Rhagovelia bowutu, 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 : 27-29

Rhagovelia bowutu n. sp.

( Figs. 17 , 41–47 , 62 )

Type material examined. Holotype, wingless male: PAPUA NEW GUINEA, New Guinea, Morobe Prov., 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: 7 wingless males, 8 wingless females, same data as holotype, CL 7243, D. A. Polhemus ( USNM): 4 wingless males, 2 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) .

Description.

Wingless male. Size: Length = 3.00– 3.10 mm (x = 3.03, n = 5); width 1.00– 1.10 mm (x = 1.04, n = 5). Wingless female, length = 3.20–3.35 mm (x = 3.27, n = 5), width = 1.10–1.15 (x = 1.11, n = 5).

Coloration: Dorsal ground color dark grey, marked with pale orange on anterior pronotum, with outer connexiva, basally on legs, basal antennae pale yellow ( Fig. 41 ). Head black dorsally, lower frons pruinose grey, tylus and jugae brown; rostrum pale yellowish-brown, fuscous medially, piceous distally; eyes dark red. Pronotum dark blackish-grey centrally, pruinose grey laterally, with transverse yellowish-orange patch anteriorly behind head vertex, this pale anterior coloration not extending laterally onto propleurae. Mesonotum, metanotum and abdominal tergites dark blackish-grey, tergites I–VI uniformly dull and lacking shining areas, tergite VII slightly shining, connexiva dark blackish-grey on inner halves, pale orange on outer halves. Antennal segment I with basal one-third pale yellow, distal half plus all of segments II–IV dark brown. Legs generally black, with coxae, trochanters, basal third of fore femur dorsally, basal one-fourth of hind femur dorsally, basal four-fifths of fore and hind femora ventrally, extreme base of middle femur ventrally pale yellow to yellowish-brown. Venter dark brown, with ventral sections of propelurae, prosternum, all acetabula pale yellow, abdominal ventrites VII–X yellowish-brown.

Structural characters: Head moderately short, declivant anteriorly, with weakly impressed median line; length 0.35, width 0.75; length of eye along inner margin 0.35, anterior/posterior interocular space, 0.15/0.45. Pronotum short, width 0.95, length along midline 0.25, shorter than dorsal length of head, leaving mesonotum broadly exposed; mesonotum smooth, tumescent, lacking foveae, length at midline 0.55. Metanotum moderately exposed, roughly crescent-shaped, length at midline 0.05. Lengths of abdominal tergites I–VIII, respectively: 0.15: 0.20: 0.18: 0.18: 0.20: 0.25: 0.40: 0.25. Connexiva with margins of even width throughout, margins nearly straight and evenly convergent posteriorly, flexed very slightly inward adjacent to abdominal tergites I–III, posterolateral angles not modified, separated by entire width of tergite VIII.

Entire dorsum and laterotergites covered with fine appressed golden pubescence, intermixed with scattered long, erect black setae laterally on thorax, a few long, slender, semi-erect golden setae on abdominal tergites; 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; fore femur with posterior margin bearing a thick fringe of pale, semi-erect, moderately long setae plus a comb of 7–8 long, slender, erect, evenly spaced black setae; fore tibia with anterior margin bearing numerous erect, pale, moderately long setae intermixed with long, slender, erect black setae; middle femur bearing 9–10 evenly spaces long, slender, erect black setae along posterior margin; fore and middle trochanters lacking pegs or teeth; fore and middle femora and tibiae with margins straight, not flattened or otherwise modified; fore tibia slightly expanded and ventrally flattened on distal one-fourth; hind trochanter bearing 10 small black denticles ventrally; hind femur highly incrassate, with scattered very long, slender, pilose brown setae posterodorsally, posterior margin bearing two parallel rows of teeth, ventral row lying in area covered by infolded hind tibia and consisting of approximately 18 tiny black pegs on basal half, bifurcating into ventral row with ~16 similar but larger stubby, subequal sized black pegs, and dorsal row commencing near middle of femur with a single moderately small acute orange-brown tooth with a black apex, followed by an open space lacking teeth, then by 1 large orange-brown tooth with black apex, then 3 smaller black teeth of progressively declining size toward femoral apex ( Fig. 43 ); hind tibia broadly and gently sinuate, inner surface bearing 2 parallel rows of 12–15 small black teeth on basal two-thirds, then a large, acute tooth, then 3 more moderate sized teeth of progressively declining size, these latter 4 teeth all orange-brown with black apices.

Venter of head and prothorax bearing small black denticles on jugae, central prosternum, and inner proacetabula; meso- and metasterna slightly depressed centrally, margins of this depression and adjacent lateral metasternum bearing long, fine gold setae arranged in a V-shaped pattern with apex directed anteriorly; abdominal venter set with short appressed gold setae; 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 incipient fashion along longitudinal midlines of ventrites III–VI, ventrite VII broadly and shallowly depressed centrally, forming a roughly ovate concavity with a transversely truncate posterior margin ( Fig. 17 ).

