Rhagovelia kolukolu, 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 : 99-103

Rhagovelia kolukolu new species

( Figs. 8 , 154–159 , 160 , 168 )

Type material examined. Holotype, wingless male: PAPUA NEW GUINEA, Milne Bay Prov., Louisiade Archipelago, Tagula [Sudest] Island, Kolukolu Creek , near Araeda village , 100–105 m., 11°26'45"S, 153°25'57"E, water temp. 23 °C., 30 August 2002, 11:00–16:00 hrs., highest pool and small rocky tributary creek above upper falls, CL 7194b, D. A. & J. T. Polhemus ( BPBM) . Paratypes: PAPUA NEW GUINEA, Milne Bay Prov., Louisiade Archipelago, Tagula [Sudest] Island: 1 winged female, 48 wingless males, 63 wingless females, same data as holotype, CL 7194b, D. A. & J. T. Polhemus ( USNM, BPBM); 1 winged male, 2 wingless males, 1 wingless female, Tagula Island , same data as preceding except along margins of main channel, CL 7194a, D. A. & J. T. Polhemus ( USNM, BPBM) .

Description.

Wingless male: Size: Length = 3.70–4.05 mm (x = 3.85, n = 5); width = 1.20–1.40 mm (x = 1.30, n = 5). Wingless female, length = 4.00– 4.10 mm (x = 4.04, n = 5); width = 1.40–1.50 mm, (x = 1.42, n = 5). Winged male, length = 4.50 mm (n = 1); width = 1.65 mm (n = 1). Winged female, length = 4.00 mm (n = 1); width = 1.60 mm, (n = 1).

Color: Dorsal ground color dark to medium brown, marked with dark yellow on basal antennae, anterior pronotum, connexiva and legs ( Fig. 154 ). Head dark brown; rostrum pale whitish yellow, fuscous medially, piceous distally; eyes dark reddish black. Pronotum dark yellow on anterior two-thirds, dark brown on posterior one-third. Mesonotum reddish brown. Metanotum and abdominal tergites dark brown, uniformly dull and lacking shining areas, connexiva medium brown on inner halves, dark yellow on outer halves. Antennal segment I with basal half dark yellow, distal half plus all of segments II–IV dark brown. Legs generally medium brown, with coxae, trochanters, basal half of fore femur, basal third of hind femur dark yellow. Venter pale yellowish white, with metasternum, genital segment, and patches on ventrolateral abdomen adjacent to spiracles brown.

Structural characters: head moderately short, declivant anteriorly, with weakly impressed median line; length 0.43, width 0.85; length of eye along inner margin 0.37, anterior/posterior interocular space, 0.25/0.50. Pronotum short, width 1.10, length along midline 0.30, leaving mesonotum broadly exposed; mesonotum smooth, lacking foveae, humeri depressed, length at midline 0.65. Metanotum length at midline 0.10. Lengths of abdominal tergites I–VIII, respectively: 0.23: 0.27: 0.20: 0.20: 0.25: 0.27: 0.45: 0.35. Connexiva with margins of even width throughout, weakly outwardly convex, 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 long, erect black setae on lateral pronotum and mesonotum, pleural areas, bases of connexiva, and central sections of 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, and anterior margins of all femora, long pilose brown setae present along posterior margins of all femora; fore and middle trochanters lacking pegs or teeth; fore and middle femora and tibiae with margins straight, not flattened or otherwise modified; hind trochanter with approximately 14 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 14 tiny black pegs basally, followed by 10 moderate sized teeth with black apices, the most basal of these teeth being the largest, the remainder somewhat smaller but generally subequal in size, dorsal row of teeth commencing with a large, acute tooth near middle of femur, followed by 4–5 teeth of progressively declining size, all these teeth pale basally with black apices, ventral surface of femur below ventral spine row with an additional 4–5 scattered small, dark teeth; hind tibia broadly and gently sinuate, inner surface bearing 2 parallel rows of 18–20 small dark teeth ( Figs. 156, 157 ).

Venter of head and thorax lacking small black denticles; mesosternum slightly depressed centrally, margins of this depression and adjacent lateral metasternum bearing long, fine gold setae; abdominal venter set with short appressed gold setae intermixed laterally with long, fine, erect pale brown 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 less pronounced form onto ventrite III, ventrites IV–VI unmodified, central section of sternite VII bearing a broad, roughly quadrate depression centrally.

Male paramere shape slender, elongate, tapering slightly distally, apex with small, downward-curved hook ( Fig. 158 ). Male proctiger lacking prominent basolateral or distolateral lobes, sides nearly parallel on basal section; apex of distal cone rounded ( Fig. 159 ).

Lengths of antennal segments I–IV: 1.00: 0.62: 0.75: 0.60.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 1.20: 1:30: 0.05: 0.02: 0.30; of middle leg, 2.00: 1.50: 0.10: 0.60: 0.85; of hind leg, 1.95: 2.00: 0.05: 0.10: 0.50.

Wingless female: Similar to wingless male in general structure and coloration, with following exceptions: connexival margins straight, converging evenly to posterior apex of abdomen, touching at base of abdominal tergite VIII ( Fig. 155 ); posterolateral connexival angles simple, rounded, not produced, lacking hair tufts; hind femora only weakly incrassate, bearing only 3 very small dark spinules on posterior face near apex; hind tibiae straight, inner surface lacking teeth; abdominal sternite II with weak longitudinal medial carina basally, central sections of abdominal sternites III–VI flattened centrally.

