Rhagovelia basima, 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 : 170-175

Rhagovelia basima new species

( Figs. 205 , 214 , 218 , 281–289 , 295 )

Type material examined. Holotype, wingless male: PAPUA NEW GUINEA, Milne Bay Prov., D'Entrecasteaux Islands, Fergusson Island, east coast, Awaetowa River , lower midreach, E. of Basima , 45 m., 9°27'41"S, 150°49'38"E, water temp. 27° C., 26 January 2003, 13:00–16:30 hrs., CL 7183a, D. A. & J. T. Polhemus ( BPBM) . Paratypes: PAPUA NEW GUINEA, Milne Bay Prov., D'Entrecasteaux Islands : 11 winged males, 4 winged females, 39 wingless males, 48 wingless females, same data as holotype, Fergusson Is., CL 7183a, D. A. & J. T. Polhemus ( USNM) ; 6 winged males, 6 winged females, 101 wingless males, 88 wingless females, Fergusson Island, east coast, Yaya River, N. of Mebulibuli Point , 0– 60 m., water temp. 25.8° C., 23 August 2002, 10:00–16:30 hrs., 9°30'34"S, 150°52'51"E, CL 7178, D. A. & J. T. Polhemus ( USNM, BPBM) ; 1 wingless male, 2 wingless females, Fergusson Island, east coast, Mebulibuli Creek and rocky tributary, 1.3 km. upstream of mouth, S. of Basima , 15– 75 m., 9°30'54"S, 150°52'04"E, water temp. 24° C., 24 August 2002, 09:00–13:00 hrs., along margins of main channel, CL 7180a, D. A. & J. T. Polhemus ( USNM) ; 2 winged males, 1 winged female, 58 wingless males, 53 wingless females, Fergusson Island , same data as preceding except on rocky tributary, CL 7180b, D. A. & J. T. Polhemus ( USNM, BPBM) ; 3 wingless males, 3 wingless females, Fergusson Island , same data as preceding except 15 m., 9°30'42"S, 150°52'06"E, cascading tributary, CL 7180c, D. A. & J. T. Polhemus ( USNM) ; 1 winged female, 25 wingless males, 30 wingless females, Fergusson Island, east coast, Awaetowa River, lower midreach, E. of Basima , 15 m., 9°27'34"S, 150°49'37"E, water temp. 23° C., 25 August 2002, 09:45–11:15 hrs., CL 7183b, D. A. & J. T. Polhemus ( USNM, BPBM) ; 2 wingless males, Fergusson Island, east coast, upper Awaetowa River and rocky tribs., W. of Basima , 575– 650 m., water temp. 22° C., 27 January 2003, 10:00–14:00 hrs., 9°30'34"S, 150°48'17"E, along margins of main channel, CL 7225a, D. A. Polhemus ( USNM) ; 3 wingless males, 3 wingless females, D'Entrecasteaux Islands, Fergusson Island , same data as preceding except on first tributary, CL 7225b, D. A. Polhemus ( USNM) ; 59 wingless males, 58 wingless females, 21 immatures, Normanby Island, south coast, coastal springs at Bunama , sea level, 10°08'22"S, 151°08'48"E water temp. 26° C., 28 January 2003, 16:00–18:00 hrs., CL 7226b, D. A. & J. T. Polhemus ( USNM, BPBM) ; 1 winged male, 2 winged females, 20 wingless males, 18 wingless females, Normanby Island, upper Apatabuia River and rocky tribs., above Bunama , 60– 90 m., 10°07'04"S, 151°09'07"E, water temp. 23.5° C. (main river), 29 January 2003, 09:00–01:00 hrs., from margins of main river channel, CL 7228a, D. A. & J. T. Polhemus ( USNM, BPBM) ; 2 winged males, 1 winged female, 19 wingless males, 33 wingless females, Normanby Island, south coast, rocky trib. to upper Apatabuia River with pools amid boulders, above Bunama , 90 m., 10°07'12"S, 151°09'07"E, water temp. 25° C. (pools), 29 January 2003, 09:00– 01:00 hrs., CL 7228b, D. A. & J. T. Polhemus ( USNM, BPBM) ; 3 winged males, 2 winged females, 23 wingless males, 29 wingless females, Normanby Is., tributary streamlet to upper Dibuwa River, W. of Yeluyelua , 320 m., 10°02'40"S, 151°15'05"E, water temp. 23° C., 30 January 2003, 08:45–09:00 hrs. and 12:45–13:00 hrs., CL 7230, D. A. Polhemus ( USNM, BPBM) ; 9 wingless males, 10 wingless females, upper Dibuwa River and rocky tribs., W. of Yeluyelua , 245 m., 10°02'46"S, 151°14'53"E, water temp. 24° C., 30 January 2003, 09:30–12:30 hrs, from ponded area along tributary, CL 7231b, D. A. Polhemus ( USNM, BPBM) ; 15 wingless males, 20 wingless females, 5 immatures, Normanby Island , same data as preceding except from small tributary near the village, CL 7231c, D. A. Polhemus ( USNM, BPBM) ; 4 winged males, 2 wingless males, Normanby Island, east coast, Golupona Stream above Yeluyelua , 90 m., water temp. 23° C., 30 January 2003, 08:00–13:00 hrs, 10°02'53"S, 151°15'35"E, CL 7232, J. T. Polhemus ( USNM) .

