Marilia namha, 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 : 89-93

Marilia namha , new species

Figs 204–210

This species resembles M. tuyetmira , new species from which it is easily separated by the presence of a single group of dark setae around the forewings nygma instead of numerous small groups of darker setae scattered over entire forewing surfaces. Another distinguishing character is presence of large, narrow and oblique lateroapical corners of tergum IX, which form plates overhanging the articulations of the preanal appendages. These plates are short in M. tuyetmira . Marilia namha represents the only examined species having the anterior sutures produced into a complete ring formed by the tergal parts. Compared to M. tuyetmira , the distance between the eyes is much shorter and the vertexal medioantennal compact setal wart are fused with the septa and are heart-shaped; and the occipital setal warts are drop-shaped, not rounded triangular as in M. tuyetmira . Male (in alcohol). Body medium-sized; pale brown; legs, antennae and palps light brown, almost yellowish; cephalic and thoracic setal warts white; forewings uniformly whitish hyaline, with white setae, small patch of black setae present around nygma. Eyes black, large. Vertex constricted; width of interocular area about 2/5ths that of eye diameter; 3 times longer than broad. Ocelli absent. Tentorium unknown. Facial groove pattern, including pair of long, narrow frontal lateral diffuse setose wart with large, white alveolus and enlarged antennal sockets dominating on frons. Anterior part of frontal grooves invisible. Frontogenal vertical groove invisible between frontal lateral diffuse warts and vertical, narrow but short frontogenal diffuse setose warts. Frontogenal diffused warts present on posterior region, below antennal sockets, represented by 4 to 5 white alveoli. Clypeogenal vertical grooves located ventrally of anterior tentorial pits; running obliquely laterad, reaching subgenal process. Subantennal grooves running vertically in narrow strip between ocellar grooves and frontogenal diffuse setose warts. Subocular grooves merging to anterior clypeogenal grooves. Vertexal groove pattern simple, constricting. Coronal grooves almost complete, forming straight line in middle of vertex, anteriorly vestigial. Postoccipital grooves encircling foramen magnum and postoccipital lobes. Labrum small, short, without setal warts, with movable anterior part, freely hanging. Mandibles almost indiscernible on uncleared head; lacinia broad, setose. Pair of long frontal lateral diffuse setal warts present on face beside short, narrow pair of frontogenal diffuse setal warts below antennal sockets along subantennal groove of pregenae. Pair of rounded vertexal lateroantennal warts on vertex forming compact setal warts; compressed, elongate, drop-shaped, with narrow posterior end, following pattern of compressed vertex. Vertexal mediantennal compact setose warts fused, septum of joining skeletal rings of compressed warts visible, heartshaped. Occipital compact setose warts large, drop-shaped at posterior end of coronal groove, following ocular groove. Pair of sensilla basiconicae rounded, located at end of coronial groove, tangential with occipital warts. Pair of postgenal compact warts following postgenal area, curving along posterior part of ocular grooves; narrow strip pressed to ocular groove. Postgenal surface glabrous; postgenal surface hidden by eyes. Maxillary palps darker than legs and antennae; maxillary palp formula (I,III,V)-IV-II; each basal segment without setose subapicomesal nodule. Scapes shorter than head. Pedicels shorter than first segment of flagellae. Median pair of pronotal warts with white surface, covered by long, white setae; transversely elongated, occupying entire pronotum, almost tamgential mesally, narrowest laterally; lateral pair of pronotal warts small, ovoid, visible on extreme lateroapical side behind lateral end of mesal pronotal warts. White mesoscutal diffuse pair of setose warts arranged in longitudinally elongate, short, narrow, irregular patch on middle of dorsal surface of mesoscutum; separated by median notal groove; median notal groove also white; narrow pair of lateral and slightly oblique white band continuing on apical half of mesoscutum. Almost entire surface of mesoscutellar area white, covered by diffuse setal warts separated by median notal groove, almost indiscernible on white surface. Each proepisternum with small-sized, ovoid setose wart being smaller than setose wart on precoxale. Large, compact, setal wart present anteriorly on cervical sclerites; forming sclerotized surface on membranous part of neck, touching anterior cervical sclerite. Lateral cervical sclerites forming narrow anterior arms articulating anteriorly to back of head with occipital condyle above posterior tentorial pits, fused to posterior cervical sclerites. Posterior cervical sclerite forming posterad broadening plate reaching prothoracic episternum; articulating to weakly sclerotized anteromedian band of prothoracic eusternum by ventral intercervical sclerites. Dark cervical sclerite complex clearly visible on pale membranous neck. Leg claws symmetrical; spur formula 2, 4, 4; foreleg spurs almost equally long; midleg and hind leg posterior spurs half as long as anterior spurs. Forewings: length 8.5 mm; membrane whitish hyaline, with white setae; without pattern, except black setae around nygma; termen straight; R1 confluent with R2 shortly before C; base of discoidal cell located proximally of mid-length of wing; fork I longer than fork II; forks I and II present; fork I sessile; fork II short petiolate, almost sessile; crossveins s, r-m and m-cu present; postanal vein present. Hind wings: R1 long, running to R2 near apical part of C; fork I slightly longer than fork II; long basal brush present on small anal lobe.

