A revision of the Australian species of the water beetle genus Hydraena Kugelann (Coleoptera: Hydraenidae)
Author
PERKINS, PHILIP D.
text
Zootaxa
2007
2007-05-31
1489
1
1
207
http://dx.doi.org/10.11646/zootaxa.1489.1.1
journal article
10.11646/zootaxa.1489.1.1
11755334
5087337
97D649AF-D141-4FBF-9729-192718525E87
Hydraena innuda
new species
(
Figs. 13
,
17
, 259)
Type Material.
Holotype
(male):
Western Australia
,
Mitchell Plateau
,
16 mi.
N Amax Camp
, in spring pool drainage over basalt road,
14° 46' S
,
125° 47' E
,
21 October 1976
,
J. Kethley
(112).
Deposited
in the
ANIC
.
Paratypes
(9):
Western Australia
,
14 km
SbyE
Kalumburu Mission
,
CALM
Site
4/3 [Western Australian Department of Conservation and Land Management], at light, open forest,
14° 25' S
,
126° 40' E
,
3–6 June 1988
,
T
.
A.
Weir
(3
ANIC
);
Mitchell Plateau
,
16 mi.
N Amax Camp
, in spring pool drainage over basalt road,
14° 46' S
,
125° 47' E
,
21 October 1976
,
J. Kethley
(112) (2
ANIC
);
Synnot Ck.
,
CALM
Site
25/1 [Western Australian Department of Conservation and Land Management], at light, closed forest margin,
16° 31' S
,
125° 16' E
,
17–20 June 1988
,
T
.
A.
Weir
(4
ANIC
)
.
Differential Diagnosis.
Similar in small size and color to
H
.
magnetica
and
H
.
miniretia
; differing therefrom by the narrower body form, the nearly quadrate pronotum, and the lack of plaques (
Figs. 11–13
). The aedeagus of
H
.
innuda
differs distinctively from that of the compared species (
Figs. 15–17
).
Description.
Size (length/width, mm)
holotype
: body (length to elytral apices) 1.16/0.48; head 0.19/ 0.30; pronotum 0.28/0.37, PA 0.33, PB 0.34; elytra 0.68/0.48. Head and pronotal disc piceous, margins of pronotum and elytra dark brown, legs and maxillary palpi brown.
Frons finely sparsely punctate, punctures distinctly smaller than 1xef; interstices strongly shining, 2– 6xpd. Clypeus shining and nearly impunctate in midline, finely sparsely punctate laterally. Mentum and postmentum dull, microreticulate. Genae raised, lacking posterior ridge. Pronotal punctures on disc ca. 1xef, interstices shining, 2–3xpd, punctures slightly denser anteriorly and posteriorly, interstices ca. 1xpd; PF1 and PF4 absent; PF2 very shallow, almost absent; PF3 shallow.
Elytral punctures about equal size of largest pronotal punctures. Intervals not raised, shining, width about 1–2xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins form very weak or no angle with one another.
Plaques absent. P1 laminate; median carina angulate in profile. P2 moderately narrow, l/w ca. 2/1, sides parallel, apex blunt. Metaventral depression deep. AIS flat, width at arcuate posterior margin slightly less than 2x P2. Legs simple, tibiae slender. Last sternite and last tergite simple, symmetrical.
Aedeagus (
Fig. 17
) main-piece in ventral view only slightly wider distally than at base, in lateral view markedly angulate; right side of main-piece produced in large process; distal piece comparatively simple, with dorsal lobe covered in small tubercles; parameres simple, about equal in length, setae rather long, not divided into distinct groups. Female last tergite with apicomedian incision delimiting two lobes, setae slender, tapering.
Etymology.
Named in reference to the lack of plaques.
Distribution.
Currently known from northern
Western Australia
(Fig. 259).