Tyloperla agumbe, 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 : 33-34

Tyloperla agumbe sp. n.

( Figs. 1-12 )

Material examined. Holotype ♂, India, Karnataka, Agumbe Ghats , 13 ° 29.386’N, 75 ° 04.537’E, 9 October 2004, G. Svenson ( USNM) . Paratypes: India, Same site as holotype specimen but 11 October 2004, canopy light trap, G. Svenson, 1♂ ( BYUC) . Maharashtra, Amboli , 15 ° 55.843’N, 73 ° 57.836’E, 3 October 2004, Svenson, Cameron, Miller, 9♂, 6♀ ( BYUC) .

Adult habitus. General color brown, patterned with pale brown. Dorsum of head covered with moderately dense patch of upright, long, brown hair; head mostly pale but with darker areas between ocelli; lappets and basal antennal segment pale ( Fig. 1 ). Pronotum with narrow median yellow band and wider lateral pale band; disc mostly brown or pale brown, reflexed margin bearing a dark brown band. Wings amber, veins darker except for pale C vein. Femora pale except narrow, dark brown band at distal tips, tibiae dark brown.

Male. Forewings ca. 13-14.5 mm long. Abdominal sterna 6-8 bearing mesal patches of short, thick sensilla basiconica; sternum 8 with ca. 20 in scattered patch, sternum 7 bearing a low, posteromedian tubercle covered rather densely with sensilla basiconica which extend to anterior third of segment in a more scattered patch ( Fig. 3 ), sternum 6 with only a few (ca. 4-5) sensilla basiconica in a marginal patch, sterna 8-9 without sensilla basiconica. Hemiterga with a well-developed basal callus and a short anterior process which reaches far short of tergum 9; a small arc of sensilla basiconica occurs between hemiterga on tergum 10 ( Fig. 2 ); terga 8-9 each with a small mesal lobe covered with sensilla basiconica. Aedeagus without spiny lobes; tube and sac in lateral aspect curved gradually ventrad and bearing a ventromedian saddle of moderately long spines, and a subapical ring of short, thick, spines ( Fig. 4 ); subapical ring interrupted by a longitudinal median groove in which few spines occur, and from which a small membranous bag-like structure is everted ( Fig. 5 ). A single seta occurs on each side between ventral saddle of spines and subapical ring ( Fig. 5 ).

Female. Forewing length 16-17 mm. Subgenital plate on sternum 8 triangular in outline, projecting over about 1/3 of sternum 9, and bearing a small U-shaped mesal notch ( Fig. 6 ). U-shaped region surrounding notch hairless; plate darker than background pigment of segment. Width of plate at base ca. ½ of sternal width.

Egg. Outline almost spherical ( Fig. 7 ). Length ca. 335 μm, equatorial width ca. 328 μm. Collar short and wide, width ca. 89 μm, rim not distinctly flanged, sides bearing ca. 11 vertical ridges in lateral aspect ( Fig. 10 ). Anchor a thin, umbrella-shaped structure with short pedicel, an irregular margin and apparently few surface globular bodies ( Fig. 8 ). Chorion covered throughout with mostly pentagonal and hexagonal follicle cell impressions ( Figs. 9-12 ); walls consist of six low, rounded tubercles set at FCI angles, forming cells ca. 27 μm across; most FCI floors contain a single central and six, fine submarginal aeropyles, but some contain 8-9 aeropyles and the central one may sometimes be displaced ( Fig. 9 ). FCI’s on lid have tubercles more tightly grouped and slightly larger than those nearer the equatorial region ( Fig. 11 ). Subequatorial eclosion ring distinct, surface of ring smooth and ca. 12 μm wide ( Fig. 12 ). Micropyles not detected.

Larva. Unknown.

Etymology. The species name, based on the type locality, is used as a noun in apposition.

Diagnosis. The short hemitergal lobes and median sclerite with sensilla basiconica on tergum 10 are features unique to this species and T. karnataka sp. n. among known Tyloperla ; males of the two are distinguished on the basis of the presence of a prominent lobe on sternum 7 in T. agumbe . The female subgenital plate, reaching near midlength of sternum 9, is somewhat shorter than that of previously described species, and the egg is generally similar to those of T. courtneyi Stark & Sivec , T. karnataka (see below), T. khang Stark & Sivec and T. trui Cao & Bae in having a distinct eclosion ring and prominent FCI’s over the entire egg ( Cao & Bae 2007; Stark & Sivec 2005). A more complete diagnosis is given below under T. karnataka .

Figures

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.