New Species and New Record of Subterranean Trechine Beetles (Coleoptera: Carabidae: Trechinae) from Southwestern China
Author
Huang, Sunbin
Author
Tian, Mingyi
text
The Coleopterists Bulletin
2015
2015-12-31
69
4
727
733
http://dx.doi.org/10.1649/0010-065x-69.4.727
journal article
10.1649/0010-065x-69.4.727
1938-4394
10106454
Shilinotrechus intricatus
Huang and Tian
,
new species
(
Figs. 1–3
, 6)
Holotype
.
Male.
CHINA
:
Da Dong cave
,
Jiuxiang
,
Yiliang
,
Kunming
,
Yunnan Province
,
25°5′47.12″ N
,
103°23′18.7″ E
,
1727 m
,
7-VII-2013
,
Mingyi Tian
,
Wei Lin
,
Weixin Liu
,
Haomin Yin
and
Sunbin Huang
leg., deposited in
South China Agricultural University
,
Guangzhou
(
SCAU
)
;
Paratypes
:
three males
and
three females
, with same data as holotype
.
Fig. 1.
Shilinotrechus intricatus
, habitus.
Description.
Length
4.52–5.86 mm
(mean
5.12 mm
) including mandibles,
4.20–5.40 mm
(mean
4.76 mm
) excluding mandibles; width
1.70–2.05 mm
(mean
1.85 mm
).
Habitus:
Very similar to
S. fusiformis
. Body fusiform (
Fig. 1
), coloration variable across individuals, ranging from light reddish brown to darker reddish brown.
Head:
Large, subquadrate, slightly wider than long, HL/HW = 0.81–0.97 (mean 0.89), widest approximately at the level of the anterior supraorbital pores; labrum transverse, emarginate, with 6 setae at apical margin; eyeless; clypeus subtrapezoidal, with 4 setae at apical margin; mandibles falcate, acute, right mandible tridentate, left mandible with 1 serratation
Figs. 2–3.
Shilinotrechus intricatus
, male genitalia.
2
) Lateral view;
3
) Dorsal view.
or none; mentum and submentum fused; submentum covered with transverse row of 10 setae; frons convex, frontal furrows arcuate from base of clypeus to posterior supraorbital pores; genae slightly convex, with several short hairs; supraorbital areas convex, with 2 pairs of supraorbital pores; neck wide, with distinct, shallow anterior constriction; antenna slender, filiform, length reaching to 3/5 of elytra, scape as long as pedicel, antennomere 5 longest, antennomeres 6–10 gradually decreasing in length towards terminal antennomere, which is as long as antennomere 8.
Pronotum:
Subtrapezoidal, widest at base (in most specimens, but widest at 1/4 to 1/3 from apex in some individuals), pronotum clearly wider than head, PW/HW = 1.19–1.29 (mean 1.22), PW/PL = 1.25–1.36 (mean 1.32), base much wider than front, PbW/PfW = 1.20–1.29 (mean 1.27); apex feebly curved, front angle small and protruding; basal margin almost straight, hind angle blunt and distinctly reflexed upward; dorsum slightly convex, median line distinctly impressed except in apical and basal part; apical transverse impression faint and uneven; basal area flat and wide at middle, gradually narrowing towards hind angles, basal transverse impression deeply impressed and subangulate at middle. Scutellum indistinct.
Elytra:
Obovate, widest at about the level of 1/3 from base, then gradually narrowed towards apices; much wider and longer than pronotum, EW/PW = 1.64–1.73 (mean 1.69), EL/PL = 3.21–3.71 (mean 3.47), longer than wide, EL/EW = 1.50–1.59 (mean 1.54); basal parts feebly uneven, with pair of basal setiferous pores; shoulders evanescent; sides moderately bordered until 1/2 from base, then gradually narrowed posteriorly and indistinct at the level of preapical dorsal pore, marginal serration feebly clear until 1/2 from base; dorsum gently convex in middle and gradually more steeper towards sides; surface sparsely covered with minute hairs; striae punctate, superficial and evanescent, stria 8 completely absent, intervals flat, interval 3 widest; apical carina sharp, with an apical curved ridge from the site of stria 5 to near suture; chaetatoxal pattern of dorsal pores and marginal umbilicate pores as in
S. fusiformis
.
Ventral surface and legs:
Anal ventrite with pair of marginal setae in male but 2 pairs in female, protarsomere
1 in
male slightly broader than in female.
Male genitalia:
Median lobe markedly different from
S. fusiformis
, shorter and stouter, about 2/9 as long as elytra, falcate and abruptly curved at about 3/7 of length of median lobe, moderately sclerotized (
Figs. 2–3
); basal orifice large; sagittal aileron small, irregular, and heavily sclerotized; inner sac armed with intricate, sclerotized copulatory piece, which is exceptionally enlarged, twisted, and interlaced with itself; in dorsal view, apical orifice large and twisted, with tip of copulatory piece porrect, apical
Fig. 4.
Distribution map of
Shilinotrechus
species.
a = Dagan Dong; b = Da Dong. ♦ =
S. fusiformis
;
·
=
S. intricatus
.
Fig. 5.
Entrance to Da Dong cave, Yunnan Province, China.
F i g. 6.
Adult
Shilinotrechus intricatus
in
Da Dong cave.
lobe absent; parameres thin and elongate, each bearing 6 apical setae.
Remarks.
Shilinotrechus intricatus
is very similar to
S. fusiformis
, but is distinguished from the latter by the arcuate frontal furrows of the head (straight in
S. fusiformis
); inner sac of aedeagus armed with an intricate copulatory piece, which is exceptionally enlarged, twisted, and interlaced (simple in
S. fusiformis
); apical orifice larger and twisted in dorsal view (smaller and less twisted in
S. fusiformis
); each paramere bearing six apical setae (only four in
S. fusiformis
).
Etymology.
The species epithet “
intricatus
” refers to the complicated structure of the copulatory piece in the male genitalia.
Fig. 7.
Sichuanotrechus dakangensis
, habitus.
Distribution.
Known only from the
type
locality, Da Dong cave in Jiuxiang, Yiliang, Kunming,
Yunnan Province
,
China
(
Fig. 4
). Da Dong is located at the base of a limestone mountain, with a large entrance (
Fig. 5
) and a main passage. It is moist and decorated by beautiful columns, helictites, and cave flowers. The trechine beetles were collected on substrate or cave walls. The cave holds a rich fauna. Apart from
S. intricatus
(Fig. 6), there are other cave animals living in the cave, such as millipedes, crickets, harvestmen, snails, moths, centipedes, leeches, and spiders.
Description.
Length:
5.42–5.92 mm
(mean
5.72 mm
) including mandibles,
5.06–5.53 mm
(mean
5.34 mm
) excluding mandibles; width:
1.80–1.95 mm
(mean
1.86 mm
).
Habitus:
Body stout; dark reddish brown (
Fig. 7
).
Head:
Fairly large, slightly longer than wide, HL/HW = 1.04–1.08 (mean 1.07), widest between levels of supraorbital pores, little more nearer to posterior supraorbital pore in distance than in
S. albidraconis
; labrum transverse, slightly emarginate at apex, with 6 setae; clypeus transverse, with 4 setae at about 3/7 from