Rhagovelia dinga, 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 : 148-151

Rhagovelia dinga new species

( Figs. 47 , 211 , 247–252 , 266 )

Type material examined. Holotype, wingless male: PAPUA NEW GUINEA, Morobe Prov., New Guinea, rocky hill stream behind Kamiali guesthouse, S. of Lababia village , nr. Cape Dinga , 30 m., 7°18'02"S, 147°08'01"E, water temp. 25.5 °C., 4 May 2003, 14:00–15:00 hrs., CL 7243, D. A. Polhemus ( BPBM) . Paratypes: PAPUA NEW GUINEA, Morobe Prov., New Guinea: 4 winged males, 23 wingless males, 19 wingless females, same data as holotype, CL 7243, D. A. Polhemus ( USNM, BPBM) ; 1 winged male, 14 wingless males, 12 wingless females, “Kerosine Creek” and rocky trib., middle Aleater [= Alewiri] River basin, W. of Lababia village , 30 m., 7°18'46"S, 147°06'30"E, water temp. 25 °C., 5 May 2003, 10:30–12:30 hrs., CL 7245, D. A. Polhemus ( USNM, BPBM) ; 7 wingless males, 8 wingless females trib to lower Aleater [= Alewiri] River , 5 m., 7°19'15"S, 147°07'35"E, 27 °C., 3 May 2003, 13:00–15:00 hrs., CL 7241 D. A. Polhemus ( USNM, BPBM) .

Description

Wingless male: Size: Length = 3.00– 3.30 mm (x = 3.16, n = 5); width = 1.00–1.10, mm (x = 1.07, n = 5). Wingless female, length = 3.10–3.30 mm (x = 3.20, n = 5); width = 1.10–1.20, mm, (x = 1.15, n = 5). Winged male, length = 3.65–3.70 mm (x = 3.67, n = 2); width = 1.30–1.35 mm (x = 1.32, n = 2).

Color: Dorsal ground colour dark brown, marked with pale orange on anterior pronotum and connexiva, pale yellow on basal antennae and legs ( Fig. 247 ). Head dark brown; rostrum medium brown, piceous distally; eyes dark reddish black, omatidia silvery. Pronotum yellowish-orange on anterior one-third, dark brown on posterior two-thirds, the pale anterior coloration overlain with faint silvery pruinosity and extending laterally and ventrally onto propleurae. Mesonotum, metanotum and abdominal tergites I–VI dark brown, tergites I–VI uniformly dull and lacking shining areas, tergites VII and VIII shining, connexiva dark brown on inner halves, dark orange on outer halves. Antennal segment I with basal one-third pale whitish yellow, distal half plus all of segments II–IV dark brown. Legs generally dark blackish-brown, with coxae, trochanters, basal two-thirds of fore femur, basal one-quarter of hind femur ventrally pale yellow. Venter brown, with lower propleurae and all acetabula pale yellowish, abdominal ventrites VII–IX yellowish brown.

Structural characters: head moderately short, declivant anteriorly, with weakly impressed median line; length 0.30, width 0.75; length of eye along inner margin 0.30, anterior/posterior interocular space, 0.20/0.40. Pronotum lacking foveae, long, width 1.00, length along midline 0.70, greater than dorsal length of head, leaving mesonotum barely exposed as only a small, thin crescent behind posterior margin; metanotum moderately exposed, length at midline 0.10. Lengths of abdominal tergites I–VIII, respectively: 0.15: 0.20: 0.20: 0.20: 0.20: 0.20: 0.30: 0.25. Connexiva with margins of even width throughout, 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 golden pubescence, intermixed with scattered longer, semi-recumbent golden setae on abdomen; legs and antennae thickly clothed with short appressed pale setae, with scattered longer, thicker, erect black setae on anterodorsal faces of antennal segments I and II, anterior margins of all femora, anterior margin of hind tibia; fore femur with 2 rows of slender, moderately long, evenly spaced black setae on along ventral margin; fore tibia with long, slender, slightly curving setae along anterior margin, intermixed with a thick fringe of moderately long, semi-recumbent pale setae; posterior and middle tibiae with scattered short, erect black setae; scattered long, slender, pilose, pale brown setae present along posterior margin of hind femur; fore and middle trochanters lacking pegs or teeth; fore femur with dorsal margin straight, not concave or depressed centrally; fore tibia slightly expanded and ventrally flattened on distal one-fourth; middle femora and tibiae with margins straight, not flattened or otherwise modified; hind trochanter bearing irregular longitudinal row of 7 small dark pegs ventrally; hind femur incrassate, bearing two rows of teeth in area covered by infolded hind tibia, consisting of approximately 15 tiny black pegs in a single irregular longitudinal row basally, followed by a dorsal row consisting of a single large, tapering tooth about two-thirds distance to femoral apex, followed distally by a much smaller tooth, then a medium-sized tooth, then 4 much smaller teeth, and a ventral row consisting of 4 small dark bumps originating near middle of femur, followed distally by a single large, tapering tooth about two-thirds distance to femoral apex, followed two much smaller teeth, then a medium-sized tooth, then 4 much smaller teeth, all of the larger teeth brown with black apices; hind tibia gently sinuate, inner surface bearing single row of about 15 small dark teeth, these teeth of larger size along central portion of tibia ( Figs. 249, 250 ).

Venter of head and thorax lacking small black denticles except on inner faces of proacetabula adjoining rostrum; mesosternum slightly depressed centrally, margins of this depression and adjacent lateral metasternum bearing long, fine gold setae; metasternum weakly tumescent centrally; abdominal venter set with short appressed gold setae, lacking tufts of long gold setae centrally ( Fig. 211 ); basal abdominal ventrites highly sculptured, ventrite I lying in vertical orientation, remaining ventrites horizontal and all in similar plane, ventrites II and III with acute longitudinal median carina of V-shaped cross section, ventrites IV–VI unmodified, ventrite VII broadly and shallowly depressed centrally, ventrite VIII sharply longitudinally carinate on basal half.

