Rhagovelia watuti, 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 : 55-58

Rhagovelia watuti new species

( Figs. 20 , 26 , 85–91 , 132 )

Type material examined. Holotype, wingless male: PAPUA NEW GUINEA, Milne Bay Prov., New Guinea, Cloudy Mountains, headwater tributary to upper Watuti River , S. of Gelemalaia , 715 m., 10°29'50"S, 150°13'58"E, water temp. 22° C., 10 April 2002, 16:00–17:30 hrs., CL 7175, D. A. Polhemus ( USNM) . Paratypes: PAPUA NEW GUINEA, Milne Bay Prov., New Guinea: 11 winged males, 8 winged females, 45 wingless males, 42 wingless females, 1 immature, same data as holotype, CL 7175, D. A. Polhemus ( USNM, BPBM) .

Description.

Wingless male: Size: Length = 3.80–4.20 mm (x = 3.94, n = 5); width 1.30–1.40 mm (x = 1.37, n = 5). Wingless female, length = 4.00– 4.30 mm (x = 4.12, n = 5), width = 1.40–1.50 (x = 1.46, n = 5). Winged male, length = 4.30 (n = 1), width = 1.60 (n = 1). Winged female, length = 4.10 mm (n = 1); width = 1.50 mm (n = 1).

Colour: Dorsal ground color black, marked with pale orangish-yellow on basal antennae, anterior pronotum, connexiva, and basal sections of fore and hind femora ( Fig. 85 ). Head black, tylus brown, juga and rostrum dark yellow, rostrum fuscous ventromedially, piceous distally; eyes dark red. Pronotum black, bearing transverse dark yellow patch centrally on anterior half behind vertex, this yellowish coloration not continuing laterally onto the propleurae, bounded laterally by pruinose grey areas. Mesonotum, metanotum and all abdominal tergites black; connexiva black on inner two-thirds, dark yellow on outer margins, ventral faces also dark yellow. Antennal segment I with basal one-third pale yellow, distal two-thirds plus all of segments II–IV dark brown. Legs generally dark brown to black, with all coxae and trochanters, basal half of fore femur dorsally, entirety of fore femur ventrally, extreme base of middle femur, basal one-quarter of hind femur dorsally and entire hind femur ventrally dark yellow to yellowish-brown. Venter dark greyish-brown, with prosternum and all acetabula creamy whitish-yellow, central portions of abdominal ventrites VII–IX yellowish brown.

Structural characters: head moderately short, declivant anteriorly, with weakly impressed median line; length 0.45, width 0.90; length of eye along inner margin 0.40, anterior/posterior interocular space, 0.20/0.60. Pronotum short, length along midline 0.35, less than dorsal length of head, leaving mesonotum broadly exposed, width 1.35; mesonotum smooth, lacking deep foveae, humeri depressed, length 0.80. Metanotum barely exposed, length 0.10. Lengths of abdominal tergites I–VIII, respectively: 0.20: 0.30: 0.25: 0.20: 0.20: 0.25: 0.55: 0.45. Connexiva with margins of even width throughout, subparallel and weakly convergent adjacent to abdominal tergites I–IV, then somewhat more strongly and evenly convergent adjacent to abdominal tergites V–VII, posterolateral angles not modified, separated by entire width of tergite VIII, bearing a few long, dark slender setae.

Entire dorsum and laterotergites covered with fine, moderately long, semi-appressed pale setae, intermixed with scattered long, stiff, semi-erect black setae on lateral portions of pronotum and metanotum, and on all abdominal tergites; legs and antennae thickly clothed with short appressed golden setae, with scattered long, erect, bristly black setae on anterodorsal faces of antennal segments I and II, and anterior margins of all femora, long, slender, straight dark setae present in evenly spaced rows along posterior margins of fore and middle femora, very 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 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 ~18 tiny, closely appressed black pegs running along basal one-quarter of femur, followed by a single moderately large, backwardly angled pale yellow tooth with a dark, acute apex, followed by 10 smaller teeth of gradually but progressively decreasing size distally running to femoral apex, these teeth all pale with dark apices, dorsal row commencing near middle of femur at distal end of basal peg row with 4 moderately large, acute, evenly spaced teeth, followed by 3 smaller teeth of progressively declining size to femoral apex, all these teeth pale yellow with black apices; hind tibia broadly and gently sinuate, inner surface bearing a row of about 10 small, stout black teeth running distally from base, then a large, acute, brown tooth with black apex approximately three-fourths the distance from base, followed by 4 more smaller black teeth of progressively decreasing size to tibial apex ( Figs. 87, 88 ).

