Oxyethira (Dampfitrichia) torresiana, Wells, Alice & Dostine, Peter, 2016

Wells, Alice & Dostine, Peter, 2016, New and newly recorded micro-caddisfly species (Insecta: Trichoptera: Hydroptilidae) from Australia’s north, including islands of Torres Strait, Zootaxa 4127 (3), pp. 591-600 : 594-596

Oxyethira (Dampfitrichia) torresiana sp. nov.

Figures 8–11

Diagnosis. Superficially this species is easily confused with Oxyethira (Dampfitrichia) incana Ulmer , which is widespread from Indonesia to New Guinea, northern Australia and New Caledonia. However, it is distinguished by the broader apical margin of abdominal segment VIII; absence of elongate spines apico-laterally on the deep apical concavity in the dorsal margin of abdominal segment VIII; phallic apparatus straight, with an elongate, anteriorly directed and free strap-like process arising subapically (compared with the phallic apparatus with a bend at mid length in O. incana ); and by the very different female terminalia that are stouter and without the darkly sclerotised quadrate area apico-ventrally on segment IX.

Description. Male. Length of each forewing 1.6–2.2 mm (n = 7). Antennae banded, each with 27 flagellomeres. Genitalia as in Figs 8–10 . Abdominal segment VIII almost quadrate in ventral view, with apical margin slightly convex, bordered by palisade of stout, distally down-turned setae, concave dorsally in lateral view; segment IX subtriangular in lateral view, antero-ventral margin tapered narrowly; gonopods fused basally, separate in distal quarter; subgenital plate similar to gonopods in shape, setose, reduced to small, fused median structure; dorsal process even smaller, fused; mid ventral apodeme elongate slender; phallic apparatus straight, stout basally, tapered distally, with strap-like sclerotised spine arising at 3/4 length, directed proximally.

Female ( Fig. 11 ). Length of each forewing 1.6–2.3 mm (n = 12). Antennae each with 19 flagellomeres, basal 7 dark, followed by 4 lighter, 4 dark, terminal 4 pale. Abdominal segment VII bearing small short, sharp midventral spine. Abdominal segment VIII length about 2x basal width, tapered distally. Segment IX with triangular sclerotised areas disto-laterally, apical margin coarsely crenulate.

Etymology. Named for Torres Strait, the origin of the types.

Types. Holotype. 1 male, NORTH EAST QUEENSLAND, Sesia via Bamaga , 20–23.iii.2012, W. Stevens, ex Culicoides trap (ANIC, slide).

Paratypes. NORTH EAST QUEENSLAND: 3 males, 3 females, data as for holotype (ANIC); 27 males, 11 females, Sesia, via Weipa, Sesia yards, 3.iv.2014, E. Cottis, ex Culicoides trap, (ANIC); 7 males, Bamaga , airport road, 19.iv.2010, J. Bond, ex Culicoides trap (ANIC); 2 males, 3 females, Sesia, 23.ii.2012, W. Namai, ex Culicoides trap (ANIC); 1 male, 4 females, Badu Island, Torres Strait, 26.iii.2012, T. Nona, ex Culicoides trap (ANIC).

Other material examined. NORTH EAST QUEENSLAND: 1 male, Badu Island, Torres Strait, 4.iv.2011, T. Nona, ex Culicoides trap ( ANIC); 2 males, NEQ, Bamaga , 31.v–3.vi.2011, J. Bond, ex Culicoides trap ( ANIC); 1 male, 3 females, Bamaga , 26.iii.2008, J. Bond, ex Culicoides trap ( ANIC).

PAPUA NEW GUINEA: 4 males, Western Province, Kautru, 8°03.267’S, 141°11.038’E, 1.vi.2009, Lt, B. Cookson & N. Harris, ex Culicoides trap ( ANIC, 1 slide, 3 alcohol).

Remarks. This new species has been collected from Badu Island and the far north of Cape York and also from Papua New Guinea. Given the large number of specimens collected from Cape York, it is probably established there, as well as in New Guinea (from whence available Trichoptera samples are so few). The closely similar O. incana has been collected from northern Australia to New Caledonia to the east, and westward through the Oriental Region to Sri Lanka.

Figures

FIGURES 8 – 13. Oxyethira and Hellyethira spp. 8 – 11, Oxyethira torresiana sp. nov., male genitalia: 8, ventral; 9, phallic apparatus; 10, lateral. 11. O. torresiana sp. nov., female terminalia, ventral. 12, 13, Hellyethira khukri sp. nov., male genitalia: 11, ventral; 12, left lateral. Abbreviations: VIII, IX = abdominal segments VIII and IX; dpl = dorsal plate; dpr = dorsal process of gonopods; gon = gonopod; mes p = mesal process of abdominal segment VII; ph = phallic apparatus; pr = paramere; stl = setose lobes of gonopods; vpl = ventral plate.