Rhagovelia mimani, 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 : 119-124

Rhagovelia mimani new species

( Figs. 2 , 3 , 9 , 33, 54, 145, 194–201)

Material examined.— Holotype, wingless male: PAPUA NEW GUINEA, Central Prov. , New Guinea, Owen Stanley Range, trib. to upper Mimani River, 2.7 km. NE of Dorobisoro, 580–685 m., water temp. 21.5 °C., 8 October 2003, 09:30–12:30 hrs., 9°27'23"S, 147°57'03"E, CL 7262, D. A. Polhemus ( BPBM) .— Paratypes: PAPUA NEW GUINEA, Central Prov., New Guinea: 15 winged males, 10 winged females, 20 wingless males, 31 wingless females, same data as holotype, CL 7262, D. A. & J. T. Polhemus ( USNM, BPBM) ; 3 winged males, 3 winged females, 23 wingless males, 29 wingless females, Owen Stanley Range, trib. to upper Mimani River , 2.0 km. NE of Dorobisoro, 565 m., water temp. 22.5 °C., 7 October 2003, 13:40–14:20 hrs., 9°27'21"S, 147°56'25"E, CL 7261, D. A. Polhemus ( USNM, BPBM) ; 2 winged males, 1 winged female, Owen Stanley Range, upper Mimani River , 1.70 km. NE of Dorobisoro, 535 m., 9°27'25"S, 147°56'15"E, water temp. 23.5 °C., 7 October 2003, 13:00–15:00 hrs., along margins of main river channel, CL 7260a, D. A. Polhemus ( USNM) ; 1 winged female, same data as preceding except from small flowing spring adjacent to main river channel, CL 7260b, D. A. Polhemus ( USNM) ; 3 winged males, 2 winged females, 7 wingless males, 9 wingless females, Owen Stanley Range, trib. to upper Mimani River , 0.95 km. NE of Dorobisoro, 520 m., 9°27'27"S, 147°55'50"E, water temp. 23 °C., 7 October 2003, 11:30–12:00 hrs., CL 7259, D. A. Polhemus ( BPBM, USNM) ; 1 winged female, 7 wingless males, 10 wingless females, Owen Stanley Range, trib. to upper Mimani River , 2.9 km. NE of Dorobisoro, 640– 670 m., water temp. 22.5 °C., 8 October 2003, 12:45–13:30 hrs., 9°27'19"S, 147°56'53"E, CL 7263, D. A. Polhemus ( USNM, BPBM) ; 1 winged male, Owen Stanley Range, trib. to upper Mimani River , 0.8 km. W of Dorobisoro, 500 m., water temp. 23.5 °C., 9 October 2003, 08:30–12:30 hrs., 9°27'39"S, 147°54'56"E, CL 7264, D. A. Polhemus ( USNM) .

Description

Size— Wingless male, length = 3.95–4.20 mm (x = 4.05, n = 5); width = 1.30–1.50 mm (x = 1.36, n = 5). Wingless female, length = 4.00– 4.20 mm (x = 4.07, n = 5); width = 1.40–1.50 mm, (x = 1.48, n = 5). Winged male, length = 4.75 mm (n= 1); width = 1.70 mm (n= 1). Winged female, length = 4.60 mm (n= 1); width = 1.85 mm (n= 1).

Colour— Wingless male: Dorsal ground colour dark blackish-brown, marked with dark yellow to orange-brown on basal antennae, anterior pronotum, central section of mesonotum, connexiva and legs ( Fig. 194 ). Head dark brown; lower frons, juga and rostrum dark yellow, rostrum fuscous ventromedially, piceous distally; eyes dark reddish black. Pronotum dark yellow on anterior half, this yellowish coloration continuing laterally as a continuous band onto the propleurae, posterior half dark brown to black. Mesonotum broadly dark reddish brown posterolaterally, broadly orange-brown centrally, this orange coloration in the form of a broad triangle with the apex directed posteriorly. Metanotum and abdominal tergites I–VI dark blackish-brown; tergite VII blackish-brown laterally, orange-brown posteromedially, abdominal tergites VIII and IX (= proctiger) black; abdominal tergites I–VI uniformly dull and lacking shining areas, tergite VII dull laterally, shining posteromedially, tergite VIII entirely shining; connexiva black on inner halves, dark yellow on outer halves, ventral faces also dark yellow. Antennal segment I with basal one-third pale yellow, distal two-thirds plus all of segments II–IV black. Legs generally dark brown to black, with coxae, trochanters, basal half of fore femur dorsally and ventrally, entire hind femur ventrally dark yellow to yellowish-brown. Venter dark brown, with prosternum and all acetabula dark yellow, mesopleurae and central portions of abdominal ventrites VII and VIII yellowish brown.

