Rhagovelia woa, Polhemus, 2024

Polhemus, Dan A., 2024, Thirty-four new species of Rhagovelia (Heteroptera: Veliidae) from the East Papua Composite Terrane, far eastern New Guinea, Zootaxa 5400 (1), pp. 1-214 : 182-183

Rhagovelia woa new species

(296–302, 309)

Type material examined.— Holotype, wingless male: PAPUA NEW GUINEA, Milne Bay Prov., Louisiade Archipelago, Rossel [Yela] Island, Woa River and rocky tributaries, approx. 4 km. upstream from estuary, 0–150 m., 11°20'37"S, 154°07'06"E, water temp. 23 °C., 31 August–1 September 2002, along margins of main river channel, CL 7196a, D. A. & J. T. Polhemus ( BPBM) . Paratypes: PAPUA NEW GUINEA, Milne Bay Prov., Louisiade Archipelago, Rossel [Yela] Island: 2 winged males, 6 winged females, 71 wingless males, 76 wingless females, same data as holotype, CL 7196a, D. A. & J. T. Polhemus ( USNM, BPBM) ; 1 winged male, 2 winged females, 28 wingless males, 31 wingless females, same data as preceding except skating on open waters of main river, CL 7196e, D. A. & J. T. Polhemus ( USNM) ; 1 wingless male, 2 wingless females, rocky tributary to Woa River , approx. 4 km. upstream from estuary, 15–30 m., 11°20'45"S, 154°07'30"E, 31 August 2002, CL 7196b, D. A. & J. T. Polhemus ( USNM) .

Description.

Wingless male: Size: Length = 2.00– 2.10 mm (x = 2.08, n = 5); width = 0.90–1.00 mm (x = 1.00, n = 5). Wingless female, length = 2.60–2.70 mm (x = 2.64, n = 5); width = 1.10–1.25 mm (x = 1.19, n = 5). Winged male, length = 3.50 mm (n = 1); width = 1.45 mm (n = 1). Winged female, length = 3.30–3.60 mm (x = 3.45, n = 2); width = 1.30–1.35 mm, (x = 1.32, n = 2).

Color: Dorsal ground colour black, sparingly marked with dark orange-brown on anterior pronotum, extreme basal sections of antennae and legs dull yellow (Fig. 297). Head black, tylus, genae and rostrum brown, tip of rostrum piceous; eyes dark reddish black. Pronotum black, with transversely ovate orange-brown spot anteromedially behind head vertex, this orange-brown coloration not extending laterally onto pleurae. Mesonotum with numerous shining black microfoveae; metanotum, abdominal tergites and connexiva uniformly dull black, lacking shining areas. Antennal segment I with basal one-third yellow, distal two-thirds plus all of segments II–IV black. Legs generally shining black, with acetabula, fore and hind coxae, fore and hind trochanters dull yellow. Venter uniformly black.

Structural characters: Head moderately short, declivant anteriorly, with weakly impressed median line; length 0.27, width 0.70; length of eye along inner margin 0.25, anterior/posterior interocular space, 0.25/0.40. Pronotum short, width 0.85, length along midline 0.15, less than dorsal length of head, leaving mesonotum broadly exposed. Mesonotum smooth, bearing numerous microfoveae, humeri depressed, length along midline 0.62. Metanotum barely exposed, length along midline 0.05. Lengths of abdominal tergites II–VIII, respectively: 0.12: 0.12: 0.12: 0.12: 0.12: 0.13: 0.25: 0.10. Connexiva with margins of even width throughout, straight, convergent posteriorly, posterolateral angles not modified, apices separated by entire width of tergite VIII.

Entire dorsum and laterotergites covered with fine appressed golden pubescence, intermixed with a few longer, erect black setae on head and propleurae; legs and antennae thickly clothed with short appressed gold setae, with scattered long, erect black spines on anterodorsal faces of antennal segments I and II, anterior and posterior margins of all femora, and anterior margins of fore and hind tibiae; all trochanters lacking pegs or teeth; fore femur gently bowed, fore tibiae strongly bowed in lateral view, not flattened or expanded distally; middle femur and tibia with margins straight, not flattened or otherwise modified; hind femur weakly incrassate, lacking spines or teeth; hind tibia straight, slender, lacking spines or teeth (Fig. 299).

