Early-diverging bumblebees from across the roof of the world: the high-mountain subgenus Mendacibombus revised from species’ gene coalescents and morphology (Hymenoptera, Apidae)
Author
Williams, Paul H.
Author
Huang, Jiaxing
Author
Rasmont, Pierre
Author
An, Jiandong
text
Zootaxa
2016
4204
1
1
72
journal article
10.11646/zootaxa.4204.1.1
3f8866d2-529e-43ad-b971-29fc52a13858
1175-5326
192302
C050058A-774D-49C0-93F9-7A055B51C2A0
9.
Bombus defector
Skorikov
(
Figs 18, 22
,
32
,
42
,
64
)
[?
Bombus mendax
Gerstaecker
;
Morawitz 1880
:340, in part, misidentification.]
<
Bombus mendax
> subsp.
defector
Skorikov 1910b
:330
, type-locality citation (Cyrillic) ‘[Fergana (Alai range)]’.
Lectotype
queen by present designation
ZISP
examined, (
Cyrillic
) ‘[
Alai
range]’ (
Alai
,
Kyrgyzstan
).
Note
1.
<
Mendacibombus mendax
subsp.>
defector
(
Skorikov); Skorikov 1914
:124
.
Mendacibombus defector
(
Skorikov); Skorikov 1923
:149
;
Skorikov, 1931
:fig. 17.
[?
Mendacibombus turkestanicus
var.
Skorikov, 1931
:215, published with name incomplete.]
Bombus mendax defector
Skorikov
;
Reinig 1932b
:163
.
Bombus defector
Skorikov
;
Reinig 1934
:172
.
Bombus
(
Mendacibombus
)
defector
Skorikov
;
Panfilov 1957
:237
;
Panfilov 1962
:195
; S.-
F. Wang 1985
:160
;
Williams, 1991
:
15
, 42 in part;
P.H. Williams 1998
:
99
in part.
[
Bombus (Mendacibombus) makarjini
Skorikov
; P.H. Williams 2011:27, misidentification. Note 2.]
Note
1 (
defector
).
Skorikov’s
original description of the taxon
defector
cites the
type
locality as
Fergana
(
Alai
range).
The
ZISP
collection studied by
Skorikov
contains a queen that agrees with the original description and carries the labels: (1) white, printed (Cryrillic) ‘[Ak-Basaga, Alai- / skii khr. 2600‒2700 mt. /
Makarin
]
29/ 30.v.
09.’; (2) white, printed (Cyrillic) ‘[
k. Skorikova
]’; (3) red, handwritten ‘
Lectotypus
Bombus
/
mendax subsp.
/
defector Skor.
/ design.
Podbolotsk
.
’ (
M. Podbolotskaya
, unpublished); (4) green, printed ‘
Mendacibombus
/ MD# 3524 det. PHW’; (5) red, printed ‘
LECTOTYPE
[female] /
Bombus mendax
ssp. /
defector
/
Skorikov
, 1910 / det.
PH Williams
2012’; (6) white, printed ‘[female]
Bombus
/ (
Mendacibombus
) /
defector
/ det
.
PH
Williams 2012’.
This
specimen, which is complete, is regarded as one of
Skorikov’s
syntypes
and is designated here as the
lectotype
in order to reduce uncertainty in the identity and application of the name.
A second queen collected at Ak-Basaga by Makarin in 1909 (MD#315, NHM, sent by Skorikov as part of an exchange with the NHM in 1934), closely similar in morphology, is designated here as a paralectotype and interpreted as conspecific.
Note 2 (
makarjini
). See note 1 on
B. makarjini
regarding the
paralectotype
. Examination of this
syntype
as the only
type
seen at the time led to the misidentification of this species in Williams (2011).
Etymology.
The species is named from the Latin
defector
for a deserter or rebel, presumably a reference to its slight difference in colour pattern from other co-occurring related bumblebee taxa from the mountains of Central Asia (the taxon
margreiteri
is closest to it in Skorikov’s original key).
Taxonomy and variation.
The interpretation of this species is based here on DNA, as well as on the form of the female labrum and of the male genitalia. This disagrees with earlier concepts (
Skorikov, 1931
), diagnosed originally in terms of the hair colour pattern (
Skorikov, 1910b
), because the species appears to be more variable in colour pattern than was originally understood.
