Acanthetropis Wasbauer, 1958

Kimsey, Lynn S. & Wasbauer, Marius S., 2015, Revision of the odd brachycistidine genus Acanthetropis Wasbauer, 1958 (Hymenoptera, Tiphiidae, Brachycistidinae), Journal of Hymenoptera Research 44, pp. 19-30 : 20-21

Genus Acanthetropis Wasbauer

Acanthetropis Wasbauer 1958: 139. Type species: Acanthetropis lamellatus Wasbauer 1958: 140. Original designation.

Diagnosis.

Species of Acanthetropis are large, relatively heavy-bodied brachycistidines. The males can be immediately distinguished by the presence of a scrobal sulcus, very long marginal cell of the forewing and metasomal sternum II with a median longitudinal carina or fold. In addition the frons bears a carina above and laterad of the antennal sockets.

Male description.

Body length 6.5-17.0 mm. Head. Rounded, broader than long; ocelli enlarged with a transverse sulcus between their posterior margins; compound eyes slightly convergent below, inner margins broadly emarginate; antennal socket rim with broad carina or thickening beneath small carina above and lateral to antennal socket; clypeus transverse, not projecting apically, clypeal L/W ratio not exceeding 0.4, central part slightly convex, with narrow, apically projecting ledge; mandibles tridentate, weakly developed external carina extending from mandibular base to point just proximad of inner tooth, obsolescent near its middle; maxillary and labial palpi well-developed, conspicuous, 6 and 4 segmented respectively. Mesosoma. Robust, moderately long; pronotum narrow, transverse, nearly vertical, humeral angles rounded, not prominent; mesonotum with parapsidal furrows long, strongly impressed; scutellum with or without median longitudinal sulcus; mesepisternum carinately produced or with low, rounded protuberance anterodorsally, irregularly convex; propodeum with dorsomedian longitudinal sulcus, area laterad of sulcus sloping abruptly posteriorly, dorsal and posterior propodeal faces separated by transverse carina; coxae simple, not carinate ventrally, with well-developed admesal stridulatory area; wings long, venation well-developed, forewing with three submarginal and two discoidal cells, third submarginal cell two-thirds or more length of second, first transverse cubital vein arising beyond basal third of first submarginal cell, marginal cell elongate, costa extending distad of stigma a distance greater than half length of stigma; hindwing with radial and cubital veins well-developed, cubitus arcuate, forming angle with transverse cubital of less than 135°, jugal lobe much shorter than submedian cell. Metasoma. Segment I narrower than II in dorsal view, sternum I with median sulcus somewhat expanded posteriorly; sternum II with strong basal median longitudinal carina or fold. Genital capsule. Paramere broadest subapically, ventrally rounded to acute apex; aedeagus slender, linear or gradually expanded toward apex; volsella with cuspus broadly rounded, digitus produced apically into short, blunt point in ventral view, inner margin of volsella with several stout spines and slender setae. Color. Reddish brown to dark brown.

Female.

Unknown, although the female of Acanthetropis may well be the "Genus A" described by Kimsey (2005).

Distribution

(Figs 15-18 ). Acanthetropis is known from geographically scattered records in the USA: Arizona, California, Idaho, Kansas, Nebraska, Nevada, New Mexico, South Dakota, Utah, and in Mexico: Baja California, Baja California Sur, Sonora, Hidalgo and Zacatecas. Further collecting in intervening areas will probably reveal a more widespread fauna.

Key to the species of Acanthetropis

1	Mesepisternal prominence high and sharp, often appearing carinate in certain lights (as in Figs 5 , 6 , 10 ); mesepisternal carina present; dorsolateral areas of propodeum sharply, carina-margined posteriorly, separated from posterior transverse carina by pronounced sulcus	2
-	Mesepisternal prominence low, rounded, not appearing carinate; mesepisternal carinae absent; dorsolateral areas of propodeum sometimes with a distinct posterior margin but never sharp and carinate	3
2	Second metasomal sternum with a median longitudinal elevation, terminating in a spine (Figs 5 , 10 ); gular carina sharply elevated anteriorly, forming a tooth visible behind the posterior mandibular condyle in full lateral view (Figs 3 , 4 )	Acanthetropis noctivaga (Bradley)
-	Second metasomal sternum with a longitudinal broad median basal ridge terminating at a transverse ledge (Fig. 6 ); gular carina low, not visible in full lateral view	Acanthetropis lamellata Wasbauer
3	Flagellomere I at least 3.5 × as long as greatest width (Fig. 8 ); metasomal segment I long and petiolate, L/H 2.5 or more (Fig. 9 )	Acanthetropis idiotes (Cockerell)
-	Flagellomere I less than 3.0 × as long as greatest width (Fig. 7 ); first metasomal segment shorter, L/H 2.0 or less	Acanthetropis aequalis (Fox)

Figures

Figures 15 - 18. Distribution maps.

Figures 1 - 10. 1 - 2 Forewing and hindwing 3 Side view of head, antennae removed 4 Ventral view of head, mouthparts and mandibles removed 5 Oblique ventral view of metasomal sterna I and II 6 Ventral view of metasomal sternum II 7, 8 Antenna 9 Lateral view of metasomal segment I showing measurement points, H = height between points c and d, L = length, between points a and b 10 Lateral view of metasomal segments I and II.