Winged male: Similar to wingless male in general structure and coloration, with following exceptions: pronotum greatly enlarged, width 1.70, length 1.55, completely covering meso- and metanotum, anterior lobe dark yellow, set off from postrior lobe by transverse line of punctillae; humeri enlarged, slightly protrusive laterally; posterior pronotal lobe dark reddish-brown, broadly margined with yellow posteriorly ( Fig. 8 ), broadly domed, posterior portion of this domed section with numerous small foveae, posterior margin broadly angular; entire pronotum covered with short recumbent gold setae, intermixed on posterior angular margin with scattered semi-erect, curling, golden setae; forewings uniformly dark blackish-brown, extending past apex of abdomen when intact, bearing 4 closed cells, consisting of two elongate cells basally followed by two smaller cells of subequal size distally near center of wing.

Winged female: Similar to wingless female in general structure and coloration, with following exceptions: pronotum greatly enlarged, completely covering meso- and metanotum, humeri enlarged, posterior apex angular, anterior margin broadly dark yellow across entire width, central section broadly medium brown, posterior margin narrowly dark yellow, posterior angular section set with numerous small, deep, blackish foveae, entire pronotum covered with short recumbent gold setae, intermixed on posterior angular section with scattered semi-erect, curling, golden setae; forewings uniformly dark brown, bearing 4 closed cells, consisting of two elongate cells in basal half of the wing followed by two smaller distal cells of subequal size near middle of wing.

Etymology. The name “kolukolu ” is a noun in apposition and refers to the Kolukolu Creek type locality. Distribution. Louisiade Archipelago; endemic to Tagula Island ( Fig. 168 ). The species range as presently known occupies the Tagula Island area of freshwater endemism (Area 38) as delineated by D. Polhemus & Allen (2007).

Discussion. Rhagovelia kolukolu is a large, robust, orange-brown species endemic to the interior highlands of Tagula Island. It is most similar to R. mbo from adjacent Rossel Island, but the male parameres of the two species are distinctly different, with that of M. kolukolu having a small, downward curving hook at the apex, while that of M. mbo is curved apically upward (compare Figs. 158 , 165 ). The male proctigers of both species have a similar basic form, being massive basally, but in R. kolukolu the proctiger is somewhat narrower, and transitions more abruptly to a narrow distal cone (compare Figs. 159 , 166 ). Females may be separated by the form of the female connexiva, which are vertically oriented and only fold inward to barely touch at their extreme posterior apices in R. kolukolu , rather than being folded slightly inward along their posterior halves as in R. mbo (compare Figs. 155 , 162 ). The coloration of both species is similar in many respects, with the male pronotum often bearing an orange-brown patch centrally. Winged morphs of M. kolukolu have the posterior margin of the prontoum broadly margined with yellow, producing a strongly contrasting, chevron-shaped pattern ( Fig. 8 ), whereas in R. mbo the posterior pronotum is less prominently margined with brown. For additional discussion of characters separating these species see the discussion under R. mbo .

Ecological notes. Kolukolu Creek at the type-locality (CL 7194) was a swift stream flowing through chutes and pools in metamorphic Calvados Schist, which underlies the entire catchment (see geologic map in Webb et al. 2014), and then dropping over a waterfall approximately 20 m high into a large, deep pool that marked the head of the terminal mangrove estuary. Rhagovelia kolukolu was found sparingly in shaded eddies below another waterfall further upstream in the upper catchment, and more abundantly on a small, rocky, shaded first order tributary that entered near this upper fall ( Fig. 160 ).

Figures

FIGS. 6–9. Rhagovelia species females from the EPCT region, dorsal views of fully winged morphs showing shapes of wings and expansion of pronotum. 6. R. suloga n. sp., specimen from Woodlark Island, CL 7217. 7. R. aviavi n. sp., specimen from Lakekamu River basin, New Guinea, CL 7156. 8. R. kolukolu n. sp., specimen from Tagula Island, CL 7194. 9. R. mimani n.sp., specimen from Dorobisoro, New Guinea, CL 7263.

FIGS. 154–159. Rhagovelia kolukolu n. sp., structural details; specimens from Tagula Is., Kolukolu Creek, CL 7194. 154. Wingless male, dorsal habitus. 155. Wingless female, dorsal habitus. 156. Male right hind leg, posterior view. 157. Male right hind leg, dorsal view. 158. Male left paramere, outer lateral view. 159. Male proctiger, dorsal view.

FIG. 160. Kolukolu Creek headwaters, Tagula Is., Milne Bay Province, Papua New Guinea, CL 7194, habitat for R. kolukolu n. sp.

FIG. 168. Distributions of species in the R. kolukolu subgroup in the Louisiade Islands.

FIGS. 161–166. Rhagovelia mbo n. sp., structural details; specimens from Rossel Is., Woa River, CL 7196. 161. Wingless male, dorsal habitus. 162. Wingless female, dorsal habitus. 163. Male right hind leg, posterior view. 164. Male right hind leg, dorsal view. 165. Male left paramere, outer lateral view. 166. Male proctiger, dorsal view.