Namtokocoris kem Sites

Sites, Robert W. & Vitheepradit, And Akekawat, 2007, Namtokocoris Sites, a new genus of Naucoridae (Hemiptera: Heteroptera) in waterfalls of Indochina, with descriptions of six new species, Zootaxa 1588, pp. 1-29 : 16-18

Namtokocoris kem Sites , NEW SPECIES

Figs. 3, 7, 10d, 11d, 12d, 13d, 14d

Descriptions

Macropterous male. See generic description; only additional details provided here. Holotype, length 8.47; maximum width 5.56. Paratypes (n = 10), length 8.22–8.63 (mean = 8.39); maximum width 5.39–5.73 (mean = 5.56). Overall coloration dorsally dark brown with yellowish-brown head, pronotum, and wide band at anterior end of embolium gradually narrowing to obsolescence near membrane of hemelytra; heavy dark punctation forming pattern on head and pronotum, heaviest near posterior margin of head and pronotum in middle 2/3 and posterior to transverse sulcus ( Fig. 10 d). Ventrally, generally medium brown; golden brown on anteclypeus, lateral margins of prothorax, and exposed portion of hemelytra.

Head length 1.40, maximum width 3.36, synthlipsis at posteromesal corner 1.22, with four pairs of setal rosettes bordering inner margin of eyes, fifth pair further mesad and slightly ventrad to anterior margin. Antennal proportions 5:7:14:9. Pronotum broad, 2.7 x as wide as long; with elongate, erect setae especially evident laterally; length at midline 1.89; maximum width at posterolateral corners 5.17; posterolateral corners rounded, produced posteriorly ( Fig. 11 d). Scutellum dark brown, heavily punctate, triangular with distinctly sinuate posterolateral margins, twice as wide as long, width 3.03, length 1.48, longitudinal protuberances broad, tumescent, each with line of erect setae. Claval commissure length 1.52. Embolium with anterolateral margin abruptly curved ( Fig. 11 d), yellowish anterior band gradually narrowing posteriorly and becoming obsolete near membrane of hemelytra, length 3.57 (chord measurement), maximum width 0.94. All coxae pale yellow, trochanters and femora yellowish brown, fore tibia/tarsus darker brown, middle and hind tibia/ tarsus yellowish brown. Leg measurements as follows: foreleg, femur 1.82, tibia 1.20, tarsus 0.32; middle leg, femur 2.02, tibia 1.44, tarsomeres 1–3 0.16, 0.28, 0.30; hind leg, femur 2.58, tibia 2.60, tarsomeres 1–3 0.30, 0.70, 0.68. Posterior margin of mediosternite III straight, IV concave, V strongly concave, VI straight or with slight concavity in middle third, VII convex, VIII broadly rounded. Posterior margin of laterosternite V broadly sinuate. Genital operculum with posterolateral margins straight, apex acuminate. Parameres rounded distally, flanking lateral margins of and slightly surpassing median process of pygophore, stout hairs on mesal 2/3 of dorsal surface; pygophore slightly asymmetrical, median process concave-tipped and with distal angles sharp; aedeagus with mid-dorsal carina, left margin gently arcuate with distinct convexity in distal fifth, right margin convex in basal 4/5 and concave in distal fifth to parallel convexity of left, series of striations in basal third on both sides of mid-dorsal carina ( Figs. 12 d, 13d).

Macropterous female. Paratypes (n = 10), length 7.80–8.47 (mean = 8.18); maximum width 5.48–6.06 (mean = 5.59). Similar to male in general structure and coloration; pad of hairs on middle tibia reduced; posterior margin of mediosternite V slightly concave, mediosternite VI straight or slight concavity at middle; subgenital plate (VII) evenly rounded; posterolateral corner of laterosternite VI with broad, rounded posterior production ( Fig. 14 d).

Diagnosis

Males of N. kem can be recognized by the tip of the aedeagus, which is not expanded distally, but bends slightly to the right with a pointed apex. The parameres are similar to those of N. siamensis , but the median process of the pygophore is concave distally with acute anterolateral corners. In females, the subgenital plate has a rounded apex. The right hemelytron has a very subtle lateral expansion at the level of abdominal segment V; however, it is far less distinct than in N. akekawati and N. khlonglan (see below). The posterior margin of laterosternite VI has a concavity near the middle. In both sexes, the head and pronotum generally are more darkly patterned than in its congeners, and the thin, yellow lateral band tends to appear complete around the wings, although becoming thin posteriorly. The posterolateral corner of the pronotum is produced posteriorly, as in N. dalanta and N. khlonglan . Also, the anterolateral margin of the embolium is abruptly curved, although less so than in N. dalanta .

Discussion

This species has been taken in northern Vietnam and northern Thailand. The habitat in Vietnam is the only limestone waterfall at which members of the genus have been collected ( Fig. 7 ). Many limestone waterfalls in Thailand were sampled, but never yielded Namtokocoris . At the type locality ( Fig. 7 ), this species was collected from the moderately deeply pitted surface of the algae-covered rocks in areas where the shear force of the water was high, as well as toward the margin of the waterfall on rocks with only a standing film of water and algae. In the area of higher shear force, it was collected syntopically with nymphs of Cheirochela , a very large naucorid.

Etymology

This species is named for the waterfall, Thac Kem , in which it was found at the type locality.

Repositories

The holotype, allotype, and some paratypes are deposited in the Enns Entomology Museum, University of Missouri-Columbia, U.S.A. Additional paratypes will be deposited in the California Academy of Sciences, San Francisco, U.S. A; the Natural History Museum – Vienna, Austria; and eventually to a museum in Vietnam to be identified.

Material examined

Holotype, macropterous male, and allotype, macropterous female: VIETNAM: Nghe An Province, Pu Mat National Park, Thac Kem , N18o 58.381, E104o 42.688, elev 256 m, 15 July 2007, rock face of limestone waterfall, R. W. Sites, L-1021. Paratypes: same data as primary type (7 males, 7 females, many nymphs); same locality, 12 July 2007, R. W. Sites & Trung Cao, L-1012, (8 males, 11 females, 25 nymphs).

Additional material examined

THAILAND: Nan Province, Namtok Tak Man, 19°17'N 100°47'E, 352 m, 21 April 2003, Vitheepradit, Prommi, & Setaphan, L-471; Namtok Sa Pan, 19°11'N 101°11'E, 532 m, 22 April 2003, Vitheepradit, Prommi, Setaphan, L-475.

Figures

FIGURE 7. Thac Kem in Nghe An Province, Vietnam, the type locality of Namtokocoris kem n. sp.

FIGURE 10. Holotypes of a) Namtokocoris siamensis, b) Namtokocoris akekawati, c) Namtokocoris dalanta, d) Namtokocoris kem, e) Namtokocoris khlonglan, and f) Namtokocoris minor.

FIGURE 11. Left margin of pronotum and embolium of macropterous a) Namtokocoris siamensis, b) Namtokocoris akekawati, c) Namtokocoris dalanta, d) Namtokocoris kem, e) Namtokocoris khlonglan, and f) Namtokocoris minor.

FIGURE 12. Genital capsule of males of a) Namtokocoris siamensis, b) Namtokocoris akekawati, c) Namtokocoris dalanta, d) Namtokocoris kem, e) Namtokocoris khlonglan, and f) Namtokocoris minor. Scale bar = 1.0 mm

FIGURE 14. Ventral aspects of terminal abdominal segments of females of a) Namtokocoris siamensis, b) Namtokocoris akekawati, c) Namtokocoris dalanta, d) Namtokocoris kem, e) Namtokocoris khlonglan, and f) Namtokocoris minor.