Structural characters— Wingless male: head moderately short, declivant anteriorly, with weakly impressed median line; length 0.35, width 0.85; length of eye along inner margin 0.30, anterior/posterior interocular space, 0.20/0.45. Pronotum short, length along midline 0.30, less than dorsal length of head, leaving mesonotum broadly exposed, width 1.15; mesonotum smooth, lacking deep foveae, humeri depressed, length 0.70. Metanotum barely exposed, length 0.07. Lengths of abdominal tergites I–VIII, respectively: 0.20: 0.25: 0.20: 0.20: 0.20: 0.25: 0.50: 0.40. Connexiva with margins of even width throughout, weakly inwardly concave basally adjacent to abdominal tergites I–III, then weakly outwardly convex adjacent to abdominal tergites IV–VII, margins convergent posteriorly, posterolateral angles not modified, separated by entire width of tergite VIII, bearing a few long dark setae.

Entire dorsum and laterotergites thickly covered with fine, appressed pale pubescence, intermixed with scattered long, stiff, semi-erect black setae on lateral portions of metanotum and 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, long dark setae present on posterior margins of fore and middle femora, long pilose pale setae present along posterior margin of hind femur; 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-fourth, longitudinally channeled adjacent to grasping comb; hind trochanter bearing 12–14 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 16 tiny, closely appressed black pegs running from base of femur to midpoint, followed by 14–15 moderately small teeth of gradually but progressively decreasing size distally running to femoral apex, these teeth yellowish brown with dark apices, dorsal row commencing near middle of femur at distal end of basal peg row with 3 large, acute, evenly spaced teeth, followed by 6 smaller teeth of progressively declining size to femoral apex, all these teeth yellowish-brown with black apices; hind tibia broadly and gently sinuate, inner surface bearing a row of about 16 small dark teeth running distally from base, then a large, acute, tooth approximately two-thirds distance from base, followed by 5 more smaller black teeth of progressively decreasing size to tibial apex ( Fig. 196, 197 ).

Venter of head and thorax lacking small black denticles; mesosternum with a shallow, triangular depression centrally, margins of this depression bearing long, fine gold setae; metasternum very slightly raised centrally; abdominal venter set with short, closely 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 a broad longitudinal carina medially between lateral depressions accommodating coxae, ventrites III–VI unmodified, posterior margin of ventrite VII anteriorly concave, ventrite VIII constricted basally.

Male paramere shape elongate, basal section stout, distal arm parallel sided, apex truncate, not expanded ( Fig. 98 ). Male proctiger with a pair (1+1) of raised vertical lamellae basally to either side of longitudinal midline, these lamellae angling slightly inward toward base of distal cone; basolateral lobes well developed, rounded; distolateral lobes small, rounded, knob-like; distal cone dome-shaped, apex slightly angular ( Fig. 199 ).

Lengths of antennal segments I–IV: 1.00: 0.60: 0.75: 0.55.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 1.15: 1:30: 0.04: 0.02: 0.35; of middle leg, 2.00: 1.50: 0.05: 0.65: 0.90; of hind leg, 1.75: 1.80: 0.05: 0.15: 0.40.

Wingless female —Similar to wingless male in general structure and coloration, with following exceptions: abdominal tergites I–VIII all dull, without shining patches, lacking setae except for small patches of very short golden setae centrally; connexival margins straight and of even width throughout, converging evenly to posterior apex of abdomen, not infolded, posterolateral angles forming right angles when viewed laterally, bearing very short, angular tufts of posteriorly-directed stiff black setae; abdominal tergite VIII horizontal, proctiger angled downward at 45°; hind trochanter bearing 4 small black pegs; hind femur only weakly incrassate, bearing a single row of teeth, beginning basally with 7 small, black, peg-like teeth, then two moderately large, sharp orange-brown teeth with black tips, then a much smaller black tooth, then a very large, sharp orange-brown tooth with a black tip, and finally 4–5 small black teeth of progressively decreasing size distally; hind tibiae straight, inner surface lacking teeth; ventral coloration predominantly orange-brown, propleurae and prosternum dark yellow, metasternum and abdominal tergite I dark brown; all abdominal ventrites lying in similar horizontal plane; gonocoxal commisure forming a small ventral carina with posteromedial apex bearing a tuft of short, stiff black setae (Fig. 33).

