Eotrechus kalidasa Kirkaldy, 1902

Duc, Tran Anh & Zettel, Herbert, 2006, Notes on Eotrechus Kirkaldy, 1902 (Heteroptera: Gerridae), with descriptions of two new species, Zootaxa 1353, pp. 39-51 : 46-48

Eotrechus kalidasa Kirkaldy, 1902

( Figs. 17–20 )

Eotrechus kalidasa Kirkdaldy, 1902: 137 (type­locality: Carin Cheba, Burma). — Distant, 1904: 182 (description), fig. 130. — Paiva, 1919: 364 (records Assam [locality today in Meghalaya]). — Andersen, 1982: 8 –11 (descriptive notes), fig. 8, 15, 28.

Material examined. Paratype: 1Ψ (macropterous), MYANMAR, Carin Cheba, 900­ 1100 m, leg. L. Fea, 1889, Distant Collection 1911­383 ( BMNH).

Other: INDIA (NE): 1ɗ (macropterous), Meghalaya, 3 km E Tura, 1150 m, 25°30'N 94°14'E, leg. L. Dembicky & P. Pacholatko, 18 Apr. 1999 ( NHMW).

Descriptive notes on macropterous male. Size: length 9.50, width 2.06.

Colour. Dorsal side mainly brownish and black with silvery or golden pubescence. Head with two yellow spots laterally on anterior margin of eyes and yellow spot on posterior margin of head; pronotum with median yellow stripe and two lateral stripes on anterior part, pronotal lobe yellowish brown; legs and wings like in females described by Andersen (1982). Venter with silvery pubescence. Venter of head dark brown; prosternum yellow; mesosternum brownish yellow medially and dark brown laterally; metasternum and abdominal venter brownish yellow.

Structural characteristics: Head width across eyes 1.72, head length 1.50; interocular width 0.64; eye kidney­shaped on dorsal view, eye size 0.76. Lengths of antennal segments 1–2: 2.70: 2.43 (3–4 missing). Pronotum length 2.84. Wing venation as illustrated in Andersen (1982). Lengths of mesosternum and metasternum: 1.72 and 1.13. Lengths of leg segments (femur: tibia: tarsal segment 1: tarsal segment 2) as follows, fore leg: 3.60: 2.85: 0.56: 0.48; mid leg: 6.50: 6.95: 0.45: 0.53; hind leg: 6.90: 8.75 (hind tarsus missing); Fore femur ( Fig. 17 ) simple and very slender, length about 13.84x maximum width (3.60: 0.26), ventral surface without spinelike hairs; fore tibia straight and simple, with row of long spinelike hairs on apical margin. Mid and hind femur slender and shorter than the body, with very few small black spines. Mid tarsi ( Fig. 18 ) without ventral row of spines. Claws stout, lengths of fore, mid claws 0.19: 0.21. Abdomen relatively long, length of abdominal venter from sternum 2 to sternum 7: 3.00, with narrow median groove from sterna 3–7; sternum 7 about 0.75x length of two preceding sterna combined (0.68: 0.91), posterior margin slightly emarginated ( Fig. 19 ). Genital segments and parameres ( Fig. 20 ) matching illustrations by Matsuda (1960: figs. 552, 557).

Remarks. Eotrechus kalidasa is the type species of the genus and was described by Kirkaldy (1902) from “Carin Cheba, Burma,” which is located in the mountains east of Toungoo in Kayin State, Myanmar. Kirkaldy wrote that the type material was to be deposited in the Museo Civico di Storia Naturale di Genova, Italy ( Kirkaldy 1902), but it apparently never was returned there by Kirkaldy ( Andersen 1982). Matsuda (1960), reviewing the Gerridae of the world, provided a more detailed description and good illustrations based on one male from the G.W. Kirkaldy Collection at the University of Kansas, USA, which originated from the type locality and which is probably a syntype. Later, this specimen was designated the lectotype by Andersen (1982) without examination, but based on the “identity confirmed by P.D. Ashlock, in litt.” (for more details, see Andersen 1982, p. 7–10). When revising the genus Eotrechus, Andersen (1982) examined only two females, one from the type locality (deposited in BMNH, London) and the other one from "Assam, Garo Hills above Tura.” Already, much earlier, Paiva (1919) had recorded E. kalidasa from Assam ( India) based on the same female, which is now in the collections of the Zoological Survey of India. Although E. kalidasa can be distinguished by the slender fore femur, the record of E. kalidasa from the Garo Hills remains still uncertain, as females of Eotrechus species are normally difficult to separate.

There was the possibility that the population from the Garo Hills belongs to another species closely related to E. kalidasa . Thanks to Dr. L. Dembicky & Dr. P. Pacholatko (Brno, Czech Republic), the authors were able to examine a male from the same area and confirm the occurrence of E. kalidasa in India. Some descriptive notes on that specimen are provided above. Unfortunately, the authors could not borrow the lectotype, but as the Meghalaya specimen matches the description and illustrations by Matsuda (1960), especially in the structures of the genitalia, we determine the Maghalaya specimen as Eotrechus kalidasa .

Figures

FIGURES 17 – 20. Eotrechus kalidasa (male): (17) right fore leg; (18) mid tarsi; (19) abdominal venter (genitalia excluded); (20) pygophore, lateral view.