Anisocentropus (Anisocentropus) vanuensis, Oláh & Johanson, 2010

Oláh, János & Johanson, Kjell Arne, 2010, Description of 33 new species of Calamoceratidae, Molannidae, Odontoceridae and Philorheithridae (Trichoptera), with detailed presentation of their cephalic setal warts and grooves 2457, Zootaxa 2457 (1), pp. 1-128 : 39-41

Anisocentropus (Anisocentropus) vanuensis , new species

Figs 78–82

This species is small, with bright chestnut brown forewings having a slightly paler patch around each forewing pterostigma. It belongs to a diagnostic species-group having shortened gonocoxites. This new species is similar to A. vitiensis , new species from the Fijian Island Viti Levu. Anisocentropus vanuensis is separated from A. vitiensis by the absence of a broad, dark brown, transverse band on the middle of the forewing; and the different shape of the gonocoxites in ventral view, i.e. being clearly sigmoid, not triangular. The cephalic, cervical, thoracic and proepisternal structural units, grooves, setal warts are similar in the 2 species.

Male (in alcohol). Body small, brown, eyes small; legs, antennae and palps light brown, denuded forewing membrane bright chestnut brown, paler at pterostigma. Head rectangular in dorsal view, almost as long as broad. Ocelli absent. Tentorium slender, without dorsal arm; posterior arms very short, robust, ending in pair of large posterior tentorial pits with strong tentorial bridge without anteromesal or posteromesal protuberance; anterior tentorial arm posteriorly robust, anteriorly slender, without median lamellate process; broad posterior half ending in median keel in dorsal view and ventral corner in lateral view. Facial groove pattern forming plate-like flange or rim connecting anterior tentorial pits, theoretical lines separating frons and clypeus (frontogenal vertical groove), forming oblique, dorsal continuation from anterior tentorial pits; almost horizontally merged with broad antennal grooves. Clypeogenal vertical grooves located ventrally of anterior tentorial pits, short, running slightly mesoventrad; well-visible pattern of plate-like flanges, and frontogenal and clypeogenal sutures, forming complex of anterior tentorial arms (frontogenal septum). Subantennal grooves small, poorly visible, horizontal sinuous between large frontogenal compact wart and palpifers; forming proximal articulation of palpi on stipes. Subocular grooves not visible. Short, pronounced frontal groove present between antennae, joining vertexal medioantennal compact setose warts. Vertexal groove pattern reduced; large, anterad directed, rounded elevation dominating anterior half of vertex, reaching interantennal area, delineated laterally by extremely large membranous antennal sockets with corrugated or granulous surface near frontogenal compact setose wart. Stem of epicranial groove (coronal groove) vestigial. Antennal and ocular grooves accompanied by occipito-postgenal grooves, partly merging anteriorly; tangential to large occipital compact setal warts. Labrum long, quadrangular, with rounded apex, freely hanging, sparsely setose. Mandibles long, slightly pigmented, oriented laterad along each labrum; laciniae narrow, elongated, bearing few setae. Frontal setal warts absent on face, frontal interantennal warts absent. Pair of large, nearly triangular frontogenal compact setal warts present on posterior pregenae, obliquely or almost horizontally from frontogenal grooves, alone representing only visible warts on face. Anterad directing, rounded triangular elevation on vertex with fused vertexal medioantennal compact setose warts anteriorly on head. Vertexal lateroantennal compact setal warts absent. Antennal sockets enlarged. Pair of small, rounded vertexal ocellar compact setose warts, and pair of very small vertexal medioocellar diffuse setose warts present, 1 or 2 setae present centrally on vertex. Occipital compact setose warts located obliquely, large, ovoid, dominating on posterior half of vertex. Postgenal compact warts small, visible between posterior section of ocular grooves and large occipital compact setose warts. Maxillary palps filiform; maxillary palp formula II-V-I-IV-VI-III. Scapes rounded, long, about half as long as head; pedicels 2/5ths as long as scapes. Two pairs pronotal warts present: 1 pair forming large, dorsal transverse ovoid, elevated humps with narrowest end almost tangential mesally; 1 pair small, rounded, located deep laterally, visible in lateral view. Mesoscutum with 1 pair diffuse warts arranged in longitudinal line along mesoscutum, composed mostly of single, double and triple setae in groups, visible as weakly pigmented alveoli. Pair of mesoscutellar warts forming small, weakly pigmented, rounded areas with 7–9 setal alveoli. Each proepisternum with minute, rounded setose wart located proximally above articulation of cervical sclerites. Large, compact setal warts present mainly on membranous part of cervix, touching anterior arm of cervical sclerites. Lateral cervical sclerites forming narrow anterior arms articulating anteriorly with back of head, with occipital condyle above posterior tentorial pits; fusing with posterior cervical sclerites. Posterior cervical sclerites forming narrow, elongated plates, reaching prothoracic episternum, articulating with weakly sclerotized anteromedian band of prothoracic eusternum by thin, ventral intercervical sclerites. Legs with symmetrical claws; spur formula 2, 4, 3; each foreleg with posteroapical spur 2 times longer than anteroapical spur; midleg anterior spurs 1/4th as long as posterior spurs; hind leg anteroapical spur 1/ 5th as long as posteroapical spurs. Forewings: length 6.4 mm; membrane chestnut brown, with pale area at pterostigma; narrow, hyaline, horizontal lines around crossvein s and on R4+5 fork base, above apical section of M, and along the stem of M1+2; Forewing R1 free to C; crossvein r appearing as diffused less pigmented area at apical margin of radial cell; base of discoidal cell ending at middle of wings; forks I, II, III, IV, V present; crossveins h, sc-r, r, s, r-m, m, m-cu and cu2 present; crossveins cu1 and cu-a absent; postanal vein absent. Hind wings: R1 fusing with R2; forks I, II, III, V present; fork I longer than fork II.