Winged male —Similar to wingless male in general structure and coloration, with following exceptions: pronotum greatly enlarged, completely covering meso- and metanotum, width 1.70, length 1.70, humeri enlarged, anterior pronotal margin with arcuate pale orange-brown patch in area behind vertex, this patch confluent with similar pale coloration on propleurae, remainder of pronotum black, posterior section angular, set with numerous tiny foveae, entire pronotum covered with short recumbent gold setae, these setae becoming longer and denser on posterior angular section; abdomen not reflexed, lying in a uniformly horizontal plane when viewed laterally; forewings uniformly dark blackish-brown, extending to tip of abdomen, bearing 4 closed cells, consisting of two long cells in the basal half of the wing plus two smaller cells distally, veins set with erect dark setae.

Winged female —Similar to winged male in general body form and coloration; pronotum width 1.85, length 1.90 ( Fig. 9 ).

Etymology. The name “mimani ” is a noun in apposition and refers to the Mimani River type-locality.

Distribution. Southeastern New Guinea; endemic to the Papuan Peninsula ( Fig. 201 ). The species range as presently known occupies the South Papuan Peninsula Foreland area of freshwater endemism (Area 30) as delineated by D. Polhemus & Allen (2007).

Comparative notes. This is a species from the upper Mimani River basin (a tributary to the Kemp Welch River), with an appearance superficially similar to members of the R. dibuwa subgroup from the Milne Bay area and D’Entrecasteaux Islands. In all these species the female connexiva are straight, broadly separated, and are evenly convergent posteriorly, and male abdominal ventrite VIII is transversely depressed basally, causing this segment to appear constricted in lateral view.

Rhagovelia mimani diverges from the basic plan of the R. dibuwa subgroup in regard to the structures of the male genitalia. The pistol-shaped male paramere with a long, parallel-sided distal arm ( Fig. 198 ) is unique among Rhagovelia species occurring on the EPCT. The vertically raised lamellae on the basal section of the male proctiger (appearing as dark crescents in the photographic illustration provided in Fig. 199 ) are also distinctive. Although similar but less prominently developed lamellae are present in a more reduced form in R. watuti from the Cloudy Mountains and in R. dibuwa ( Figs. 4, 5 ) from the D’Entrecasteaux Islands, in those species the posterior margin of the sclerotized portion of the proctiger lies posterior to the basolateral lobes, whereas in R. mimani the posterior margin of sclerotization is broadly curved anteriorly beyond the basolateral lobes, creating a large basal sinus (compare Figs. 90 , 199 ). This character state in R. mimani again has no analog among the currently known New Guinea Rhagovelia species. In addition, the male paramere shape in R. watuti is much broader and apically produced into a rounded, upward-angling lobe ( Fig. 89 ), similar to the character state seen in the other members of the R. dibuwa subgroup. Therefore, R. watuti represents a mix of character states seen in R. mimani and the R. dibuwa subgroup, and suggests some level of relationship among all of these taxa.

Another distinctive character state in R. mimani is the heavily armed female hind femur, which bears two moderately long, sharp spines at about half the distance from the base to the apex, followed by a larger, acuminate spine at two-thirds distance ( Fig. 195 ). One aberrant female taken along the Mimani River (CL 7260a) has this female hind femur spine pattern modified, consisting of two pairs (2 + 2) of large spines, with each pair arising from a common base in a V-shape, with the basal pair slightly shorter than the distal pair.

Biological notes. Rhagovelia mimani was common along Mimani River and its tributary streams in the vicinity of Dorobisoro (Figs. 54, 145, 200), where the river emerges from the mountains and enters the premontane foreland. This village name does not appear on the Australian 1:100,00 topographic maps of Papua New Guinea, even though this village was referred to by that name in Australian patrol reports as far back as 1962, and it is still the official name of the modern airstrip. The airstrip is instead shown as the Menumu Landing Ground on the 1:100,000 Efogi topographic map, printed in 1974, but this may be a cartographic error, since this same map she et al so shows another landing strip named Manumu at a village on the upper Brown River. By contrast, Dorobisoro and its airstrip are properly located and named on the Tactical Pilotage Chart 1:250,00 scale map sheet prepared in the late 1970s.

