Rhagovelia peninsularis, 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 : 58-63

Rhagovelia peninsularis new species

( Figs. 21 , 27 , 61 , 92–98 , 132 )

Type material examined. Holotype, wingless male: PAPUA NEW GUINEA, Milne Bay Prov., New Guinea, Upalai River at Haluwia , 13.7 km. E. of Alotau on East Cape road, midreach and waterfall approx. 2.5 km. above mouth, 45–75 m., 10°19'39"S, 150°34'36"E, water temp. 24.5 °C., 5 April 2002, 09:45–16:30 hrs., CL 7163, D. A. & J. T. Polhemus ( BPBM) . Paratypes: PAPUA NEW GUINEA, Milne Bay Prov., New Guinea: 10 winged males, 8 winged females, 13 wingless males, 15 wingless females, same data as holotype, CL 7163, D. A. & J. T. Polhemus ( USNM, BPBM) ; 2 winged males, 5 winged females, 1 wingless males, 6 wingless females, headwater reach of Goilayoli River above crossing on road from Watunou to Huhuna , 11.5 mi. ENE of Alotau, 275 m., 6 April 2002, 10:00–13:00 hrs., CL 7161, D. A. & J. T. Polhemus ( USNM, BPBM) ; 1 winged female, 1 wingless male, 1 wingless female, same locality as preceding but 1 February 2002, 10:00–13:00 hrs., CL 7161, D. A. & J. T. Polhemus ( USNM) ; 21 wingless males, 37 wingless females, 3 immatures, streamlet and roadside seeps above Huhuna on road to Watunou , 11.2 mi. ENE of Alotau, 260 m., 10°18'19"S, 150°36'56"E, water temp. 28° C., 6 April 2002, 14:00–15:00 hrs., CL 7164, D. A. & J. T. Polhemus ( USNM, BPBM) .

Description.

Wingless male: Size: Length = 3.50–3.75, mm (x = 3.65, n = 5); width = 1.20–1.30 mm (x = 1.25, n = 5). Wingless female, length = 3.60–3.80 mm (x = 3.66, n = 5); width = 1.30–1.40 mm, (x = 1.37, n = 5). Winged male, length = 3.95–4.15 mm (x = 4.07, n = 2); width = 1.40–1.50 mm (x = 1.45, n = 2). Winged female, length = 4.00– 4.10 mm (x = 4.05, n = 4); width = 1.50–1.60 mm (x = 1.53, n = 4).

Color: Dorsal ground color black, marked with pale yellow on basal portions of antennae and legs, pronotum dark orange anteromedially ( Fig. 92 ). Head black, tylus brown, jugae dark yellow; rostrum golden brown with dark brown stripe ventromedially, apex piceous; eyes dark red. Pronotum black, with a transversely ovate yellowish-orange spot anteromedially behind vertex, this yellowish coloration bounded by pruinose grey laterally, very narrowly confluent behind eyes with similar yellow coloration on propleurae. Mesonotum, metanotum, all abdominal tergites and connexiva black; abdominal tergites uniformly dull, lacking glabrous areas. Antennal segment I with basal one-third pale yellowish-white, distal two-thirds plus all of segments II–IV black. Legs generally black, with all coxae, all trochanters, basal half of fore femur ventrally, basal two-thirds of hind femur ventrally dark yellow. Venter black, with prosternum and all acetabula dark yellow, abdominal ventrite VII and basal half of VIII dark yellow, distal half of VIII and IX dark brown.

Structural characters: Head moderately short, declivant anteriorly, with weakly impressed median line; length 0.35, width 0.80; length of eye along inner margin 0.35, anterior/posterior interocular space, 0.20/0.45. Pronotum short, length along midline 0.25, less than dorsal length of head, leaving mesonotum broadly exposed, width 1.00; mesonotum smooth, lacking deep foveae, length 0.65, humeri slightly depressed. Metanotum barely exposed, length 0.10. Lengths of tergites I–VIII, respectively: 0.20: 0.25: 0.20: 0.20: 0.20: 0.20: 0.40: 0.45. Connexiva with margins of even width throughout, very weakly sinuate, convergent posteriorly, posterolateral angles not modified, separated by entire width of tergite VIII, bearing a few long dark setae.