Venter of head and thorax lacking small black denticles; mesosternum with a shallow, triangular depression centrally, flanked by low, posterolaterally angling tumescences 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 with a small, posteriorly-directed triangular process medially, remaining ventrites horizontal and all in similar plane, ventrite II with a strongly raised longitudinal carina medially between lateral depressions accommodating coxae, ventrites III–VI swollen, unmodified, ventrite VII biconcave, bearing a pair (1+1) of shallow depressions to either side of weakly raised longitudinal midline, ventrite VIII strongly constricted basally.

Male paramere shape elongate, with scattered short, stiff setae present centrally along ventral margin, distal portion expanded, apex upturned and bluntly rounded ( Fig. 89 ). Male proctiger with basolateral lobes prominent, angular; distolateral lobes not developed; apical cone tapering evenly to an angular apex ( Fig. 90 ).

Lengths of antennal segments I–IV: 1.00: 0.50: 0.75: 0.60.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 1.25: 1:30: 0.03: 0.02: 0.35; of middle leg, 2.00: 1.45: 0.05: 0.60: 0.85; of hind leg, 1.95: 2.00: 0.05: 0.20: 0.40.

Wingless female: Similar to wingless male in general structure and coloration, with following exceptions: abdominal tergites I–VIII lacking long, erect black setae, bearing only 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 ( Fig. 86 ), posterolateral angles forming rounded right angles when viewed laterally, bearing very small, short, angular tufts of posteriorly-directed stiff gold setae ( Fig. 20 ); abdominal tergite VIII horizontal, proctiger angled downward at 45°; all trochanters unarmed, hind trochanter lacking small black pegs; hind femur only weakly incrassate, bearing a single row of teeth, beginning basally with 3 small, black, peg-like teeth, then 3 moderately large, sharp dark brown teeth, then a very large, sharp pale yellow tooth with black tip, and finally 3–4 small black teeth of progressively decreasing size distally; hind tibiae straight, inner surface lacking teeth; ventral coloration predominantly rusty brown, propleurae and prosternum creamy whitish-yellow, mesosternum, metasternum, abdominal tergite I and basal half of abdominal tergite II dark brown; all abdominal ventrites lying in similar horizontal plane; abdominal sternite VII weakly produced medially; gonocoxal commisure forming a small ventral carina ( Fig. 26 ).

Winged male: Similar to wingless male in general structure and coloration, with following exceptions: pronotum greatly enlarged, completely covering meso- and metanotum, width 1.60, length 1.50, humeri enlarged, anterior pronotal margin bearing transverse dark yellow patch centrally on anterior half behind vertex, this yellowish coloration not continuing laterally onto the propleurae, bounded laterally by pruinose grey areas, remainder of pronotum black, posterior section angular, set with scattered tiny foveae, entire pronotum covered with short recumbent gold setae, longer dark setae present along posterior margin; abdomen not reflexed, lying in a uniformly horizontal plane when viewed laterally; forewings uniformly dark blackish-brown, wing apices 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 of subequal size distally, veins set with erect dark setae. Hind femur less incrassate than in wingless male, with armature reduced.

Winged female: Similar to winged male in general form and coloration, but slightly smaller and less robust; pronotum width 1.50, length 1.45.

Etymology. The name “watuti ” is a noun in aposition and refers to the Watuti River type-locality.

