Eotrechus konkakinh, Tran & Zettel & Sites, 2023

Tran, Anh Duc, Zettel, Herbert & Sites, Robert W., 2023, Revision of the genus Eotrechus Kirkaldy (Hemiptera, Heteroptera, Gerridae), with descriptions of six new species, Deutsche Entomologische Zeitschrift 70 (1), pp. 69-111 : 69

Eotrechus konkakinh sp. nov.

Figs 1B , 16 , 17 , 25

Material examined.

Holotype: Vietnam • ♂ (apterous); Gia Lai Province, Kon Ka Kinh National Park, H’Ngoi, Thác Ba T ầng waterfall and stream; 27 Apr. 2022; Tran A.D. & Phan Q.T. leg.; TAD2224; ZVNU.

Paratypes: Vietnam • 12 ♂♂, 12 ♀♀ (apterous) , 1 ♂, 1 ♀ (macropterous); same locality data as holotype; ZVNU • 3 ♂♂, 3 ♀♀ (apterous); same locality data as holotype; ZRC • 3 ♂♂, 3 ♀♀ (apterous); same locality data as holotype; NHMW .

Description.

Size: apterous males, length 7.20-7.80 (holotype 7.70), width 2.06-2.25 (holotype 2.18); macropterous male, length 9.10, width 2.16; apterous females, length 8.00-8.90, width 2.31-2.59; macropterous female, length 9.10, width 2.52.

Colour (Figs 1B , 16 ): Dorsum generally dark-brown to black, covered with golden pubescence. Anterolateral sides and posterior margin of head with orange marks. Pronotum with three longitudinal orange stripes, one median (longer) and two sublateral, all not reaching posterior margin. Mesonotum with anterior half brownish-yellow and posterior half with a pair of dark marks on either side of mid-line, posteriorly suffusion with darker-yellow ground colour. Propleuron black, with a longitudinal brownish-yellow stripe behind eye and yellowish area dorsad of black proacetabulum. Mesoacetabulum mostly black and metacetabulum black dorsally and orange ventrally. Proacetabulum and mesopleuron with thin stripe of reflective silvery pubescence; meso-, metacetabula and sides of abdomen with patch of reflective silvery pubescence. Antennae brown. All legs chiefly brownish-yellowish. Venter of head and prosternum mainly yellowish; in some females, venter of head with median brown mark. Mesosternum and metasternum varying from yellowish to brown, with suffusion of indistinct brown marks. Abdominal sterna varying from yellowish to brown, darker brown dorsally just ventrad of terga.

Structural characteristics: Apterous male (holotype): Head width across eyes 1.66; interocular width 0.63; eye kidney-shaped in dorsal view, length of eye 0.84. Antennae: length 6.83 and shorter than body length, lengths of segments I-IV: 1.95: 1.65: 1.35: 1.88; segment I with six spines subapically. Pronotum broader than long, shorter than head length (0.96: 1.38). Lengths of mesosternum and metasternum: 1.90 and 0.73. Lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II) as follows: fore leg: 2.78: 2.70: 0.30: 0.43; middle leg: 6.95: 6.65: 0.49: 0.47; hind leg: 7.10: 7.75: 0.48: 0.49. Fore leg (Fig. 17A, B ): trochanter with three long, fine setae (about as long as width of trochanter, one on ventral, two on dorsal surface); femur moderately incrassate, with a large basal tubercle on flexor side, length of femur ca. 4.8 × maximum width at basal tubercle (2.78: 0.58), 5.2 × maximum width at basal part, excluding basal tubercle (2.78: 0.53); subbasal tubercle of femur bearing a distinct round nodule covered by black, minute setae; distal part of femur gradually tapering towards apex, along flexor side of femur with a row of eight long, stiff setae; tibia almost straight, slightly thickened near middle of flexor side before narrower distal part, with scattered long, stiff setae on extensor side and some shorter, stout setae on apical part; tarsus covered with long, soft, yellowish setae on ventral surface, and only with short setae on dorsal surface. Middle and hind femora slender and slightly shorter than body length; middle and hind femora, middle and hind tibiae with scattered, short, brown spines (denser on middle femur). Claws stout, lengths of fore, mid- and hind claws: 0.14: 0.18: 0.18. Abdomen short, total length of abdominal sterna II-VII: 1.75, sterna II-V not medially grooved, only sternum VI weakly medially grooved. Sternum VII longer than length of two preceding sterna combined (0.58: 0.43), broadly depressed, posterior margin with a large median notch about as deep as one-third length of sternum VII (Fig. 17C ). Genitalia (Fig. 17C-G ): abdominal segment VIII large, ventral side distinctly longer than sternum VII, near posterior margin with dense, yellowish, soft setae; pygophore with a dense posterolateral tuft of long, black, bristle-like setae, caudal projection constricted before laterally-expanded apex, forming two broad, lateral lobes directed dorsad, apical margin of projection almost straight (thus, the shape of pygophore in ventral view appearing somewhat like "a snifter beer glass", with caudal projection as the base of the glass); paramere subovoid; proctiger with small lateral tubercles situated ventrally, proctiger with a dense lateral fringe of long, black, bristle-like setae, long brown setae along lateral and posterolateral margins.