All specimens have yellow-banded and none has a white-banded colour pattern.
Skorikov (1910b)
described females of the taxon
defector
from the Alai mountains (MD#3524) as having the corbicula framed with black hairs, with the pale bands yellow, and with the hair on the lower side of the thorax and on the ventral side of the metasoma black. Our COI tree shows that similar specimens but with the hair on the lower side of the thorax yellow, and even some with yellow hair on the ventral side of the metasoma, have very short branch lengths between them and typical
defector
(with the lower side of the thorax black) and these are interpreted as conspecific (
Fig. 13
: the extensively yellow females labeled ‘light’ MD#352, 365, 373, 1246, 1285, 1344, 4024 and females of the darker taxon
defector
s. str
. MD#1251, with the black hair most extensive in the worker ‘dark’ MD#1336). The form of the female labrum is diagnostic (
Fig. 18
).
Skorikov’s illustration of the male genitalia of ‘
Mendacibombus
defector’
(
Skorikov 1931: his fig. 17
) is correctly identified. Males usually have the hair of T3‒7 orange at least in part, but occasionally the hair of T3‒7 is entirely black (
Fig. 13
: the black-tailed male labeled ‘blacktail’ MD#1250, 1256 and the lighter taxon
defector
s. str
. MD#1251).
Diagnostic description.
Wings nearly clear.
Female hair colour pattern:
generally black, but with yellow hair in a large patch below the base of the antenna, in a large patch or almost absent on the vertex of the head, in a transverse band anteriorly on the thoracic dorsum and extending laterally and ventrally to half way down the side of the thorax, or more rarely to the midleg base, in a transverse band posteriorly on the thoracic dorsum (scutellum; so the thoracic dorsum between the wing bases has the hair entirely black), on T1‒2, although T2 with a few black hairs intermixed along the posterior margin, orange hair on T3 as a posterior fringe, and throughout on T4‒6, except T6 dominated medially by long black hairs. Hindleg tibia with corbicular fringes usually uniformly black, but sometimes with a few hairs on the corbicular surface and in the adjacent fringes orange, or rarely the fringes predominantly orange with black hairs (
Fig. 21
) (
cf.
B. makarjini
,
B. turkestanicus
).
Female morphology:
labrum with the basal depression broad, the transverse ridge narrower medially than the basal depression, in the median fifth gradually subsiding and narrowly interrupted by a longitudinal band of many dense medium punctures overflowing across it from the basal depression (
cf.
B. margreiteri
,
B. turkestanicus
), lateral tubercles with few punctures (
Fig. 18
). Clypeus in its central half with many widely spaced medium punctures (
cf.
B. margreiteri
,
B. turkestanicus
). Hindleg tibia distal edge with the broad spines (rastellum) not continuing onto the posterior edge (
cf.
B. margreiteri
,
B. turkestanicus
).
Male morphology
: genitalia (
Fig. 32
) with the volsella distally rounded (finger-shaped) and curled back dorsally but not anteriorly; 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. Penis-valve inner shoulder located at 0.63× the length of the penis valve from the distal end to the broadest point of the spatha.
Material examined.
77 queens
233 workers
173 males
, from
China
,
Kazakhstan
,
Kyrgyzstan
, and
Tajikistan
(
Fig. 64
:
AMNH
,
IAR
,
ISEAN
,
IZB
,
KUK
,
NHM
,
OLL
, PW,
RMNH
,
ZISP
), with
29 specimens
sequenced (interpretable sequences listed in
Figs. 11–13
).
Habitat and distribution.
Flower-rich alpine and subalpine grassland, at elevations 936‒(2174)‒
3108 m
a.s.l.. A species of the Tian Shan (including the Bogda Shan) and Alai mountains. Compared to
B. turkestanicus
, the distribution of
B. defector
extends further to the east in the Bogda Shan, overlaps broadly in the mid part of the range (the two species often occur together), but extends less far to the south.
Bombus defector
overlaps with
B. margreiteri
in the Tian Shan and the two sometimes occur together.
Food plants.
Williams (1991
, 2011), under the name
B. makarjini
.
Behaviour.
No records (see comments on
B. turkestanicus
).