Bombus incertoides Vogt 1911, stat. rev.

Bombus incertoides Vogt, 1911 stat. rev.

Figs 16, 153–156, 201, 212

Bombus separandus [subsp.] incertoïdes Vogt, 1911: 58 by indication of Vogt (1909): 61, not infrasubspecific after Skorikov 1923: 153 (ICZN 1999: Art. 45.6.4.1).

Bombus keriensis (part) – Reinig 1935: 341. — Williams 1991: 96 (non Morawitz, 1887: 199).

Bombus incertoides was first treated as a separate species by Skorikov (1923), without explanation, but has since been treated as a part of B. keriensis s. lat. (the keriensis -complex) by Reinig (1935) and by Williams (1998).

Our PTP analysis (Fig. 10) of coalescents in the COI gene within the keriensis -complex supports six species including B. incertoides, corroborated by differences in morphology. These species are also supported by the absence of a positive divergence-with-distance relationship among them (Fig. 20) (see Divergence and geographical distance, page 12).

From morphology, B. incertoides has enlarged male eyes and has a bright white banding pattern in the hair with (most strongly for the keriensis -complex) the thoracic dorsum with the posterior white band particularly narrowed by black hair anteriorly on the scutellum.

Bombus incertoides can co-occur locally with the closely similar (but locally yellow-banded) B. separandus, at least in the Altai mountains of Mongolia.

Diagnosis

Females

Queens medium-sized body length 18–21 mm, workers 10–12 mm. Can be distinguished within Mongolia by the hair of the face black, the pale hair anteriorly on the thoracic dorsum pure white, the hair on the side of the thorax in its lower half black, the anterior half of the scutellum black, and by the hair of T4–5 red (cf. B. sichelii, B. separandus).

Males

Body length 12–15 mm. Can be distinguished within Mongolia by the hair of the face black. Genitalia (Fig. 201) heavily sclerotised and dark, with the gonostylus longer than broad, its inner basal projection reduced to a stub (cf. rufipes- group, festivus- group, rufofasciatus -group); volsella with the inner distal corner broadly produced but without a narrow hook (cf. rufipes- group, festivus- group, rufofasciatus - group); antenna short and eye slightly enlarged relative to female eye.

Material examined

Holotype

MONGOLIA • ♀ (queen), holotype of Bombus separandus incertoides Vogt, 1911 by monotypy (Williams, 1991); “N.[orth]” (Leder’s material from northern Mongolia is likely to have come from

a site between Kyakhta and Ulaanbaatar: Williams et al. 2012a); “[18]92”; H. Leder leg.; RMNH (examined PW).

Material sequenced (9 specimens)

MONGOLIA • 1 ♀ (queen); Tov, Tuul river; 47.8118° N, 106.6139° E; 24 Jun. 2005; D. Altanchimeg leg.; NHMUK seq: NHMSR2; DA: ML148 • 1 ♂; Khovd, Monkhkhairkhan; 46.9676° N, 91.6496° E; 9 Aug. 2014; D. Altanchimeg leg.; NHMUK seq: NHMSR6; DA: ML173 • 1 ♀ (queen); Arkhangai, Bat-olziit; 46.7974° N, 101.7551° E; 18 Jun. 2014; R. DeJonghe leg.; BOLD seq: 6880B06; RDJ: ML490 • 1 ♂; Arkhangai, Chuluut Khujirt Mts; 47.4418° N, 100.3643° E; 7 Aug. 2018; R. DeJonghe leg.; BOLD seq: 6880B07; RDJ: ML491 • 1 ♂; same collection data as for preceding; BOLD seq: 6880B08; RDJ: ML492 • 1 ♀ (worker); Arkhangai, Chuluut Khujirt Mts; 47.2697° N, 100.3387° E; 8 Aug. 2018; R. DeJonghe leg.; BOLD seq: 6880B09; RDJ: ML493 • 1 ♂; Arkhangai, Chuluut Khujirt Mts; 47.2700° N, 100.3387° E; 9 Aug. 2018; R. DeJonghe leg.; BOLD seq: 6880B10; RDJ: ML494 • 1 ♂; same collection data as for preceding; BOLD seq: 6880B11; RDJ: ML495 • 1 ♀ (queen); Khovsgol, Khatgal; 50.4815° N, 100.2170° E; 7 Jun. 2015; R. DeJonghe leg.; BOLD seq: 6880C04; RDJ: ML501.

Global distribution

(Mongolian mountain species) North Asia: MONGOLIA. (DA, NHMUK, RMNH, PW, RDJ.) This species is widespread but not common (Fig. 212).

Behaviour

Expected to be food-plant generalists but no records. The male mate-searching behaviour is unknown.