Rhynostelis Moure & Urban, 1995

Urban, Danuncia & Parizotto, Daniele Regina, 2012, A revised key to the Neotropical cleptoparasitic anthidiine genera (Hymenoptera, Megachilinae) with notes and description of the male of Rhynostelis Moure & Urban, ZooKeys 249, pp. 27-35 : 29

Rhynostelis Moure & Urban, 1995 Figs 1-715, 17

Rhynostelis Moure & Urban, 1995: 297.

Hoplostelis ( Rhynostelis ) Michener, 2007: 518.

Male description.

Diagnosis. Mandibles with only apical tooth elongated, upper distal angle rounded (Fig. 2); clypeus protuberant, with a basal tubercle at middle; supraclypeal area protuberant (Fig. 1); scutum and scutellum bigibbous; axillae and dorso-ventral area of mesepisternum gibbous (Figs 3, 5); distal tergum short and sinuous at middle (Fig. 6); sternum sixth with laminar rounded, lateral projections.

Description.

Mandibles with distal margin almost straight, only with apical tooth elongated; upper distal angle slightly marked, condylar carina elevated and strongly laminated, slightly wider at base (Fig. 2). Clypeus protuberant with median basal tubercle elongated, extended in low irregular carina in basal half, apex depressed without projections, not exceeding labrum, covered by many long hairs. Labrum weakly bilobed near clypeal base. Supraclypeal area with wide, somewhat flat median carina; frons with long, well marked carina. Juxtantennal carina laminated, ventrally short, not arising at base of antennal sockets and extending upward (Fig. 1). Scutum and scutellum bigibbous; axillae gibbous; base of propodeum with irregular foveae (Fig. 3, 5). Omaulus lamellate, almost extending ventrally; mesepisternum with gibbous area near mesocoxal cavity. Fore and middle tibiae with midapical spine on outer surface (Fig. 15); arolia present. Fifth and sixth terga with transverse, median low carina; sixth tergum with apical projection at middle; distal tergum slightly emarginated at apex (Fig. 6). Second sternum enlarged, with apex weakly emarginated at middle, with long pilosity at apex; third to fifth sterna with dense apical pilosity, laterally with longer and curved hairs; sixth sternum with distal margin almost straight, with large, angled, laminar, lateral projections subapically.

Genitalia. Gonostylus slightly longer than penis valves; apical half with dense and long pilosity on inner margin; apex rounded, laterally slightly convex. Gonobase incomplete dorsally, only visible laterally (Fig. 7).

Comments.

Moure and Urban (1995) mentioned that the base of the propodeum in Rhynostelis lacks foveae. Michener (2007), also pointed out this feature as one of the characteristics that separates Rhynostelis from Hoplostelis . However, a re-examination of Rhynostelis specimens revealed the presence of irregular fovea in the base of its propodeum, which are difficult to see due the shiny yellow integument. Michener (2007) considered Rhynostelis as a subgenus of Hoplostelis and in his key, the male agrees with the female by the characters he listed, except for the absence of foveae in the base of propodeum, as commented above. The male of Hoplostelis further differs from Rhynostelis by the following combination of characters: three strong mandibular teeth and two basal depressions near the articulation of the head; omaulus carinate only in the dorsal one-half or one-third; sixth sternum with narrow lateral projections and without gibbous mesosoma.