Distribution. Southeastern New Guinea; endemic to the Papuan Peninsula ( Fig. 132 ). The species range as presently known occupies the Cloudy Mountains area of freshwater endemism (Area 34) as delineated by D. Polhemus & Allen (2007).

Comparative notes. Rhagovelia watuti occurs in the Cloudy Mountains of far southeastern Papua New Guinea, to the east of Orangerie Bay ( Fig. 132 ). It is allied to the species of the R. dibuwa subgroup occurring in the D’Entrecasteaux Islands by its male paramere shape, with the apex somewhat expanded into a gently upturned lobe ( Fig. 89 ); the elongate abdominal segment VIII that is transversely excavate basally; the gently sinuate male connexival margins ( Fig. 85 ); and the straight female connexival margins that converge evenly toward the posterior apex while leaving all abdominal tergites exposed, giving the abdomen an elongate triangular appearance ( Fig. 86 ).

Rhagovelia watuti possesses a pair of raised ridges on the basal portion of the male proctiger ( Fig. 90 ), a character state also seen in R. dibuwa and R. kalawai , but otherwise known only in R. mimani from further to the west on the southern Papuan Peninsula; such basal carinae on the proctiger are also present but only weakly developed in R. awaetowa and R. torrenticola . In addition, females of R. watuti have shining patches on the dorsal abdomen limited to tergites VII and VIII, versus the more extensive shining patches present on additional tergites in the insular D'Entrecasteaux species, and the tufts of setae at the posterolateral angles of abdominal connexiva small and barely developed (compare Fig. 20 to Figs. 21–25 ). This character is useful for separating the winged females of R. watuti from those of R. loriae when the two occur in mixed series, since the latter species has such connexial tufts well-developed and acuminate.

Ecological notes. The type series was taken from a clear, rocky, first-order stream in the upper elevations of the Cloudy Mountains, very near the crest of the range ( Fig. 91 ). This stream was one of the headwater branches of the Watuti River, which was also sampled at a lower elevation near Mila village (see discussion under R. grisea ), and had a steeply descending profile with alternating small waterfalls, rapids and flowing pools, all heavily shaded by relatively intact upland rain forest. Rhagovelia watuti was found on the flowing pools, in company with R. loriae , a member of the R. papuensis group.

Figures

FIGS. 20–25. Species of the Rhagovelia dibuwa subgroup, female terminal abdomen, lateral view, showing structural variation on ventrites VII and VIII. 20. R. watuti n. sp., specimen from New Guinea, Cloudy Mtns., CL 7175; 21. R. peninsularis n. sp., specimen from New Guinea, Alotau, CL 7163; 22. R. kalawai n. sp., specimen from Sideia Is., Kwabunamoa River, CL 7287; 23. R. dibuwa n. sp., specimen from Normanby Is., Dibuwa River, CL 7230; 24. R. awaetowa n. sp., specimen from Fergusson Is., Awaetowa River, CL 7225; 25. R. torrenticola n. sp., specimen from Goodenough Is., Tuabeda River, CL 7184.

FIGS. 26–31. Species of the Rhagovelia dibuwa subgroup, female terminal abdomen, ventral view, showing structural variation on posterior margin of ventrite VII. 26. R. watuti n. sp., specimen from New Guinea, Cloudy Mtns., CL 7175; 27. R. peninsularis n. sp., specimen from New Guinea, Alotau, CL 7163; 28. R. kalawai n. sp., specimen from Sideia Is., Kwabunamoa River, CL 7287; 29. R. dibuwa n. sp., specimen from Normanby Is., Dibuwa River, CL 7230; 30. R. awaetowa n. sp., specimen from Fergusson Is., Awaetowa River, CL 7225; 31. R. torrenticola n. sp., specimen from Goodenough Is., Tuabeda River, CL 7184.

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. 91. Watuti River headwaters, Cloudy Mountains, Milne Bay Province, Papua New Guinea, CL 7175, type-locality for R. watuti n. sp.

FIG. 132. Distributions of species in the R. dibuwa subgroup in eastern New Guinea and adjacent islands.