Symphitoneuria neboissi, Wells, Alice, 2011

Wells, Alice, 2011, The Trichoptera of Lord Howe Island, including 3 new species, larvae and keys, Zootaxa 2987, pp. 45-55 : 52-54

Symphitoneuria neboissi sp. nov.

(Figs 22–30)

Material examined. Holotype male, Soldiers Creek, 22.xi.1996, A. Wells & L.A. Mound.

Paratypes: 4 males, 1 female, Soldiers Creek, 22–23.xii.2001, A. Wells; 1 female, Rocky Run, 23–24.xii.2001, A. Wells; 1 male, 2 females, Rocky Run, 24.xii.2001, A. Wells; 3 males, 2 females, Soldiers Creek, 25.xii.2001, A. Wells; 1 male, Rocky Run, 27.xii.2007, A. Wells.

Other material examined. 3 larvae, cases, Soldiers Creek, 3.xii.1993, P.S. Cranston; 1 larva, 2 pupae, Soldiers Creek (lower), 22.xi.1996; larvae, pupa, Rocky Run, 22.xii.2001, A. Wells; larvae, Rocky Run, 23.xii.2001, A. Wells; larvae, Erskine Creek, 27.xii.2001, A. Wells; larvae, Erskine Creek, 22.xii.2007, A. Wells; larvae, Rocky Run, 24.xii.2007, A. Wells; larvae, Rocky Run, 27.xii.2007, A. Wells; larvae, Soldiers Creek, 27.xii.2007, A. Wells.

Diagnosis. This species is clearly distinguished from all other Symphitoneuria species [found elsewhere on mainland Australia and Tasmania (3 spp.), New Guinea (1 sp.), New Caledonia (5 spp.), Sabah (1 sp.) and the Sumba Islands (1 sp.)] by a set of stout setae on a ventrally directed, meso-basal lobe of each gonopod of the male; and in the female, forewings each with a tuft of black setae between Rs and M, and genitalia with cerci far narrower and more elongate than in other congeners, their length well exceeding that of the valvae.

Male. Forewing length: male 8.9–12.4 mm (N =9); female 8.8–10.4 (N =6).

Forewings ( Fig. 25 ): in general form resembling those described for other species in having distinctive dark composite vein derived by fusion of S3 and S4 with M and Cu for part of their length; discoidal cell elongate; and MP, Cu1 and Cu2 arising from composite vein. Genitalia as in Figs 27–29 . Abdominal segment IX very short, tergite slightly produced distally, shallowly concave apically. Tergite X in ventral view with length about 3X width, exceeding length of gonopods by almost 1/3rd; divided narrowly in distal half; in lateral view tapered to narrowly rounded apex. Cerci elongate, length about 5X maximum width, tapered towards narrowly rounded apices. Phallic apparatus short, slightly expanded laterally at apex. Gonopods each tri-lobed; dorsal branch slightly shorter than 2nd branch; 3rd branch shortest, in ventral view curved laterally, in lateral view upturned; dorsal branch bearing tuft of stout setae on meso-basal lobe.

Female. Forewings ( Fig. 26 ): without composite vein seen in male, but distinctive, with distal 3rd expanded beyond arculus, apically rounded; small tuft of black setae between Rs and M at about level of origin of proximal end of discoidal cell. Genitalia as in Fig. 30 : cerci prominent, exceeding length of valvae by about 1/3rd.

Larval cases. Cases tubular, generally constructed of sand alone in earlier instars; however, materials can comprise a mixture of sand and leaf fragments as in the early instar case in Fig. 22; cases of later instars also highly variable, sometimes sand alone (Fig. 23) and sometimes leaf fragments aligned in 1 plane forming more-flattened case (Fig. 24).

Remarks. This is usually a common species in fresh to brackish flowing water on the Island, and appears to be a leaf shredder.

Figures

FIGURES 25 – 30. Symphitoneuria neboissi sp. n., 25, 26, male and female forewings, respectively; 27 - 29, male holotype genitalia in ventral, left lateral, and dorsal views, respectively; 30, female terminalia, ventral view.