Anisocentropus (Anisocentropus) thinlin, 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 : 52-54

Anisocentropus (Anisocentropus) thinlin , new species

Figs 105–108

This species is medium-sized, with dark ochraceous-brown body and brown forewings. It belongs to the Anisocentropus brevipennis diagnostic species-cluster in the Anisocentropus latifascia diagnostic species-group, characterized by having abbreviated gonocoxites, but has a digitate process on the apicodorsal corner of the gonocoxites in lateral view. The lateral flank between the preanal appendages and the gonocoxites is small. The species is most similar to Anisocentropus hoisat , new species, from which it is separated by segment X being longer than the gonocoxites; ventrad-curving apices are blunt and not spine-like; and the digitate process on the apicodorsal corner of each gonocoxite is short. The forewings of A. thinlin have no visible setal or membrane patterns while the forewings of A. hoisat have an inconspicuous band and dots.

Male (in alcohol). Medium-sized; body dark ochraceous-brown; forewings brown, without patch or band pattern, with small light dots on membrane. Head rectangular in dorsal view, almost as long as broad. Ocelli absent. Tentorium slender, without dorsal arm; posterior arms short, robust, ending in pair of large posterior tentorial pits; strong tentorial bridge without anteromesal or posteromesal protuberance; anterior tentorial arms posteriorly robust, anteriorly slender, without median lamellate process; posterior half broad, ending in median keel in dorsal view and in ventral corner in lateral view. Facial groove pattern with plate-like flange, or rim, of frontal sclerite between anterior tentorial pits. Theoretical lines separating frons and clypeus manifested by transverse frontal rim. Frontogenal vertical groove forming oblique, dorsal continuation from anterior tentorial pits; almost horizontally merging with antennal grooves. Clypeogenal vertical grooves located ventrally of anterior tentorial pits, short, running slightly mesoventrad; plate-like flanges, and frontogenal and clypeogenal sutures forming complex of anterior tentorial arms (frontogenal septa). Subantennal grooves small, sinuous, running almost horizontally between frontogenal compact setal wart and palpifers, forming proximal articulation of palpi on stipes. Subocular grooves invisible. Frontal groove pronoumced, short, present between antennae, joining vertexal medioantennal compact setose warts. Vertexal groove pattern reduced; large anterad directed, rounded elevated hump dominating anterior half of vertex, reaching interantennal area, laterally delineated by large membranous antennal sockets with corrugated or granulous surface near frontogenal compact setose wart. Epicranial groove (coronal groove) with vestigial stem. Antennal and ocular grooves accompanied by occipito-postgenal grooves, partly merging anteriorly; tangential to large occipital compact setal warts. Labrum heart-shaped, distal half narrow, freely hanging. Mandibles long, weakly pigmented, orienting laterad along each labrum; laciniae narrow, elongated, with few setae. Frontal setal warts absent on face; frontal interantennal warts absent due to anterad directed vertexal elevation. Pair of large, nearly triangular frontogenal compact setal warts present on posterior pregenae, directed obliquely or almost horizontally from frontogenal grooves, representing only visible setal warts on face. Triangular elevation on vertex with fused vertexal medioantennal compact setose warts located anteriorly on head. Vertexal lateroantennal compact setal warts absent. Antennal sockets large. Pair of small, rounded vertexal ocellar compact setose warts and pair of minute vertexal medioocellar diffuse setose warts present, each with 1 or 2 setae in middle of vertex. Pair of large, obliquely located, ovoid occipital compact setose warts dominating on posterior half of vertex. Pair of small postgenal compact setose warts visible between posterior section of ocular grooves and occipital compact setose warts. Maxillary palps filiform, each segment with long setae, maxillary palp formula II-IV-VI-I-V-III. Scapes rounded, about half as long as head; pedicels 2/5ths as long as scapes. Two pairs pronotal warts present: pair of large dorsal transverse ovoid warts almost touching mesally; second wart pair small, rounded, located deep laterally, visible in lateral view. Mesoscutum with 1 pair diffused warts, arranged in longitudinal line along entire mesoscutum, forming single, double and triple setae in groups visible as weakly pigmented alveoli. Pair of mesoscutellar warts forming small, less pigmented, rounded area with 5 to 6 setal alveoli. Each proepisternum with minute, rounded setose wart located proximally above articulation of each cervical sclerite. 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 present 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; foreleg posteroapical spur and hind leg anteroapical spur half as long as other spurs; midleg anteroapical spurs 1/5th as long as posteroapical spur. Forewings: length 8.0 mm, membrane brown, without patches, with densely scattered, small, light dots on brown membrane; R1 confluent with, or recurrent into R2 well before C, without clearly visible continuation to C; base of discoidal cell located around middle of wing; forks I, II, III, IV, V present; crossveins h, sc-r, s, rm, m, m-cu, cu2 and cu-a present, crossveins r and cu1 absent; postanal vein absent. Hind wings: R1 meeting R2; forks I, II, III, V present, fork I and fork II equal.

