Rhagovelia aviavi, 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 : 107-113

Rhagovelia aviavi new species

( Figs. 62 , 169–180 )

Type material examined. Holotype, wingless male: PAPUA NEW GUINEA, Gulf Prov., New Guinea, Ivimka Creek along Kakoro Track , SE of Ivimka Research Station, 30 m., 07°44'20"S, 146°30'06"E, water temp. 25° C., 17 January 2001, 07:30–13:00 hrs., CL 7149, D. A. Polhemus ( BPBM) . Paratypes: PAPUA NEW GUINEA ,

Gulf Prov., New Guinea: 2 wingless males, 9 wingless females, same data as holotype, CL 7149, D. A. Polhemus ( BPBM); 2 wingless males, Sapoi River and rocky tributary upstream of Ivimka Research Station , 120–150 m., 7°43'36"S, 146°29'59"E, water temp. 27° C. (river), 24.5° C. (rocky trib.), 16 January 2001, 07:00–13:00 hrs., from margins of pools on main river channel, next to logs and vertical banks, CL 7148b, D. A. Polhemus ( USNM); 29 wingless males, 24 wingless females, same locality as preceding but from CL 7148c, rocky trib., D. A. Polhemus ( BPBM); 3 wingless males, 1 wingless female, Sapoi River , 1.2 km. SW of Ivimka Research Station, 30 m., 07°44'30"S, 146°29'26"E, water temp. 27° C., 18 January 2001, 11:00–12:00 hrs., CL 7151, D. A. Polhemus ( USNM). Additional material examined (not paratypes): PAPUA NEW GUINEA , Gulf Prov.: 4 wingless males, 1 wingless female, small rocky tributary to Wampupayo River at old Bulldog Track, 1.75 km. NE of Ivimka Research Station, 70–100 m., 07°43'06"S, 146°30'09"E, water temp. 24° C., 19 January 2001, 08:30–13:00 hrs., on tributary with cascades, CL 7153b, D. A. Polhemus ( USNM, BPBM). Central Prov. : 1 wingless male, Yaniwe River and small tributary streamlets at Tekadu , 300 m., 7°40'36"S, 146°33'05"E, water temp. 24° C., 21 January 2001, 12:00–16:30 hrs., CL 7157a, D. A. Polhemus ( USNM); 1 winged male, Omoi River at Bulldog Track, 3 km. SE of Tekadu, 180 m., 07°41'56"S, 146°32'03"E, water temp. 24° C., 21 January 2001, 11:00 hrs., CL 7156, D. A. Polhemus ( USNM); 2 wingless males, 2 wingless females, Eio Creek , nr. Baruanumu, E. of Port Moresby, 505 m., [vic. 9°25'27"S, 147°24'10"E], 22 September 1983, CL 1840, D. A. & J. T. Polhemus ( USNM ex JTPC, BPBM); 1 wingless male, 2 wingless females, Musgrave (Aieme) River at Awarere Plantation, E. of Port Moresby, 230 m., [9°26'12"S, 147°35'57"E], 22 September 1983, CL 1841, D. A. & J. T. Polhemus ( USNM ex JTPC) .

Description.

Wingless male: Size: Length = 3.50–3.70 mm (x = 3.60, n = 5); width = 1.20–1.30 mm (x = 1.27, n = 5). Wingless female, length = 3.30–3.50 mm (x = 3.37, n = 5); width = 1.35–1.40 mm, (x = 1.39, n = 5). Winged male, length = 3.90 mm (n = 1); width = 1.60 mm (n = 1).

Color: Dorsal ground colour black, sparingly marked with dark yellow to orange-brown on basal antennae, anterior pronotum, connexiva and basal femora ( Fig. 169 ). Head black, posterior margins of juga and basal rostrum orange-brown, rostrum fuscous ventromedially, piceous distally; eyes dark red. Pronotum black, with a transversely ovate dark orange-brown spot anteromedially behind vertex, this orange-brown coloration bounded by black laterally and not extending downward onto the propleurae. Mesonotum, metanotum and all abdominal tergites black, abdominal tergites uniformly dull and lacking glabrous areas; connexiva black on inner halves, dark orange-brown on outer halves, ventral faces also dark orange-brown. Antennal segment I with basal one-third pale yellowish, distal two-thirds plus all of segments II–IV black. Legs generally black dorsally, with coxae, fore and hind trochanters, basal one-fourth of fore femur posterodorsally yellowish-white. Venter black, anterior margins of propleurae adjacent to eyes very narrowly dark yellow, all acetabula dark orange-brown, abdominal ventrites I–VI dull black, ventrites VII and VIII semi-shining dark brown.