Male genitalia. Abdominal segment IX fused annularly, without longitudinal groove separating dorsal mesal and ventral parts; tergum shorter than venter; venter produced into narrow quadrangular process in lateral view; segment IX with ventrad directed, convex anterior margin; posterior margins concave at ventral half, with well developed, long lateral flank below preanal appendages above gonocoxites. Antecostae weakly developed, forming narrow, marginal rim, equally thin along margins, without conspicuous external groove of antecostal sutures; in dorsal view, tergum with small, triangular mesal elevation; spine row absent on posterior margins of segment IX; entire segment smooth, glabrous, covered by acanthae, except with small dorsopleural and large ventropleural setal areas. Intersegmental depression between segments IX and X gently sloping. Segment X much longer than gonocoxites, slightly longer than preanal appendage, forming broad hood with ventrad directing apical rim characterised by sinuous excavations visible in dorsal and ventral view, excavations forming tooth-like pattern on ventrad curving margin, with 2 visible teeth; apicoventral setose lobes reduced to setose, subapical surfaces or shallow protuberances; apicodorsal setose lobes with few tiny setae above middle of segment X. Dorsal interlobular gap forming narrow, deep cleft. Preanal appendages depressed in lateral view; broad at mid-length, slightly narrowing apically. Gonocoxites each without harpago; short triangular in lateral view; with subapical hump visible on ventral half; elongate, slightly sigmoid in ventral view, with pronounced mesal “knee” formed by large protuberance covered with long, stout spines.

Phallic apparatus curving; basal part slightly convex; ventral part concave; ventral apical lobe elongated, sclerotized; part of phallicata visible in retracted state above ventral lobe. Phallotremal sclerite nearly invisible in lateral view, forming complex unit inside membranous phallicata; complex, U-shaped, with laterad curving corners. Ejaculatory duct thin, ending in phallotremal sclerite.

Holotype male: FIJI ISLANDS: Vanua Levu : Savudvodra Dam, 10.ii.1971 [G.S. Robinson] – ( NHML).

Paratypes: same data as holotype — 1 male, 1 female paratypes ( NHML) .

Distribution: Fiji Islands.

Etymology: Vanuensis, named after the type locality, Vanua Levu Island.

Figures

FIGURES 78–82. Anisocentropus vanuensis, new species, holotype. 78 — right forewing; 79 — genitalia, lateral; 80 — genitalia, ventral; 81 — phallus, lateral; 82 — phallus, ventral.