Heleocoris malayensis, Polhemus & Polhemus, 2013

Polhemus, Dan A. & Polhemus, John T., 2013, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. Xi. Infraorder Nepomorpha- Families Naucoridae And Aphelocheiridae, Raffles Bulletin of Zoology 61 (2), pp. 665-686 : 676-678

publication ID

https://doi.org/ 10.5281/zenodo.5352700

persistent identifier

https://treatment.plazi.org/id/03FE7253-F512-FFE8-FF12-FB78FDC3FAB1

treatment provided by

Tatiana

scientific name

Heleocoris malayensis
status

sp. nov.

Heleocoris malayensis , new species

( Figs. 24 View Figs , 30 View Figs , 32 View Figs , 33 View Fig , 34 View Figs )

posterior margin broadly dark, width across eyes/length = 4.20/1.40; eyes dark red, shining, roughly teardrop-shaped when viewed from above with well developed lateral flange, tapering anteriorly, width/length = 0.70/1.20, inner margins straight and slightly convergent anteriorly, lateral margins broadly curving, separated from vertex by shallow furrows, anterior/posterior interocular width = 1.70/2.20; posterior margin of vertex nearly straight, not produced behind eyes; anteclypeus broadly rounded, not projecting ahead of eyes, anterior margin projecting beyond rostrum for 0.42 length of rostrum, bearing a pair (1+1) of transversely ovate dark brown pits widely spaced to either side of longitudinal midline, these pits bearing short, pale setae; labrum golden, roughly triangular, broadly rounded, apex blunt; rostrum evenly tapering to apex, dark yellow, terminal segment dark brown; antennae with all segments thickened, not extending to lateral margin of head, segment III longest.

Pronotum yellowish brown, irregularly dotted with numerous small, dark brown spots, lateral margins translucent golden, posterior margin broadly grayish brown; dorsal surface broadly and evenly domed, not depressed medially behind vertex, width/length (midline) = 6.15/3.60, lateral margins not explanate, posterolateral angles truncate, rounded.

Material examined. — Holotype, male, MALAYSIA, Pahang, Sungai Cheroh, 6 km E. of Tapah , 18 Aug.1985, CL 2072, coll. D. A. & J. T. Polhemus ( JTPC) . Paratypes: MALAYSIA, Pahang: 17 males, 18 females, same data as holotype ( JTPC, ZRC) ; 1 female, Taman Negara , coll. L. C. Fong ( ZRC) ; 1 female, Raub, Sungai Kla , 11 Nov.1992, coll. J. Cramphorn ( ZRC) . Perak: 19 males, 16 females, Sungai Kerunai, 9 km N. of Grik , 19 Aug.1985, CL 2078, coll. D. A. & J. T. Polhemus ( JTPC) ; 1 female, Sungai Kenderong at Gerik , 17 Feb.1997, coll. H. K. Lua, LHK0324 ( ZRC) ; 1 male, Sungai Korbu at Jalong , 16 Feb.1997, coll. H. K. Lua, LHK0321 ( ZRC) ; Trengganu : 1 male, Sungai Trengganu tributary, Sekayu , 16 May 1995, coll. B. Tan & G. Sumita, TG06 ( ZRC) ; 1 male, tributary of Sungai Trengganu downriver of Sekayu Waterfall Park , 18 Mar.1992, LHK179c ( ZRC) ; 8 males, 5 females, Sekayu, Sungai Brang , 21 Oct.1998, coll. H. K. Lua, LHK0401 ( ZRC) .

Description. — Macropterous form: Of moderate size for genus, general body form ovate, widest across embolium of hemelytra ( Fig. 33 View Fig ), basic colouration pale yellowish brown, with scutellum, hemelytra and wing membrane dark brown. Male length 11.00 mm; maximum width (across embolia) 7.40 mm; female length 10.90 mm, maximum width 7.35 mm.

Head pale yellowish brown, with scattered dark brown dots medially and 3 ovate, evenly spaced dark patches along lateral margins of vertex adjacent to each inner eye margin; Scutellum mottled medium to dark brown, set with numerous tiny pale asperities, extreme apex pale yellow, width/length (midline) = 4.00/1.92, basal margin broadly posteriorly concave, lateral margins broadly sinuate.

Hemelytra dark blackish-brown set with numerous tiny pale aperities, outer half of embolium translucent golden yellow, inner margin of this pale area forming a straight line angling from inner anterior base of embolium backward and outward to outer posterior terminus; clavus and corium well defined, membrane highly reduced, obscure; tips of hemelytra broadly rounded, extending to apex of genital segment; embolium demarcated by broadly arcuate furrow along inner margin, furrow marking posterior margin obscure, basal half of lateral margin bearing very short, posteriorly angling reddish-brown spinules.

Abdomen with lateral portions of segments II–IV exposed when viewed dorsally, all visible paratergites pale golden yellow, dark brown at extreme posterolateral angles, these posterolateral angles symmetrical, produced into short, curving spinose projections on paratergites II–V, lateral margins immediately ahead of each projection inwardly notched, these notches each bearing 3 short, stout spines plus acuminate tufts of very long golden setae, remaining lateral margins of paratergites set with very short reddish posteriorly angling brown spinules; lateral margin of left paratergite VI bearing a hooked process ( Fig. 34 View Figs ).

