Key to northeastern Nearctic Eumeninae genera

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

Subfamily Eumeninae (mason or potter wasps)

The subfamily includes 29 genera in America north of Mexico (Carpenter 2004a), 13 of which occur in the northeast.

References. – Carpenter, 2004a (key to Nearctic genera), 1986a (checklist of World genera); Menke and Stange, 1986 (update to Carpenter and Cumming’s, 1985 key); Carpenter and Cumming, 1985 (key to Nearctic genera); Parker, 1966 (key to Nearctic genera).

2. Key to northeastern Nearctic Eumeninae genera (mason or potter wasps)

1.	Metasoma petiolate, segment 1 at least twice as long as wide and only half as wide as segment 2 (Figs 2.1–2)	2
-	Metasoma not petiolate, segment 1 at most 1.4x as long as wide, its width at least 0.7x that of segment 2 (e.g., Figs 2.26–27)	3
2.	Clypeal margin strongly produced and angulate, extending distinctly below level of lower eye margin (Fig. 2.3). Minimum width of metasomal segment 2 slightly less than width of segment 1 (Fig. 2.1). Vein M nearly straight at base of submarginal cell II (Fig. 2.5)	*Eumenes*
-	Clypeal margin truncate and more or less straight, not extending below level of lower eye margin (Fig. 2.4). Minimum width of metasomal segment 2 less than half width of segment 1 (Fig. 2.2). Vein M with two distinct kinks at base of submarginal cell II (Fig. 2.6) (U.S.: MA and IL southward)	Zethus
	one species: Zethus spinipes
3.	Anterior face of pronotum with a pair of pits medially (Fig. 2.12)	4
-	Anterior face of pronotum lacking pair of pits medially	5
4.	Metasomal tegum 1 with overhanging hind margin long, covering an acarinarium (i.e., a space used to accommodate symbiotic mites; mites may be present or not); base of tergum 2 essentially smooth (Fig. 2.9), sometimes minutely roughened but not pitted	*Parancistrocerus*
-	Metasomal tergum 1 with short overhang, the space below not serving as acarinarium (mites never present); base of tergum 2 usually with a row of shallow to deep pits (Fig. 2.10 ), the pits sometimes obsolete medially leaving only 1–2 shallow pits at each end; in one species (S. krombeini) completely without pits	Stenodynerus
	Note: due to the difficulties in separating these two genera, the species of Parancistrocerus and Stenodynerus are treated in a single key.
5.	With one or both of the following features: metasomal tergum 1 with transverse carina at summit (Figs 2.11, 2.19); pronotum lacking transverse carina	6
-	Pronotum always with transverse carina (e.g., Fig. 2.12), tergum 1 always without transverse carina	8
6.	Metasomal tergum 1 with shallow median groove posterior to carina (Fig. 2.11). Male antenna simple apically (Fig. 2.7). Omaulus well-defined in both sexes, curved backward ventrally (Fig. 2.13)	*Symmorphus*
-	Metasomal tergum 1 without median groove. Male antenna hooked (Fig. 2.24) or coiled apically (Fig. 2.8). Female without omaulus	7
7.	Tegula rounded posteriorly (Fig. 2.16). Tergum 1 lacking transverse carina. Male: apical six flagellomeres flattened and coiled (Fig. 2.8); mid femur with two deep emarginations ventrally (Fig. 2.18). Female: cephalic foveae as far apart as hind ocelli (Fig. 2.14)	*Odynerus*
	one species: Odynerus dilectus
-	Tegula pointed posteriorly (Fig. 2.17). Tergum 1 with transverse carina (Fig. 2.19), rarely indistinct. Male: apical flagellomeres neither flattened nor coiled; flagellomere XI reflexed (similar to Fig. 2.24; see also 3.5); mid femur simple. Female: cephalic foveae closer together than hind ocelli (Fig. 2.15), sometimes coalescent	*Ancistrocerus*
8.	Pronotum with complete humeral carina (extending to pronotal hind margin) (Fig. 2.20). Male flagellum with ten flagellomeres, simple apically, flagellomere X minute. Body black, with extensive ferruginous to orange markings (Fig. 2.37); yellow markings absent except for male clypeus (Fig. 2.37) and small male frontal spots	*Pachodynerus*
	one species: Pachodynerus erynnis
-	Pronotum without or rarely with an incomplete humeral carina (ending far from pronotal hind margin, e.g., similar to Fig. 7.3). Male flagellum with eleven flagellomeres, hooked apically (e.g., Fig. 2.24). Body colour variable, with well developed yellow or ivory markings on meso- and metasoma	9
9.	Propodeum with dorsal carina broadly separated from (i.e., distinctly posterior to) hind margin of metanotum; propodeal dorsum in between almost horizontal, shelf-like (Fig. 2.21). [Black, with purplish wings and ivory markings, including propodeal spots and complete apical fasciae on terga 1 and 2; Fig. 2.40] (U.S.: from NJ, PA, OH and IL southward)	*Pseudodynerus*
	one species: Pseudodynerus quadrisectus
-	Propodeum with or without dorsal carina, if present the carina almost at level of (not posterior to or at most slightly posterior to) hind margin of metanotum; propodeum without distinct shelf-like area behind metanotum (e.g., Fig. 2.27)	10
10.	Flagellomere I approximately as long as II (Fig. 2.23). Vein M with two distinct kinks at base of submarginal cell II (similar to Fig. 2.6). Propodeal valvula large and with free upper, lower and posterior margin (i.e., not fused to submarginal carina); submarginal carina strongly produced posteriorly and pointed (Fig. 2.22). Small wasps, <9 mm	*Leptochilus*
-	Flagellomere I at least 1.3x as long as II (Fig. 2.24 ). Vein M nearly straight or very slightly angled at base of submarginal cell II (similar to Fig. 2.5). Propodeal valvula variably developed but dorsally always fused to submarginal carina (e.g., Fig. 5.31); submarginal carina rarely posteriorly produced (some Euodynerus; Fig. 5.22). Larger, usually >9 mm	11
11.	Metasomal tergum 1 only 0.70–0.75x as wide as segment 2 (Fig. 2.26). Terga 2 and 3 with thin, translucent, reflexed, apical lamella (Fig. 2.26 ). Propodeum rounded laterally (Fig. 2.26 , 2.42)	*Parazumia*
	one species: Parazumia symmorpha
-	Width of metasomal tergum 1 subequal to segment 2 (e.g., Fig. 2.27). Terga 2 and 3 rarely with translucent, reflexed, apical lamella (Euodynerus hidalgo), but then propodeum angled posterolaterally (similar to Fig. 2.27 )	12
12	Mandible entirely black; postocular spot absent (Fig. 2.28). Body black with ivory markings; only tergum 1 with apical fascia, metasoma otherwise black (Fig. 2.43). Tegula with truncate hind margin, the truncation nearly perpendicular to main body axis (Fig. 2.25)	*Monobia*
	one species: Monobia quadridens
-	Mandible always with at least a small pale spot near base, sometimes extensively ferruginous; postocular spot pale to ferruginous, usually small (Fig. 2.29). Body variably coloured, often with yellow (sometimes also ferruginous) markings (e.g., Fig. 2.44); apical fasciae present at least on terga 1 and 2, if body marked with ivory and only tergum 1 fasciate (E. bidens, Fig. 2.45) then tegula pointed posteriorly and with curved oblique posterolateral margin (shape similar to Fig. 2.17), not truncate	*Euodynerus*

Gallery of Eumeninae genera