Tyloperla khang, Stark & Sivec, 2005

Stark, Bill P. & Sivec, Ignac, 2005, New Species Of Tyloperla (Plecoptera: Perlidae) From Vietnam And Thailand, Illiesia 1 (1), pp. 1-7 : 4-7

Tyloperla khang , sp. n. ( Figs. 11-20 ) Material. Holotype ♂ from Vietnam, Gia Lai, An Khe District, Tram Lap, Azun River , 3 km NE forestry building, 21 June 1996, D. Currie, J. Swann, ROM 961076 ( ROM). Paratypes : Vietnam: Gia Lai, Buoenloy , May 1995, A. Gorohov, 1 ♂ ( PMSL) . Thua Thien-Hue, Bach Ma National Park, junction Rhododendron and Five Lakes trails, 16 June 2000, 1200 m, B. Hubley, D.C. Darling, ROM 2000531 , 1 ♀ ( IEBR) .

Adult habitus. Triocellate. Head with dark spot over ocelli distinctly narrowed anteriorly ( Fig. 11 ). Wing membrane pale brown, veins darker. Legs banded, femora dark brown apically, tibiae with apical and basal dark bands.

Male. Forewing length 12-13 mm. Hair brushes on abdominal sterna 5-7 and thoracic metasternum. Tergum 7 with a low posterior mound and a few sensilla basiconica in mesal patch. Tergum 8 with a mesal patch of sensilla basiconica on a slightly raised sclerite. Tergum 9 with a small mesal patch of sensilla basiconica ( Fig. 12 ). Hemitergal processes rounded dorsolaterally ( Fig. 14 ) and grooved along inner margin; basal cushion almost half as long as entire inner length of hemitergal process ( Fig. 13 ). Everted aedeagal sac tubular, curved ventrad and without additional lobes ( Fig. 15 ); armature consists of a subapical band of spines narrowly interrupted on dorsum, and a smaller mesal patch, narrowly connected to subapical band but broadly interrupted dorsolaterally.

Female (putative). Forewing length 15 mm. Subgenital plate generally triangular in outline, produced over about half of sternum 9 and slightly excavated on apical margin ( Fig. 16 ). Vagina longer than wide, sparsely armed with small triangular spines around periphery but with several denser clusters near base of spermathecal stalk ( Fig. 17 ). Spermatheca hook shaped but apex rounded.

Egg. Outline more or less spherical ( Fig. 18 ), collar reduced to a small button-like bump. Chorion covered throughout with large square pits with punctate floors ( Fig. 19 ). Opercular ring distinct as a narrow ridge separating lid from egg body ( Fig. 20 ). Micropyles with large funnel-like orifices located above opercular ring.

Larva. Unknown.

Diagnosis. Males of this species are similar to T. formosana (Okamoto) and T. courtneyi (described above) in the absence of a distinctly produced lobe on tergum 8. In the former species the basal cushions of the hemitergal processes are long and less rounded and the aedeagal sac has a pair of small, subapical ear-like lobes. Tyloperla courtneyi can be distinguished on the basis of the paired basolateral lobes on the aedeagal sac which are absent in T. khang . Other species of Tyloperla differ in having a distinct mesal lobe on tergum 8. The putative female is associated on the basis of shared color pattern.

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Etymology. The species name, used as a noun in apposition, honors the Khang people of Vietnam.

Figures

Figs. 11-17. Tyloperla khang. 11. Head and pronotum. 12. Male terminalia. 13. Hemitergal process, dorsal. 14. Hemitergal process, lateral. 15. Aedeagus, lateral. 16. Female terminalia. 17. Vagina and spermateca.

Figs. 18-20. Tyloperla khang egg structures. 18. Entire egg, lateral. 19. Egg collar end with anchor. 20. Opercular ring and lid.