Rhagovelia auga, 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 : 83-88

Rhagovelia auga new species

( Figs. 110 , 11 , 133–139 , 153 )

Type Material examined. Holotype, wingless male: PAPUA NEW GUINEA, Central Prov. , New Guinea, Owen Stanley Range, Hane River, 1.8 km. SSE of Fane, 1310–1370 m., water temp. 19 °C., 3 October 2003, 10:30–13:30 hrs., 8°34'00"S, 147°05'10"E, CL 7253, D. A. Polhemus ( USNM) . Paratypes: PAPUA NEW GUINEA, Central

Prov., New Guinea: 6 winged males, 12 winged females, 34 wingless males, 25 wingless females, same data as holotype, CL 7253 ( USNM, BPBM) ; 16 winged males, 12 winged females, 58 wingless males, 46 wingless females, Owen Stanley Range , Mas River, 2.0 km. SW of Fane, 1235 m., 8°33'25"S, 147°04'04"E, water temp. 20 °C., 5 October 2003, 10:00–13:30 hrs., CL 7257, D. A. Polhemus ( USNM, BPBM) ; 2 winged males, 4 winged females, 1 wingless male, 3 wingless females, Owen Stanley Range , trib. to Mas River, 1.9 km. SW of Fane, 1220–1250 m., 8°33'33"S, 147°04'12"E, water temp. 20.5 °C., 5 October 2003, 10:45–12:30 hrs., CL 7258, D. A. Polhemus ( USNM, BPBM) ; 2 winged males, 5 winged females, 60 wingless males, 49 wingless females, 15 immatures, Owen Stanley Range , Udabe River headwaters, 1.75 km. WNW of Woitape, 1615–1645 m., 8°32'02"S, 147°14'16"E, water temp. 16.5–18.5 °C., 1 October 2003, 09:00–14:00 hrs., from margins of main river channel, CL 7247a, D. A. Polhemus ( USNM, BPBM) ; 1 winged female, 27 wingless males, 37 wingless females, Owen Stanley Range , Udabe River headwaters, 1.75 km. WNW of Woitape, 1615–1645 m., 8°32'03"S, 147°14'20"E, water temp. 16.5–18.5 °C., 1 October 2003, 09:00–14:00 hrs., tributary creek entering main river channel, CL 7247b, D. A. Polhemus ( USNM, BPBM) ; 8 wingless males, 9 wingless females, Owen Stanley Range , Om Creek, trib. to upper Udabe River, 1.85 km. SSE of Woitape, 1585 m., 8°33'28"S, 147°15'22"E, water temp. 19 °C., 2 October 2003, 12:00–12:30 hrs., CL 7251, D. A. Polhemus ( USNM, BPBM) .

Description.

Wingless male: Size: Length = 4.40–4.45 mm (x = 4.41, n = 6); width = 1.50–1.60 mm (x = 1.52, n = 6). Wingless female, length = 4.20– 4.90 mm (x = 4.54, n = x); width = 1.60–1.80 mm, (x = 1.68, n = x). Winged male, length = 4.80–4.90 mm (x = 4.85, n = 2); width = 1.70–1.80 mm (x = 1.75, n = 2). Winged female, length = 4.50–4.90 mm (x = 4.70, n = 2); width = 1.80–1.85 mm (x = 1.82, n = 2).

Coloration: Dorsal ground colour black, marked with dark yellow on basal antennae, anterior pronotum, connexiva and legs ( Fig. 133 ). Head black; juga and rostrum dark yellow, rostrum fuscous ventromedially, piceous distally; eyes dark reddish black. Pronotum dark yellow on anterior third, this yellowish coloration continuing laterally as a narrow continuous band onto the more broadly yellow propleurae, posterior half of pronotum black. Mesonotum, metanotum and all abdominal tergites black; all abdominal tergites uniformly dull and lacking glabrous areas; connexiva black on inner halves, dark yellow on outer halves, ventral faces also dark yellow. Antennal segment I with basal one-third dark yellow, distal two-thirds plus all of segments II–IV black. Legs generally black, with coxae, fore and hind trochanters, basal half of fore femur, ventral face of hind femur dark yellow. Venter black, with all acetabula and prosternum dark yellow, central portions of abdominal ventrites VI–IX brown.

Structural characters: Head moderately short, declivant anteriorly, with weakly impressed median line; length 0.45, width 0.85; length of eye along inner margin 0.40, anterior/posterior interocular space, 0.20/0.45. Pronotum short, length along midline 0.50, slightly exceediing dorsal length of head, leaving mesonotum broadly exposed, width 1.50; mesonotum smooth, lacking deep foveae, humeri depressed, length 0.70. Metanotum barely exposed, length 0.10. Lengths of abdominal tergites I–VIII, respectively: 0.25: 0.30: 0.25: 0.25: 0.25: 0.30: 0.55: 0.45. Connexiva with margins of even width throughout, margins straight, evenly convergent posteriorly, bearing numerous long, erect black setae; posterolateral angles not modified, separated by entire width of tergite VIII, bearing sparse tufts of long black setae.

