Oecetis ancala, Wells, 2004

Wells, Alice, 2004, The long-horned caddisfly genus Oecetis (Trichoptera: Leptoceridae) in Australia: two new species groups and 17 new species, Memoirs of Museum Victoria 61 (1), pp. 85-110 : 106-107

Oecetis ancala sp. nov.

Figures 95–97, 130

Material examined. Holotype, male, SE Qld, Bulimba Creek , nr Brisbane Site R 1, near Kimmax Street riffle, 23 Oct 1979 ( NMV T-18523).

Paratypes. Qld: 3 males, Camp Mountain , 31 Mar 1967, N. Dobrotworsky ( NMV) ; 2 males, female, Coondoo Creek , 30 km NE of Gympie, Toolara State Forest, 28 Oct 1980, A. Neboiss ( NMV) ; 3 males, female, Cooloola National Park , Freshwater Lake, 27 Nov 1985, D. Bickel and G. Cassis ( NMV) .

Other material. WA: male, N end of Lake Argyle nr Kununurra, 6 Feb 1977, M.S. and B. Moulds ( NMV) ; 7 males, female, Geikie Gorge , 18°06'S 125°42'E, 5 Oct 1996, I. Edwards ( NMV) . NT: 2 males, 2 females, Nourlangie Creek , 6 km E of Mt Cahill, 12°52'S 132°46'E, 18 Nov 1972, J.C. Cardale ( ANIC) ; male, Katherine River Gorge National Park , 13 Aug 1979, J. Blyth ( NMV) ; male, 2 females, Adelaide River , 15 km E of Stuart Highway, 15 Aug 1979, J. Blyth ( NMV) ; male, Devil Devil Creek , 70 km SW of Daly River Mission, 23 Aug 1979, J. Blyth ( NMV) ; 2 males, 2 females, 12°52'S 132°46'E, Nourlangie Creek , 6 km E of Mt Cahill, 18 Nov 1972, J.C. Cardale ( ANIC) ; male, ARRS, SAR at Gimbat OSS Stn , 13°34.3'S 132°36.7'E, Wells and Suter, 24 May 1988 ( NTM) ; 3 males, ARRS, Kambolgie Creek , 13°28.9'S 132°22.0'E, 25 May 1988, Wells and Suter ( NTM) ; male, 12°36'S 132°53'E, ARRS, Gulungul Creek , Inlet to Gulungul Billabong, 20 Apr 1989, Wells and Suter ( NTM) ; 2 males, SAR Site 1, 30 Sep 1988, P. Dostine ( NTM) ; male, 3 females, 12°42'S 132°57'E, Kakadu National Park , Magela Creek, OSS Site 009, 15 Feb 1991, Wells ( NTM) ; male, 12°42'S 132°57'E, Kakadu National Park , Magela Creek, OSS Site 009, 8 Jul 1991, Wells and Webber ( NTM) . Qld : males, female, Cape York Peninsula , Pascoe River crossing (to Iron Range), 4 Oct 2002, G. Theischinger ( ANIC) ; Cape York Peninsula , Dulhunty River crossing at Telegraph rd, 7 Oct 2002, G. Theischinger ( ANIC) . NSW: Barrington Tops , Barrington Tops Country Retreat, Dam, 22 Dec 2000, A. Wells ( ANIC) . Vic : male, Tyers River, LRES, 24 Feb 1974, Site 22 ( NMV) (slide) ; male, female, Yarra River , below Upper Yarra Dam, 28 Feb 1976, A. Neboiss ( NMV) ; male, female, Yarra River , Diamond Creek junction, 14 Mar 1976, A. Neboiss ( NMV) .

Diagnosis. Forewing as for O. digitata . In male genitalia, paired, sharply angled, sclerotised processes ventral to tergite X, in ventral view appearing to be lateral to the phallus.

Description. Spurs 1, 2, 2. Male forewing length 7.9–9.4 mm. Wings, broad: forewing with fork 1 sessile, veins prominent; posterior anastomosis almost linear, oblique, marked by dark membrane forming a line across wing; Cu1a with a proximally directed bulge. Male genitalia, Figs 95–97. Segment IX narrow, preanal appendages discrete, slender, elongate, apices obliquely truncate in lateral view. Tergite X slender, setose. Inferior appendages stoutly clasper-shaped in ventral view, a subapical notch mesially, in lateral view swollen baso-ventrally, then rod-shaped to rounded apex. Phallus long for a laustra -group species, arched ventrally. A pair of slender processes occur ventral to tergite X, appearing to be lateral to phallus in ventral view, sharply angled inwards at about half their length (ankle-shaped), in lateral view broad-based, tapered and slender distally.

Distribution. Northern WA, northern NT, south-eastern Qld, eastern NSW and south-central Vic (Fig. 130).

Remarks. The homologies of the unusual lateral processes are obscure, being impossible to determine from the prepared slides. In lateral view they seem to be associated in some way with tergite X, although in ventral view they appear to be closely associated with the phallus. If they are derived from the phallotheca, then this species should probably be placed in the complexa -group in the Australian fauna, but for the present they are dealt with as part of the laustra -group. Only few specimens have been collected at any one time, which suggests that the species may be far more widespread, but not often collected. This is consistent with the very curious distribution. Etymology. Latin, ancala — a bent arm, descriptive of the structures lateral to the phallus.