4. Bombus (Sibiricobombus) morawitzi Radoszkowski, 1876

Figs 1, 7–8, 26‒30, 93

Bombus Morawitzi Radoszkowski, 1876: 101.

BOMBUS OPPOSITUS Smith, 1878: 9.

Bombus hydrophthalmus Morawitz, 1883: 240.

Bombus morawitzii ‒ von Dalla Torre 1896: 535, unjustified emendation.

Diagnosis

Females

Queens body length 19‒23 mm, workers 12‒18 mm. Colour pattern of the hair with the head predominantly black with only a few brown hairs intermixed on the vertex, the thoracic dorsum and metasomal T1‒5 bright orange-red, the side of the thorax and legs predominantly black (Figs 26‒27). Morphology with the hind basitarsus outer surface in the centre with short branched hairs dense, black and strongly overlapping so that reflections from the outer surface are interrupted; (in large individuals) T6 subapically medially with a raised boss.

Males

Body length 14‒18 mm. Colour pattern of the hair with the head predominantly black including the clypeus, often with orange hairs more or less intermixed on the vertex, the thoracic dorsum and metasomal T1‒6 bright orange-red, either the side or the lower side of the thorax and the legs predominantly black (Figs 28‒30). Morphology with the eye greatly enlarged relative to the eye of a female bumblebee, from the dorsal aspect the eye separated from the lateral ocellus by 1× the ocellar breadth; S6 with the posterior margin in the middle nearly straight; penis-valve head recurved section narrow curved and finger-like, concave posteriorly at the base (Fig. 93).

Type material

Lectotype of Bombus morawitzi (by designation of Tkalců 1968: 199) UZBEKISTAN • ♀ (queen); “ Samarkand ”; ZMB (examined PW).

Holotype of Bombus oppositus (by monotypy) CHINA • ♀ (queen); Xinjiang, “Yark. Exp.” “No precise locality indicated” [mountains west of Yarkant?]; F. Stoliczka leg.; NZSI (examined PW).

Syntype of Bombus hydrophthalmus KAZAKHSTAN • ♂; “im Hochgebirge bei Wernoye” [Almaty]; A. Kuschakewitsch leg.; NHMUK (examined PW).

Material examined

AFGHANISTAN • 1 ♀ (worker); Wakhan, N of Borak; 37.09° N, 73.63° E; 9 Jul. 1971; GG, SB095 / GG002.

CHINA ‒ Xinjiang • 1 ♀ (worker); Kuqa, Ku’ergan; 42.4358° N, 83.2538° E; 31 Jul. 2011; IAR, SB015 /NHMC06 • 1 ♀ (worker); Akqi, Sumutashi; 40.9055° N, 78.3568° E; 15 Jul. 2012; IAR, SB019 / NHMC01.

TAJIKISTAN • 1 ♀ (worker); Pamir, Rushan; 37.9901° N, 71.5846° E; Jul. 2000; Gurko leg.; BOLD no.: 6880F04 (COI); MM, SB077.

Distribution

Central Asian high montane species ‒ Central Asia: AFGHANISTAN, TAJIKISTAN, KYRGYZSTAN, KAZAKHSTAN, CHINA: Xinjiang. (AB, GG, IAR, IZCAS, Naturalis, NHMUK, NZSI, PW, UMons, ZIN, ZMB.)

Behaviour

Because the male eye is greatly enlarged relative to the eye of a female bumblebee and the male antenna is strongly elongated, the male mate-searching behaviour is expected to be similar to the “racing” behaviour described for “ B. asiaticus ” (actually B. longiceps stat. rev.) with these morphological characteristics by Williams (1991).

Taxonomic remarks

The taxon concept of the species B. morawitzi here agrees with the recent interpretation as a distinctive species (Tkalců 1968; Williams 1998; Ghisbain et al. 2020). We present evidence that: (1) our PTP analysis supports independent species-level coalescents in the COI gene (Fig. 1); corroborated by (2) diagnostic morphological character states (see the keys).

The colour pattern of this species shows little variation, although there is some variation in both sexes in how much black hair is intermixed on T1 and in males in the extent of the black hair on the side of the thorax.