Bremus formosellus Frison, 1934: 163
Bremus formosellus
Frison, 1934: 166
Bremus formosellus
Frison, 1934: 167
Bombus pyrosoma
Williams 1991: 102
Morawitz, 1890: 349
Widespread polytypic species or complexes of local species? Revising bumblebees of the subgenus Melanobombus world-wide (Hymenoptera, Apidae, Bombus)
Williams, Paul H.
Altanchimeg, Dorjsuren
Byvaltsev, Alexandr
Jonghe, Roland De
Jaffar, Saleem
Japoshvili, George
Kahono, Sih
Liang, Huan
Mei, Maurizio
Monfared, Alireza
Nidup, Tshering
Raina, Rifat
Ren, Zongxin
Thanoosing, Chawatat
Zhao, Yanhui
Orr, Michael C.
European Journal of Taxonomy
2020
2020-10-02
719
1
120
MFJM
(Frison, 1934)
Frison
1934
[582,1005,434,461]
Insecta
Apidae
Bombus
Animalia
Hymenoptera
65
66
Arthropoda
species
formosellus
Figs 13, 98–102, 192
Bremus formosellus Frison, 1934: 163. Bremus formosellusvar. [subsp.] derivatus Frison, 1934: 166. Bremus formosellusvar. [subsp.] gradatus Frison, 1934: 167. Bombus pyrosoma(part) – Williams 1991: 102(non Morawitz, 1890: 349).
Bombus formosellusis known only from Taiwan( Frison 1934; Chiu 1948; Starr 1992). Bombus pyrosoma s. lat.has been treated as a widespread Asian species by Williams (1998), to include the taxon formosellus. Here, B. formosellusis recognised as separate from the north Chinese B. pyrosoma s. str.because of their unique and strongly divergent species coalescents in the COI gene ( Fig. 10), corroborated by differences in morphology (see the Diagnosis). The morphological differences are subtle, but do appear to support the two as separate species within a morphologically more distinctive complex of pyrosoma s. str. + formosellus. Our PTP analysis ( Fig. 10) supports relatively strongly two coalescents in the COI gene for the north Chinese B. pyrosoma s. str., and the Taiwanese B. formosellus. The two coalescent groups differ in COI barcode sequences for at least 12 diagnostic nucleotide positions (1.8% of the barcode region). These nucleotide differences are all synonymous, making no difference to the amino acid sequences at translation. From morphology, B. formosellushas a paler colour pattern of the hair than B. pyrosoma s. str.for the females and especially for the queens. The queen of B. formosellus(below) has the hair of the thoracic dorsum with broad anterior and posterior bands strongly dominated by white, whereas for B. pyrosoma s. str.these areas are black or usually with a small minority of white hairs intermixed. The male gonostylus inner process is also not clearly divided into two teeth as it is in B. pyrosoma s. str. Queens of this species have not previously been described. However, S. Lu located a female (ML503) in the TFRI collection that appears to be large enough (body length 20 mm) and collected early enough in the year (July 14, by I. Sung) to be a queen. This individual has lost much of its hair so the colour pattern is not clear, but females appear to show weak size-dependent dimorphism in the colour pattern of the hair: the queen has the remaining hair of T2 extensively black but with white hair narrowly anteriorly and medially and with orange hair narrowly posteriorly, especially in the lateral corners ( Fig. 98); whereas workers (which are smaller) either have T2 chocolate-coloured anteriorly and black posteriorly or have T2 extensively dull yellow ( Figs 99–101). Recently queens of this species have been reared in laboratory colonies, from which this colour pattern is confirmed (I. Sung in litt.). Males have the thoracic bands and T1–2 yellow ( Fig. 102).
Diagnosis Females
Queens medium-sized body length 20 mm, workers 10–15 mm. Can be distinguished within Taiwanby the hair of the thoracic dorsum with white bands (cf. B. eximius). Males Body length 13–14 mm. Can be distinguished within Taiwanby their combination of the hair of the thoracic dorsum with yellow bands, side of the thorax yellow, and T3–7 red. Genitalia ( Fig. 192) with the gonostylus much reduced, less than a quarter as long on its outer side as broad, with the distal edge concave and the inner distal corner with two indistinct adjacent teeth, the proximal tooth slightly shorter than the distal tooth and the two not clearly separated by an indentation (emargination) ( cf. pyrosoma s. str.); volsella with the inner distal corner produced as a narrow curved hook ( cf. rufipes-group, B. simillimus, lapidarius-group, sichelii-group, keriensis-group); eye unenlarged relative to female eye.
Material examined Holotype CHINA• ♂, holotypeof Bremus formosellus Frison, 1934by original designation; Taiwan, Roeichi; 15 Sep. 1924; T. Shirakiand J. Sonanleg.; INHS(examined PW). Material sequenced( 5 specimens) CHINA– Taiwan• 1 ♀(worker); Tayuling; 23.9767° N, 121.5206° E; 5 Aug. 1991; C. Starrleg.; NHMUKseq: NHMPW07; PW: ML317• 1 ♀(worker); Tahsuehshan; 24.3428° N, 121.1243° E; M. Kuoleg.; NHMUKseq: NHMPW09; PW: ML318• 1 spec.; Taiwan; 24.1806° N, 121.3101° E; GenBankseq: AF279522; SEHU: ML184• 2 ♀♀(workers); Taiwan; 15 Jun. 2019; I. Sungleg.; TFRIseq: L11 LL12; TFRI: ML573 ML574.
Global distribution (Taiwanese mountain species) East Asia: CHINA: Taiwan. (INHS, NHMUK, PW, TFRI.) The species is narrowly distributed but not rare in collections.
Behaviour Expected to be food-plant generalists. Male mate-searching behaviour is expected to resemble the patrolling of B. eurythorax.
2867606481
1924-09-15
INHS, PW
T. Shiraki & J. Sonan
China
Taiwan
Roeichi
66
67
1
holotype
2867606620
1991-08-05
NHMUK, PW
C. Starr
China
23.9767
Tayuling
7
121.5206
66
67
ML317
1
1
Taiwan
2867606465
NHMUK, PW
M. Kuo
China
24.3428
Tahsuehshan
7
121.1243
66
67
ML318
1
1
Taiwan
2867606411
SEHU
GenBank
China
24.1806
Taiwan
7
121.3101
66
67
ML184
1
Taiwan
2867606308
2019-06-15
TFRI
I. Sung
China
Taiwan
66
67
ML573, ML574
2
2
Taiwan