A Review of Genus Cyclosomus Latreille (Coleoptera: Carabidae: Lebiinae: Cyclosomini) in Asia.
Author
Kavanaugh, David H.
Department of Entomology, California Academy of Sciences, 55 Music Concourse Drive, Golden Gate Park, San Francisco, CA 94118.
Author
Cueva-Dabkoski, Mollie
Student Science Fellow, California Academy of Sciences, San Francisco, and & 2355 Pearl Street, Santa Monica, CA 90405.
text
Proceedings of the California Academy of Sciences
2023
2023-02-15
67
21
493
537
journal article
299696
10.5281/zenodo.11512952
2b56e3b0-2274-4963-b243-9c991b07072c
0068-547X
11512952
Cyclosomus suturalis
(Wiedemann)
Figures 12
,
14H
,
16G
,
17G
,
18B
,
22
Scolytus suturalis
Wiedemann, 1819:169
.
LECTOTYPE
, here designated, a male, in
ZMUC
, labeled: “Type” [red label]/ “Bengala Westermann flexuosus F. suturalis Wied.” [handwritten]/ “
ZMUC
00022690”/ “
LECTOTYPE
Scolytus suturalis
Wiedemann 1819
design. by D.H. Kavanaugh & M. Cueva-Dabkoski 2023” [red label].
Paralectotypes
examined:
1 male
, also in
ZMUC
, labeled: “Mus. Westerm.”/ “TYPE” [red label]/ “
S. flexuosus
var.
S. suturalis Wied. Bengal
May 1809
” [handwritten]/
PARALECTOTYPE
Scolytus suturalis
Wiedemann 1819
design. by D.H. Kavanaugh & M. Cueva-Dabkoski 2023” [yellow label]/ “
Cyclosomus marginatus
Motschulsky
det. D.H.
Kavanaugh 2023
”.
Type
locality: “Bengal” [area which now includes
West Bengal
(eastern
India
) and
Bangladesh
].
Cyclosomus flexuosus
,
Chaudoir 1876:32
.
Cyclosomus suturalis
(Wiedemann)
,
Chaudoir (1876:32)
;
Andrewes (1921:166
,
1924:464
);
Csiki
(1932:1295);
Lorenz (2005:452)
.
Notes on types and nomenclature.
Chaudoir (1876:32)
considered
C. suturalis
as a junior synonym of
C. flexuosus
, but
Andrewes (1921:166)
confirmed its status as a distinct species. In that same paper, Andrewes recognized
C. marginatus
as a junior synonym of
C. suturalis
. This difference of opinion between these two superb taxonomists can possibly be explained by the fact that the type series of
C. suturalis
includes
two specimens
, which are not, in our view, conspecific. Thus, they may have examined different specimens in making their assessments. The male specimen that we have selected as
lectotype
actually resembles some small male specimens of
C. flexuosus
in size and elytral color pattern. The female specimen we designate as
paralectotype
appears to be a specimen of
C. marginatus
, with the size and elytral color pattern matching the
lectotype
of that species. If Chaudoir had studied the male specimen and Andrewes the female specimen, their respective opinions are quite understandable. Because of variation in elytral color pattern seen in each of these species, Wiedemann’s original description is insufficient to distinguish between specimens of
C. flexuosus
,
C. marginatus
, and
C. suturalis
. By selecting the male specimen as
lectotype
of
C. suturalis
, we are able to recognize Motschulsky’s
C. marginatus
as the valid name for a distinct species (see above). If we had chosen the female specimen as
lectotype
, then
C. marginatus
would have remained a junior synonym of
C. suturalis
and the male specimen would represented a new species currently without a name.
Diagnosis.
