Mendacibombus

Williams, Paul H., Huang, Jiaxing, Rasmont, Pierre & An, Jiandong, 2016, Early-diverging bumblebees from across the roof of the world: the high-mountain subgenus Mendacibombus revised from species’ gene coalescents and morphology (Hymenoptera, Apidae), Zootaxa 4204 (1), pp. 1-72 : 23-24

Key to Mendacibombus species for males

1. Volsella at its broadest near the midpoint of its length, the dorsal surface just distal to this point with a raised curved ridge, usually with small teeth, just inside the inner margin, running for 0.3‒0.5× the remaining distal length of the volsella ( Fig. 36 )..................................................................................................... 2

- Volsella at its broadest near the midpoint of its length, the dorsal surface just distal to this point without a raised curved ridge just inside the inner margin ( Fig. 37 )..................................................................... 4

2 (1). Volsella distally terminating in a rounded right angle and barely curled back dorsally and not at all anteriorly ( Fig. 38 ); hair of the anterior thoracic dorsum yellow.............................................................. B. superbus

- Volsella distally sharply acute (pointed) and curled back dorsally and anteriorly ( Fig. 39 ); hair of the anterior thoracic dorsum black or black with white hairs intermixed................................................................ 3

3 (2). Gonostylus length 1.25× its greatest breadth ( Fig. 40 ); penis-valve head (defined by an outer toothed flange) length 0.33× the penis-valve total length from its distal apex to the broadest point of the spatha ( Fig. 40 ); hair of the anterior thoracic dorsum black and hair of metasomal T4‒5 black or orange, although often all of these hairs have white tips............ B. waltoni

- Gonostylus length 2× its greatest breadth ( Fig. 41 ); penis-valve head (defined by an outer toothed flange) length 0.25× the penis-valve total length from its distal apex to the broadest point of the spatha ( Fig. 41 ); hair of the anterior thoracic dorsum and hair of metasomal T4‒5 with a mixture of entirely white and entirely black hairs...................... B. convexus

4 (1). Penis-valve inner shoulder located at 0.63× the penis-valve length from the distal end to the broadest point of the spatha ( Fig. 42 )........................................................................................ B. defector

- Penis-valve inner shoulder located at ± 0.5× the penis-valve length from the distal end to the broadest point of the spatha ( Fig. 43 )................................................................................................ 5

5 (4). Penis valve proximal to the outer shoulder> 2× as broad as the penis-valve head (defined by an outer toothed flange) ( Fig. 44 )....................................................................................................6

- Penis valve proximal to the outer shoulder <2× as broad as the penis-valve head (defined by an outer toothed flange) ( Fig. 45 )....................................................................................................9

6 (5). Gonostylus distally strongly dorso-ventrally flattened and plate-like, thickness <0.25× its own breadth ( Fig. 46 ); wings light brown.................................................................................. B. avinoviellus

- Gonostylus distally thick, thickness> 0.25× its own breadth ( Fig. 47 ); wings nearly clear........................... 7

7 (6). Gonostylus with the inner distal corner a right angle from both the inner and dorsal aspects ( Fig. 48 ); thoracic dorsum between the wing bases with the hair usually entirely black; hair of T2 yellow with always at least a distinct black band along the posterior margin or T2 sometimes predominantly black.................................................. B. mendax

- Gonostylus with the inner distal corner distinctly acute from both the inner and the dorsal aspects ( Fig. 49 ); hair of the thoracic dorsum between the wing bases black but sometimes with many yellow or white hairs intermixed; hair of T2 yellow or white

with only a few black hairs along the posterior margin....................................................... 8 8 (7). Gonostylus thick and nearly black, in dorsal aspect short and broad, 1.5× as long as its greatest breadth, the inner and outer lateral margins strongly diverging in the anterior proximal half, the penis-valve head (defined by an outer toothed flange) in dorsal aspect narrowing towards its distal end often (not always) gradually in its distal two thirds............. B. margreiteri

- Gonostylus thin and brown, in dorsal aspect long and narrow, 2× as long as its greatest breadth, the inner and outer lateral margins nearly parallel in the anterior proximal half, the penis-valve head (defined by an outer toothed flange) in dorsal aspect narrowing only in its distal third.................................................................. B. makarjini

9 (5). Penis-valve breadth just proximal to the penis-valve head (defined by an outer toothed flange) 0.06× the penis-valve length from its distal apex to the broadest point of the spatha ( Fig. 50 ).................................. B. handlirschianus

- Penis-valve breadth just proximal to the penis-valve head (defined by an outer toothed flange) 0.11× the penis-valve length from its distal apex to the broadest point of the spatha ( Fig. 51 )................................................10

10 (9). Volsella with the apex narrowed, narrower than the adjacent penis-valve head ( Fig. 52 ); hindleg tibia with the anterior and posterior fringes entirely yellow............................................................... B. turkestanicus

- Volsella with the apex broad, broader than the adjacent penis-valve head ( Fig. 53 ); hindleg tibia with the anterior and posterior fringes either black or with many black hairs, only rarely entirely yellow....................................... 11

11 (10).Gonostylus from the dorsal aspect rectangular, with a distinct outer distal corner ( Fig. 54 ); hair of the thoracic dorsum between the wing bases either usually almost entirely black or occasionally yellow with many black hairs intermixed across the breadth........................................................................................ B. himalayanus

- Gonostylus from the dorsal aspect almost triangular, without a distinct outer distal corner but broadly rounded ( Fig. 55 ); hair of the thoracic dorsum between the wing bases entirely yellow except in a central spot that sometimes has black hairs................................................................................................. B. marussinus

Figures

FIGURES 36 ‒ 55. Morphology of parts of the male genitalia from the dorsal aspect of the left side, anterior to the left of the image, posterior to the right, white bars indicating morphological characters referred to in the key to males: 36, B. waltoni; 37, B. mendax; 38, B. superbus; 39, B. convexus; 40, B. waltoni; 41, B. convexus; 42, B. defector; 43, B. mendax; 44, B. mendax; 45, B. turkestanicus; 46, B. avinoviellus; 47, B. mendax; 48, B. mendax; 49, B. makarjini; 50, B. handlirschianus; 51, B. himalayanus; 52, B. turkestanicus; 53, B. himalayanus; 54, B. himalayanus; 55, B. marussinus.