Description.

Wingless male: Size: Length = 3.20–3.30 (x = 3.24, n = 5); width = 1.00–1.10 (x = 1.08, n = 5). Wingless female, length = 3.20–3.70 mm (x = 3.69, n = 5); width = 1.20–1.30 (x = 1.26, n = 5). Winged male, length = 3.70–3.90 mm (x = 3.82, n = 4); width = 1.40–1.50 mm (x = 1.46, n = 5). Winged female, length = 3.65–3.80 mm (x = 3.71, n = 3); width = 1.30–1.40 mm (x = 1.36, n = 3).

Color: Dorsal ground color black, marked with pale orange on anterior pronotum and connexiva, pale yellow on basal antennae and legs ( Fig. 281 ). Head black; rostrum pale brown, piceous distally; eyes dark red. Pronotum yellowish-orange on anterior one-third, black on posterior two-thirds, the pale anterior coloration extending laterally and ventrally onto propleurae. Mesonotum, metanotum and abdominal tergites I–VI, VIII and IX black, tergite VII orange-brown, all tergites except tergite VII uniformly dull and lacking shining areas, tergite VII broadly shining centrally, connexiva black on inner halves, dark orange on outer halves. Antennal segment I with basal two-thirds pale yellow, distal third plus all of segments II–IV black. Legs generally black, with coxae, trochanters, basal half of fore femur, basal quarter of hind femur dorsally, majority of ventral fore and hind femur pale yellow. Venter dark orange, except acetabula pale yellow.

Structural characters: Head moderately short, declivant anteriorly, with weakly impressed median line; length 0.30, width 0.80; length of eye along inner margin 0.37, anterior/posterior interocular space, 0.20/0.40. Pronotum long, width 1.05, length along midline 0.75, much greater than dorsal length of head, leaving mesonotum barely exposed, posterior lobe lacking evident foveae; mesonotum exposed only as a small crescent posterior to pronotum, lacking foveae, length at midline 0.05. Metanotum moderately exposed, length at midline 0.15. Lengths of abdominal tergites I–VIII, respectively: 0.20: 0.25: 0.25: 0.25: 0.25: 0.25: 0.40: 0.35. Connexiva with margins of even width throughout, margins nearly straight and evenly convergent posteriorly, posterolateral angles not modified, separated by entire width of tergite VIII.