Entire dorsum thickly covered with fine, appressed pale pubescence, intermixed with numerous longer, semi-erect black setae except on central pronotum and mesonotum; legs and antennae thickly clothed with short appressed golden setae, with scattered long, erect, bristly black setae on anterodorsal faces of antennal segments I and II, and anterior margins of all femora, plus long pilose brown setae along posterior margin of hind femur, length of these latter setae equal to three-fourths the maximum thickness of the hind femur; fore and middle trochanters lacking pegs or teeth; fore and middle femora and middle tibia with margins straight, not flattened or otherwise modified; fore tibia slightly flattened ventrally on distal one-third, with small concavity near apex adjacent to grasping comb; hind trochanter bearing 10 small dark pegs ventrally; hind femur highly incrassate, bearing two rows of teeth and pegs lying in area covered by infolded hind tibia, ventral row consisting of approximately 18 small, similarly sized black pegs running from base of femur to one-third distance from base, followed by a small-sized dark yellow tooth with a black apex, then 1 medium-sized dark yellow tooth with a sharp black apex, then ~12 much smaller dark brown teeth of gradually decreasing size running to apex of femur, dorsal row consisting of 1 moderately large dark yellow tooth with a black apex arising near middle of femur, followed 4–5 smaller dark brown teeth of progressively declining size to femoral apex; hind tibia very gently sinuate, inner surface bearing a row of about 20 small black teeth, these teeth of subequal size except for two larger black teeth lying approximately three-fourths the distance from base ( Figs. 94, 95 ).

Venter of head and thorax, including jugum and adjacent inner prosternum, lacking small black denticles; mesosternum slightly depressed centrally, margins of this depression bearing long, fine pale setae; metasternum slightly tumid, with fine, erect pale setae laterally; abdominal venter set with short appressed pale setae intermixed with longer, fine, semi-erect pale setae laterally; basal abdominal ventrites highly sculptured, ventrite I lying in vertical orientation with small, posteriorly-directed tumescence medially, remaining ventrites horizontal and all in similar plane, ventrite II with an broad longitudinal carina of V-shaped cross section medially; ventrites III–VI unmodified but slightly swollen, ventrite VII with a pair (1+1) of shallow longitudinal concavities separated by slightly raised midline, lacking setal patches, posterior margin straight; ventrite VIII constricted basally, lacking a pronounced longitudinal medial carina.

Male paramere elongate, ventral margin nearly straight, with stiff setae present on basal two-thirds, distal section transversely expanded, hammer-like in shape with posterodorsal apex acute ( Fig. 96 ). Male proctiger with basolateral lobes well developed, apices angular; distolateral lobes not developed; distal cone triangular, apex blunt ( Fig. 97 ).

Lengths of antennal segments I–IV: 0.85: 0.45: 0.65: 0.55.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2, tarsal 3 of fore leg, 1.10: 1.20: 0.02: 0.02: 0.25; of middle leg, 1.70: 1.25: 0.05: 0.50: 0.80; of hind leg, 1.50: 1.60: 0.05: 0.15: 0.35.

