Stenchaetothrips spinulae, Tyagi, Kaomud & Kumar, Vikas, 2008

Tyagi, Kaomud & Kumar, Vikas, 2008, Two new species of Stenchaetothrips (Thysanoptera: Thripidae) from India, Zootaxa 1851, pp. 58-64 : 62-63

Stenchaetothrips spinulae sp. n.

Female macroptera. Body brown. Antennal segments I-II, IV-VII brown, III pale yellow. Fore wing brownish in distal ¾ and yellow in proximal ¼. Legs pale brownish.

Ocellar seta pair III situated between fore and hind ocelli, just inside the ocellar triangle; smaller than pair II. Postocular setae III longer than setae I, setae II and setae IV subequal.

FIGURES 8–12. S. spinulae 8. Head & Pronotum Female, 9. Meso- & Metanotum Female, 10. Meso- & Metasternum female, 11. Abdominal tergites VIII–X female, 12. Abdominal sternites III–VII male.

Pronotum with few transverse lines of sculpture. Mesonotum with anterior pair of campaniform sensilla present; with weak, transverse lines of sculpture at middle. Metanotum without campaniform sensilla, with closely spaced longitudinal lines of sculpture converging posteriorly at middle somewhat like Thrips palmi ; median setae slightly back of anterior margin. Spinula present on mesosternum. Fore wing costa with 22-27 setae; second vein with 10-16 setae.

Abdominal tergites II-VII with only few teeth at extreme lateral sides. Tergite IX with two pairs of campaniform sensilla. Sternite I with three minute setae apically at middle; median pair of primary setae on VII usually far ahead of posterior margin.

Male macroptera. Body bicoloured, head, thorax, and legs yellow. Abdominal segments I-V yellow but tergites II-V with light brown patch in middle, rest of the segments brown. Antennal segments I-IV yellow, V- VII light brown. Fore wing brown in distal ¾ and yellow in proximal ¼. Legs yellow. Abdominal tergites I-VI without teeth on posterior margin; tergite VII with a few small teeth at posterior margin; tergite VIII without posteromarginal comb. Abdominal sternites III-VII with oval glandular areas.

Measurements (holotype female in microns): Total body length 1480. Head length 145, width at eyes 152, at cheeks 145. Ocellar setae pair II length 27, pair III length 15. Postocular setae I length 27, setae III length 37. Total antennal length 285-320, Length (width) of antennal segments I 27 (30), II 35 (25), III 57 (17), IV 57 (17), V 41 (15), VI 55 (16), VII 20 (5). Pronotum length 132, width 167. Posteroangular inner setae length 67, outer setae length 65. Fore wing length 560-700, width at middle 35-45. Fore femur width 57; hind tibia length 162. Ovipositor length 250.

Male total body length 1280. Length (width) of glandular areas on sternites III-VII 42 (7), 47 (10), 45 (7), 37 (7), 35 (12). Fore wing length 650, width at middle 40.

Specimens examined: Holotype female: India: Delhi, on Bamboo, 21-iii-2003. Paratypes: India: Delhi, on Bamboo, 10 females, 5 males, 21-iii-2003 (Vikas Kumar).

Comments: This species shows sexual dimorphism in colour, as females are entirely dark brown and males are bicoloured. Further, abdominal tergite VIII has a complete posteromarginal comb in females but this is lacking in males.

S. spinulae is closely related to S. tenebricus (Ananthakrishnan & Jagdish) and the females are not separable. However, the males of tenebricus are brown in colour, lack a glandular area on sternite VII, and possess a complete comb on tergite VIII.

The male of this new species runs to couplet 19 in the key to Indian species ( Bhatti 1982). That couplet includes bicolor with the median pair of metanotal setae placed far back of anterior margin and a complete comb of microtrichia on abdominal tergite VIII. However, in spinulae these setae are placed just near to the anterior margin and abdominal tergite VIII lacks a comb of microtrichia. Moreover, glandular areas on abdominal sternites III-VII of bicolor are small and even rudimentary on S7, but spinulae has well-developed oval glandular areas these sternites.

Etymology: The species name refers to the presence of the spinula on the mesosternum.