Entire dorsum and laterotergites covered with fine, appressed pale pubescence, intermixed with scattered longer, semi-recumbent setae, a few stout black setae present anterolaterally on pronotum; legs and antennae thickly clothed with short appressed gold setae, with scattered long, erect black setae on anterodorsal faces of antennal segments I and II, anterior margins of all femora, posterior margins of fore and middle femora; fore tibia with a brush of semi-erect brown setae along posterior margin; hind femur with a few long, pilose, brown setae along posterior margin; fore and middle trochanters lacking pegs or teeth; fore and middle femora straight, with ventral faces slightly flattened; fore tibia slightly expanded and ventrally flattened on distal one-fourth; middle tibia straight, cylindrical, not modified; hind trochanter bearing 5 small dark pegs ventrally; hind femur highly incrassate, bearing two parallel rows of teeth, ventral row lying in area covered by infolded hind tibia and consisting of approximately 18 tiny black pegs basally, followed by 3 subequal sized small black teeth, then a much larger tooth, then three much smaller teeth of progressively decreasing size toward apex; dorsal row of teeth commencing near middle of femur with two small teeth preceding a much larger, acute orange-brown tooth with a black apex, followed by 3 smaller black teeth of subequal size, then another large, robust orange-brown tooth with a black apex, then 3–4 small black teeth of progressively decreasing size; hind tibia broadly and gently sinuate, inner surface bearing 2 parallel rows of 10–12 small dark teeth on basal two-thirds, then a dorsal row of 7 larger black teeth of gradually decreasing size approaching tibial apex, plus a ventral row of 2 moderate sized black teeth followed by 4 smaller teeth running to apex ( Fig. 285, 286 ).

Venter of head and thorax with jugum, adjacent inner propleural area bordering eye, lateral portions of meso- and metasterna, pro- and metacetabulum, and abdominal ventrites II and III centrally on flanks of medial carina bearing small black denticles, such denticles occasionally present in small numbers on mesoacetabulum, but absent on metapleura ( Fig. 214 ); mesosternum slightly depressed centrally, margins of this depression and central metasternum bearing long, fine, erect gold setae; abdominal venter set with short appressed gold setae, patches of longer, fine, erect gold setae present along longitudinal midline of abdominal ventrites II–VI; basal abdominal ventrites highly sculptured, ventrite I lying in vertical orientation, remaining ventrites horizontal and all in similar plane, ventrite II with an acute longitudinal carina of V-shaped cross section medially, this carina continuing in less pronounced form onto ventrites III–VI, ventrite VII broadly and shallowly depressed centrally, ventrite VIII longitudinally carinate medially, with a pair (1+1) of shallow, concave depressions to either side of this raised midline.

Male paramere small, bean-shaped, distal section curving upward and bearing scattered stout setae, apex broadly blunt ( Fig. 287 ). Male proctiger elongate, with basolateral lobes small, angular; distolateral lobes large, rounded; distal cone with apex broadly rounded ( Fig. 288 ).

Lengths of antennal segments I–IV: 0.75: 0.50: 0.60: 0.55.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 1.00: 1:00: 0.02: 0.03: 0.25; of middle leg, 1.75: 1.25: 0.10: 0.35: 0.75; of hind leg, 1.60: 1.50: 0.05: 0.15: 0.30.

Wingless female: Similar to wingless male in general structure and coloration, with following exceptions: abdominal tergites V–VII orange-brown and shining centrally; connexival margins strongly convergent posteriorly adjacent to abdominal tergites I–IV, then nearly parallel with only slight posterior convergence adjacent to tergites V–IX, margins slightly infolded so as to cover extreme lateral sections of tergites V–IX ( Figs. 282, 283 ), connexival margins adjacent to tergites III and IV narrowed and glabrous, shining gold in colour ( Fig. 218 ); posterolateral connexival angles forming right angles, bearing dense tufts of moderately long black setae, these tufts posteriorly angular in lateral view; abdominal tergite VIII and proctiger deflected downward 45° from vertical, bearing tufts of golden-brown setae laterally; hind femur only weakly incrassate, posterior margin bearing a single row of teeth, consisting of three small black teeth, then a large, slender, sharp tooth with a black apex, followed by 4 smaller black teeth of progressively decreasing size to tibial apex; hind tibia straight, inner surface lacking teeth or pegs; ventral coloration predominantly orange-brown, with meso- and metasternum plus abdominal ventrites I and II darker reddish brown; all abdominal ventrites lying in similar horizontal plane; metasternum and abdominal ventrites I–III medially tumescent, with patches of short, dense gold setae centrally, ventrites IV and V depressed basomedially ( Fig. 205 ).