Structural characters: Head length 0.35, width 0.80; length of eye along inner margin 0.35, anterior/posterior interocular space, 0.20/0.42. Pronotum length along midline less than dorsal length of head, leaving mesonotum broadly exposed, length 0.25, width 0.95; mesonotum smooth, lacking deep foveae, humeri depressed, length along midline 0.70. Metanotum barely exposed, length 0.10. Lengths of tergites I–VIII, respectively: 0.20: 0.20: 0.20: 0.20: 0.20: 0.28: 0.38: 0.40. Connexiva with margins straight, of even width throughout, convergent posteriorly, posterolateral angles not modified, separated by entire width of tergite VIII, bearing a few long, curving, dark setae.

Entire dorsum thickly covered with fine, appressed pale pubescence, intermixed with scattered longer, semi-erect black setae on lateral pronotum and mesonotum, and along posterior margins of all abdominal tergites; legs and antennae thickly clothed with short appressed pale setae, with scattered long, erect, bristly black setae on anterodorsal faces of antennal segments I and II, and anterior margins of all femora, regularly spaced long, straight dark setae along posterior margins of fore and middle femora, and long pilose brown setae along posterior margin of hind femur, length of these long setae equal to the thickness of the respective femora on which they occur; 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, longitudinally channelled near apex adjacent to grasping comb; hind trochanter bearing 3–4 very small dark pegs ventrally; hind femur moderately incrassate, bearing two rows of teeth and pegs lying in area covered by infolded hind tibia, ventral row consisting of approximately 12 small, sharp black teeth of subequal size commencing at about one-third distance from the femoral base and running to the distal femoral apex, dorsal row consisting of 8–9 very small, black teeth running from base of femur to one-third distance from base, followed by a moderately large dark brown spine with a black apex, separated by a gap from another moderately large spine of similar form, followed by 8 smaller black spines of decreasing size running to distal femoral apex; hind tibia straight, inner surface bearing a single row of teeth consisting of 12 subequally sized, small, stout black teeth basally, followed by 2 slightly larger stout black teeth at about two-thirds distance to apex, followed by 4–5 more small black teeth of progressively decreasing size distally ( Figs. 174, 175 ).

Venter of head and thorax lacking small black denticles; mesosternum slightly depressed centrally, margins of this depression bearing long, fine gold setae; metasternum broadly and gently tumid, with fine, erect pale setae laterally; abdominal venter set with short appressed pale setae intermixed with longer, fine, semi-erect pale setae laterally and posteromedially; basal abdominal ventrites highly sculptured, ventrite I lying in vertical orientation and bearing a small, rounded bump centrally, remaining ventrites horizontal and all in similar plane, ventrite II with a longitudinal carina of V-shaped cross section medially, ventrites III–V slightly swollen, unmodified, ventrite VII slightly flattened and semi-shining centrally, black, posterior margin very broadly and shallowly concave, fringed with short, pale setae; ventrite VIII constricted basally, with a pair (1+1) of shallow, concave depressions to either side of a weakly carinate longitudinal midline.

Male paramere thick, elongate, basal section with ventral margin broadly rounded, central section with stout setae ventrally, distal section slightly expanded, posterior margin broadly truncate, posterodorsal apex forming a rounded angle ( Fig. 176 ). Male proctiger with basolateral lobes well-developed, anterolateral apices forming slightly obtuse angles; distolateral lobes incipient, not expanded; distal cone triangular, apex bearing a small, nipple-like process ( Fig. 177 ).

Lengths of antennal segments I–IV: 0.75: 0.38: 0.48: 0.52.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2, tarsal 3 of fore leg, 1.00: 1.00: 0.02: 0.02: 0.25; of middle leg, 1.75: 1.15: 0.05: 0.50: 0.75; of hind leg, 1.50: 1.50: 0.05: 0.10: 0.35.

Wingless female: Similar to male in general structure and coloration, with following exceptions: long, semi-erect dark setae absent on posterior margins of abdominal tergites II–VI; connexival margins weakly sinuate, convergent adjacent to abdominal tergites I–III, then bowed slightly outward adjacent to tergites IV and V, then convergent again adjacent to tegites VI and VII, slightly thickened adjacent to abdominal tergites III and IV ( Fig. 170 ), posterolateral angles forming right angles when viewed laterally, lacking angular setal tufts but bearing a few long, erect black setae immediately anterior to apices; abdominal tergite VIII and proctiger angled downward at 45°, proctiger elongate; ventral surface of middle tibia flattened; hind trochanter lacking small black pegs; hind femora only weakly incrassate, area along ventral midline in area covered by infolded hind tibia bearing a single spine row consisting of 1–2 small, sharp black spines basally, then a moderately long, slender, sharp, spine, followed by a gap which may contain a small spine, then another long, slender, acute black spine, then 5 much smaller spines of progressively decreasing size to apex; hind tibiae straight, inner surface lacking teeth; ventral coloration predominantly dull black, ventral head and adjacent prothorax lacking tiny black denticles, abdominal sternites VII–IX orange-brown; all abdominal ventrites lying in similar horizontal plane, posterior margin of abdominal sternite VII unmodified.

