Namtokocoris minor 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 : 21-22

Namtokocoris minor Sites , NEW SPECIES

Figs. 3, 9, 10f, 11f, 12f, 13f, 14f

Descriptions

Macropterous male. See generic description; only additional details provided here. Holotype, length 7.05; maximum width 4.56. Paratypes (n = 10), length 6.64–7.14 (mean = 6.89); maximum width 4.23–4.56 (mean = 4.39). Overall coloration dorsally reddish-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 indistinct pattern on head and pronotum, heaviest on vertex and near posterior margin and of head and middle 2/3 of pronotum, especially near midline and posterior to transverse sulcus ( Fig. 10 f). Ventrally, generally medium brown; golden brown on anteclypeus, lateral margins of prothorax, and exposed portion of hemelytra.

Head length 1.14, maximum width 2.75, synthlipsis at posteromesal corner 0.86, with four pairs of setal rosettes bordering inner margin of eyes, fifth pair further mesad and slightly ventrad to anterior margin. Antennal proportions 4:5:10:9. Pronotum broad, 2.9 x as wide as long; with elongate, erect setae especially evident laterally; length at midline 1.43; maximum width at posterolateral corners 4.10, posterolateral corners evenly rounded ( Fig. 11 f). Scutellum dark reddish-brown with lighter reddish-brown U-shape marking on tumescent protuberances and posterolateral borders; heavily punctate; triangular with distinctly sinuate posterolateral margins; 2.2x as wide as long, width 2.75, length 1.27; pair of broad, tumescent, longitudinal protuberances without lines of erect setae, although scattered setae present. Claval commissure length 1.02. Embolium with anterolateral margins evenly curved ( Fig. 11 f), yellowish anterior band gradually narrowing posteriorly and becoming obsolete near membrane of hemelytra, length 2.83 (chord measurement), maximum width 0.66. All coxae pale yellow, trochanters and femora golden brown, fore tibia/tarsus darker brown, middle and hind tibia/tarsus golden brown. Leg measurements as follows: foreleg, femur 1.40, tibia 0.86, tarsus 0.30; middle leg, femur 1.52, tibia 1.12, tarsomeres 1–3 0.14, 0.24, 0.24; hind leg, femur 1.96, tibia 1.86, tarsomeres 1–3 0.24, 0.58, 0.58. Posterior margin of mediosternite III straight, IV concave, V strongly concave, VI slightly concave, VI broadly rounded, VIII semicircular. Posterior margin of laterosternite V straight. Genital operculum with posterolateral margins straight, apex narrowly pointed. Parameres symmetrical, distal margin rounded with notch near mesal angle, flanking lateral margins of and extending to approximately same level as median process of pygophore, hairs on mesal 2/3 of dorsal surface; median process of pygophore digitate with rounded apex; aedeagus with mid-dorsal carina, left margin gently arcuate with distinct convexity in distal quarter, right margin broadly convex in basal 4/5 and concave in distal fifth to form distinct apical hook, series of striations in basal third on right side of mid-dorsal carina ( Figs. 12 f, 13f).

Macropterous female. Paratypes (n = 10), length 6.89–7.64 (mean = 7.20); maximum width 4.40–4.73 (mean = 4.55). Similar to male in general structure and coloration; pad of hairs on middle tibia reduced; posterior margin of mediosternite V and VI slightly concave, subgenital plate (VII) with posterior margin nearly flattened with broadly posterolateral angles; posterior margin of laterosternite VI nearly straight ( Fig. 14 f).

Diagnosis

This species can be recognized by its small size. Its coloration, especially that of the hemelytra, is slightly lighter than that of its known congeners. The scutellum has a large, reddish-brown U-shaped marking on broad, tumescent protuberances and posterolateral margins. Distinct hair lines are absent from the scutellar protuberances, although a few scattered stout hairs are present. The anterolateral margin of the embolium is gradually and evenly curved. Males have a strongly hooked apex of the aedeagus, and the parameres are distinctly concave along the distal margin in dorsal view.

Discussion

This species has been collected only in two locations in Kanchanaburi Province, near Thong Pha Phum. At the type locality, the water in which the insects occurred was reduced to a barely detectable trickle, although the insects were in a film of water with substantial algal growth on the rocks. At the Jok Kra Din site, a substantial volume of water was present and conditions were typical as for congeners. This species was collected with Oocyclus sitesi Short & Swanson ( Coleoptera : Hydrophilidae ), Onychotrechus esakii Andersen , and Eotrechus hygropetricus Andersen ( Hemiptera : Gerridae ) (see Vitheepradit & Sites 2007a) at the type locality.

Etymology

The specific epithet “ minor ”refers to the small size of this species relative to its five known congeners.

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 Royal Forestry Department, Bangkok, Thailand; Entomology Collection, Kasetsart University, Bangkok, Thailand; United States National Museum, Washington, D.C., U.S.A., California Academy of Sciences, San Francisco, U.S. A; John T. Polhemus Collection, Englewood, Colorado, U.S.A.; and the Natural History Museum – Vienna, Austria.

Material examined

Holotype, macropterous male, and allotype, macropterous female: THAILAND: Kanchanaburi Province, Amphur Thong Pha Phum, small waterfall 6.3 km W of Border Police Stn. at Ban Padsadoo Klang, 14°32.399'N 98°32.753'E, 568 m, 10 April 2003, UMC and CMU teams, L-463. Paratypes: same data as primary type (4 males); same locality, 4 June 2006, Sites, Vitheepradit, Prommi, L-913 (13 males, 4 females, 2 nymphs).

Additional material examined

Same locality as primary type, 25 Feb 2002, G. W. Courtney; Namtok Jok Kra Din, 14°41.43'N 98°23.18'E, 4 June 2006, Sites, Vitheepradit, Prommi, L-916.

Figures

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.