Male paramere shape gently sinuate, basal section with ventral margin broadly curving, bearing stout setae, distal section expanded, ventral margin bearing a truncate process ( Fig. 45 ). Male proctiger with basolateral lobes well-produced, angular; distolateral lobes weakly produced, broadly rounded; distal cone dome-shaped, apex blunt ( Fig. 46 ).

Lengths of antennal segments I–IV: 0.75: 0.40: 0.52: 0.52.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 0.80: 0.90: 0.02: 0.03: 0.10; of middle leg, 1.50: 1.10: 0.05: 0.40: 0.65; of hind leg, 1.45: 1.25: 0.05: 0.10: 0.30.

Wingless female. Similar to wingless male in general structure and coloration, with following exceptions: connexival margins unmodified, bearing short, stiff black setae, nearly straight except for slight inward concavity adjacent to abdominal tergites III and IV, converging evenly to posterior apex of abdomen, separated by full width of abdominal tergite VII and just slightly covering posterolateral sections of tergite VIII ( Fig. 42 ), posterolateral angles of connexiva bending at ~90°, with short, posteriorly-directed tufts of black setae when viewed laterally; abdominal tergites I and II slightly raised and domed, tergites III–V with longitudinal midlines weakly raised, bearing narrow patches short golden setae, tergite VI very slightly convex, tergites VI–VIII with small, longtitudinally elongate, shining brown patches centrally, these patches bearing very short golden setae; abdominal tergite VIII lying in horizontal orientation, proctiger angled downward at slightly less 45° from horizontal, projecting well beyond tergite VIII when viewed dorsally; all trochanters unarmed; hind femur only weakly incrassate, bearing a single row of teeth below infolded tibia, beginning with 2 small, sharp black teeth near midpoint, followed by a much longer, slender, acuminate tooth with a black apex, then 7 more smaller teeth of progressively decreasing size to femoral apex ( Fig. 44 ); hind tibia straight, inner surface lacking teeth; ventral coloration predominantly dark grey, with ventral section of propleura, prosternum, proacetabula, abdominal ventrites and gonocoxae yellowish orange; all abdominal ventrites unmodified, lacking carinae or depressions ( Fig. 42 ).

Winged male: Unknown.

Winged female: Unknown.

Etymology. The name “bowutu ” is a noun an apposition and refers to the Bowutu Mountains , from which this species was collected.

Distribution. Eastern New Guinea ( Fig. 62 ). The species range as presently known occupies the Morobe Highands area of freshwater endemism (Area 22) as delineated by D. Polhemus & Allen (2007).

Discussion. Within the EPCT Rhagovelia assemblage, R. bowutu may be diagnosed by the presence of denticles on the prosternum and proacetabula; the structures of the male genitalia ( Figs. 45, 46 ); the presence of a broad, shallow, longitudinally ovate concavity on male abdominal ventrite VII ( Fig. 17 ); and the uniformly black and shining female abdominal tergite VII. For characters separating this species from the similar R. tufi , see the preceding discussion under that species.

Ecological notes. The type series was taken from a small first order streamlet descending from the hill slope above Kamiali village (CL 7243). The stream was clear and shaded, being surrounded by partly disturbed lowland rain forest. The bed profile consisted of alternating riffles, cascades, and flowing pools, with R. kamiali being taken on the latter, in company with R. dinga , a species in the R. papuensis group.

Rhagovelia bowutu was also taken at a second site in the hills further inland from Kamiali, known as “Kerosine Creek” due to the slightly blue color of its waters created by underlying ophiolitic bedrock that formed much of the stream channel. This stream was of moderate gradient, with alternating riffles and shallow pools amid dark bedrock and fine alluvium ( Fig. 47 ). The forest surrounding this site was rather impoverished, as is typical of ultramafic terrain, consisting of widely spaced Casuarina and Pandanus trees, which provided partial shading. Rhagovelia bowutu was once again taken here in company with R. dinga , as well as with a few specimens of R. hirsuta , the latter species at the lower margin of its elevational range.

Figures

FIGS. 16–19. Species of the Rhagovelia tufi subgroup, male terminal abdomen, ventral view, showing structural variation on ventrites VII and VIII. 16. R. tufi n. sp., specimen from New Guinea, Kofure River, CL 7304; 17. R. bowutu n. sp., specimen from New Guinea, Kamiali, CL 7243; 18. R. obscura n. sp., specimen from New Guinea, Dorobisoro, CL 7264; 19. R. upalai n. sp., specimen from New Guinea, Alotau, CL 7163.

FIGS. 41–46. Rhagovelia bowutu n. sp., structural details; specimens from New Guinea, Kamiali, Aleater River tributary, CL 7243. 41. Wingless male, dorsal habitus. 42. Wingless female, dorsal habitus. 43. Wingless male left hind femur, ventral view. 44. Wingless female left hind femur, ventral view. 45. Male left paramere, outer lateral view. 46. Male proctiger, dorsal view.

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

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