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 sumatrensis
Bouchard
Figures 11
,
14G
,
15C
,
16F
,
17F
,
22
Cyclosomus sumatrensis
Bouchard, 1903
a:174
.
HOLOTYPE
, sex and present location unknown (see notes below). Type locality:
Indonesia
,
Sumatra
, Palembang.
Andrewes (1930:364)
;
Csiki (1932:1295)
;
Lorenz 2005:452
).
Notes on types and nomenclature.
Andrewes (1930:364)
reported on his study of the unique type of
C. sumatrensis
in the Förster collection, which was housed at that time in the Museum of the Lycée at Mulhouse, Strasbourg (
France
). Our efforts to borrow and study the Bouchard
holotype
were facilitated by Thierry Deuve, who contacted colleagues in several institutions in Strasbourg on our behalf. According to Mary Meister (Zoological Museum of Strasbourg (ZMSC)), the insects from the Lycée at Mulhouse collection were at one time offered to the ZMSC but a transfer was never completed. Efforts to learn whether or not the Mulhouse collection still exists have failed thus far. It seems likely that the collection, including the
holotype
of
C. sumatrensis
, has been lost or destroyed. However, this species is geographically and morphologically distinct enough from other
Cyclosomus
species
that we see no need to designate a
neotype
until the loss of the
holotype
can be confirmed.
FIGURE
11.
Cyclosomus sumatrensis
Bouchard
, dorsal habitus. A. Dark male (Kras, Kediri, East Java, Java, Indonesia); B. Pale male (Taman Negara, Pahang, Malaysia). Scale lines = 1.0 mm.
Diagnosis.
Adults of
C. sumatrensis
can be distinguished from those of other
Cyclosomus
species
in Asia by the following combination of character states: Body size medium for genus, BL males =
7.7 to 8.1 mm
, females =
7.1 to 7.4 mm
; body form (
Fig. 11
) slightly elongate ovoid; pronotum (
Fig. 14G
) relatively narrow (ratio PWM/PL = 2.25 to 2.43), disc piceous to black with lateral pale bands slightly narrower than average for genus, distinctly defined, and slightly narrowed basally, apical angles narrower and less broadly rounded, lateral margins smoothly arcuate, not sinuate near anterior angles; elytra (
Fig. 11
) with pattern of dark maculae more extensively developed and less varied than average for genus, with middle transverse dark band thick and extended from midline at least across interval 8, also onto interval
9 in
some specimens, preapical dark spot present; elytral striae deeply impressed and intervals slightly to moderately 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. 16F
), apical lamella rounded and of medium length in dorsal aspect (
Fig. 17F
); specimen from West
Malaysia
or northern
Indonesia
(
Fig. 22
).
Andrewes (1930)
distinguished members of
C. sumatrensis
from those of
C. flexuosus
on the basis of their smaller size, narrower form, and deeper elytral striae, as well as minor differences in elytral color pattern. He concluded that
C. sumatrensis
was probably a distinct species closely related to
C. flexuosus
, but suggested that additional material might show it to be only a “variety” of the latter. Specimens of
C. sumatrensis
can be confused only with those of
C. flexuosus
, but members of these species are easily distinguished by the setae of the epipleura, which are long only in the humeral and subhumeral regions and progressively and distinctly shorter toward the apex in
C. sumatrensis
specimens but longer throughout the epipleural length in
C. flexusosus
members. Specimens of
C. sumatrensis
are also slightly smaller (
7.1 to 8.1 mm
compared with
8.2 to 9.8 mm
for
C. flexuosus
specimens), and males have the apical lamella of the median lobe longer and narrower in dorsal aspect (compare
Fig. 17F
with
Fig. 17B
).
Habitat distribution.
Unknown, but presumed to be restricted to the sandy shores of medium to large rivers at low elevation, like members of most other species of the genus.
Geographical distribution.
We
have examined a total of
14 specimens
(
six males
and
eight females
) from the following localities:
INDONESIA
:
Java
:
East Java
(
Kediri
,
Kras
[
one female
;
IRSNB
],
[
one female
;
MFNB
],
[
five males
and
three females
;
NHMUK
],
[
one female
;
NHRS
])
;
Sumatra
:
Bengkulu
(
Mana
[“
Manna
”] 1902,
M. Knappert
collector
[
one female
;
NHMUK
])
;
North Sumatra
(
Deli Serdang
[“
Deli
”], 1894,
W. Reisch
collector
[
one female
;
MFNB
])
.
MALAYSIA
:
Pahang
:
Taman Negara
(
5 January 1992
,
J. Nielsen
collector [
one male
;
CAS
])
.
The known geographical range of
C. sumatrensis
(
Fig. 22
) extends from the Malaysian portion of the Malay Peninsula south to
Sumatra
and
Java
. It was previously known only from
Sumatra
,
Indonesia
and specimens reported here from the Malay Peninsula and
Java
represent new records for these areas.
Geographical variation.
We found slight individual variation (
Figs. 11A, B
) in development of the dark color pattern of the elytra within the largest sample of this species (from Kras,
East Java
). Specimens from all other localities were similar to at least some specimens from that sample, so we recognized no particular geographical variation.
Geographical relationships with other
Cyclosomus
species.
No other congeneric species is known to occur in
Malaysia
or
Indonesia
; and the nearest
Cyclosomus
records are for
C. inustus
, in
Cambodia
, across the Gulf of
Thailand
and more than
800 km
distant to the northeast, and
C. flexuosus
in
Sri Lanka
, across the Bay of Bengal and more than
1600 km
distant to the west.