Venter of head and thorax lacking small black denticles; meso- and metasternum bearing long, fine dark setae; all abdominal ventrites lying in same plane, lacking a medial carina.

Paramere small, stout, in shape of elongated inverted triangle, posteroventral margin bearing a few short, stout setae, apex rounded (Fig. 300). Proctiger small, compact, lacking basolateral or distolateral lobes; distal cone broadly rounded (Fig. 301).

Lengths of antennal segments I–IV: 0.80: 0.40: 0.60: 0.50.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 0.90: 1:00: 0.01: 0.01: 0.16; of middle leg, 1.50: 1.25: 0.05: 0.75: 0.70; of hind leg, 1.20: 1.65: 0.02: 0.05: 0.20.

Wingless female: Similar to wingless male in general structure and coloration, with following exceptions: mesonotum broadly domed, shape roughly inverted trapezoidal, shorter posterior margin straight; mesopleural regions slightly depressed, weakly concave when viewed from above; metanotum and adjacent medial abdominal tergite I flat, angling downward in a posterior direction; first through third connexival segments vertical, leaving abdominal tergites I–III exposed, then curving broadly and evenly inward to cover lateral sections of abdominal tergite IV, fourth connexival segments strongly convergent, meeting posteriorly and covering all but central one-third of abdominal tergite V, connexival segments V and VI strongly appressed and parallel, entirely covering tergites VI and VII ( Fig. 296 , 298), connexival margins angled broadly and distinctly upward in area of closest appression above tergites VI and VII, posterolateral connexival angles rounded when viewed laterally, not produced; abdominal tergite VIII and proctiger angling downward at 45° angle, tergite VIII dull black, proctiger darker shining black; abdominal ventrite VII shining dark brown.

Winged male: Similar to wingless male in general structure and coloration, with following exceptions: pronotum greatly enlarged, width 1.30, length 1.25, completely covering meso- and metanotum, anterior margin bearing small, transversely ovate, dark orange patch anteromedially behind head vertex, bounded laterally by pale silvery pruinose areas; humeri enlarged, slightly protrusive laterally; posterior pronotal lobe broadly domed, lacking obvious foveae, posterior margin broadly angular, bearing scattered long, gently curving, semi-erect black setae; forewings uniformly dark blackish-brown, extending past apex of abdomen when intact, bearing 3 closed cells, all in basal half of wing, consisting of two elongate cells basally followed by a single smaller cell distally, this distal cell nested centrally between the posterior apices of the two basal cells.

Winged female: Similar to winged male in general body form and coloration, pronotum width 1.40, length 1.40.

Etymology. The name “woa ” is a noun in apposition and refers to the Woa River type-locality on Rossel Island.

Distribution. Louisiade Archipelago; endemic to Rossel Island ( Fig. 309 ). The species range as presently known occupies the Rossel Island area of freshwater endemism (Area 39) as delineated by D. Polhemus & Allen (2007).

Discussion. Rhagovelia woa is a small, dark-colored member of the R. caesius group, and is similar in many respects to R. riu from Tagula Island, but easily separated by the brown to black coloration of the middle coxa and trochanter in contrast to the yellow coxae and trochanters on the fore and hind legs; in R. riu , by contrast, all the coxae and trochanters are yellow.Also easily distinguished from that species by the very different form of the female abdomen, with the metanotum and abdominal tergite I flat and angling downward rather than produced upward to form a setiferous tumescence, and by the structure of the connexival margins, which are strongly infolded over the lateral abdomen only on their posterior halves ( Figs. 296 , 298), rather than along their entire lengths as in R. riu .

Ecological notes. For a general discussion of the Woa River type-locality, see the earlier discussion under R. mbo . The type series of R. woa was taken from the tailraces of riffles where small tributaries entered the main river channel ( Fig. 302 ). The insects gathered in schools, with a few scattered individuals also being taken on shallow flows at the heads of riffles.

Figures

FIG. 296. Rhagovelia woa n. sp., wingless female, dorsal habitus; specimen from Rossel Is., Woa River, CL 7196. Young Sohn illustration.

FIG. 309. Distributions of species in the R. woa subgroup in the Louisiade Islands.

FIG. 302. Woa River, Rossel Is., Milne Bay Province, Papua New Guinea, CL 7196, type-locality for R. woa n. sp.