Namtokocoris akekawati 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 : 11-13

Namtokocoris akekawati Sites , NEW SPECIES

Figs. 3, 5, 10b, 11b, 12b, 13b, 14b

Descriptions

Macropterous male. See generic description; only additional details provided here. Holotype, length 9.46; maximum width 5.98. Paratypes (n = 10), length 8.55–9.63 (mean = 9.26); maximum width 5.73–6.22 (mean = 6.03). Overall coloration dorsally dark brown with yellowish-brown head, pronotum, and wide band at anterior end of embolium gradually narrowing to obsolescence near membrane; heavy dark punctation forming subtle, indistinct pattern on head and pronotum, heaviest near posteromesal corner of eye and pronotum in middle 2/3 and posterior to transverse sulcus ( Fig. 10 b). Ventrally, medium brown, darker laterally on meso- and metathorax; yellowish on anteclypeus, lateral margins of prothorax, and exposed portion of hemelytra.

Head length 1.58, maximum width 3.85, synthlipsis at posteromesal corner 1.20, with four pairs of setal rosettes bordering inner margin of eyes, fifth pair further mesad and slightly ventrad to anterior margin.

Antennal proportions 5:7:13:9. Pronotum broad, 2.8 x as wide as long, with scattered elongate, erect setae; length at midline 2.00; maximum width at posterolateral corners 5.70; posterolateral corners rounded, straight immediately mesad of corner to level of wing base ( Fig. 11 b). Scutellum dark brown, occasionally with reddish on protuberances on apex, heavily punctate, triangular with distinctly sinuate posterolateral margins, 2.1x as wide as long, width 3.81, length 1.80, longitudinal protuberances broad, tumescent, each with line of erect setae. Claval commissure length 1.52. Embolium with anterolateral corner gently, evenly arcuate ( Fig. 11 b); yellowish anterior band gradually narrowing posteriorly and becoming obsolete near posterolateral end of embolium; length 4.02 (chord measurement); maximum width 0.98. All coxae yellowish brown; trochanters and femora medium brown, femora lighter distally; fore tibia/tarsus dark brown; middle and hind tibia/tarsus light brown, tip of tarsomere 3 dark brown. Leg measurements as follows: foreleg, femur 1.90, tibia 1.32, tarsus 0.38; middle leg, femur 2.18, tibia 1.56, tarsomeres 1–3 0.18, 0.30, 0.36; hind leg, femur 2.80, tibia 2.68, tarsomeres 1–3 0.36, 0.74, 0.92. Posterior margin of mediosternite III straight, IV concave, V strongly concave, VI nearly straight, VII convex, VIII broadly pointed. Posterior margin of laterosternite V straight with rounded posteromesal corner. Genital operculum with posterolateral margins straight, apex acuminate. Parameres symmetrical, rounded distally, double the size of median process of pygophore, with transverse excavation just above base deepening laterally; median process of pygophore abruptly glabrous and shining, rounded, asymmetrically oriented to left, slightly overlapping mesal margin of left paramere; aedeagus with mid-dorsal carina, left margin nearly straight, right margin angulate, narrowed and concave in distal quarter, hooked to right at apex, series of striations at middle on both sides of mid-dorsal carina ( Figs. 12 b, 13b).

Macropterous female. Paratypes (n = 10), length 9.13–9.96 (mean = 9.67); maximum width 5.89–6.31 (mean = 6.19). Similar to male in general structure and coloration; pad of hairs on middle tibia reduced; posterior margin of mediosternite V and VI straight; subgenital plate (VII) about as long as wide, lateral margins convergent, posterior margin straight, posterolateral corners broadly rounded; posterolateral corner of laterosternite VI rounded and slightly produced posteriorly ( Fig. 14 b); pronounced lateral lobe on costal margin of right hemelytron at position of abdominal segment V.

Diagnosis

Males can be recognized by the abruptly angled right margin of the aedeagus and asymmetrically oriented (to the left) median process of the pygophore. Females have a distinct lobe on the costal margin of the right hemelytron at the level of abdominal segment V, a condition which is shared with N. khlonglan (see below). Females of these species differ in that the posterolateral corners of mediosternite VI in N. akekawati are not distinctly deflected ventrad from the sternum. Using somatic characters, this species can be recognized by the broad tumescent protuberances on the scutellum, whereas they are more linear in N. siamensis . Also, the anterolateral margin of the embolium is gradually, shallowly, and evenly curved, whereas in N. siamensis the curvature is stronger. In addition, the tips of the middle and hind tarsi are more distinctly dark brown.

Discussion

This species has been collected from the Tennaserim mountain range in Kanchanaburi Province and the Phuket mountain range in Rangong Province. At Namtok Jok Kra Din, N. akekawati occurred syntopically with N. minor (see below), which was the only waterfall in which we found more than one species of Namtokocoris . This species exhibits a broader range of habitat selection in that it was found on vertical to horizontal wet, algae-covered rocks that received distant misting from the waterfall at Haew Lome. Thus, at the type locality, these insects were not immersed within a water film. However, at Namtok Jok Kra Din and Namtok Ngao, they were collected in a film of water associated with the waterfall, which is typical habitat for the genus. It was collected with Onychotrechus esakii Andersen ( Hemiptera : Gerridae ) at the type locality ( Fig. 5 ).

Etymology

This species is named for Akekawat Vitheepradit, doctoral student at the University of Missouri. His dedication to field work led directly to the discovery of this species and many other undescribed aquatic Heteroptera in Thailand.

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: Ranong Province: Khun Mae Yam Oum Wildlife Sanctuary, Namtok Haew Lome, 09º43.740’N 98º40.953’E, 122 m, 14 June 2004, R. W. Sites, L-765. Paratypes: same data as primary type (90 males, 36 females); Namtok Ngao National Park, Namtok Ngao, 9º51’N 98º37’E, 50 m, 2 April 2005, T-O Prommi (6 males, 3 females, 1 nymph).

Additional material examined.

THAILAND: Chumphon Province: Khun Mae Yam Oum Wildlife Sanctuary, Namtok Chum Poon, 0 9°47’N 98°54’E, 100 m, 30 May 2004, Vitheepradit & Prommi, L-731; Kanchanaburi Province: Amphur Thong Pha Phum, Namtok Jok Kra Din, 14°41.43'N 98°23.18'E, 4 June 2006, rock face of waterfall, Sites, Vitheepradit, Prommi, L-916; Ranong Province: Khun Mae Yam Oum Wildlife Sanctuary, Namtok Haew Lome, 09º43.740’N 98º40.953’E, 122 m, 21 May 2003, Vitheepradit & Ferro, L-555; same locality, 7 June 2006, Sites, Vitheepradit, Prommi, L-921a; same locality, 22 May 2005, Sites, Vitheepradit & Prommi, L- 785b; Thung Raya-Na Sak Wildlife Sanctuary, Namtok Chumsang, 10°30'N 98°53'E, 176 m, 20 May 2003, Vitheepradit & Ferro, L-550; Amphur Muang, Namtok Pun Ya Ban, 10°03'N 98°40'E, 86 m, 20 May 2003, Vitheepradit & Ferro, L-553; Namtok Khao Pha Na Rai, 09°36'N 98°35'E, 94 m, 21 May 2003, Vitheepradit & Ferro, L-554; Namtok Ngao National Park, Namtok Ngao, 9º51’N 98º37’E, 50 m, 23 May 2005, Sites, Vitheepradit, Prommi, L-787.

Figures

FIGURE 5. Namtok Haew Lome in Ranong Province, Thailand, the type locality of Namtokocoris akekawati 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.