Neboissomina riyala, Cartwright, David I., 2011

Cartwright, David I., 2011, Descriptions of Neboissomina, new genus and 6 new species of Ecnomidae from Australia (Trichoptera), Zootaxa 2736, pp. 17-30 : 23-24

Neboissomina riyala sp. nov.

Figs 18–20, 28

Diagnosis. Neboissomina riyala is most similar to N. philsuteri and N. kuranya in possessing inferior appendages which are fused to form a single large sub-rectangular plate, but it is distinguished by small differences in the inferior appendages, in ventral view without a single small central process distally, in lateral view narrowed subapically, length about 4.5 times width.

Description. Head, body, and wings light brown, abdomen paler ventrally; wings similar to those of N. jardinei (Fig. 2), length of each forewing: male 2.3–3.1 mm, female 2.8–3.1 mm, length about 3.0 times width; length of each hind wing 3.2–3.3 times width. Wing venation: Each forewing with forks 2, 3, 4 and 5 present; fork 2 sessile, length about 1.3–1.4 times length of fork 3; fork 3 with short footstalk, length of fork about 3.8 times length of footstalk, length of footstalk of fork 3 about same length as cross-vein m, cross-veins r-m and m nearly contiguous at fork 3, r-m and m separated by 0.4–0.6 times length of cross-vein m; length of fork 5 about 1.7 times length of fork 4. Hind wings each with forks 2, 3 and 5 present; fork 2 sessile or with very short footstalk, footstalk of fork 2 length 0.0–0.2 times length of cross-vein r-m, fork 2 length 1.3–1.4 times length of fork 3.

Male. Tergum X membranous, with pair of long, slender dorsal processes, converging and crossing near middle (Fig. 20). Superior appendages short and robust, in lateral view broad-based, slightly tapered distally, length about 2.5 times width (Fig. 18), in dorsal view length about 3 times width, slightly dilated distally (Fig. 20); pair of long, slender processes (mesal processes of tergum X) ventro-basal of superior appendages. Phallus simple, tubelike, (Fig. 18). Inferior appendages slightly longer than superior appendages, fused, in ventral view large, sub-rectangular shield, truncate distally, length about 1.5 times width (Fig. 19), in lateral view broad-based, slightly tapered distally, narrowed subapically, dilated apically, length about 4.5 times width (Fig. 18).

Female. Genitalia with pair of small sub-quadrate lobes on sternite VIII, widely separated (Fig. 28).

Holotype male: Northern Territory, ARRS Radon Springs, 12°45'S, 132°55'E, lt tr., 13–14 Apr 1988, P. Suter and A. Wells ( NMV, T- 21063).

Paratypes: Northern Territory. 7 males, collected with holotype; 2 males, same loc. and coll., 1 hr before dawn, 14 Apr 1988; 2 males, same loc. and coll., 6V lt tr., dawn, 14 Apr 1988; 1 male (specimen CT-470 figured), 1 female (specimen CT-492 figured), Jim Jim Falls campsite, Kakadu Nat. Pk, 13°16'S, 132°49'E, 13 Aug 1996, I. Edwards ( NMV).

Other material examined: Northern Territory. 1 male, 2 females, Adelaide R., 15 km E of Stuart Hwy, 15 Aug 1979, J. Blyth; 2 males, ARRS Bowerbird Billabong outlet, 12°47'S, 133°02'E, 1 Oct 1988, P. Dostine; 1 male, ARRS Baroalba Springs, 22 May 1988, A. Wells and P. Suter; 1 male, Nourlangie camp lagoon, Kakadu N.P., 4 Sep 1979, J. Blyth; 3 males, 1 female, Rock Hole Ck, lt tr., Nov 1988, P. Dostine; 6 males, 13 females, S Alligator R., UDP Falls, 7 Sep 1979, J. Blyth; 1 male, ARRS Kambolgie Ck, 6V lt tr., 25–26 May 1988, P. Suter and A. Wells; 1 male, S Alligator R. nr Koolpin Crossing, 14 Oct 1987, P. Dostine; 7 males, 11 females, ARRS ck 5 km W of OSS field station, 13°?, 132°34'E, 19 Apr 1988, A. Wells and P. Suter; 4 males, 2 females, ARRS S Alligator R. at Gimbat OSS Stn, 28 Apr 1988, P. Dostine; 1 male, same loc., 6V lt tr., 24–25 may 1988, P. Suter and A. Wells; 5 males, 7 females, Butterfly Gorge, Katherine Gorge N.P., 27 Jan 1977, M.S. and B.J. Moulds; 1 male, Amagule Pool, Groote Eylandt, MV lt, 6 Feb 1984, M. Davies.

Etymology. Riyala - Northern Territory Aboriginal word for “springs, streams, and rivers,”referring to the typical habitat.

Remarks. Neboissomina riyala is a relatively common and widespread species having been collected from about 13 localities across the northern Northern Territory (latitudinal range 12°45'– 14°19'S).