Tyloperla karnataka, Stark & Sivec, 2014

Stark, Bill P. & Sivec, Ignac, 2014, Three New Species Of Tyloperla Sivec & Stark (Plecoptera: Perlidae) From India, Illiesia 10 (4), pp. 32-42 : 38

Tyloperla karnataka sp. n.

( Figs. 21-30 )

Material examined. Holotype ♂, India, Karnataka, Agumbe Ghats, 13 ° 29.452’N, 75 ° 04.221’W, 9 October 2004, Svenson, Cameron, Miller ( USNM) . Paratypes: Same data, 2♀ ( BYUC). Same site but 11 October 2004, canopy light trap, G. Svenson, 1♂ ( BYUC) .

Adult habitus. General color pale yellow-brown patterned with darker brown pigment. Head pale brown but with darker markings lateral to and forward of median ocellus, anterolateral to posterior ocelli, on lappets and limited amounts between ocelli ( Fig. 21 ); pronotal disk pale brown with darker markings; a slender pale longitudinal band lies parallel to, but does not touch the median suture. Wings pale, veins pale amber except C and Sc pale. Femora pale except narrow, dark distal ring; tibiae pale brown. Head with scattered dark hairs over much of surface.

Male. Forewing length 15.5 mm. Abdominal sterna without lobes, sensilla basiconica patches or hair brushes. Hemitergal process short, reaching far short of tergum 9, and basal callus poorly offset from process ( Fig. 22 ). A pair of small sclerites covered with fine spines occur on membranous area of tergum 10 between hemitergal processes; tergum 9 with a small mesal lobe covered by a large sensilla basiconica patch and tergum 8 with a smaller mesal sensilla basiconica patch ( Fig. 22 ). Aedeagus without spiny lobes; tube and sac in lateral aspect curved gradually ventrad and bearing a broad subapical band of variably sized spines ( Fig. 24 ); band open in a narrow, mid dorsal, longitudinal spineless strip; basal-most spines small, relatively sparse, forming a band which extends from mid-length of aedeagus along ventral margin to the apical third on the dorsal margin ( Fig. 24 ); basal spine band grades abruptly into a similar sized median band of larger, more regularly grouped spines, which abruptly changes into a narrow band of fine, elongate spines. Apex of aedeagal sac membranous and dorsal margin of tube lightly sclerotized; basal envelope armed with very fine spinules in irregular rows.

Female. Forewing length 19-21 mm. Subgenital plate on sternum 8 triangular in outline, barely projecting over base of sternum 9, and bearing a small U-shaped mesal notch; lobes of notch about as wide as notch and slightly darker than background color of sternum 8 ( Fig. 23 ). Width of plate ca. 1/3 of sternal width.

Egg. Outline barrel-shaped. Length ca. 437 μm, equatorial width ca. 377 μm ( Fig. 25 ). Smooth eclosion ring adjacent to unusually short lid; lid ca. 76 μm long. Collar short and wide, width ca. 164-186 μm ( Figs. 25-27 ); rim flanged and irregularly and deeply incised ( Figs. 26-27 ), ca. 14 irregular lobes in apical aspect ( Fig. 27 ). Chorion covered throughout (except on smooth subequatorial eclosion ring) with mostly pentagonal and hexagonal follicle cell impressions; FCI cells located on equatorial side of eclosion ring have impunctate floors elevated above marginal grooves ( Figs. 26, 29 ), those located on lid have corners of cells marked with shallow pits ( Figs. 28, 30 ); aeropyles absent from FCIs. Micropyles with simple orifices located near opercular ring ( Fig. 28 ). Eclosion ring ca. 24 μm wide in thicker areas, FCI cells ca. 27 μm across greatest width ( Fig. 29 ).

Larva. Unknown.

Etymology. The species name, used as a noun in apposition, is based on the Indian state in which the holotype was collected.

Diagnosis. This species is similar to, but slightly larger and paler than T. agumbe (see description above), and the two species co-occur at the Agumbe Ghats site. Males of T. karnataka lack the distinctive lobe present on sternum 7 of T. agumbe ( Fig. 3 ), and the aedeagus has a single broad band of variably sized spines and lacks a long laterally located seta ( Fig. 24 ), whereas the aedeagus of T. agumbe bears two distinctly separated bands of similarly sized spines ( Figs. 4-5 ) and bears on either side a single, long seta. The walls of the FCIs on most of the egg are slightly recessed as hexagonal grooves with the floors elevated and without aeropyles ( Figs. 26, 28 ), but in T. agumbe the FCI corners are marked with small rounded tubercles and the floors have 5-7 aeropyles ( Figs. 9-12 ). Female subgenital plates are similar and may overlap in basic morphology, but the present sample indicates the plate of T. karnataka is shorter and narrower at the base than the plate of T. agumbe ( Figs. 6 , 23 ). It would also appear possible to distinguish adults of these species by comparing the pigment patterns of the head ( Figs. 1 , 21 ). The following keys are provided to assist in identifying Tyloperla specimens collected on the Indian subcontinent.

Figures

Figs. 21-24. Tyloperla karnataka structures. 21. Head and pronotum. 22. Male terminalia, dorsal. 23. Female terminalia, ventral. 24. Aedeagus, lateral.

Figs. 25-30. Tyloperla karnataka egg structures. 25. Entire egg, lateral aspect. 26. Collar end. 27. Collar, apical aspect. 28. Equatorial zone, eclosion line and lid. 29. Chorionic detail, equatorial zone. 30. Chorionic detail, lid.

Figs. 1-6. Tyloperla agumbe structures. 1. Head and pronotum. 2. Male terminalia, dorsal. 3. Male abdominal sterna 7-8. 4. Aedeagus, lateral. 5. Aedeagus, ventral. 6. Female subgenital plate.

Figs. 7-12. Tyloperla agumbe egg structures. 7. Entire egg, lateral aspect. 8. Collar end with anchor. 9. Chorionic detail, equatorial zone. 10. Collar end with most of anchor removed. 11.Chorionic detail, lid. 12. Equatorial zone, eclosion line and lid.