The type series of R. mimani was taken from a clear, rocky, heavily shaded creek in primary rain forest (CL 7262), descending steeply through a bed of mixed igneous and metamorphic rocks ( Fig. 145 ). The gradient became steadily steeper as one progressed upstream, with bedrock encountered at about 700 m elevation, forming a set of falls. Rhagovelia mimani was taken on flowing stream pools from the river confluence upstream to the base of these falls, in company with R. obscura , R. loriae and R. peggiae . At another tributary 2 km upstream from Dorobisoro (CL 7261), this species was again taken in company with R. loriae on a heavily shaded, rocky creek in primary forest, leading back to a waterfall 20 m tall, cascading over metamorphic bedrock. Rhagovelia mimani was also taken along the margins of the main stem Mimani River 1.3 km NE of the village (CL 7260). At this point the river was moderately large, and swift, flowing in a clean, boulder-strewn bed with gravel and cobble runs and flanked by rugged bedrock exposures. The channel appeared to carry a large amount of additional flow in the rainy season, so it is likely that the tributary creeks serve as refugia for this species and other Rhagovelia during periods of high river discharge.

Figures

FIG. 2. Rhagovelia mimani n. sp., male, dorsal and ventral habitus views with major morphological structures as used in this work labelled; specimen from Papua New Guinea, Central Prov., Dorobisoro. Dorsal view, An1–An4 = antennal segments I–IV; Eye = eye; Vt = vertex; PrN = pronotum; MsN = mesonotum; MtN = metanotum; Cnx = connexiva; AT1–AT8 = abdominal tergites I–VIII; Pr = proctiger; FF = fore femur; FT = fore tibia; MF = middle femur; MT = middle tibia; Mts1–3 = middle tarsal segments I–III; HF = hind femur; HT = hind tibia. Ventral view, G = gula; R = rostrum; PP = propleura; PS = prosternum; Pac = proacetabula; MsS = mesosternum; MP = mesopleuron; MsAc = mesoacetabula; MtS = metasternum; MtAc = metacetabula; AV1–9 = abdominal ventrites I–IX; FTr = fore trochanter; FTs3= fore tarsal segment III; MCx = middle coxa; MTr = middle trochanter; HCx = hind coxa; HTr = hind trochanter; HTs1–3 = hind tarsal segments I–III.

FIG. 3. Rhagovelia mimani n. sp., female, dorsal and ventral habitus views with major morphological structures as used in this work labelled; specimen from Papua New Guinea, Central Prov., Dorobisoro. Dorsal view, An = antenna; Eye = eye; Vt = vertex; PrN = pronotum; MsN = mesonotum; MtN = metanotum; Cnx = connexiva; AT1–AT8 = abdominal tergites I–VIII; Pr = proctiger; FF = fore femur; FT = fore tibia; MF = middle femur; MT = middle tibia; HF = hind femur; HT = hind tibia. Ventral view, G = gula; R = rostrum; PP = propleura; PS = prosternum; Pac = proacetabula; MsS = mesosternum; MP = mesopleuron; MsAc = mesoacetabula; MtS = metasternum; MtAc = metacetabula; AV1–8 = abdominal ventrites I–VIII; FTr = fore trochanter; FTs3= fore tarsal segment III; MCx = middle coxa; MTr = middle trochanter; Mts1–3 = middle tarsal segments I–III; HCx = hind coxa; HTr = hind trochanter; HTs1–3 = hind tarsal segments I–III.

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. 194–199. Rhagovelia mimani n. sp., structural details; specimensfrom New Guinea, Mimani River basin, nearDorobisoro. 194. Wingless male, dorsal habitus; specimen from Mimani River tributary, CL 7262. 195. Wingless female, dorsal habitus. 196. Male right hind leg, posterior view. 197. Male right hind leg, dorsal view; 195–197 from Mimani River tributary, CL 7263. 198. Male left paramere, outer lateral view. 199. Male proctiger, dorsal view; 198 and 199 from Mimani River tributary, CL 7259.

FIG. 98. Goilayoli River headwaters, east of Alotau, Milne Bay Province, Papua New Guinea, CL 7161, habitat for R. peninsularis n. sp.

FIG. 201. Distributions in eastern New Guinea of species held as Incertae Sedis within the R. novacaledonica group in regard to subgroup assignments.

FIGS. 4, 5. Rhagovelia dibuwa n. sp., male genitalic structures, with specific characters as discussed in text labelled. 4. Proctiger. 5. Intact male genitalic complex, right lateral view.

FIGS. 85–90. Rhagovelia watuti n. sp., structural details; specimens from New Guinea, Cloudy Mountains, CL 7175. 85. Wingless male, dorsal habitus. 86. Wingless female, dorsal habitus. 87. Male right hind leg, posterior view. 88. Male right hind leg, dorsal view. 89. Male left paramere, outer lateral view. 90. Male proctiger, dorsal view.

FIG. 145. Tributary to the upper Mimani River, near Dorobisoro, Central Province, Papua New Guinea, CL 7262, habitat for R. peggiae Kirkaldy, R. mimani n. sp., and R. loriae n. sp.