Adults of
C. suturalis
can be distinguished from those of other
Cyclosomus
species
in Asia by the following combination of character states: Body size medium to large for genus, BL males =
8.2 to 9.1 mm
, female =
9.2 mm
; body form (
Fig. 12A, C
) slightly elongate ovoid; pronotum (
Fig. 14H
) relatively broader (ratio PWM/PL = 2.44 to 2.50), disc rufopiceous to black, lateral pale bands well-defined, slightly narrowed at least in apical half and broadened basally, apical angles slightly narrowed and less broadly rounded, lateral margins smoothly arcuate, not sinuate near anterior angles; elytra with pattern of dark maculae less varied, with middle band of average (
Fig. 12A
) to distinctly greater than average (
Fig. 12C
) thickness for the genus and extended from midline to interval
6 in
most specimens, onto interval 7 and part of interval
8 in
some specimens, preapical dark spot present, striae deeply impressed and intervals flat or slightly convex; elytral epipleura with long setae only in humeral and subhumeral areas, setae in apical two-thirds distinctly shorter; male median lobe with apical lamella extended in line with ventral curvature of shaft in lateral aspect (
Fig. 16G
), apical lamella short and bluntly triangular in dorsal aspect (
Fig. 17G
); specimen from eastern
India
to westernmost Yunnan (
Fig. 22
).
Specimens of
C. suturalis
are most similar to those of
C. acutangulus
and atypical specimens of
C. inustus
that have the elytral preapical dark spot present. Refer to the key and Diagnosis sections for each of those species for distinguishing features.
Habitat distribution.
Specimens from
Yunnan
were collected at night on the upper sandy banks of the Longchuan River (
Fig. 18B
) at an elevation of
734 m
(H.B Liang, personal communication).
Geographical distribution.
Fig. 22
. We examined a total of
seven specimens
(
four males
and
three females
) from the following localities:
CHINA
:
Yunnan
:
Mangshi
,
Zhefang Township
(
Longchuan Jiang
at
Nongkan village
, 24.16534°/98.10266°,
734 m
,
22 May 2020
,
H.B. Liang
and
Y. Xu
collectors
[
two males
and
two females
;
IOZ
])
.
BANGLADESH
/
INDIA
: “
Bengala
” ([
one male
;
ZMUC
])
.
BANGLADESH
/
INDIA
/
MYANMAR
: “India Or.” ([
one female
;
MNFB
])
.
INDIA
:
Sikkim
:
Melli
(
Teesta River valley
,
240 m
,
14 October 1918
,
H. Stevens
collector [
one male
;
NHMUK
])
.
This species ranges from the
type
area, “Bengala” or “Bengal” (no specific locality), which includes present-day eastern
India
and/or
Bangladesh
, at least to westernmost Yunnan Province,
China
.
The
westernmost confirmed limit of the species is in
Sikkim
and the easternmost limit in western Yunnan.
Andrewes’
records from northern
India
(
Andrewes 1921
) may have been based on misidentified specimens of
C. vespertilio
, which is described below.
Geographical variation.
We found some individual variation (
Figs.12A, C
) in development of the dark color pattern of the elytra within the sample of this species from Mangshi,
Yunnan
,
China
. Specimens from all other localities were similar to one or more of the specimens from that sample, so we recognized no particular geographic variation.
FIGURE
12.
Cyclosomus suturalis
(Wiedemann)
. A.
Scolytus suturalis
Wiedemann
, lectotype male, dorsal habitus; B. Labels associated with lectotype; C. Dark male ((Longchuan Jiang at Nongkan village, Zhefang Township, Mangshi, Yunnan, China). Scale lines = 1.0 mm.
Geographical relationships with other
Cyclosomus
species
.
Because of the uncertainty with regard to where the exactly the
type
specimen was collected in “Bengala”, the northwestern limits to the range of this species remain unclear.
Cyclosomus marginatus
is also known only from the similarly vague “
India
Or.,” again without specific locality, so it is possible that these species co-occur or at least overlap in their geographical ranges. Whether or not the range of
C. suturalis
overlaps those of
C. flexuosus
and/or
C. vespertilio
cannot yet been confirmed. The range of
C. inustis
approaches that of
C. suturalis
at least in northern Indochina so there is at least potential for co-occurrence of these species, although the two have not yet been found near each other.