Male paramere moderately small, bean-shaped, apex curved, blunt ( Fig. 251 ). Male proctiger with basolateral lobes well-developed, angular; distolateral lobes moderately developed, rounded, distal cone dome-shaped; apex broadly rounded ( Fig. 252 ).

Lengths of antennal segments I–IV: 0.75: 0.40: 0.50: 0.45.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 0.75: 0.95: 0.01: 0.02: 0.2; of middle leg, 1.40: 1.00: 0.10: 0.40: 0.65; of hind leg, 1.35: 1.10: 0.05: 0.20: 0.30.

Wingless female: Similar to wingless male in general structure and coloration, with following exceptions: abdomen with tergites V–VII shining centrally; connexival margins strongly convergent posteriorly adjacent to abdominal tergites I–IV, then parallel adjacent to tergites V–IX, margins not infolded, all tergites visible from above ( Fig. 248 ), connexival margins adjacent to tergite IV narrowed; posterolateral connexival apices forming right angles when viewed laterally, bearing small, tapering, posteriorly-directed tufts of moderately long brown setae; abdominal tergite VIII and proctiger deflected downward approximately 30° from vertical, lacking tufts of black setae laterally; hind femur only weakly incrassate, posterior margin bearing a moderately large, acuminate black tooth at about two-thirds distance from the base, followed by 4 much smaller black teeth of progressively decreasing size distally; hind tibia straight, inner surface lacking teeth or pegs; ventral coloration medium dull brown, with lower propeurae and all acetabula pale yellowish; all abdominal ventrites lying in similar horizontal plane, ventrites IV–VII flattened centrally.

Winged male: Similar to wingless male in general structure and coloration, with following exceptions: pronotum greatly enlarged, width 1.30, length 1.20, completely covering meso- and metanotum, anterior lobe orange-brown, not divided by dark stripe along longitudinal midline; humeri enlarged, slightly protrusive laterally; posterior pronotal lobe dark brown, broadly domed, posterior half with obscure dark foveae, posterior margin rimmed with brown, broadly angular, bearing scattered long, gently curving, semi-erect black setae; forewings mostly dark blackish-brown, slightly paler basally, veins black, 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 distally near center of wing, with outer distal cell smaller than inner; male hind femur less incrassate than in wingless male.

Winged female: Unknown.

Etymology. The name “dinga ” is a noun in apposition, and refers to the Cape Dinga type-locality area.

Distribution. Southeastern New Guinea; endemic to the Bowutu Mountains ( Fig. 266 ). The species range as presently known occupies the Morobe Highands area of freshwater endemism (Area 22) as delineated by D. Polhemus & Allen (2007).

Comparative notes. Rhagovelia dinga is small, dark brown species currently known from the Bowutu Mountains of the northern Papuan Peninsula. It is most similar to R. priori , but the two species may be separated by the characters discussed under that latter species. The female connexival margins which are parallel rather than convergent and touching posteriorly ( Fig. 248 ), the differing armature of the male hind femur (compare Figs. 249, 250 to Figs. 243, 244 ), and the presence of more extensive black denticles on the abdominal ventrites are salient diagnostic characters.

Ecological notes. Rhagovelia dinga was common on small, shaded first and second order hill streams behind the research station at Kamiali ( Fig. 47 ), where it occurred syntopically with R. bowutu n. sp. and occasionally with R. hirsuta Lansbury. Notes on the type-locality, a small first order hill streamlet descending from the hills immediately behind Kamiali village (CL 7243), can be found in the discussion under R. bowutu .

This species was also taken at Kerosine Creek (CL 7145), also discussed under R. bowutu , and on a tributary off the terminal reach of the Aleater River (CL 7141). At this latter site the main river channel had been scoured by recent floods, but the tributary had been relatively unaffected, and was a smoothly flowing, moderately deep stream of cool, clear water, bordered and partially shaded by a Casuarina forest growing on sandy soils.

Figures

FIG. 47. Rocky tributary to middle Aleater River, Morobe Prov., Papua New Guinea, CL 7245, locality for R. bowutu n. sp.

FIGS. 209–211. Rhagovelia papuensis group, female ventral abdomen showing locations of depressions and patterns of setiferation. 209. Rhagovelia suloga n. sp.; specimen from Woodlark Is., Suloga Peninsula, CL 7217. 210. Rhagovelia ivimkana n. sp.; specimen from New Guinea, Tekadu, CL 7157. 211. Rhagovelia dinga n. sp.; specimen from New Guinea, Kamiali, CL 7243.

FIGS. 247–252. Rhagovelia dinga n. sp., structural details; specimens from New Guinea, Kamiali. 247. Wingless male, dorsal habitus. 248. Wingless female, dorsal habitus. 249. Male right hind leg, posterior view. 250. Male right hind leg, dorsal view. 251. Male left paramere, outer lateral view. 252. Male proctiger, dorsal view; 247–250 from rocky stream at Kamiali, CL 7243, 251 and 252 from Aleater River, CL 7241.

FIG. 266. Distributions of species in the R. priori and R. transbintuni subgroups on eastern New Guinea and adjacent islands.

FIGS. 241–246. Rhagovelia priori Lansbury, structural details; specimens from New Guinea, Tufi, Kofure River, CL 7304. 241. Wingless male, dorsal habitus. 242. Wingless female, dorsal habitus. 243. Male right hind leg, posterior view. 244. Male right hind leg, dorsal view. 245. Male left paramere, outer lateral view. 246. Male proctiger, dorsal view.