The Neotropical species of the genera Pseudespeson L, 1994 and Espeson S, 1882 (Coleoptera: Staphylinidae: Osoriinae)
Author
Irmler, U.
text
Beiträge Zur Entomologie = Contributions to Entomology
2012
2012-12-20
62
2
331
360
journal article
6439
10.21248/contrib.entomol.62.2.331-360
4e2d6f56-fddc-4e28-bfd5-065db656475d
0005-805X
4812872
Espeson mexicanus
FAUVEL
, 1902:37
(
Figs 4
a-e, 17C)
Type
material examined:
Mexico
:
1 female
, without further data (
holotype
,
IRSNB
)
Additional material examined:
Mexico
:
Prov.
Veracruz
,
1 mi.
S Huatusco
(
96°57'W
,
19°8'N
),
Berlese
extraction,
1344 m
elevation,
45 specimens
,
2.8.1969
, leg.
S. & J. Peck
(
AMNH
,
UIC
)
.
Diagnosis:
The species resembles
E. simplex
,
E. franiae
,
E. dybasi
, and
E. hermani
in the darker reddish colouration and it size of at least 2.0 mm. It can be differentiated from the similarly large
E. hermani
by the position of the pronotal impression. In
E. mexicanus
the longitudinal impression is placed in the posterior half and drop-shaped, whereas in
E. hermani
the longitudinal impression is placed in the anterior half. Moreover, the elytra in
E. hermani
are lighter red than head and pronotum, whereas no different colouration between head, pronotum, and elytra is found in
E. mexicanus
. In males, tergite VIII and aedeagus distinctly differ between the two species.
E. simplex
,
E. dybasi
, and, in particular,
E. franiae
are larger with at least
2.3 mm
length. In
E. simplex
a pronotal impression is absent, in
E. dybasi
and
E. franiae
the pronotal impression is placed also in the posterior half, but with a circular shape.
Description:
Length
: 2.0 mm.
Colour
: dark reddish, elytra dark yellow, antennae and legs yellow.
Head
:
0.28 mm
long,
0.36 mm
wide; eyes 0.3 times longer than temples; temples smoothly rounded; punctation dense and deep; distance between punctures half as wide as diameter of punctures; a space in the middle of disc without punctures; without microsculpture; surface polished.
Antennae
as long as head and pronotum combined; 2
nd
and 3
rd
antennomeres equal in length; following antennomeres quadrate and slightly increasing in width; 8
th
antennomere slightly smaller than preceding and following antennomeres.
Pronotum
:
0.30 mm
long,
0.38 mm
wide; distinctly emarginate in front of posterior edge; sides in front of emargination smoothly rounded; widest in anterior third; 0.3 times wider than at posterior angles; punctation deep and dense; on average distance between punctures half as wide as diameter of punctures; at posterior edge with coriaceous punctation; a longitudinal impression in the anterior half; with sparse and weak microsculpture; surface shiny.
Elytra
:
0.48 mm
long,
0.53 mm
wide; punctation similar as on pronotum; without microsculpture; surface polished.
Abdomen
with sparser and finer punctation as on elytra, but microsculpture more distinct; surface less shiny than on elytra; abdominal tergite VIII slightly narrowed posteriad and with undulate straight edge; with few longer setae among sparse pubescence.
Aedeagus
with slender, more or less straight apical part placed in obtuse angle to basal part of central lobe; paramera thick and long with large apical transparent plate; diameter of apical plate nearly as long as length of apical segment of paramera.