Male genitalia. Abdominal segment IX fused annularly, without longitudinal groove separating dorsal mesal and ventral parts; tergum shorter than venter; acrotergite (precostal lip of tergum), less pigmented, with granulous surface due to presence of conspicuous microtrichia; contrasting in colour from heavily sclerotized antecosta and antecostal suture; anterolateral margins of segment IX convex, each triangular in ventral half; posterior margins irregularly straight, slightly concave; with short, dorsad curving groove and ridge running obliquely from bottom or middle of concavity, visible in lateral view; additional lateral flank below each preanal appendage small, glabrous, less pigmented. Antecosta well developed, orienting mesad before curving apicad, lateral rims not tangential; gap between filled by acrotergite. Antecosta broader ventrally than dorsally in lateral view; spine row absent on posterior margins of segment IX; segment smoothly glabrous, except with small, ventropleural, setose area. Intersegmental depression between segment IX and segment X completely filled, forming almost straight horizontal line in lateral view, with small slope. Segment X longer than gonocoxites and preanal appendages, forming broad hood with ventrad directed blunt apices; in dorsal view, segment X rounded quadrangular, without mesal excision, with wide V-shaped excising on apical margin visible in caudal view. Apicoventral setose lobes reduced to setose surfaces before apex. Apicodorsal setose lobes forming sparsely setose surfaces above middle of segment X. Dorsal interlobular gap wide V-shaped. Preanal appendages long, filiform in lateral view, straight clavate in dorsal view. Gonocoxites without harpago, quadrangular, with short digitate process on apicodorsal corner in lateral view. Phallic apparatus curving; dorsal margin slightly convex, ventral margin concave with elongate, sclerotized ventral apically shallow trough hosting endotheca and phallicata; phallotheca curving ventrad as basis. Phallotremal sclerite feeble in lateral view, forming complex of sclerotized structure accompanied by spines in membranous phallicata. Phallotremal sclerite complex in ventral view, Y-shaped. Ejaculatory duct thin, nearly reaching phallotremal sclerite complex.

Holotype male: LAOS PDR: Odomxai Prov. : Hoi Nga stream, next to R13, just upstr. Hoi Nga Village, 870 m, UTM 48Q0199131, 2277876, 28.iv–2.v.2005, Malaise trap, loc 20 [N. Jönsson, T. Malm & B. Viklund] — ( NRM).

Paratypes: same data as holotype — 1 male ( NRM); Luang Namtha Prov.: Nam Ha NBCA, Lakkhammai Village, Nam Leung stream, 749 m, UTM 47Q0744602, 2339873, 30.iv.2005, light trap, loc 29 [N. Jönsson, T. Malm & B. Viklund] – 1 male ( OPC) .

Distribution: Laos.

Etymology: Thinlin, from Vietnamese “thinh linh”, short, referring to the short, digitate process on the gonocoxites.

Figures

FIGURES 105–108. Anisocentropus thinlin, new species, holotype. 105 — genitalia, lateral; 106 — genitalia, dorsal; 107 — gonocoxite, ventral; 108 — phallus, lateral.