Winged male: Similar to wingless male in general structure and coloration, with following exceptions: pronotum greatly enlarged, width 1.50, length 1.40, completely covering meso- and metanotum, anterior lobe orange-brown centrally, faint silvery pruinose laterally, divided by narrow dark brown stripe along longitudinal midline; humeri enlarged, slightly protrusive laterally; posterior pronotal lobe dark brown, broadly domed, posterior half with obscure dark fovae, posterior margin broadly angular, bearing scattered long, gently curving, semi-erect black setae; forewings dark blackish-brown, slightly paler brown basally, 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, subequal sized cells distally near center of wing. Hind femur less incrassate than in wingless male, hind tibia only weakly sinuate ( Fig. 284 ).

Winged female: Similar to winged male in general body form and coloration, pronotum width 1.35, length 1.25.

Etymology. The name “basima ” is a noun in apposition and refers to the type-locality at the village of Basima, on Fergusson Island, in the D’Entrecasteaux Islands.

Distribution. D’Entrecasteaux Islands; endemic to Fergusson and Normanby islands ( Fig. 295 ). The species range as presently known falls within the D’Entrecasteaux Islands area of freshwater endemism (Area 35) as delineated by D. Polhemus & Allen (2007), but also includes Normanby Island. Recent tectonic analyses have indicated that Normanby Island is geologically composite, with its northwestern section having a petrology similar to Goodenough and Fergusson islands, and its southeastern section containing rock units more similar to those in the Owen Stanley Range of the Papuan Peninsula ( Baldwin et al. 2012; Wallace et al. 2014). Therefore the definition of Area 35 as provided by D. Polhemus & Allen (2007) may need to be modified to accommodate this.

Discussion. The characters separating this species from others in the R. loriae subgroup are provided in the key, and further discussed under R. loriae .

The female body form in R. basima is typical of members of the R. loriae subgroup, with the connexival margins thinned, glabrous, and bowed inward adjacent to abdominal tergites III and IV. The female ventral abdomen has abdominal ventrites II–III medially tumescent, bearing patches of short, dense, posteriorly-directed gold setae centrally, and ventrites IV and V depressed basomedially. The male proctiger is more elongate than in the other members of the R. loriae subgroup, with well-developed basolateral and distolateral lobes (compare Fig. 288 to Figs. 272 , 279 , 294 ).

As interpreted here, R. basima occurs on both Fergusson and Normanby islands. There are slight differences between the Fergusson and Normanby island populations, but these seem insufficient to justify separate species status.

Ecological notes. The Awaetowa River at the type-locality near the village of Basima on Fergusson Island (CL 7183) was a clear, cool, swiftly-flowing stream in a broad bed of water-rounded metamorphic rocks and boulders composed of greenschists and blueschists, with alternating shallow riffles and pools, the latter 0.3–1.5 m deep. The banks were bordered by tall, dry grass and partially shaded by scattered trees ( Fig. 289 ). Rhagovelia basima occurred here in sheltered pockets along the stream margins, co-occurring with a few specimens of R. awaetowa , a species in the R. novacaledonica group more abundant at higher elevations.

Specimens from the Dibuwa River near the village of Wamua in the interior of Normanby Island (CL 7230, CL 7231) have a more orange-brown ground color than other populations sampled, similar to the situation seen populations of R. dibuwa in the R. novacaledonica group occurring at the same locality (see discussion under the latter species).

Figures

FIGS. 203–208. Rhagovelia papuensis group, female ventral abdomen showing locations of depressions and patterns of setiferation. 203. Rhagovelia loriae n. sp.; specimen from New Guinea, Dorobisoro, CL 7260. 204. Rhagovelia guiagoila n. sp.; specimen from Basilaki Is., Kalawai River, CL 7294. 205. Rhagovelia basima n. sp.; specimen from Fergusson Is., Yaya River, CL 7178. 206. Rhagovelia elongata n. sp.; specimen from Goodenough Is., Matalamoia River, CL 7187. 207. Rhagovelia bwagabwaga n. sp.; specimen from Misima Is., Keyana Creek, CL 7206. 208. Rhagovelia priori n. sp.; specimen from New Guinea, Kofure River, CL 7304.

