Hydraena porchi, Published, 2007

PERKINS, PHILIP D., 2007, A revision of the Australian species of the water beetle genus Hydraena Kugelann (Coleoptera: Hydraenidae), Zootaxa 1489 (1), pp. 1-207: 19-20

publication ID

http://doi.org/ 10.11646/zootaxa.1489.1.1

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scientific name

Hydraena porchi

new species

Hydraena porchi   new species

( Figs. 14 View FIGURES 11–14 , 23 View FIGURES 23–26 , 211, 228, 259)

Type Material. Holotype (male): Victoria, Kangaroo Creek on Springhill Rd. , 5.8 km E Glenlyon, elev. 510 m, amongst weeds in shallow water at edge of creek (perennial) pools, dry sclerophyll forest, 37° 18' S, 144° 18' E, 31 January 1999, N. Porch (NP 24a). Deposited in the ANIC GoogleMaps   . Paratypes: Same data as holotype (31 ANIC) GoogleMaps   .

Differential Diagnosis. Externally most similar to H. millerorum   ; differing therefrom by the denser and smaller dorsal punctation, the slightly smaller elytra, and the less deeply impressed pronotal foveae PF2 ( Figs. 14 View FIGURES 11–14 , 19 View FIGURES 19–22 ). The most reliable determinations will be based on examination of the aedeagi of the two species ( Figs. 23, 24 View FIGURES 23–26 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.52/0.59; head 0.25/ 0.35; pronotum 0.36/0.46, PA 0.38, PB 0.39; elytra 0.91/0.59. Dorsum dark brown, legs and maxillary palpi brown, tip of last palpomere not darker.

Frons punctures ca. 1xef; interstices shining, 1–2xpd. Clypeus microreticulate laterally, finely sparsely punctate medially. Mentum shining, very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotal punctures on disc ca. 2xpd and deeper those of frons, interstices shin- ing, ca. 1xpd anteriorly and posteriorly, ca. 2–3xpd on disc; PF1 and PF4 absent; PF2 moderately deep, oblique; PF3 moderately deep, broad. Anterior margin of pronotum broadly emarginate.

Elytral punctures about equal size of largest pronotal punctures. Intervals not raised, shining, width about 1xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly moderately sharply rounded, in posterior aspect margins do not form angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/2/7/4. P1 laminate; median carina angulate in profile. P2 narrow, l/w ca. 5/2, sides parallel, apex blunt. Plaques almost parallel, not raised, located on each side of deep depression. No midlongitudinal carina between mesoventral intercoxal process and plaques. Carina behind mesocoxae strong. AIS flat, width at arcuate posterior margin ca. 2x P2. All femora thickened. Protibia (male) widest at midlength, excavate on inner surface, prominent spine at beginning of excavation; mesotibia simple; metatibia nearly straight, very weakly emarginate on inner surface over distal 3/4. Last sternite symmetrical; last tergite with small, slightly off-center notch.

Aedeagus ( Fig. 23 View FIGURES 23–26 ) main-piece with distal extended part arcuate, tapering to a fimbriate tip, continuing slightly above and beyond distal piece; distal piece with two lobes of about equal size, the left with a process near the base (ventral view), the right with the apex blunt and expanded (lateral view); left paramere slender, straight, about twice as long as right paramere, with cluster of about five setae on inner margin near apex; right paramere very slightly arcuate, with setae in two groups at weakly widened apex, all setae about equal in length. Female last tergite with apicomedian incision delimiting two lobes, setae slender, tapering; gonocoxite and spermatheca as illustrated (Figs. 211, 228).

Etymology. Named in honor of the collector, Nicholas Porch.

Distribution. Currently known only from the type locality in Victoria (Fig. 259).


Australian National Insect Collection