A review of the Neotropical genus Diochus ERICHSON, 1840 (Coleoptera: Staphylinidae: Staphylininae)
Author
Irmler, Ulrich
text
Beiträge Zur Entomologie = Contributions to Entomology
2017
2017-06-30
67
1
1
62
journal article
10.21248/contrib.entomol.67.1.001-062
0005-805X
5212522
6526DDDB-7F27-41AC-8575-AF3C28A4177C
Diochus vicinus
SHARP, 1876
Figs 10A–C
,
39D
,
43C
Diochus vicinus
SHARP, 1876: 185
Diochus flavicans
SHARP, 1876: 185
new synonymy
Type material examined
:
1 female
,
Brazil
:
Pará
,
Tapajos
(
BMNH
)
;
2 female
syntypes
of
D. flavicans
,
Brazil
:
Pará
,
Tapajos
(
BMNH
)
.
Further material examined
:
Colombia
:
Vichada
, PNN
El Tuparro
,
Cerro Tomás
(
67°51'W
,
5°21'N
),
140 m
elev.,
Malaise trap
, male, 22.5.–
3.6.2001
, leg.
I. Gill
(
KNHM
)
;
Brazil
:
Amazonas
,
Ilha de Marchanteria
(
59°58'W
,
3°15'S
),
Varzéa
, floating meadow,
3 males
,
16.2.1982
,
22.1.1982
, leg.
J. Adis
(
UIC
)
;
Ilha Muratú
(
60°21'W
,
3°34'S
),
2 females
,
25.2.1975
, leg.
U. Irmler
(
UIC
)
;
Roraima
, mouth of
Rio Branco
,
Lago Adauaú
(
61°51'W
,
1°19'S
), male,
22.8.1971
, leg.
U. Irmler
(
UIC
)
;
Pará
,
5 km
E Belém
, soil litter layer, in primary terra firme forest, male,
30.5.1973
, leg.
R.T. Schuh
(
AMNH
)
;
IPEAN, from litter in “
Mocambo
”, male,
3.7.1973
, leg.
R.T. Schuh
(
AMNH
)
;
Mato Grosso
,
Barra de Tapirapé
, at light,
4 males
,
1 female
,
15.12.1960
, leg.
B. Malkin
(
FMNH
)
;
male, same location, same collector, but 1.–
11.1.1963
(
FMNH
)
;
Peru
:
Loreto
,
Lake Yarinachocha
,
10 km
NW Pucallpa
,
150 m
elev., collected at light, male,
27.12.1971
, leg.
R.T. Schuh
(
AMNH
)
;
Madre de Dios
,
Tambopata
, male,
26.10.1982
, leg.
L.E. Watrous
,
G. Mazurek
(
FMNH
)
.
Diagnosis
: In size, colouration and length of antennae,
D. vicinus
resembles
D. inornatus
and
D. hanagarthi
. The EL: HL is 0.24, slightly shorter than in
D. hanagarthi
, separates both species from
D. inornatus
with longer temples (EL: HL = 0.21). Moreover, the antennae are slightly longer than
in
D. hanagarthi
and
D. inornatus
. The species can be easily separated from the other
Diochus
species
by the elongate hooked apical process of the paramere. Unfortunately, the
two syntypes
of
D. flavicans
are females. As I found no significant differences to
D. vicinus
,
D. flavicans
is synonymised to
D. vicinus
.
Description
: Length:
4.3 mm
. Colouration: head and pronotum totally yellow-brown; elytra light brown with dark transverse spot in anterior half on each side of suture; abdomen darker than fore-body, but posterior margin of segments as light elytra; legs yellow; antennomeres 1, 2, and 11 yellow; antennomeres 4–10 darker, brown.
Head:
0.46 mm
long,
0.40 mm
wide; eyes slightly prominent; moderately large; temples 2.5 times as long as eyes; EL: HL = 0.24; temples slightly divergent posteriad; PW: EW 1.14; posterior angles nearly rectangular; sharply rounded; clypeus widely rounded; neck one third as wide as head; inter-ocular space and clypeus densely and deeply punctate; wide midline impunctate; on average, interstice between punctures as wide as or slightly shorter than diameter of setiferous punctures; on average, setae distinctly longer than interstices; on vertex sparsely punctate; large area without punctures; laterad densely punctate; surface without microsculpture; shiny.
Antennae slightly longer than head and half of pronotum combined; first to third antennomere distinctly longer than following antennomeres; nearly twice as long as wide; fourth to eleventh antennomeres approximately quadrate; first antennomere with long thick setae; fourth to eleventh antennomere pubescent;.
Pronotum:
0.54 mm
long,
0.49 mm
wide; widest close to posterior margin; slightly narrowed to anterior margin, but nearly parallel; posterior and anterior angles widely rounded; sides finely margined; in dorsal aspect, margin covered in anterior half; setiferous punctures large, but sparse; on average, interstices between punctures twice as wide as diameter of punctures; on each side of impunctate midline with 3–4 setiferous punctures in longitudinal line; without microsculpture, but indistinct extremely weak ground sculpture; surface shiny.
Elytra:
0.67 mm
long,
0.67 mm
wide; sides divergent to posterior margin; posterior angles and shoulders widely rounded; shoulders obtuse; setiferous punctures in longitudinal lines; setae pointing posteriad; interstices between punctures of lines and between lines at least two to three times as wide as diameter of punctures; surface with indistinct weak ground sculpture; shiny.
Abdomen densely pubescent and matt in contrast to fore-body.
Aedeagus with seminal vesical slightly longer than half of total length of central lobe; basal inner duct looped; apical inner duct with large coil; paramere narrow at base; slightly widened to apex; not projecting apex of central lobe; with long asymmetric acute process at apex with short apical hook.
Spermatheca
0.47 mm
long,
0.21 mm
wide; bursa copulatrix in central position of coiled oval duct; coiled duct widest in anterior half; narrowed at middle and slightly widened in posterior half.