Wingless female: Similar to wingless male in general structure and coloration, with following exceptions: long, semi-erect dark setae absent on thoracic and abdominal dorsum except in propleural region and sparsely on metanotum and abdominal tergite I; abdomen with connexival margins straight and of even width throughout, converging evenly to posterior apex of abdomen, lacking tufts of posteriorly-directed setae; posterolateral connexival angles forming right angles when viewed laterally, bearing short golden setae, but lacking tufts of posteriorly-directed, stiff black setae ( Fig. 21 ); abdominal tergite I transversely swollen and domed, bearing short gold setae centrally intermixed with a few longer black setae; abdominal tergite II angled slightly upward in anterior direction to accommodate swollen tergite I; abdominal tergites III–VI horizontal, bearing a faintly indicated longitudinal median carina set with scattered short golden setae, a small shining patch present posteromedially on tergite VI, a more longitudinally elongate shining patch present medially on posterior half of tergite VII; proctiger angled downward at ~30°; hind trochanter lacking small black pegs; hind femora only weakly incrassate, ventral midline in area covered by infolded hind tibia bearing a single spine row consisting of a moderate-sized slender, sharp, spine with black apex arising near middle of femur, followed by similar but larger spine at about two-thirds distance to apex, followed by 2– 3 much smaller spines of progressively decreasing size to apex; hind tibiae straight, inner surface lacking teeth or spines; ventral coloration predominantly dark pruinose grey, with prosternum plus all acetabula dark yellow, lower propleural region lacking tiny black denticles adjacent to rostrum; all abdominal ventrites lying in similar horizontal plane, abdominal sternite I incipiently carinate medially, with a small, posteriorly-directed triangular process centrally; ventrite VII barely produced posteromedially ( Fig. 27 ); gonocoxal commissure weakly carinate.

Winged male: Similar to wingless male in general structure and coloration, but with following exceptions: pronotum greatly enlarged, width 1.45, length 1.40, completely covering meso- and metanotum, humeri prominent, anterior lobe with transverse dark yellow patch centrally, overlain with silvery pruinosity, areas lateral to this patch silvery pruinose, underlying dark yellow coloration confluent with dark yellow areas on propleurae, remainder of pronotum black, posterior pronotal lobe angular, central portion domed, posterior portion lacking obvious foveae, entire pronotum covered with short recumbent gold setae, propleurae and posterior margin bearing scattered long, erect black setae; abdomen not reflexed, lying in a uniformly horizontal plane when viewed laterally; forewings uniformly dark blackish-brown, bearing 4 closed cells, consisting of an elongate cell in outer basal half of wing lying between subcosta and radius+media+cubitus, plus 2 smaller cells of subequal size flanking inner and distal margins of long cell.

Winged female: Similar to winged male in general form and coloration, with following exceptions: body size larger, pronotum width 1.55, length 1.50, with humeri prominent.

Etymology. The name “peninsularis ” is derived from the Latin peninsula and refers to the range of this species, which is confined to the eastern extremity of the Papuan Peninsula of far eastern New Guinea.

Distribution. Southeastern New Guinea; endemic to the Papuan Peninsula ( Fig. 132 ). The species range as presently known occupies the South Papuan Peninsula Foreland area of freshwater endemism (Areas 30) as delineated by D. Polhemus & Allen (2007).

Discussion. In regard to general body form, Rhagovelia peninsularis exhibits male and female character states that typify the R. dibuwa subgroup, but deviates from the other members of that subgroup in regard to certain key aspects. In particular, the male paramere, although distally expanded and dorsally produced, has a distinctively angular apex ( Fig. 96 ), in contrast to the more blunt and rounded apex seen in R. watuti and the species found on the D’Entrecasteaux Islands. The male proctiger lacks raised ridges basally, with the anterior margins of the basolateral lobes nearly straight and transverse ( Fig. 97 ). In females, the posterolateral connexival angles are rounded and lack tufts of posteriorly-directed setae ( Fig. 21 ), and abdominal tergites III–VI bear a faintly indicated longitudinal median carina set with scattered short golden setae, with small shining patches present only on tergites VI and VII.

Rhagovelia peninsularis has so far been collected only from the narrow spine of mountains that forms the elongate peninsula along the north side of Milne Bay ( Fig. 132 ). By contrast, it has not yet been taken in the Pini Range and Cloudy Mountains, which lie south of Milne Bay and enclose the Sagarai River Basin. This would suggest that these two areas may have existed as separate islands until relatively recently, allowing allopatric speciation to occur.

