Key to northeastern Nearctic Euodynerus 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

Euodynerus Dalla Torre

A primarily Holarctic genus with several species in Central America, the Caribbean, as well as the Afrotropical and Oriental regions. The Nearctic fauna (north of the Isthmus of Tehuantepec) includes 31 species. Twenty-four described species occur north of Mexico (Krombein 1979, Bohart 1982, Rodríguez-Palafox 1996), thirteen of which are found in the northeast. In addition, two undescribed species were newly discovered during this project.

References. – Bohart, 1939a (key to E. auranus [= E. boscii auctt.] and related species), 1945 (description of E. planitarsis), 1948a (key to E. foraminatus subspecies and related species); Bequaert, 1937 (key to subspecies of E. hidalgo), 1939 (key to E. annectens and related species); Krombein, 1962 (description of E. schwarzi).

5. Key to northeastern Nearctic Euodynerus species

Note: extralimital taxon in brackets.

1.	Inner orbit completely black (e.g., Fig. 5.2). Metanotum with yellow or ivory band along anterior margin (Figs 5.44–52), scutellum rarely with a pair of small pale spots. Tergum 1 with at least a few long erect hairs (length greater than mid ocellar diameter) behind declivity (Fig. 5.3). Male mid and hind tarsus with darkened last tarsomere (Figs 5.10–11) or tarsus entirely black	E. foraminatus -group 2
-	Inner orbit marked with yellow, ivory or ferruginous (e.g., Fig. 5.1). Metanotum often without pale band along anterior margin but scutellum usually with a pair of pale or ferruginous spots (e.g., Figs 5.53–54, 5.56–57, 5.59–61). Tergum 1 usually with short hair (length less than mid ocellar diameter) or bare behind declivity. Male mid and hind tarsus yellow to ferruginous, last tarsomere not darkened	14
2.	Body marked with ivory	3
-	Body marked with yellow	7
3.	Wings dark brown with purplish reflections (Figs 5.44–46). Usually only first one or two terga with apical fasciae (Figs 5.44–46; in male rarely up to five but then posterior fasciae very narrow or interrupted as in Fig. 5.15)	4
-	Wings at most slightly tinged with pale brown, lacking purplish reflections (Figs 5.47–48). At least first four terga with well-developed apical fasciae (Figs 5.47–48)	6
4.	Tergum 1 largely ivory behind declivity except for narrow median black streak. Tergum 2 black or with evanescent apicolateral spots, its hind margin simple, without translucent border (Fig. 5.5). Propodeum with well-developed lateral angle, dorsal surface ivory on each side of concavity (Fig. 5.5). Fore femur with extremely short hair ventrally (length less than 0.2x mid ocellar diameter). Female: notauli strongly impressed and areolate, very obvious among fine, general scutal punctation (Fig. 5.4) (U.S.: MN and NJ southward)	*E. bidens* (de Saussure)
-	Tergum 1 largely black behind declivity except for apical fascia, which may extend forward laterally (Figs 5.45–46). Tergum 2 with well-developed apical fascia (Figs 5.45–46), its hind margin sometimes thickened and reflexed, with translucent border (Fig. 5.46). Propodeum evenly rounded laterally, without distinct angle, black (Figs 5.45–46), rarely with small ivory spot(s). Fore femur with long, erect hair ventrally (length greater than mid ocellar diameter; as in Fig. 5.12). Female: notauli hardly differentiated, obscured by coarse scutal macropunctation	5
5.	Female: tibiae black (Fig. C31.1) or with small ivory spots on outer surface. Male: flagellomere XI (measured along outer surface*) 0.75–0.90x as long as flagellomere I (i.e., its minimum length along anterior surface); smooth ventral area of flagellomere IX straight in profile (Fig. 5.8); aedeagus with small ventromedial lamellae (Fig. 5.40). Both sexes: upper half of propodeal concavity enclosed laterally by relatively high, uninterrupted carina (Fig. 5.6)	*E. megaera* (Lepeletier)
-	Female: outer surface of tibiae largely or entirely ivory (Fig. C34.1). Male: flagellomere XI* 0.95–1.10x as long as flagellomere I; smooth ventral area of flagellomere IX convex in profile (Fig. 5.9); aedeagus with large ventromedial lamellae (Fig. 5.41). Both sexes: upper half of propodeal concavity usually not enclosed by continuous carina laterally, the carinal development varying from absent (except for dorsal tooth-like projection) to low and rim-like (less than 0.5x mid ocellar diameter high) and usually partially interrupted (Fig. 5.7)	*E. schwarzi* (Krombein)
	*Note: for correct measurement flagellomere XI needs to be adducted (i.e., in its natural position).
