Tanycricos inequalis Sites

Sites, Robert W., 2008, New species of Nesocricos and Tanycricos (Hemiptera: Heteroptera: Naucoridae: Cheirochelinae: Tanycricini) in the mountains of West Papua, Indonesian New Guinea, Zootaxa 1714, pp. 19-30 : 24-30

Tanycricos inequalis Sites , n.sp.

Figs. 8–13

Descriptions. Brachypterous male. Holotype, length 13.45; maximum width 5.98. Paratypes (n = 4), length 12.28–13.45 (mean = 12.91); maximum width 5.64–6.14 (mean = 5.89). Anteriorly mostly yellowish brown with medium brown patterning on pronotum and scutellum; dark brown hemelytra and medium brown abdominal terga ( Fig. 8 a).

Head. Length 2.46, maximum width 2.95. Yellowish brown; anterior margin hemispherical, projecting beyond eyes 24% of head length; posterior margin deeply convex between compound eyes; eyes black, shining, lateral margins rounded, inner margins straight, slightly convergent, anterior/posterior interocular widths 1.50/1.72; vertex flattened, separated from eye by furrow bearing line of erect setae; anteclypeus anterior to eyes thinned and slightly explanate, apex with shallow depression on each side of midline. Labrum and maxillary plates yellow, set back from anterior margin of head; labrum deeply recessed, oriented anteroventrally; maxillary p1ates well developed, antennae slender, segments 1–2 yellowish, 3–4 brown, 4 longest, relative lengths 4:5:8:14, most of segment 4 exceeding anterior margin of eye. Ventral surface largely covered with fine brown setation except near rostral cavity. Midline with sharp carina terminating in posterior tooth.

Thorax. Pronotum pale yellowish-brown, patterned with brown pigmentation and punctures; flattened anteromedially between anteriorly diverging rows of punctures; widest at posterolateral corners, width 4.71; length at midline 2.05; lateral margins gently convex; depressed, narrow, brown strip along posterior margin; posterior margin straight with slight posterior deflection near lateral margin; anterolateral corners pointed; posterolateral corners narrowly rounded. Scutellum with dark suffusion, pale yellow area near apex on midline and paired near anterior margin lateral to midline; shining; width 3.73; length at midline 2.66 (measured through translucent posterior margin of pronotum); distinct elevation beginning near ¼ distance from anterior margin, continuing posteriorly to near apex; lateral margins sinuate. Wings dark brown, finely punctate, truncate posteriorly, apices extending to near anterior margin of abdominal tergite V, length 6.14; embolium and embolar suture distinct; margin golden yellow where not overlapping pleuron or tergum II; clavus present, claval suture complete but poorly developed; membrane a narrow dark apical flap; hemelytron with faint venation visible with transmitted light; hindwing not folded, with 4 longitudinal veins and two closed cells. Sterna mostly light brown to yellow. Prosternum with median longitudinal carina in anterior half; proepimeron with an elongate-oval, golden sense organ lateral to procoxal acetabulum; inner margin meeting prosternum, with thin flaplike extension over deep pit at posterior margin behind coxa. Mesosternum with band of short, brown, recumbent setae in middle 1/5; longitudinal depressions just lateral to midline beginning near middle and extending posteriorly to mesosternal apophyseal pits; pits adjacent to mesocoxal cavity; terminating posteriorly in acute point between mesocoxae. Mesepisternum anterior margin with long, brown setae extending from beneath proepimeral plate above pit. Mesepimeron, metasternum, and metepimeron glabrous; metaxyphus terminating in obtuse angle, with row of elongate, golden setae along posterolateral margins.

Legs. Mostly pale yellow, except fore tibia, tarsus, claw golden brown. Fore femur dorsal surface with scattered dark spots on anterior half; posterior margin bearing row of small brown spines just ventrad to band of elongate, dark brown setae; anterior margin bearing thick pad of short, stiff brown setae. Fore tibia and single tarsal segment slender, gently curving, with concave occlusal surface bearing row of setae. Pretarsal claw single. Fore coxa with dark brown, triangular apical patch; middle and hind coxae each with raised, brown, scale-like apical tubercle; middle and hind femora with tiny reddish spinules sparsely scattered on anterior surface and numerous on posterior surface. Middle and hind tibiae with numerous small, reddish spines and spinules, except on ventral surface; apices with 4–5 and 5 transverse rows of stout reddish spines, respectively. Middle and hind femora, tibiae and tarsi all bearing fringe of long, golden swimming hairs along posterior margins. Claws evenly curved, tips dark, subtlely constricted at base of dark tips, parempodia setiform. Leg measurements as follows: foreleg, femur 4.51, tibia 3.36, tarsus 0.74; middle leg, femur 4.14, tibia 3.78, tarsomeres 1–3 0.25, 0.74, 1.02; hind leg, femur 5.25, tibia 7.01, tarsomeres 1–3 0.37, 0.90, 1.27.

