Key to eastern Nearctic Eumenes species

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

Eumenes Latreille

The genus Eumenes has a worldwide distribution, and is represented in the Nearctic by twelve species north of the Isthmus of Tehuantepec (Krombein 1979, Rodríguez-Palafox 1996). Four species occur in northeastern North America.

References. – MacLachlan, 1980 (key to Nearctic species); Bequaert, 1938 (revision of Canadian species, key), 1944b (key to Canadian species).

4. Key to eastern Nearctic Eumenes species

Note: extralimital taxon in brackets.

1.	Scape ferruginous (Fig. 4.1); body with more or less extensive ferruginous markings (Figs 4.1, 4.2–3, 4.13–14)	2
-	Scape black, sometimes marked with yellow or ivory (Fig. 2.3); body with yellow or ivory markings only (Figs 4.9–10, 11–12, 4.15–17)	3
2.	Pronotum rounded anteriorly, lacking transverse carina between humeral angles. Metasomal segment 1 with long erect hair (length up to 3x mid ocellar diameter, Fig. 4.3) (western half of U.S. east to MN)	*E. bollii* Cresson
-	Pronotum with fine transverse carina (Fig. 4.1). Segment 1 with short, more or less appressed hair (Fig. 4.2) (eastern U.S.: NC and TN southward)	[E. smithii de Saussure]
3.	Fore wing strongly infuscated along anterior margin (Fig. 4.7). Male: pubescence of hind femur ventrally in basal half almost as long as mid ocellar diameter (Fig. 4.4). Female: propodeum dorsolaterally with well-spaced macropunctures, at least some interspaces much larger than one puncture diameter, the interspaces sparsely micropunctate and polished (Fig. 4.9); propodeum with pale dorsolateral spot. [Male flagellomere XI similar to Fig. 4.6.]	*E. fraternus* Say
-	Fore wing slightly infuscated along anterior margin (Fig. 4.8). Male: pubescence below hind femur short, less than half as long as ocellar diameter. Female: propodeum dorsolaterally with close macropunctures, interspaces at most as large as puncture diameter (Fig. 4.10), often dull and rugose; propodeum often completely black or with ventrolateral pale spot	4
4.	Mid femur with yellow apex, the yellow area sharply delimited from black remainder of femur (Fig. 4.12). Male: flagellomere XI more slender, externally without carina, on inner surface with fine microtomentum (Fig. 4.5). Female: propodeum usually with ventrolateral pale spot (Fig. 4.12; often with smaller dorsolateral spot as well), rarely completely black	*E. verticalis* Say
-	Mid femur gradually becoming reddish apically, its apex sometimes also with yellow spot* (Fig. 4.11). Male: flagellomere XI stout, outer surface with longitudinal carina, inner surface without microtomentum (Fig. 4.6). Female: propodeum either with a pair of dorsolateral pale spots only (Fig. 4.11) or completely black	*E. crucifera* Provancher
	Note: specimens from Atlantic Canada show a mid femoral pattern similar to E. verticalis*. Females of the two species from this area are sometimes difficult to separate.

Metasoma of Eumenes species