6.	Male: mid tarsomeres 1–4 extremely compressed laterally (Fig. 5.11); fore femur with ventral hairs long (length subequal to mid ocellar diameter; as in Fig. 5.12). Female: sternum 2 with complete apical fascia (rarely with small interruptions)	*E. planitarsis* (Bohart)
-	Male: mid tarsus only moderately compressed (Fig. 5.10); fore femur with ventral hairs unusually short (length ca. 0.3x mid ocellar diameter; Fig. 5.13) (but femur with longer hair posteriorly). Female: sternum 2 with a pair of posterolateral ivory spots	*E. leucomelas* (de Saussure), in part
7.	Male (seven metasomal segments)	8
-	Female (six metasomal segments)	11
8.	Basal half of fore femur with long, erect hair ventrally and posteriorly (length subequal to mid ocellar diameter; Fig. 5.12). Flagellomere XI stout (Fig. 5.14)	9
-	Basal half of fore femur with very short hair ventrally (length at most 0.3x mid ocellar diameter; Fig. 5.13) and sometimes also posteriorly. Flagellomere XI slender (Fig. 5.17)	10
9.	Terga 1–4 with complete apical fascia, tergum 5 almost always* and 6 often with complete apical fascia or posteromedial spot (Fig. C28.1), the one or two most posterior fasciae never interrupted medially, if reduced then abbreviated laterally. Parategula almost always yellow. Aedeagus with very short ventromedial lamellae (Fig. 5.42)	*E. foraminatus* (de Saussure)
	Note: only 1–2% of male E. foraminatus* lack yellow markings on tergum 5.
-	Terga 1 and 2 with complete apical fascia; usually one or more of terga 3–5 with yellow posterolateral spots or, rarely, with more or less complete but narrow apical fascia, in which case the one or two most posterior fasciae are interrupted medially (Fig. 5.15); fasciae never abbreviated laterally. Parategula black, at most very narrowly reddish at apex. Aedeagus with prominent ventromedial lamellae (Fig. 5.43)	Euodynerus sp. F
10.	Posterior surface of metanotum and propodeal concavity dull, not shining (Fig. 5.18). Propodeum with at most a small lamellate tooth just behind posterolateral corners of metanotum (U.S.: NJ southwards*)	*E. blakeanus* (Cameron)
	Note: range insufficiently known due to previous confusion with E. foraminatus*.
-	Posterior surface of metanotum and propodeal concavity moderately to highly shining despite ridging and/or punctation (as in Fig. 5.6). Propodeum with prominent lamellate tooth just behind posterolateral corners of metanotum (similar to Fig. 5.6)	yellow colour form of *E. leucomelas* (de Saussure)
11.	Terga 3 and 4 without apical fascia. Wings dark brown with strong purplish reflections (Fig. 5.50); scape amber to brown below (Fig. C35.4), rarely brownish yellow. Tegula often without yellow. Parategula black, at most very narrowly reddish at apex	Euodynerus sp. F
-	Terga 3 and 4 with complete apical fascia. Wings pale brown, with weak purplish reflections (Fig. 5.51 ). Scape bright yellow below (as in Fig. 5.2). Tegula always marked with yellow. Parategula marked with yellow	12
12	Clypeus with yellow apical spots (Fig. 5.2) besides paired basal spots or crescent-shaped basal mark. Posterior surface of metanotum and propodeal concavity dull, not shining (Fig. 5.18). Propodeum without or with small lamellate tooth just behind posterolateral corners of metanotum	*E. blakeanus* (Cameron)
-	Clypeus without yellow markings in apical half, basal half with crescent-shaped yellow mark or paired spots. Posterior surface of metanotum and propodeal concavity moderately to highly shining despite ridging and/or punctation (as in Fig. 5.6). Propodeum with prominent lamellate tooth just behind posterolateral corners of metanotum (similar to Fig. 5.6)	13
13.	Tergum 2 with apical margin truncate, slightly to considerably thicker than that of tergum 3 in posterior view (apical thickness up to 0.8x mid ocellar diameter); terga 2–4 with punctation in preapical area coarse, deep and usually dense (Figs 5.15 , 5.51). Sternum 2 with distinct median longitudinal groove in basal half	*E. foraminatus* (de Saussure)
-	Tergum 2 with apical margin thin and rounded, not noticeably thicker than that of tergum 3; terga 2–4 with punctation in preapical area shallower, finer and usually more widely spaced (Figs 5.16, 5.49). Sternum 2 with median groove often weakly developed	yellow colour form of *E. leucomelas* (de Saussure)
14.	Tergum 1 with long erect or semi-erect hairs behind declivity (their length greater than mid ocellar diameter). Male fore femur with small ventrobasal tubercle (Fig. 5.19) (eastern U.S.)	15
