On the Lathrobium fauna of Japan (Coleoptera: Staphylinidae: Paederinae)
Author
Assing, V.
text
Linzer biologische Beiträge
2013
2013-12-20
45
1
1615
1641
journal article
55790
10.5281/zenodo.5303069
ea43a301-d225-4ca2-835f-3e6515240025
0253-116X
5303069
Lathrobium biexcisum
nov.sp.
(
Figs 7-12
)
Type material
Holotype
: "
Gumma
Pref.,
Nikko
distr., L. Maranuma [recte: Marunuma] /
1430-1500 m
., 11-12.viii.80 /
JAPAN
:
Honsu
, B.M. 1980-492,
P.M. Hammond
/ Holotypus
Lathrobium biexcisum
sp.n.
, det.
V. Assing
2013" (
BMNH
).
Etymology: The specific epithet (adjective) alludes to the posterior excisions of both the male sternite VII and the male sternite VIII.
Description: Species of large size; body length
11.5 mm
; length of forebody
5.1 mm
. Habitus as in
Fig. 7
. Coloration: body dark-brown; legs reddish; antennae reddish.
Other external characters (
Fig. 8
) as in
L. pollens
.
Figs 7-12
:
Lathrobium biexcisum
nov.sp.
: (
7
) habitus; (
8
) forebody; (
9
) male sternite VII; (
10
) male sternite VIII; (
11-12
) aedeagus in lateral and in ventral view. Scale bars: 1.0 mm.
: protarsomeres I-IV strongly dilated; tergite VIII with very weakly convex posterior margin; sternites III-VI unmodified; sternite VII (
Fig. 9
) distinctly transverse, posteriorly with pronounced median impression, this impression with moderately dense black setae; posterior margin with distinct and broad concavity in the middle, lateral margins of this concavity furnished with dense and long dark setae; sternite VIII (
Fig. 10
) weakly transverse, posterior excision of nearly semi-circular shape, margin of this excision and posterior median impression furnished with dense dark setae, posterior margin on either side of posterior excision acutely produced; aedeagus (
Figs 11-12
)
2.5 mm
long and symmetric; ventral process slender, weakly curved in lateral view, subapically abruptly narrowed, and apically needle-shaped, ventrally with pair of long and pronounced carinae; dorsal plate very long, slender, lamellate, and apically acute, basal portion longer than apical portion; internal sac without sclerotized structures.
: unknown.
Comparative notes: The similar external and the similarly derived male sexual characters suggest that
L. biexcisum
is closely allied to
L. pollens
, from which it is distinguished by the less deep posterior excision of the male sternite VII and by the different shape of the slightly smaller aedeagus. The aedeagus is most similar to that of
L. nasuense
WATANABE 1992
, which was described from the environs of Nasu in the northeast of
Tochigi Prefecture
. From this species,
L. biexcisum
differs by the broader posterior excision of the male sternite VIII and by the different shape of the ventral process of the aedeagus in lateral view (straight basal portion shorter).
Distribution: The
type
locality is situated in the northeast of
Gunma Prefecture
, Honshu, at an altitude of
1430-1500 m
.