On the Palaearctic and Oriental species of Scymbalium and Micrillus (Coleoptera: Staphylinidae: Paederinae)
Author
Assing, V.
text
Linzer biologische Beiträge
2013
2013-12-20
45
2
1479
1520
journal article
55748
10.5281/zenodo.5301289
55b2b0bc-d79f-48e3-8be1-81424185dea7
0253-116X
5301289
Micrillus suturalis
(
CAMERON
1930)
,
nov.comb.
(
Figs 48-55
,
Map 3
)
Scimbalium
[sic]
suturale
CAMERON 1930: 155
.
Scimbalium javanicum
CAMERON 1936b:
53
f.;
nov.syn.
Scimbalium
(
Schatzmayria
)
borneense
CAMERON 1941: 230
;
nov.syn.
Type material examined
S. suturale
:
Holotype
: "
Malay Penin.
,
Kedah
,
Alor Star
, /
March 30th 1928
. /
Scimbalium suturale Cam.
Type / Type / M. Cameron. Bequest. B.M. 1955-147. / Holotypus
Scymbalium suturale Cameron
, rev. V. Assing 2013 /
Micrillus suturalis (Cameron)
, det.
V. Assing
2013" (
BMNH
).
S. javanicum
:
Holotype
: "F. C. Drescher, Preanger, Bandoeng [today Bandung] Dago,
22.III.1929
/
Java
:
F.C. Drescher
, B.M. 1934.-264. /
Scimbalium javanicum Cam.
Type / Type / Holotypus
Scymbalium javanicum Cameron
, rev.
V. Assing
2013/
Micrillus suturalis (Cameron)
, det.
V. Assing
2013" (
BMNH
).
S. borneense
:
Holotype
: "Pontianak, Borneo /
S. borneense Cam.
Type / Type /
M. Cameron. Bequest.
B.M. 1955-147. / Holotypus
Scymbalium borneense Cameron
, rev.
V. Assing
2013 /
Micrillus suturalis (Cameron)
, det.
V. Assing
2013" (
BMNH
).
Additional material examined:
Thailand
: 1,
Bangkok
(BMNH).
Comment: The original description of
Scymbalium suturale
is based on a unique
holotype
from "Malay Peninsula.
Kedah
; Alor Star" (
CAMERON 1930
).
The
specimen, unfortunately a female in rather poor condition, was located in the
Cameron
collection at the BMNH.
The original description of
S. javanicum
is based on a unique
holotype
from "Bandoeng Dago, Preanger" (Java) (
CAMERON 1936b
), that of
S. borneense
on a unique
holotype
from "W. Borneo: Pontianak" (
CAMERON 1941
). Both
holotypes
were located in the Cameron collection at the BMNH. In the description of
S. borneense
,
CAMERON (1941)
compares the species with
Scymbalium suturale
CAMERON 1930
from
Malaysia
, but there is no reference to
S. javanicum
. An examination of the type material, however, revealed that both
holotypes
are undoubtedly conspecific; the male primary and secondary sexual characters are identical (
Figs 52-55
), and no significant external differences were found either.
The types of
S. javanicum
and
S. borneense
are distinguished from the
holotype
of
S. suturale
only by the more pronounced microsculpture on the pronotum. However, the additional specimen seen from
Thailand
is intermediate in this respect. Since no additional evidence was found suggesting that
S. javanicum
represents a distinct species, both
S. javanicum
and
S. borneense
are placed in synonymy with
S. suturale
. Based on the undilated protarsomeres I-IV,
S. suturale
is moved to
Micrillus
.
Redescription: Body length 6.5-7.0 mm, length of forebody
3.5-3.6 mm
. Habitus as in
Fig. 48
. Coloration: head blackish; pronotum and elytra dark-brown to blackish-brown, except for the narrowly and indistinctly dark-reddish posterior margins and suture of the elytra; abdomen blackish, with the paratergites, the posterior margins of segments III-VI, the posterior portion of segment VII, and segments VIII-X dark-reddish; legs and antennae pale reddish-brown.
Head (
Figs 49-50
) approximately 1.1 times as long as broad and with subparallel lateral margins; posterior angles moderately marked; punctation extremely fine, sparse, and barely noticeable in median dorsal portion, dense and more distinct in posterior and lateral portions; interstices with shallow microsculpture. Eyes slightly more than half the length of postocular region in dorsal view. Antennae slender, approximately
3 mm
long; antennomeres IV-XI distinctly oblong; antennomere X approximately 1.5 times as long as broad.
Pronotum (
Figs 49-50
) 1.11-1.14 times as long as broad and 1.05-1.09 times as broad as head; general shape rather variable: widest near anterior angles and converging posteriad from anterior fourth or with subparallel lateral margins in anterior half (dorsal view); posterior margin weakly to distinctly concave; punctation fine and very dense; interstices with microsculpture.
Elytra (
Figs 49-50
) 0.91-0.94 times as long as pronotum; surface matt and with microsculpture; punctation extremely fine and dense. Hind wings fully developed. Metatarsomere I longer than the combined length of II and III, but at least slightly shorter than the combined length of II-IV. Protarsomeres I-IV not distinctly dilated.
Abdomen narrower than elytra; punctation dense and rather fine; anterior tergites with distinct, posterior tergites with shallow to indistinct microsculpture; posterior margin of tergite VII with palisade fringe.
: sternite VIII (
Fig. 51
) strongly oblong, posterior excision broad and moderately deep; aedeagus (
Figs 52-55
) approximately
1.3 mm
long, slender, distinctly asymmetric, and with conspicuously shaped spines in internal sac.
Comparative notes: This species is readily distinguished from other
Micrillus
species known from the
Oriental region
by distinctly larger body size, darker coloration, and by the completely different morphology of the aedeagus (much larger, more slender, internal sac with series of strongly sclerotized spines).
Figs 56-62
:
Scymbalium badium
(MOTSCHULSKY)
, lectotype (
56-60
) and
S. nepalense
nov.sp.
, holotype (
61-62
): (
56
) forebody; (
57, 61)
median dorsal portion of head; (
58, 62
) male sternite VIII; (
59-60
) aedeagus in lateral and in ventral view. Scale bars: 56: 1.0 mm; 58, 62: 0.5 mm; 59- 60: 0.2 mm; 57, 61: 0.1 mm.
Figs 63-66
:
Scymbalium nepalense
nov.sp.
, holotype: (
63
) habitus; (
64
) male sternite VIII; (
65-66
) aedeagus in lateral and in ventral view. Scale bars: 63: 1.0 mm; 64: 0.5 mm; 65-66: 0.2 mm.
Distribution and natural history:
Micrillus suturalis
is apparently widespread, but not common in the Oriental region. It is currently known from Java, Borneo, Peninsular
Malaysia
, and
Thailand
(
Map 4
).