Oecetis digitata, 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 : 105-106

Oecetis digitata sp. nov.

Figures 91–93, 129

Material examined. Holotype, male, NT, Jim Jim Waterhole, Kakadu National Park , 5 Sepember 1979, J. Blyth ( NMV T-18522).

Paratypes. NT: 7 males, 3 females, Muirella Park , 12 Oct 1972, E.F. Riek ( ANIC) ; male, 12°06'S 133°04'E, 19 km E by S of Mt Borrodaile , 5–6 Jun 1973, J.C. Cardale ( ANIC) ; male, Jim Jim Creek , 19 km WSW of Mt Cahill, 12°5'S 132°33'E, 17 Jun 1973, J. Cardale ( ANIC) ; 1 male, 1 female, Gulungul Billabong , East Jabiru, 23 Feb 1988, P. Dostine ( NTM) ; 1 male, 12°38'S 132°53'E, Gulungul Billabong , East Jabiru, 20 May 1989, A. Wells and P. Suter ( NTM) ; 1 male, ARRS, South Alligator River at Gimbat OSS Station, 13°34.3'S 132°36.7'E, 24 May 1988, A. Wells and P. Suter ( NTM) ; 3 males, ARRS, Kambolgie Creek , 13°28.9'S 132°22.0'E, 25 May 1988, A. Wells and P. Suter ( ANIC) ; 1 male, ARRS, East Alligator River at Cahills Crossing, 27 May 1988, A. Wells and P. Suter ( NTM) ; 2 males, SAR site 1, 30 Sep 1988, P. Dostine ( NTM) ; 5 males, 12°48'S 132°49'E, Baroalba Springs , 25 Apr 1991, Wells and Webber ( NMV) ; 1 male, 12°42'S 132°57'E, Kakadu National Park , Magela Creek, OSS Site 009, 8 Jun 1991, Wells and Webber ( NTM) ; 1 male, 12°48'S 132°49'E, Little Baroalba Creek , 10 Jul 1991, Wells and Webber ( NTM) ; 5 males, female, Alligator River , Two Mile Hole, 12°42'S 132°09'E, 5 Aug 1996, I Edwards ( NMV) .

Other material. WA: Kimberley , Four Mile Creek, 2 Feb 1979, J.E. Bishop ( ANIC) (slide) ; male, female, 14°25'S 126°38'E, CALM site 13/H 12 km S of Kalumburu Mission , 7–11 Jun 1988, T.A. Weir ( ANIC) ; 5 males, female, NT, Alligator River Two Mile Hole, 12°42'S 132°09'E, 5 Aug 1996, I. Edwards, NMV. Qld: female, Palmer River, 20 Jun 1971, E.F. Riek ( ANIC) ; male, 15°41'S 145°12'E, Annan River , 3 km W by S Black Mountain, 17 Sep 1980, J.C. Cardale ( ANIC) ; male, 4 females, 15°25'S 141°53'E, Hann River , 7 km NW by W Laura, 27 Jun 1986, J.C. Cardale ( ANIC) . NT: male, 12°57'S 132°33'E, Jim Jim Creek , 19 km WSW of Mt Cahill, 17 Jun 1973, J.C. Cardale, ANIC ; female, Howard Creek , 3 km E of Howard Springs, 12°27.5'S 131°3.1'E, 17 Aug 1979, J. Blyth ( NMV) ; 1 female, Magela Creek at Ranger pipe outlet, 20 May 1988, P. Suter and A. Wells ( NTM) ; female, Magela Creek at Ranger Pipe Outlet , Suter and Wells, 23 May 1988 ( NMV) .

Diagnosis. Forewing length less than 4 times width, veins sclerotised, appear very prominent,footstalk absent on fork 1; an unusual forward bulge present at base of vein Cu1a. In male genitalia, inferior appendages with mesial margin irregular, not smoothly curved; phallus smoothly arched, length about 4 times width.

Description. Spurs 1, 2, 2. Male forewing length 6.6–8.1 mm. Wings strongly sclerotised with veins dark, hair short; in forewing (Fig. 91) fork 1 sessile, anterior anastomosis with t1 and t2 almost linear, and well distad of t3, a forwardly directed bulge on Cu1a. Male genitalia, Figs 92, 93. Segment IX almost of uniform length on all sides, but excavated deeply midventrally; preanal appendages slender, elongate. Segment X elongate in lateral view, slightly swollen towards base. Inferior appendages in ventral view with small inner lobe at about half length. Phallus,curved, slender with length about 4 times width.

Distribution. Qld, NT, Kimberley Region of northern WA (Fig. 129).

Remarks. Several of the New Guinean Oecetis species resemble O. digitata in having broad wings with bold or prominent venation, and may be allied to this species. However, none has Cu1a as in O. digitata and O. ancala sp. nov.

Etymology. Latin, digitata — having fingers, for the finger-like appearance of the male genitalia in lateral view.