 10–12.5 mm (♀♀). Colour of pale markings always ivory. Female clypeus with an arched dorsal mark, sometimes interrupted medially. Female scape black, sometimes with pale basal spot. Mesopleuron rarely with a dorsal spot in female. Propodeum in male rarely with a pair of dorsal pale spots. Apices of femora at most with small pale spot. Tergum 1 exceptionally with a pair of pale spots. Spots of tergum 2 rarely small or absent in male. Preapical fasciae usually present on terga 1–4 or 5 in male and 1–4(5) in female. Fasciae on sterna highly variable, more or less developed or absent on sterna 3–6 in male; female usually with a pair of lateral spots on sterna 3 and sometimes 4.

Distribution. Canada: ON. Eastern U.S.: NH and MA south to FL, west to MN, NE, KS, OK, TX (Krombein 1979, Bequaert 1938).

Biology. Builds jug-like mud nests that are usually attached to twigs. Prey are caterpillars (Krombein 1979).

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