Oecetis atarpa Mosely, 1953

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 : 90

Oecetis atarpa Mosely

Figures 7–9, 103

Oecetis atarpa Mosely and Kimmins, 1953: 287 , fig. 202.

Material examined. Paratype. Male , National Park [Royal National Park], NSW, 34°3.9'S 151°3.1'E ( BMNH) .

Other material. 27 samples in ANIC and NMV.

Diagnosis. Forewing (Fig. 7) length 3–4 times maximum width, fork 1 with footstalk, posterior anastomosis with t2 and t3 contiguous, t1 more proximal than both t2 and t3; in the male genitalia (Figs 8, 9) abdominal segment IX in lateral view produced distally in a down-turned peg ventral to preanal lobe; and inferior appendages in lateral view long and slender distally, rounded and swollen basally with basal third about 4 times broader than distal two-thirds which is less than twice length of basal section.

Distribution. Throughout Australia but only small scattered collections taken in NT (Fig. 103).

Remarks. Closely resembling Oecetis scirpicula and O. aeoloptera in form of male genitalia but distinguished by the stepped arrangement of crossveins in the posterior anastomosis in forewing, and the dorsolateral ‘peg’ on abdominal segment IX. The very slight difference between O. atarpa and O. scirpicula Neboiss —mainly the more strictly linear posterior anastomosis in the forewing of the latter and in the male genitalia a small difference in proportions in inferior appendages—is well within the range of variation exhibited by other Australian Oecetis , particularly those with temperate to tropical distributions. For the present, however, the two names are retained.