Abdomen. Medium brown recumbent setae densely covering terga except laterally and in paired glabrous patches on terga II–V. Golden brown lateral band of terga III–VIII with submarginal row of long, fine, pale setae; marginal row of short, stout, golden-brown spine-like setae with dense group in posterolateral corners. Posterolateral angles of terga II–V gently squared; VI produced as broadly pointed lobe; VII–VIII produced as elongate, rounded lobes. Posterior margin of tergum V nearly symmetrical, with deep notch near midline giving margin bilobed appearance ( Fig. 11 ), expanded posteriorly, covering most of tergum VI. Lateral part of tergum VII bearing distinct patch of short elongate brown setae near anterior margin, and continuing mesad to beneath overlapping tergum V ( Fig. 11 ). Posterior margin of tergum VII asymmetrical, shallowly notched at midline, giving bilobed appearance ( Fig. 11 ). Ventrally, covered in short, brown, recumbent setae. Ventral paratergites II–VII with spiracle 1/5 distance from lateral margin to midline; single depressed, glabrous, oval patch anterior to spiracle near anterior margin; paired depressed, glabrous, oval patches mesad of spiracle, glabrous oblique line on III–V, this less evident posteriorly and sometimes absent on V. Posterior margin of sternum V deeply concave asymmetrically to left. Genital capsule golden brown, rounded, with transverse striations, generally covered with short setae ( Fig. 9 ). Left paramere oriented to right, overlapping right paramere, broad, stout, gently angled anteriorly, ventral surface slightly concave ( Figs. 9, 10 ); right paramere L-shaped, distal section broadly excavated dorsolaterally to embrace cylindrical aedeagus ( Figs. 9, 10 ).

Brachypterous female. Paratypes, including allotype (n = 3), length 13.78–14.61 (mean = 14.28); maximum width 6.47–6.64 (mean = 6.58). Similar to brachypterous male in general structure and coloration, but with following exceptions: Posterior margin of tergum V slightly bilobed near midline; VI broadly concave and with left posterolateral spine elongate, acute, extending to or slightly beyond tip of VII ( Fig. 12 ); right posterolateral corner of VI rounded, unmodified. Ventral abdominal tumescence of middle third beginning at anterior margin of IV continuing to posterior margin of abdomen. Posterior margin of sternum V gently concave. Posterior 2/3 of V and all of VI with mid-ventral flattening of tumescence, each with glabrous band on lateral margin of tumescence, each with single tubercle just posterior to midlength (tubercles poorly expressed or absent in some paratypes). Subgenital plate broadly triangular, with deep U-shaped cleft distally ( Fig. 12 ).

Macropterous male. ( Fig. 8 b). Paratype (n = 1), length = 13.94; maximum width = 5.98). Similar to brachypterous male in general structure and coloration, but with following exceptions: Fore femur with dark stripe along mid-dorsal ridge. Pronotum markedly produced laterally near posterolateral corner; scutellum distinctly elevated throughout. Hemelytra extending to genital operculum, not exceeding abdomen; clavus, intraclaval suture, and embolium distinct; mostly dark brown, whitish at claval commisure, with fine punctation throughout. Hindwing well-developed. Mesosternum with longitudinal depressions just lateral to midline restricted to vicinity of sternal apophyseal pits.

Macropterous female. Unknown.

Diagnosis. Females can easily be recognized by the dramatic asymmetry of the posterolateral spines of abdominal segment VI. Specifically, the left spine is greatly enlarged and extends to or slightly surpasses the posterior end of VII, whereas the right spine is unmodified. The congeners T. acumentum La Rivers and T. binarius La Rivers also have asymmetry of these spines, but the left is only slightly longer than the right ( Polhemus 1999). Males of T. inequalis can be distinguished from those of known congeners by the unique shape of the left paramere. In addition, in males the posterior margin of abdominal tergum VII is shallowly notched at the midline, giving a bilobed appearance, a condition which is shared with T. binarius .

Etymology. This species is named “ inequalis ” for the unequal sizes of the posterolateral spines of abdominal segment VI in females.

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; the Natural History Museum – Vienna, Austria; and Zoological Museum Bogor of the LIPI Research Centre for Biology, Indonesia.

Discussion. This is the first record of Tanycricos from the Vogelkop Peninsula in West Papua Province of northwestern New Guinea. Four other species are known from the mostly contiguous central mountains of Indonesian New Guinea ( Polhemus 1999). This species was collected from rocky, high velocity runs only at the type locality ( Fig. 13 ), where Nesocricos ingging Sites and an unidentified species of Idiocarus were also present. Although this genus is known as a high elevation, cold water taxon, additional habitat requirements are probably at work because we collected in other similar streams slightly higher and lower in elevation than Ingging River without finding Tanycricos .

Material examined. Holotype, brachypterous male, and allotype, brachypterous female: INDONESIA: New Guinea: West Papua Province, Ingging River, 9 April 2007, R. W. Sites and Suputa, S 0 1 o 07.746’ E 133o 52.164’, elev 1348 m, L-987. Paratypes: same data as primary type (2 brachypterous males, 2 brachypterous females, 1 macropterous male); same locality, 8 April 2007, L-979 (2 brachypterous males).

Additional material examined. Same data as holotype (28 nymphs); same locality, 8 April 2007, L-979 (8 nymphs).

Figures

FIGURE 13. Tanycricos inequalis n. sp. (a) live adult brachypterous male, (b) habitat of nymphs and adults in Ingging River.

FIGURES 8 – 10. Tanycricos inequalis n. sp. (8) a) brachypterous and b) macropterous forms, (9) male genital capsule, (10) male left and right parameres.

FIGURES 11 – 12. Tanycricos inequalis n. sp. (11) abdominal terga V – VIII and genital capsule of male, (12) abdominal sterna V – VII of female.