Entire dorsum and laterotergites thickly covered with fine, appressed pale pubescence, intermixed except on central pronotum and mesonotum with numerous longer, erect black setae; 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, plus long pilose brown setae along posterior margins of all femora; 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 strongly expanded and ventrally concave centrally, this elongate concavity bordered by a curving brush of dense black setae on central portion of posterior margin ( Fig. 133 ); hind trochanter bearing 12–14 small dark pegs ventrally; hind femur highly incrassate, bearing a single row of teeth lying in area covered by infolded hind tibia and consisting of approximately 10 tiny black spinules running from base of femur to midpoint, followed by a large, acute tooth, then 3 much smaller teeth of progressively declining size, then another large, acute tooth, followed by 7 smaller teeth of progressively declining size, all these teeth orange-brown basally with black apices; hind tibia very slightly sinuate, inner surface bearing a row of about 14 small dark teeth, plus one large, acute, tooth approximately two-thirds distance from base ( Fig. 135, 136 ).

Venter of head and thorax lacking small black denticles; meso- and metasterna slightly depressed centrally, margins of this depression bearing long, fine gold setae; abdominal venter set with short appressed gold setae intermixed with scattered longer, fine gold setae centrally on ventrites II–IV; 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 and V unmodified, ventrite VI slightly flattened centrally, ventrite VII stongly flattened and slightly depressed centrally, raised margins surrounding this roughly quadrate depressed area bearing moderately long, semi-erect black setae; ventrite VIII strongly constricted basally, longitudinal midline slightly raised, flanked by deep, concave depressions.

Male paramere thick, elongate, broadly curving upward, ventral margin densely setiferous centrally, distal section slightly expanded, posterior margin gently curving, apex broadly truncate ( Fig. 137 ). Male proctiger elongate, with basolateral lobes prominent and rounded; distolateral lobes not produced; distal cone elongate, densely setiferous, apex acute ( Fig. 138 ).

Lengths of antennal segments I–IV: 1.00: 0.60: 0.85: 0.70.

Lengths of leg segments as follows: femur, tibia, tarsal 1, tarsal 2 of fore leg, 1.30: 1:50: 0.05: 0.03: 0.30; of middle leg, 2.25: 1.75: 0.10: 0.85: 1.05; of hind leg, 2.20: 2.00: 0.05: 0.15: 0.15.

Wingless female: Similar to wingless male in general structure and coloration, with following exceptions; fore tibia only very weakly expanded distally, with a shallow longitudinal concavity ventrally; abdominal tergites III– VII lacking long, erect black setae; connexival margins strongly convergent and thickened adjacent to abdominal tergites I and II, the thickened areas bearing long black setae; connexival margins adjacent to abdominal tergites III–VIII moderately but steadily convergent, folded inward over lateral portions of abdominal tergites IV–VII, and completely covering tergite VII and basal section of tergite VIII ( Fig. 134 ), posterolateral angles slightly produced posteriorly when viewed laterally, bearing long, thick, angular tufts of posteriorly-directed stiff black setae, smaller tufts of black setae also present on posterolateral margins of abdominal segment VII, and on posterolateral margins of abdominal tergite VIII; abdominal tergite VIII angled downward over 45°, proctiger lying in a nearly vertical orientation; hind femora only weakly incrassate, bearing only 4 very small dark teeth on posterior third, these teeth of progressively decreasing size distally; hind tibiae straight, inner surface lacking teeth; ventral coloration predominantly orange-brown, with mesosternum, metasternum and abdominal ventrite I dark brown to black; all abdominal ventrites lying in similar horizontal plane, sternite II with incipient longitudinal medial carina basally, central sections of abdominal sternites III–VI flattened centrally.

Winged male: Similar to wingless female in general structure and coloration, with following exceptions: pronotum greatly enlarged, completely covering meso- and metanotum, width 1.75, length 1.90, humeri enlarged, posterior apex angular, anterior lobe with anterior half transversely whitish-pruinose underlain by orange pigmentation, this pale coloration narrowly confluent behind eyes with broader area of yellow-orange coloration on propleurae, remainder of pronotum black, posterior angular section set with numerous tiny foveae, entire pronotum covered with short recumbent gold setae, these setae becoming longer and denser on posterior angular section; propleurae bearing a few long, erect black setae; forewings uniformly dark blackish-brown, bearing 4 closed cells, consisting of two long cells in the basal half of the wing plus 2 smaller distal cells of subequal size near the center of the wing ( Fig. 10 ).