Apterous female: Head width across eyes 1.70; interocular width 0.68; eye kidney-shaped in dorsal view, length 0.81. Antennae 0.8 × body length (6.94: 8.40), lengths of segments I-IV: 1.93: 1.60: 1.43: 1.98; segment I with five dark spines subapically. Pronotum shorter than head length (0.98: 1.41). Lengths of mesosternum and metasternum: 2.16 and 0.83. Lengths of leg segments (femur: tibia: tarsal segment I: tarsal segment II): fore leg: 2.78: 2.50: 0.32: 0.42; middle leg: 7.15: 6.90: 0.50: 0.48; hind leg: 7.30: 7.95: 0.47: 0.49. Fore trochanter with two long, fine setae on ventral side (seta length subequal to width of trochanter). Fore femur simple, moderately incrassate, length ca. 7.1 × maximum width (2.78: 0.39), moderately thickened at basal part and gradually tapering towards apex, along flexor side with a row 10-12 long, stiff setae, all shorter than greatest width of fore femur. Fore tibia straight with many long, stout setae on extensor surface and some shorter, stout setae on apical part. Fore tarsus covered with long, soft, yellowish setae on ventral surface, and only with short setae on dorsal surface. Middle and hind femora slender and shorter than body length; middle and hind femora, middle and hind tibiae with scattered, short, brown spines (denser on middle femur). Claws stout, lengths of fore, mid- and hind claws: 0.15: 0.20: 0.18. Total length of abdominal sterna II-VII ca. 0.36 × body length (3.06: 8.40). Sternum VII ca. 1.1 × length of two preceding sterna combined (0.98: 0.88), posterior margin almost straight. Connexival apex of sternum VII truncate, and lateral and ventral surfaces of sternum VII set with a few long, golden setae interspersed by denser, short, golden setae (Fig. 17I ). Genitalia: not concealed by sternum VII; tergum VIII simple; proctiger short, with pointed apex and directed caudad (Fig. 17H, I ).

Macropterous male (Fig. 16C ): Similar to apterous male but with following differences: Pronotal lobe black with scattered, golden setae, irregularly punctured; wings chiefly black with four closed cells and with relatively denser golden setae on wing veins and scattered, golden setae elsewhere, membrane greyish-brown. Pronotum length (including posterior lobe) 2.94, humeral width 1.91. Fore wing length 6.10.

Macropterous female: Colouration similar to macropterous male. Pronotum length (including posterior lobe) 3.00, humeral width 1.97. Fore wing length 6.10. Other characteristics similar to apterous female.

Remarks.

Eotrechus konkakinh sp. nov. is placed in the E. pingae species group on the basis of having a large basal tubercle on the fore femur of the male and a broad caudal projection of the pygophore. In this species group, E. konkakinh sp. nov. is most similar to E. siamensis in having the caudal projection of the pygophore expanded posterolaterally and dense tufts of long, black, bristle-like setae on both the pygophore and proctiger. Eotrechus konkakinh sp. nov. can be distinguished from E. siamensis by the structure of the basal part of the male fore femur and shape of the caudal projection of the pygophore. In males of E. konkakinh sp. nov., the fore femur has a distinct sub-basal nodule, which is covered with minute, black setae, whereas in males of E. siamensis , a pointed tooth is in the same position. The caudal projection of the pygophore of E. konkakinh sp. nov. is longer and its lateral lobes are broad and directed dorsad, whereas that of E. siamensis is shorter and crescent-shaped (distinctly concave posteriorly and angular posterolaterally).

Etymology.

The name Eotrechus konkakinh refers to the type locality, Kon Ka Kinh National Park. It is used as a noun in apposition.

Distribution.

Vietnam: Gia Lai (Fig. 25 ).

Eotrechus hygropetricus species group

Diagnosis. Male: fore femur simple, tapering towards apex; pygophore not modified posteriorly, but with patches of long, dark, bristle-like setae posterolaterally; proctiger simple, with lateral patches of long, dark, bristle-like setae. Female: genitalia small, but visible in lateral view.

Species included. E. hygropetricus Andersen, 1982, E. pilicaudatus Tran & Zettel, 2006, and E. boukali sp. nov.

Figures

Figure 1. In-situ photographs of Eotrechus. A. E. vietnamensis, apterous male, from Ha Giang Province, Vietnam; B. E. konkakinh sp. nov., apterous male, from Gia Lai Province, Vietnam.

Figure 16. Eotrechus konkakinh sp. nov., habitus. A. Apterous male; B. Apterous female; C. Macropterous male.

Figure 17. Eotrechus konkakinh sp. nov. A, B. Right fore leg of male, dorsal and ventral views; C. Abdomen of male, ventral view; D. Genitalia, lateral view; E, F. Pygophore, ventral and dorsal views; G. Proctiger, dorsal view; H, I. Posterior part of abdomen of female, dorsal and ventral views (A-C, H, I. Same scale; D-G. Same scale).

Figure 25. Distribution records of species of Eotrechus. Squares represent E. kalidasa species group; circles represent E. pingae species group; triangles represent species unassigned to a group.