-	Tergum 1 with extremely short, appressed pubescence behind declivity. Male fore femur not tuberculate	16
15.	Body marked with ivory. Interocellar area not tuberculate. Metanotum black. Tergum 1 virtually impunctate behind declivity (Fig. 5.53) (U.S.: VA southward)	*E. annectens* (de Saussure)
-	Body marked with yellow and sometimes ferruginous (Fig. 5.54). Each hind ocellus bordered medially by low tubercle; the tubercle projecting above level of ocellus in lateral view (similar to Fig. 7.28). Metanotum with yellow band along anterior margin. Tergum 1 distinctly punctate (Fig. 5.54) (U.S.: MD southward)	*E. boscii* (Lepeletier)
16.	Terga 2 and 3 with hind margin thin, reflexed and translucent (Fig. 5.21). [Scutellum black; metanotum with yellow band along anterior margin (Fig. 5.55)]	*E. hidalgo* (de Saussure)
-	Tergum 2, at most, with hind margin reflexed, its margin thickened or thin and translucent	17
17.	Disc of tergum 2 and tergum 1 impunctate (Fig. 5.56) (western U.S., occurrence in Ontario doubtful)	[E. pratensis (de Saussure)]
-	Disc of tergum 2 punctate; tergum 1 strongly punctate to impunctate (Figs 5.57–61)	18
18.	Propodeum with submarginal carina distinctly produced, more or less rectangular with narrowly rounded apex (Fig. 5.22). Metanotum with yellow band along anterior margin and scutellum black (Fig. 5.58; rarely scutellum with a pair of small yellow spots). Male: flagellomere XI conspicuously flattened, obliquely truncate apically (Fig. 5.26); mid femur with anteroventral depression near base (Fig. 5.24); hind femur posterobasally with dense long semi-erect hair (Fig. 5.25). [Female: apical tooth of mandible as long as second and third combined]	*E. annulatus* (Say)
-	Propodeum with submarginal carina very low and rim-like, not projecting posteriorly (e.g., Fig. 5.31). Metanotum usually without yellow band along anterior margin (Figs 5.59–61), if present then scutellum largely ferruginous or with a pair of large ferruginous spots (Fig. 5.57). Male: flagellomere XI smaller, neither flattened nor broadly truncate; mid femur without anteroventral depression near base; hind femur with short hairs posterobasally, with a few scattered longer hairs	19
19.	Tergum 1 practically impunctate (Fig. 5.57). Male: fore trochanter with long, erect hair (Fig. 5.20); flagellomeres III–VII black; hind margin of tergum 2 neither thickened nor double-edged. Female: cephalic foveae in deep depression (Fig. 5.23); mandible with apical tooth at least as long as second and third combined (Fig. 5.28)	E. crypticus (Say)
-	Tergum 1 sparsely to densely punctate (Figs 5.59–61). Male: fore trochanter with short, decumbent hair; flagellomeres III–VII yellow to brownish beneath (Fig. C22.3); hind margin of tergum 2 slightly to strongly thickened (0.4–1.3x mid ocellar diameter), double-edged and often reflexed (Fig. 5.33). Female: area around cephalic foveae flattened, at most slightly and very gradually depressed below level of vertex; mandible with apical tooth at most slightly longer than second	20
20.	Propodeum with lateral ridge dentate below angle (Fig. 5.31). Male: flagellomere XI yellowish to pale brown on outer surface; flagellomeres I–VII with scattered short, bristle-like hairs (spicules) on ventral surface (Fig. 5.27; their length ca. 0.15–0.2x mid ocellar diameter); mandible with second tooth longer than third (Fig. 5.30). Female: fore basitarsus without rake (Fig. 5.34)	E. castigatus (de Saussure)
-	Propodeum with lateral ridge not dentate below angle (Fig. 5.32). Male: flagellomere XI black; flagellomeres I–VII without short, bristle-like hairs on ventral surface; mandible with second tooth as long as third (Fig. 5.29). Female: fore basitarsus with distinct rake setae (Fig. 5.35)	21
21.	Sternum 2 abruptly sloping up from basal groove towards slightly concave, plateau-like middle part (thus forming strongly convex welt just behind transverse basal groove; Fig. 5.36). Transverse basal groove of sternum 2 granulose or with fine longitudinal or oblique ridging (> 25 ridges) (Fig. 5.38). Female: wings very slightly infuscated (Fig. 5.60) (ON and MI westward)	E. auranus (Cameron)
-	Sternum 2 rising gradually towards slightly convex middle part which is not plateau-like; median area immediately behind basal groove almost flat, conspicuously inclined towards basal groove (Fig. 5.37). Basal groove of sternum 2 with ca. 16–22 coarse to moderate longitudinal ridges (Fig. 5.39). Female: wings moderately infuscated (Fig. C36.1) (U.S.: MA southward)	Euodynerus sp. G

Metasoma of Euodynerus species