Oecetis quadrula, Wells, 2006

Wells, Alice, 2006, A review of Australian long-horned caddisflies in the Oecetis pechana-group (Trichoptera: Leptoceridae), with descriptions of thirteen new species, Memoirs of Museum Victoria 63 (2), pp. 107-128 : 121-122

Oecetis quadrula sp. nov.

Figures 40–42, 70

Material examined. Holotype. Male, NT, Kakadu National Park , UDP Falls, 7 Sep 1979, J. Blyth ( NMV T-18844, on slide).

Paratypes. NT: 1 male, Litchfield National Park , Florence Falls, 9 Apr 1991, Horak, Upton and Wells ( ANIC) ; 1 male, Jabiru Town Lake , 13 May 1991, C. Humphrey ( ANIC) ; 1 male, Kakadu National Park , Baroalba Springs, 4 Oct 1991, Wells and Webber ( NTM) ; 1 male, same locality, 16 Jan 1992, Wells, Webber and Bickel ( NTM) ; 1 male, Magela Creek Site 009, 3 Mar 1992, A. Wells ( NTM) .

Other material. NT: 1 male, Muirella Park , 12 Oct 1972, J.C. Cardale ( ANIC) ; 1 male, 12°17'S, 133°13'E, Birraduk Ck , 18 km E by N of Oenpelli, 4–5 Jun 1973, J.C. Cardale ( ANIC) ; 1 male, 12°31'S, 132°54'E, 9 km N by E of Mudginberri HS, 10–11 Jun 1973, J.C. Cardale ( ANIC) ; 1 male, 12°50'S, 132°51'E, 16 km E by N of Mt Cahill , 16 Jun 1973, J.C. Cardale ( ANIC) ; 1 male, 16°25'S, 136°05'E, 45 km SW by S of Borroloola , 5 Nov 1975, J.C. Cardale ( ANIC) ; male, Jim Jim Creek , 3 km below falls, Kakadu National Park, 1 Sep 1979, J. Blyth ( NMV, on slide) ; male, South Alligator R. at UDP Falls [Gunlom], 7 Sep 1979, J. Blyth ( NMV, on slide) ; 1 male, ARR, creek 5 km W of OSS South Alligator Field Station , 19 Apr 1989, Wells and Suter ( NMV) ; 1 male, Melville I., Andranangoo Creek , 11°31'S, 130°54'E, 8 Oct 1996, G.R. Brown ( NTM) ; 1 male, Melville I., Maxwell Creek , 11°33'S, 130°35'E, 14 Oct 1996, G.R. Brown ( NTM) ; 1 male, same locality and collector, 15 Oct 1996 ( NTM) . WA: numerous males, females, 15°02'S, 126°55'E, Drysdale R., 3–5 Jul 1975, I.B.F. Common ( ANIC) ; numerous males, females, 15°02'S, 126°55'E, Drysdale R., 3–8 Aug 1975, I.B.F. Common and M.S. Upton ( ANIC) ; male, Mitchell Plateau , Camp Creek, 31 Jan 1978, J.E. Bishop ( NMV, on slide) ; male, Mitchell Plateau , Camp Creek at Crusher, 15 Feb 1979, J.E. Bishop ( NMV, on slide) ; 3 males, Mitchell Plateau , at Mining Camp, 14°49'S, 125°50'E, 9–19 May 1983, J.C. Cardale ( ANIC) ; 1 male, Kimberley , Mt Barnett Station, Manning Gorge, 30 Apr 1992, P.S. Cranston ( ANIC) ; 1 male, 15°55'S, 127°56'E, El Questro Station , Chamberlain R. pool, 26 Aug 1996, I. Edwards, NMV ); numerous males, females, 15°42'S, 126°22'E, Drysdale R. Crossing, Kalumburu Road, 28 Aug 1996, I. Edwards ( NMV) ; 2 males, 14°54'S, 126°12'E, King Edward R., 3 Sep 1996, I. Edwards ( NMV) ; 1 male, 16°40'S, 125°56'E, Manning R. near Mt Barnett, 8 Sep 1996, I. Edwards ( NMV) . Qld : 1 male, The Crater , Atherton Tableland, 25 Apr 1970, S.R. Curtis ( ANIC) ; numerous males, females, Tewah Creek , Tin Can Bay, 17–18 Oct 1971, S.R. Monteith ( ANIC) ; 1 male, Upper Freshwater Creek , Whitfield Range near Cairns, 15 Dec 1974, Moulds ( NMV, on slide) ; 1 male, Mulgrave R. W of Gordonvale , 29 Apr 1979, Wells ( NMV) ; 1 male, 15°12'S, 143°52'E, Hann R. NW by W of Laura, 27 Jun 1986, J.C. Cardale ( ANIC) . NSW: 4 males, 8 females, Wallagarough R., Princes Highway bridge, 29 Jan 1975, A. Neboiss ( NMV) . Vic .: 1 male, Wingan R., 8 km S Princes Hwy, 30 Jan 1975, A. Neboiss ( NMV, slide) ; 1 male, Tanjil R. near Old Tanjil, S 34, Latrobe C. Survey, 5 Feb 1980 ( NMV) .

Diagnosis. In the male, resembling O. australis and O. burtoni in having long downy vestiture on the wings and no scales, but distinguished by absence of acute ventro-mesial processes on the inferior appendages, and inferior appendages short and stout in ventral view, tapered distally in lateral view, phallus short and beak-like, with a short slightly curved paramere. The form of the inferior appendages of this species is similar to O. jenniae , but the phallus is far shorter, its paramere short and slender.

Description. Male. Wings rounded apically, with long hair on veins; forewing without scales, length 4.6–7.0 mm. Antennae with a brush of long setae on leading edge of segments. Abdominal segments 3–5 with tergites sclerotised; segment IX narrow, lateral angles produced, segment X elongate coneshaped in ventral view, in lateral view elongate, rounded apically and with a small triangular ventral process. Genitalia, see figs 40–42. Pre-anal appendages short, rounded, phallus scarcely longer than wide, with membranous apex of aedeagus folded and down-turned; a short, slightly curved paramere present. Inferior appendages in ventral view subquadrate, with apico-lateral lobes short, convergent; in lateral view, simple, straight, tapered at apex, without basi-dorsal pouch.

Distribution. Found across northern Australia, from WA, NT and Qld, and from south-eastern Vic.

Remarks. With a dense brush of setae on the leading edge of the antennae, antennae erect (at least in spirit material), and long maxillary palpi, males of this species look particularly moth-like. Material here referred to O. quadrula shows variability in genitalic form, but a conservative approach is taken in assigning all to a single species as examination of more material from the south-east of the continent is required to justify recognition of two distinct morpho-species.

Etymology: Derived from the Latin, quadra — square, for the shape of the inferior appendages in ventral view.