FIGS. 212–215. Rhagovelia loriae subgroup, ventral thorax showing distribution and density of black denticles on the fore and middle acetabula. 212. Rhagovelia loriae n. sp.; specimen from New Guinea, Dorobisoro, CL 7260. 213. Rhagovelia guiagoila n. sp.; specimen from Basilaki Is., Kalawai River, CL 7294. 214. Rhagovelia basima n. sp.; specimen from Fergusson Is., Yaya River, CL 7178. 215. Rhagovelia elongata n. sp.; specimen from Goodenough Is., Kuliana Creek, CL 7185.

FIGS. 216–219. Rhagovelia loriae subgroup, female dorsal abdomen showing central portion of the connexival margin, with varying degrees of flexure and thinning. 216. Rhagovelia loriae n. sp.; specimen from New Guinea, Watuti River, CL 7175. 217. Rhagovelia guiagoila n. sp.; specimen from Sideia Is., Kwabunamoa River, CL 7287. 218. Rhagovelia basima n. sp.; specimen from Fergusson Is., Yaya River, CL 7178. 219. Rhagovelia elongata n. sp.; specimen from Goodenough Is., Matalamoia River, CL 7187.

FIGS. 281–284. Rhagovelia basima n. sp., dorsal habitus photographs showing different color forms and morphs; specimens from the D’Entrecasteaux Islands. 281. Wingless male, orange-brown color form, dorsal habitus; specimen from Normanby Is., Dibuwa River, CL 7230. 282. Wingless female, orange-brown color form, dorsal habitus; specimen from Normanby Is., Dibuwa River, CL 7230. 283. Wingless female, dark color form, dorsal habitus; specimen from Fergusson Is., Yaya River, CL 7178. 284. Winged male, dark color form, specimen from Fergusson Is., Mebulibuli Creek, CL 7180.

FIGS. 285–288. Rhagovelia basima n. sp., structural details; specimens from the D’Entrecasteaux Islands. 285. Male right hind leg, posterior view. 286. Male right hind leg, dorsal view; 285 and 286 from Normanby Is., Dibuwa River tributary, CL 7230. 287. Male left paramere, outer lateral view. 288. Male proctiger, dorsal view; 287 and 288 from Fergusson Is., Yaya River, CL 7178.

FIG. 289. Lower midreach of the Awaetowa River, near Basima, Fergusson Is., Milne Bay Prov., Papua New Guinea, CL 7183, type-locality for R. basima n. sp.

FIG. 295. Distributions of species in the R. loriae subgroup on eastern New Guinea and adjacent islands.

FIGS. 267–272. Rhagovelia loriae n. sp., specimens from eastern New Guinea. 267. Wingless male, dorsal habitus; specimen from Dorobisoro, CL 7260. 268. Wingless female, dorsal habitus; specimen from the Cloudy Mountains, CL 7175. 269. Male right hind leg, posterior view. 270. Male right hind leg, dorsal view; 269 and 270 from Dorobisoro, CL 7264. 271. Male left paramere, outer lateral view. 272. Male proctiger, dorsal view; 271 and 272 from Dorobisoro, CL 7263.

FIGS. 274–279. Rhagovelia guiagoila n. sp., structural details; specimens from the China Strait islands. 274. Wingless male, dorsal habitus. 275. Wingless female, dorsal habitus; 274 and 275 from Sideia Is., Kwabunamoa River, CL 7287. 276. Male right hind leg, posterior view. 277. Male right hind leg, dorsal view; 278. Male left paramere, outer lateral view. 279. Male proctiger, dorsal view; 276–279 from Basilaki Is., Kalawai River, CL 7294.

FIGS. 290–294. Rhagovelia elongata n. sp., structural details; specimens from Goodenough Island. 290. Wingless male, dorsal habitus; specimen from Kuliana Creek, CL 7185. 291. Wingless female, dorsal habitus; specimen from Matalamoia River, CL 7187. 292. Male left hind leg, dorsal view; specimen from Kuliana Creek, CL 7185. 293. Male left paramere, outer lateral view. 294. Male proctiger, dorsal view; 293 and 294 from Matalamoia River, CL 7187.