Ventral surface pale brown, generally lacking setae, with posterolateral sections of propleuron and central sections of abdominal ventrites I–VII covered with thick recumbent gold hydrofuge pile; propleura not reflexed posteriorly, barely covering basolateral portions of mesosternal plate, anterolateral angles bearing depressed, brown, ovate hydrostatic sense organs present below lateral eye margins; mesosternal plate broadly tumescent centrally, anterior margin of this tumescence transversely folded and raised, entire medial tumescence bearing long, scattered, fine golden setae; metasternal plate elongate, posterior section elongate and triangular with acute posterior apex, longitudinal midline raised into a sharp carina on basal half, this carina becoming widened and rounded on posterior half. Abdominal sternites and parasternites delineated by distinct sutures; all parasternites dull brown, each with 1–3 elongate glabrous patches.

Legs pale yellow; fore coxa unmodified; fore trochanter bearing roughly circular patch of very short, densely packed reddish brown setae centrally; anterior femur uniformly pale yellow, bearing a thick fringe of short, dense gold setae along anterior margin, posterior margin lacking setae; anterior tibia slender, straight, slightly expanded distally, broadly grooved along inner face, ventral margin bearing a distally expanding fringe of short, dense, reddish-brown setae along entire length; anterior tarsi two segmented, bearing two moderately large golden-brown claws, ventral tarsal surfaces bearing thick hair pads similar to that on anterior tibia; middle and hind coxae each bearing a single glabrous tubercle distally; middle and hind femora ventrally with a longitudinal row of tightly packed, elongate, reddish spinules, additional spinules of this same type present ventrally on basal part of anterior margin, posterior margin of middle femur also bearing thick fringe of short, dense, reddish-golden setae; middle tibiae bearing numerous short, stout brown spines, ventral surface with thick pad of dark golden setae on distal four-fifths, tarsal segments of middle leg bearing similar hair pads ventrally; hind tibiae with scattered moderately long, stout dark brown spines, posterior margin with fringe of long gold swimming hairs.

Male genitalia with proctiger elongate, apex acute ( Fig. 30 View Figs ); parameres highly reduced, elongate ovate ( Fig. 24 View Figs ); male phallotheca asymmetrical, with apex expanded into a rounded lobe ( Fig. 24 View Figs ). Female subgenital plate roughly trapezoidal, posterior broadly concave ( Fig. 32 View Figs ).

Brachypterous form: Unknown.

Distribution. — Peninsular Malaysia (below the Isthmus of Kra).

Hwy. 19, 365 m., 13°57'53"N, 108°45'48"E, water temp. 22°C, 14 Mar.2001, CL 4293, coll. J. T GoogleMaps . Polhemus & P. Nguyen ( USNM). THAILAND, Chiang Mai Prov.: 11 males, 10 females, Fang Dist., Mae Mao River, S. of Fang Horticultural Station , 500 m, 16 Nov.1985, CL 2200, coll. D. A. & J. T . Polhemus ( JTPC); 1 male, 1 female, stream 10 km NW of Mae Rim , 19 Nov.1985, CL 2204, coll. D.A. & J. T . Polhemus ( USNM). BURMA, Shan Division: 10 males, 11 females, Magwe River at confluence with clear tributary in sandstone bed, 26 km NW of Kalaw along Kalaw to Thazi road, 520 m, 20°43.796'N, 96°29.477'E, water temp. 29°C (main river), 24 Oct.1998, CL 4023, coll. D. A. & J. T GoogleMaps . Polhemus ( USNM). HONG KONG: 1 male, 2 females, Lam Tsuen River , lower course, from trailing vegetation, coll. D. Dudgeon ( JTPC) .

Diagnosis. — Length 10.2–11.0 mm, maximum width (across abdomen) 7.0– 7.4 mm, general body form ovate. Head and pronotum dull medium brown finely maculated with dark brown or black; scutellum blackish brown, extreme Discussion. — The larger of the two Heleocoris species currently known to occur in Peninsular Malaysia, H. malayensis may be recognised by its body size in excess of 11 mm; the generally dark hemelytra with the anterolateral half of the embolium broadly pale yellow ( Fig. 33 View Fig ); the hooked process on the lateral margin of male abdominal left paratergite VI ( Fig. 34 View Figs ), the shape of the male phallotheca ( Fig. 24 View Figs ); the elongate shape of the male proctiger ( Fig. 30 View Figs ), and the shape of the female subgenital plate ( Fig. 32 View Figs ).

Previous records of Laccocoris nervicus Montandon from the Peninsular Malaysian states of Perak and Selangor (Fernando & Cheng, 1974) are referable to this species, whereas L. nervicus is endemic to the mountains of Sumatra. Previous records of H. ovatus Montandon from Peninsular Malaysia are also represent this species (see below).

T

Tavera, Department of Geology and Geophysics

JTPC

Colorado Entomological Museum (formerly John T. Polhemus collection)

ZRC

Zoological Reference Collection, National University of Singapore

USNM

Smithsonian Institution, National Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hemiptera

Family

Naucoridae

Genus

Heleocoris

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