Ecological notes. For notes regarding the Upalai River type-locality ( Fig. 61 ) see the discussion under R. upalai . Additional specimens of R. peninsularis were collected from the upper reach of the Goilayoli River above the bridge crossing on the road that goes over the East Cape peninsula from Watunou to Huhuna; this site lay approximately 2 km west of the Upalai River. The stream here was clear and cool, flowing in a narrow channel partially incised into bedrock, with a profile consisting of pools up to 1 m deep, alternating with riffles over cobble and gravel, and interspersed with a few small cascades at transverse bedrock sills ( Fig. 98 ). Numerous seeping rock faces occurred along the margins of the channel, and a number of steeply-dropping tributary streamlets also entered along this reach, these latter having stair-step profiles of small pools connected by laminar flow over bedrock. Rhagovelia peninsularis was found on flowing pools along both the main stream and the tributaries, all of which were shaded by barely disturbed upland rain forest.

Another series of R. peninsularis was taken at a set of roadside seeps not far beyond the Goilayoli bridge. These rheocrenes provided flow to a small, mostly unshaded roadside ditch, which contained shallow runs feeding into small pools perhaps 0.3 m in size and about half as deep. Such habitats are often favorable for Rhagovelia , and R. peninsularis was abundant here.

Figures

FIGS. 20–25. Species of the Rhagovelia dibuwa subgroup, female terminal abdomen, lateral view, showing structural variation on ventrites VII and VIII. 20. R. watuti n. sp., specimen from New Guinea, Cloudy Mtns., CL 7175; 21. R. peninsularis n. sp., specimen from New Guinea, Alotau, CL 7163; 22. R. kalawai n. sp., specimen from Sideia Is., Kwabunamoa River, CL 7287; 23. R. dibuwa n. sp., specimen from Normanby Is., Dibuwa River, CL 7230; 24. R. awaetowa n. sp., specimen from Fergusson Is., Awaetowa River, CL 7225; 25. R. torrenticola n. sp., specimen from Goodenough Is., Tuabeda River, CL 7184.

FIGS. 26–31. Species of the Rhagovelia dibuwa subgroup, female terminal abdomen, ventral view, showing structural variation on posterior margin of ventrite VII. 26. R. watuti n. sp., specimen from New Guinea, Cloudy Mtns., CL 7175; 27. R. peninsularis n. sp., specimen from New Guinea, Alotau, CL 7163; 28. R. kalawai n. sp., specimen from Sideia Is., Kwabunamoa River, CL 7287; 29. R. dibuwa n. sp., specimen from Normanby Is., Dibuwa River, CL 7230; 30. R. awaetowa n. sp., specimen from Fergusson Is., Awaetowa River, CL 7225; 31. R. torrenticola n. sp., specimen from Goodenough Is., Tuabeda River, CL 7184.

FIG. 61. The upper midreach and waterfall along the Upalai River, east of Alotau, Milne Bay Prov., Papua New Guinea, CL 7163, type-locality for R. upalai n. sp., and habitat for R. peninsularis n. sp. and R. loriae n. sp.

FIGS. 92–97. Rhagovelia peninsularis n. sp., structural details; specimens from New Guinea, Alotau area, CL 7163. 92. Wingless male, dorsal habitus. 93. Wingless female, dorsal habitus. 94. Male right hind leg, posterior view. 95. Male right hind leg, dorsal view. 96. Male left paramere, outer lateral view. 97. Male proctiger, dorsal view.

FIG. 98. Goilayoli River headwaters, east of Alotau, Milne Bay Province, Papua New Guinea, CL 7161, habitat for R. peninsularis n. sp.

FIG. 132. Distributions of species in the R. dibuwa subgroup in eastern New Guinea and adjacent islands.