Heleocoris mcphersoni, Sites, Robert W. & Vitheepradit, Akekawat, 2011

Sites, Robert W. & Vitheepradit, Akekawat, 2011, Heleocoris (Heteroptera: Naucoridae: Laccocorinae) of Thailand, with description of a new species, Zootaxa 2736, pp. 1-16 : 12-14

Heleocoris mcphersoni n. sp.

Figs. 4 , 8 , 11 , 12

Description. Macropterous male. Holotype, length 6.88; maximum width across embolium at abdominal segment II 4.06. Elongate, nearly parallel-sided. Dorsally, overall coloration brown with yellowish head, pronotum, proximal 2/3 of embolium gradually narrowing to obsolescence before costal fracture ( Fig. 4 ); brown punctation on head and pronotum. Ventrally, mostly medium brown, lighter anteriorly; yellowish propleuron, coxae. Head, pronotum, and hemelytra sparsely covered with fine setae.

Head length 1.28, maximum width 2.56; inner margin of eyes convergent anteriorly; synthlipsis at anterior margin 0.84, interocular distance at posteromesal corner 1.32; head margin laterad of eye evenly rounded; brown, light punctation forming paired broad crescentic markings, meeting anteriorly, extending to anterior margin; irregular row of setae bordering inner margin of eyes; labrum hemispherical, almost twice as wide as long, evenly convex apically; antennal proportions 1:4:6:5.

Pronotum broad, 2.5 x as wide as long, length at midline 1.52; maximum width at posterolateral corners 3.80; wide, transverse, impunctate band across posterior margin; anterior punctate area with small brown punctures scattered throughout middle third except in small yellow area in middle; large brown punctures scattered in lateral third nearly to lateral margin; lateral margin evenly convex; posterolateral corners rounded; posterior margin concave in middle third; anterior margin shallowly concave. Ventrally with golden brown coloration becoming lighter laterally on propleuron. Scutellum punctate, brown, triangular with distinctly arcuate posterolateral margins, 1.8x as wide as long, width 2.48, length 1.36. Hemelytra finely punctate. Claval commisure length 0.64. Embolium length 2.40 (chord measurement), greatest width 0.60; lateral margin curvature greatest at humerus and near costal fracture; scattered elongate setae especially evident near lateral margin; yellowish anterior band broad in anterior 2/3, gradually narrowing posteriorly and becoming obsolete before costal fracture; yellow band with small brown punctures. Metaxyphus broad, posterolateral margins concave distally, with strong mid-ventral ridge, 1.4x as long as wide, acuminate posteriorly, with stout spines ( Fig. 8 ). Coxae yellowish, all other leg segments light brown. Mesofemur with posteroventral row of spines distinctly shorter distally. Middle and hind legs with tarsomere 1 extending beneath tarsomere 2, pretarsal claws straight in basal ¾, curved distally. Leg measurements as follows: foreleg, femur 1.66, tibia 1.10, tarsomeres 1-2 0.16, 0.18; middle leg, femur 1.62, tibia 1.20, tarsomeres 1-3 0.12, 0.22, 0.26; hind leg, femur 1.92, tibia 2.00, tarsomeres 1-3 0.18, 0.42, 0.50.

Abdomen dorsally with lateral margins of III–VI with regular row stout, golden brown spines. Ventral laterotergites II–VII each dark anteriorly, light posteriorly. Ventrally with dense mid-ventral band of light colored hairs beginning on III, continuing to posterior margin of abdomen. Posterior margin of mediosternite III straight, IV slightly concave, V deeply concave, VI–VIII straight. Asymmetry negligible. Aedeagus elongate, linear, narrow basally, widest at middle of part visible beyond pygophore; lateral margins diverging to widest point, converging apically to tip; parameres elongate, directed apically, symmetrical, anteromesal margins rounded, not overlapping pygophore, with elongate setae directed mesad; margin of pygophore concave between parameres ( Fig. 11 ); pygophore with fine setae.

Female. Unknown.

Diagnostic information. This is the smallest species of Heleocoris in Thailand; thus, size easily distinguishes it from H. ovatus and H. strabus . It can be distinguished from H. bengalensis montandoni by the presence of stout spines on the metaxyphus, the less dense brown punctation on the pronotum, and slightly shorter body length. The type locality of H. mcphersoni is close to Tenasserim, Myanmar, the type locality of Heleocoris laeviceps Montandon , with which it also might be confused because of its small size. However, H. laeviceps has not been recorded from Thailand. Attributes of H. laeviceps , given by Montandon (1897a) and Distant (1906) in a supplemental description, which differ from those of H. mcphersoni , include a black scutellum, 8.2 mm length, oval body shape, the head smooth only in the anterior half, and a brown median band on the head. We have been unable to locate the type specimen of H. laeviceps for comparison, which was reported by Montandon (1897a) as in the Bergroth collection. However, it is not in the Finnish Museum of Natural History in Helsinki, where most of the Bergroth collection is housed (L. Huldén, pers. comm.).

Discussion. This specimen was collected by kick-sampling loose gravel immediately downstream from the plunge pool of a waterfall ( Fig. 12 ). It was collected in the same stream with its congener, H. strabus .

Etymology. The species is named in honor of J. E. McPherson, our friend and colleague, and former mentor of RWS. That the specimen also has an irregular row of hairs over the eyes and is one-of-a-kind are coincidental.

Repository. The holotype is deposited in the Enns Entomology Museum, University of Missouri. Material examined. Holotype, macropterous male, THAILAND: Phang Nga Province, Khao Lampi-Hat Thai Mueang National Park, Lam Pi Waterfall, 08º27.862’N 98º16.880’E, elev. 51 m, 12 June 2004, coll: Sites, Vitheepradit, Prommi, L-762.

Figures

FIGURE 11. Heleocoris mcphersoni n. sp., male genital capsule with aedeagus and parameres. Perimeter setae of the pygophore are not shown.

FIGURE 12. Gravel bar at Lam Pi Waterfall, type locality of Heleocoris mcphersoni n. sp. AV is standing where the holotype was collected.

FIGURES 1 – 4. Habitus of (1) Heleocoris bengalensis montandoni, (2) Heleocoris ovatus, (3) Heleocoris strabus, (4) Heleocoris mcphersoni n. sp.

FIGURES 5 – 8. Metaxyphus of (5) Heleocoris bengalensis montandoni, (6) Heleocoris ovatus, (7) Heleocoris strabus, (8) Heleocoris mcphersoni n. sp.