Male genitalia. Abdominal segment IX fused annularly, with 1 longitudinal groove, widening into sclerotized plate on distal margin of apical lobes above articulation of gonocoxites; dorsal longitudinal grooves absent; vestigial path forming fold in lateral and dorsal view; tergum IX much longer than venter; anterior margins straight, vertical, slightly convex at middle; posterior margins each with rounded apical lobe, deeply excised at preanal appendages; lateroapical corners of tergum IX forming long, narrow, oblique plates over articulation of preanal appendages. Antecostae well developed, forming complete ring and dark marginal rim connecting to longitudinal grooves; spine rows absent on posterior margins of segment IX; setose areas absent on apicopleural and apicoventral areas; few setal alveoli scattered around apical lobes and on ventropleural region. Depression between segment IX and segment X slightly sloping. Segment X weakly pigmented, forming quadrangular plate with rounded apex as long as gonocoxites in lateral view; in dorsal view central ridge separating lateral concavities long triangular, running to subapical end of segment. Apicoventral setose lobes representing few subapical setae. Apicodorsal setose area not discernible. Apex of segment X filled; dorsal interlobular gap absent. Preanal appendages long, filiform in lateral and dorsal view. Gonocoxites as long as segment X; longer than preanal appendages; coxopodites straight almost parallel-sided in lateral and ventral view; harpagones slightly clavate, with small cone-shaped setae in ventral view. Phallic apparatus 3-partite in lateral view. Sclerotized phallotheca widening apicad. Endotheca and phallicata indiscernible; longitudinal section after phallotheca possibly representing endophallus; apex with phallotremal sclerites and transverse marginal strips possibly representing phallicata. Enlarged phallotremal sclerite widely V-shaped in ventral view; forming single dorsal arm in lateral view.

Holotype male: LAOS PDR: Luang Namtha Prov.: Nam Ha NBCA, Nam Mat Noi stream, 600 m upstr. Don Sai Village , 100 m upstream junction to Nam Mat Ngai , 719 m, UTM 47Q0744378, 2333774, 30.iv–2.v.2005, Malaise trap, loc 28 [N. Jönsson, T. Malm & B. Viklund] – ( NRM).

Distribution: Laos.

Etymology: Namha, named after the type locality, Nam Ha.

Figures

FIGURES 204–206. Marilia namha, new species, holotype. 204 —head, frontal; 205 —head, dorsal; 206 — right wings.

FIGURES 207–210. Marilia namha, new species, holotype. 207 — genitalia, lateral; 208 — genitalia, dorsal; 209 — gonocoxite, ventral; 210 — phallus, lateral.