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

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Tyloperla karnataka

sp. n.

Tyloperla karnataka sp. n.

( Figs. 21-30 View Figs View Figs )

Material examined. Holotype ♂, India, Karnataka, Agumbe Ghats, 13 ° 29.452’N, 75 ° 04.221’W, 9 October 2004, Svenson, Cameron, Miller ( USNM) GoogleMaps . 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 View Figs ); 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 View Figs ). 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 View Figs ). 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 View Figs ); 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 View Figs ); 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 View Figs ). Width of plate ca. 1/3 of sternal width.

Egg. Outline barrel-shaped. Length ca. 437 μm, equatorial width ca. 377 μm ( Fig. 25 View Figs ). 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 View Figs ); rim flanged and irregularly and deeply incised ( Figs. 26-27 View Figs ), ca. 14 irregular lobes in apical aspect ( Fig. 27 View Figs ). 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 View Figs ), those located on lid have corners of cells marked with shallow pits ( Figs. 28, 30 View Figs ); aeropyles absent from FCIs. Micropyles with simple orifices located near opercular ring ( Fig. 28 View Figs ). Eclosion ring ca. 24 μm wide in thicker areas, FCI cells ca. 27 μm across greatest width ( Fig. 29 View Figs ).

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 View Figs ), and the aedeagus has a single broad band of variably sized spines and lacks a long laterally located seta ( Fig. 24 View Figs ), whereas the aedeagus of T. agumbe bears two distinctly separated bands of similarly sized spines ( Figs. 4-5 View Figs ) 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 View Figs ), but in T. agumbe the FCI corners are marked with small rounded tubercles and the floors have 5-7 aeropyles ( Figs. 9-12 View Figs ). 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 View Figs , 23 View Figs ). It would also appear possible to distinguish adults of these species by comparing the pigment patterns of the head ( Figs. 1 View Figs , 21 View Figs ). The following keys are provided to assist in identifying Tyloperla specimens collected on the Indian subcontinent.


Smithsonian Institution, National Museum of Natural History