Hydroptila roperi, 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 : 592-594

Hydroptila roperi sp. nov.

Figures 1–5

Diagnosis. This species is most closely similar to Hydroptila explicata Wells , a widespread species in northern Australia and the Oriental Region, from which males of H. roperi are distinguished by the more regularly clubshaped gonopods each with a jet black spur subapically, compared to the abruptly swollen gonopods of H. explicata and presence subapically only of a swelling bearing several setae; the more sharply, but widely V-shaped apical cleft on the dorsal plate of H. roperi ; and the slender, finely divided apex of the phallic apparatus. Females are distinct from those of H. explicata , having the abdominal segment VIII distal margin smoothly convex ventrally and smoothly and deeply concave dorsally, not produced dorso- or ventro-medially.

Description. Male ( Figs 1–3 ). Length of each forewing 1.5–1.7 mm (n = 5). Head without postoccipital scent glands. Antennae each with 23 flagellomeres, bearing dense sensilla placodea. Genitalia as in Figs 1–3 . Lateral lobes of abdominal segment IX elongate, length about 4x width; Dorsal plate (segment X) triangular in dorsal view, produced beyond other genitalic structures, apically bifurcate, lobes tapered sharply. Gonopods slender, in ventral view rod-shaped in basal 3/4, each sharply tapered distally with sclerotised lateral tooth subapically, in lateral view gradually expanded to broadly rounded apex. Ventral plate triangular in ventral view. Phallic apparatus elongate, slender, finely bifurcate apically, titillator thread-like, sinuous.

Female ( Figs 4, 5 ). Length of each forewing 1.6–1.9 mm (n = 6). Antennae each with 18 flagellomeres. Terminalia forming tapered oviscapt, with abdominal segment IX broadly rounded apico-ventrally, and deep Ushaped concavity dorsally.

Types. Holotype, male, NORTHERN TERRITORY, Roper River, McMinn Station, 16.x.2014, P. Dostine, lt tr. (NTM, slide).

Paratypes. 5 males (one headless), 6 females, data as for holotype (NTM, ANIC, slides).

Etymology. Named for the Roper River where the specimens were collected.

Remarks. The 10 species of Hydroptila now known to occur in Australia are all very uniform in general genitalic morphology in comparison with many described from New Guinea and parts of SE Asia to the north, possibly representing a single evolutionary lineage (but see Bennik et al. 2016 who, in a molecular phylogenetic study on genus of moths, demonstrated repeated evolution of some complex genitalic structures).

Figures

FIGURES 1 – 7. Hydroptila and Oxyethira spp. 1 – 5, Hydroptila roperi sp. nov.: 1 – 3, male genitalia: 1, left lateral; 2, phallic apparatus; 3, ventral; 4, 5, female terminalia: 4, abdominal segment VIII, dorsal; 5, abdominal segments VIII – X, ventral. 6, 7, Oxyethira bamaga sp. nov., male genitalia: 6, ventral; 7, phallic apparatus. Abbreviations: VIII, IX = abdominal segments VIII and IX; dpl = dorsal plate; dpr = dorsal process of gonopods; gon = gonopod; l lb IX = lateral lobe of segment IX; tlr = titillator; vpl = ventral plate.