Psilotreta kurenschikovorum, Arefina-Armitage & J, 2011

Arefina-Armitage, I. & J, Brian, 2011, The genus Psilotreta Banks (Trichoptera: Odontoceridae) in Vietnam, Insecta Mundi 2011 (180), pp. 1-6 : 3-5

Psilotreta kurenschikovorum sp. n.

Fig. 1-2

Diagnosis. Psilotreta kurenschikovorum is unique compared to all other species of the genus by fork I in the forewing short, arising at the junction of R2+3 and crossvein s; by the absence of an anal cell; and, by the hindwing with fork I petiolate and R4+5 without a base (discoidal cell incomplete). In addition, it differs by the shape of the epicranial suture on the vertex, with long arms; by the bifid apical segment of the inferior appendage; and, by the presence of nipple-like processes on the bottom of the endotheca. Psilotreta kurenschikovorum sp. n. shares similarities with a group of Psilotreta species (e.g., P. albogera Malicky 1995 , P. aran Malicky 2009 , P. dardanos Malicky 2000 , P. kwantungensis Ulmer 1926 , and P. quin Malicky and Chantaramongkol 1991 ). In all these species, the basal segment of the inferior appendage has a developed posteroventral portion, and the apical segment arises apicodorsally.

Adult. Length of male forewing: 7.1-7.4 mm. Head, thorax and legs light brown to yellowish; setal warts slightly darker than background. Eyes large, globular. Head nearly as long as wide in dorsal view. Frons with a pair of elongated warts subtending eyes below antennae. Vertex with Y-shaped epicranial suture having long arms (more than 2/3 of entire length of head), surrounding pair of prominent frontal warts ( Fig. 1A ); and with antennal warts oval, located below antennal socket between edge of eye and epicranial arm; posterior warts larger than antennal warts, round, connected to anterior margin of very long posterolateral warts subtending eyes posteriorly. Antennae slightly longer than wings. Scapus subequal in length to head. Maxillary palpi thin, segments 3, 4, and 5 subequal in length, longer than segments 1 and 2. Labial palpi segment 3 slightly longer than segment 2. Wings ( Fig. 1B ) elongate, subequal in width. Forewings yellow-brownish with a few small light spots scattered in anterior part; hind wings paler. Forks I, II, and V present in both wings. Discoidal cell medium size and situated in middle of forewing; absent in hind wing. Fork I in forewing short, arising at junction of R2+3 and crossvein s; fork I in hind wing petiolate. Crossveins sc-r and r faint in forewing, indistinct in hind wing. In forewing, M without base (no thyridial cell), represented by single apical branch, originating from R4+5; Cu2 indistinct or missing; single anal vein without basal cell; postanal vein long. In hind wing, R4+5 without a base; M divided to M1+2 and M3+4; fork V very long; 2 anal veins; sparse long hairs along posterior edge of anal area.

Male genitalia ( Fig. 2 ). Segment IX stout, with anteromesal margin prominently produced anteriorly; posterior margin nearly straight below preanal appendage; a few setae located posterolaterally and ventromesally. Dorsum of segment IX triangular, finely granular. Preanal appendage very large, evenly elongate, bearing scattered long setae. Segment X truncated, with shallow depression posteromesally; subbasally with pair of setal warts; subapically with pair of finger-like lobes covered with setae. Intermediate appendage located on side of segment X, saber-like, slightly curved posterodorsally in lateral view and posteromesally in dorsal view; longer than main body of segment X, but shorter than subapical finger-like lobes of segment. Basal segment of inferior appendage thick, with elongate posteroventral portion nearly as long as preanal appendage and protruding slightly beyond apical segment of inferior appendage; in lateral view, apical segment bifid, arising apicodorsally, and covered with numerous short, dark spines. Phallic apparatus with tubular sclerotized phallotheca; endotheca membranous with large phallotremal sclerite, dorsal part spoon-shaped in dorsal view; 2 slender, acute parameres located ventrally; 3 pairs of membranous, nipple-like processes on bottom of distal portion of endotheca, with tips lightly sclerotized, each with straight seta located off-center of tip. In holotype, basal portion of endotheca bearing 2, similar nipple-like processes located posterolaterally on left side, and 1 process on right side; paratype specimens with single process on each side.

Female and immature stages. Unknown.

Holotype male: Vietnam, Thua Thien-Hue Province, Bach Ma National Park, Parashorea trail, dry stream bed in dipterocarp forest, 9 km from park entrance, 1000 m, 16 o 12’2.4”N, 107 o 50’49.6”E, Malaise trap, 26 May - 13 June 2001, C. Darling and N. Tatarnic ( ROM 2001503 , ROME) . Paratypes: 5 males, same data as holotype ( ROM 2001503, ROME). All types were deposited in the Royal Ontario Museum.

Distribution. Known only from the type locality in Thua Thien-Hue Province ( Vietnam).

Etymology. This species is named after our friends, Andrei and Natalia Kurenschikov, living in Port Vanino, Russia.

Remarks. The nipple-like processes on the bottom of the endotheca are suggestive of a tactile function used during copulation.

Taxonomic Notes. Among the Asian Psilotreta species keyed by Parker and Wiggins (1987: 32), P. kurenschikovorum sp. n. is most similar to P. kwantungensis Ulmer and P. lobopennis Hwang. The following changes are made to the aforementioned key:

2(1). Inferior appendages with ventral lobe of basal segment subequal in length to apical segment ....

....................................................................................................... P. kwantungensis Ulmer — Inferior appendages with ventral lobe of basal segment extending beyond apex of apical segment

. .................................................................................................................................................. 3

3(2). Apical segment of inferior appendage bifid; fork I of forewing short, arising at junction of R2+3 and crossvein s .......................................................................... P. kurenschikovorum sp. n.

— Apical segment of inferior appendage acuminate; fork I of forewing long, arising at a point halfway down the discoidal cell .......................................................................... P. lobopennis Hwang

Figures

Figure 1. Psilotreta kurenschikovorum sp. n., male holotype: A) Head, dorsal; B) Wings (abbreviations: Sc – subcostal vein; R – radial vein; M – median vein; Cu – cubital vein; A – anal vein; DC – discoidal cell; sc-r, r, s – crossveins).

Figure 2. Psilotreta kurenschikovorum sp. n., male genitalia. Holotype: A) Lateral; B) Dorsal; C) Ventral; D) Endotheca ventral. Paratype: E) Phallic apparatus, lateral; F) Endotheca dorsal (parameres not illustrated).