Winged male: Similar to wingless male in general structure and coloration, with following exceptions: pronotum greatly enlarged, width 1.60, length 1.50, completely covering meso- and metanotum; anterior lobe with transversely ovate pale yellowish patch along anterior margin in area behind head vertex, this patch bounded laterally by silvery pruinose areas overlaying dark coloration behind eyes, thus separated from paler coloration on propleurae; humeri enlarged, slightly protrusive laterally; posterior pronotal lobe dark black, broadly domed, posterior half with small, obscure foveae, posterior margin broadly angular, bearing a few moderately long, gently curving black setae; forewings uniformly dark blackish-brown, wing apices extending past apex of abdomen when intact, bearing 4 closed cells consisting of two elongate cells in basal half of wing followed by two smaller cells of subequal size distally near center of wing.

Winged female: Unknown.

Etymology. The name “aviavi ” is a noun in apposition, and refers to the type-locality on the lower course of the Sapoi River, which is also locally known as the Aviavi.

Distribution. Southeastern New Guinea; currently known from the Lakekamu River basin and certain catchments behind Port Moresby ( Fig. 62 ). The species range as presently known occupies the Papuan Gulf Foreland area of freshwater endemism (Area 25) as delineated by D. Polhemus & Allen (2007).

Discussion. This species is a small-sized member of the R. novacaledonica group that in many respects resembles the species of the R. tufi subgroup, including the general form of the male paramere and proctiger ( Figs. 176–179 ), but lacks black denticles on the prosternum and proacetabula. Male abdominal tergite VII is flattened and shining centrally, lacking a significant central depression or raised lateral ridges, and its posterior margin is broadly and shallowly concave, with this concavity fringed with short, pale setae ( Fig. 173 ), this being a useful diagnostic character.

The female abdominal tergites lack shining patches, and the female connexival margins show some degree of intraspecific variation, with those of lowland populations (CL 7148, 7149, 7151) being slightly sinuate ( Fig. 170 ), while those from populations taken at slightly higher elevations (CL 7153, 7157) are straight and evenly convergent posteriorly ( Figs. 172 ). The variability in connexival form initially led to the supposition that two species might be present in the material from the Lakekamu River basin upon which the species concept is based, but the male pregential and genital structures are similar and show intermediate gradation across all these series ( Figs. 176–179 ), so they are treated under a single species concept for the present, but with specimens from the more upland localities at the Wampupayo River and Tekadu not included as paratypes. Similarly, several series are at hand from the Astrolabe Range behind Port Moresby that also fall within the current broad concept of this species adopted here, but are not listed as paratypes given the possibility that a complex of closely related taxa may be involved.

Ecological notes. Ivimka Creek at the type-locality (CL 7149) was a clear, moderately swift, well-shaded, gravel-bottomed creek traversing a nearly flat, tall-stature primary lowland rain forest ( Fig. 180 ). The bed substrate consisted primarily of gravel and cobbles, with smaller percentages of fine sediment, sand, and a few larger rocks, while the bed profile featured pools up to 1 m deep separated by shallow riffles. Rhagovelia aviavi was common here on the flowing pools, in company with a few individuals of the larger R. sapoi , the latter occurring in sheltered pockets along the bases of low cut banks.

Additional paratypes were taken along the Sapoi River upstream of the Ivimka research station, and on small tributaries entering this river from the south (CL 7148). The river here formed a long, wide, and fairly shallow pool against the base of a hill, with a swift, rocky, higher gradient tributary entering at the downstream end. The substrate here consisted of rocks, cobbles and gravel, with the banks of the river heavily shaded by primary lowland rain forest, but with the center of the river channel unshaded. Rhagovelia aviavi was taken sparingly here from eddies along the margins of the flowing river channel, and far more abundantly from flowing pools on the tributary.

Figures

FIG. 62. Distributions of species in the R. tufi subgroup and R. aviavi n. sp. in eastern New Guinea.

FIGS. 169–172. Rhagovelia aviavi n. sp., dorsal habitus photos, specimens from New Guinea, Lakekamu River basin, Gulf Prov., Papua New Guinea. 169. Wingless male; specimen from Sapoi River tributary, CL 7148. 170. Wingless female; specimen from Ivimka Creek, CL 7149. 171. Wingless male; upland variant; specimen from Wampupayo River, CL 7153. 170. Wingless female; upland variant; specimen from Wampupayo River, CL 7153.

FIGS. 173–179. Rhagovelia aviavi n. sp., structural details; specimens from New Guinea, Lakekamu River basin, Gulf Prov., Papua New Guinea. 173. Male ventral terminal abdomen. 174. Male right hind leg, posterior view. 175. Male right hind leg, dorsal view. 176. Male left paramere, outer lateral view. 177. Male proctiger, dorsal view; 173–177 from Sapoi River tributary, CL 7148. 178. Male left paramere, outer lateral view. 179. Male proctiger, dorsal view; 178 and 179 from Wampupayo River, CL 7153.

FIG. 180. Ivimka Creek in the Lakekamu River basin of Gulf Province, southern Papua New Guinea, CL 7149, habitat for R. aviavi n. sp. and R. ivimkana n. sp.