Potamophilinus Grouvelle, 1896

Barr, Cheryl B. & Shepard, William D., 2021, A review of the Larainae of Australia with description of seven new species and the new genus Australara (Coleoptera, Byrrhoidea, Elmidae), ZooKeys 1073, pp. 55-117 : 55

Genus Potamophilinus Grouvelle, 1896

Type species.

Potamophilus longipes Grouvelle, 1892.

Differential diagnosis.

Pronotum with a wide, U-shaped, transverse impression at the anterior third, without basal sublateral carinae; pronotal posterior angles blunt, not distinctly bidentate; elytral apices angulate; prosternal process carinate, broad between procoxae, abruptly narrowed and spinose between mesocoxae, acuminate apically; apices of metatibiae exceeding apices of elytra; abdominal ventrites 1+2 longer than 3+4+5, ventrite 1 very long, ventrite 2 long, ventrites 3-5 each very short, loosely fitted to epipleura. Potamophilinus is easily differentiated from all other Australian laraine genera by the above characteristics of the pronotum, elytral apices and prosternal process. Although Potamophilus Germar and Parapotamophilus Brown have not been reported from Australia, like Potamophilinus they occur in Papua New Guinea and therefore are being included here in the generic diagnosis. Potamophilus differs by having the pronotal posterior angles acute, distinctly bidentate; elytral apices acute, divergent; apices of metatibiae just reaching apices of elytra; abdominal ventrites 1+2 shorter than ventrites 3+4+5. Parapotamophilus has the pronotum without a transverse impression; elytral apices rounded; prosternal process broad, not spinose; abdominal ventrites 1+2 shorter than ventrites 3+4+5.

Distribution.

Thirteen species of Potamophilinus occur from eastern Asia to Australia.

Comments.

Grouvelle (1896) erected Potamophilinus and designated Potamophilus longipes Grouvelle, 1892, as the type species.

In his unpublished checklist of elmid species, Calder (1992) listed an undescribed species of Potamophilinus from north Queensland based on three specimens in ANIC labeled "W. Claudie River / Iron Range, NQ / 13 May 1971 / J.G.Brooks". We examined the specimens and concluded that they are P. papuanus Satô, described from New Guinea, by comparison with paratypes of that species, the original description, and the male genitalia. Lawrence and Britton (1994) first reported the genus from Australia, probably from Calder’s determination. As mentioned in the differential diagnosis, two other genera of Larainae besides Potamophilinus occur in nearby Papua New Guinea, Potamophilus and Parapotamophilus . Possibly they too will be found in Australia in the future. Glaister (1999) keyed and illustrated larvae from the Northern Territory which she assumed to be Potamophilinus , but this was not verified by rearing to adult.