Winged female: Similar to winged male in general body form and coloration, with following exceptions: pronotum width 1.80, length 1.80; abdominal connexiva not reflexed, lying in a uniformly horizontal plane when viewed laterally.

Etymology. The name “auga ” is a noun in apposition and refers to the Auga River basin of southern New Guinea in which this species was collected.

Distribution. Southeastern New Guinea; endemic to the Owen Stanley Range ( Fig. 153 ). The species range as presently known occupies the Owen Stanley Range area of freshwater endemism (Area 31) as delineated by D. Polhemus & Allen (2007).

Discussion. This is a predominantly black species with narrowly pale connexival margins. The female connexiva are folded inward, covering the lateral portions of abdominal tergites II–VIII ( Fig. 134 ) and possess acuminate tufts of setae at their posterolateral angles. The female proctiger is folded downward into a vertical position, which in combination with the connexival tufts is of utility in associating winged morphs in mixed series containing this species and R. goilala , with which it frequently co-occurs. Male abdominal ventrite VII is quadrately flattened and depressed centrally, and flanked by low, elongate, longitudinal tumescences bearing black setae, while ventrite VIII is strongly constricted and biconcave basally. The male proctiger has well developed, apically rounded basolateral lobes and a conical distal cone ( Fig. 138 ), and the male paramere is expanded distally, with a broadly truncate posterior margin ( Fig. 137 ).

The male of R. auga is utterly distinctive among the assemblage of Rhagovelia species currently known from the EPCT region, possessing a concave fore tibia bearing a curving brush of setae centrally along its posterior margin that produces an expanded and spoon-like appearance ( Fig 133 ). This character state is shared with two species occurring in the northern coastal ranges of New Guinea: R. thysanotos Lansbury from the Torricelli Mountains, and R. crinita Lansbury , which apparently ranges from the Finisterre Mountains to the Wau area ( Lansbury 1993). Rhagovelia auga may be separated from both of these taxa by the much more closely appressed female connexiva, which nearly meet over the top of abdominal tergites V–VIII ( Fig. 134 ), rather than being widely separated as in the other two species, and by the shape of the male paramere, which is broadly expanded and truncate posteriorly ( Fig. 137 ).

Ecological notes. The Hane River at the type-locality (CL 7253) was a swift, clear mountain stream in a bed of boulders and cobbles, with a channel 3–5 m wide and a water depth of 0.3–1.3 m. The riparian vegetation was grassy and weedy at the trail crossing and near the mini-hydro intake that served the nearby mission station, but changed over to good, relatively intact montane forest upstream. Rhagovelia auga occurred here syntopically with R. goilala , a species of similar size but with an orange-brown ground color, and lacking the distinctive modification of the fore femur seen in males of R. auga , and with R. cheesmanae , a member of the R. caesius group.

At the Udabe River headwaters (CL 7247) northwest of Woitape ( Fig. 139 ), R. auga was taken along the heavily shaded main channel of a second order river, 5–7 m wide and 0.3–1.0 m deep, with clear, moderately swift water. The only other Rhagovelia species present here was R. cheesmanae .

Figures

FIGS. 110–115. Rhagovelia dibuwa n. sp., structural details; specimens from Normanby Island. 110. Male right hind leg, weakly developed individual, posterior view. 111. Male right hind leg, weakly developed individual, dorsal view. 112. Male right hind leg, strongly developed individual, posterior view. 113. Male right hind leg, strongly developed individual, dorsal view; 110–113 from Dibuwa River, CL 7230. 114. Male left paramere, outer lateral view. 115 Male proctiger, dorsal view; 114 and 115 from Bunama, Apatabuia River, CL 7228.

FIGS. 10, 11. Rhagovelia auga n. sp., wings; specimen from Mas River near Fane, Owen Stanley Mountains, New Guinea, CL 7257. 10. Forewing, showing the presence of two large distal closed cells of subequal length. 11. Hind wing.

FIGS. 133–138. Rhagovelia auga n. sp., structural details; specimens from New Guinea, Owen Stanley Range. 133. Wingless male, dorsal habitus; specimen from Udabe River, CL 7247. 134. Wingless female, dorsal habitus; specimen from Hane River, CL 7253. 135. Male right hind leg, posterior view. 136. Male right hind leg, dorsal view; 135 and 136 from Mas River, CL 7257. 137. Male left paramere, outer lateral view. 138. Male proctiger, dorsal view; 137 and 138 from Udabe River, CL 7247.

FIG. 139. Tributary to the upper Udabe River, near Woitape, Central Province, Papua New Guinea, CL 7247, habitat for R. auga n. sp.

FIG. 153. Distributions of species in the R. auga and R. peggiae subgroups in eastern New Guinea.