Ranatra bendanilloi, Tran & Zettel, 2021

Tran, A. D. & Zettel, H., 2021, Taxonomic review of the Ranatra gracilis group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of four new species, Raffles Bulletin of Zoology 69, pp. 45-70 : 55-57

Ranatra bendanilloi , new species

( Figs. 1C , 4 )

Material examined. Holotype (male): “Philippines: Negros Or.\ Valencia, Apolong,\ Banica River \ leg. Fidel Bendanillo ” ( USC) . Paratypes ( NHMW, UPLB, USC, ZCW, ZRC): PHILIPPINES: Negros: Negros Oriental Province, 1 male, same collection data as holotype ; 5 males, 5 females, Negros Oriental Province, Valencia, Apolong, Banica River . Masbate : 6 males, 4 females, Masbate Island, 3.5 km SE Masbate, Tugbo, Tugbo River .

Description. General colouration: mostly light brown to brown; eyes dark brown; all coxae brown; all femora and tibiae usually distinctly annulated brown and yellow; fore tarsus mostly yellowish with dark brown apex; apices of middle and hind tibiae, middle and hind tarsi dark brown. Hemelytra mostly light coloured, usually with mottled greyish corium.

Measurements. Males: body length 31–32 (holotype: 32); length of siphon 8.7–9.3 (holotype: 9.0); width of head 2.65–2.73 (holotype: 2.71); interocular width 1.09–1.13 (holotype: 1.12); width of eye 0.76–0.81 (holotype: 0.79); pronotal length 7.8, anterior pronotal length 5.9; posterior pronotal length 3.3; anterior width of pronotum 2.30; posterior width of pronotum 2.98; lengths of leg segments: fore leg: coxa 4.8, femur 8.23, tibia 3.58, tarsus 0.75; middle leg: femur 11.2, tibia 10.0, tarsus 1.42; hind leg: femur 11.5, tibia 12.7, tarsus 1.84.

Females: body length 32–38; length of siphon 8.4–9.3; width of head 2.68–3.04; interocular width 1.10–1.22; width of eye 0.79–0.92; pronotal length 8.06, anterior pronotal length 6.1; posterior pronotal length 3.5; anterior width of pronotum 2.48; posterior width of pronotum 3.2; lengths of leg segments: fore leg: coxa 5.25, femur 8.61, tibia 3.67, tarsus 0.76; middle leg: femur 11.7, tibia 10.25, tarsus 1.81; hind leg: femur 12.0, tibia 13.3, tarsus 2.02.

Head ( Fig. 4B, C ): Vertex above eyes with an obtuse tubercle, narrow in dorsal view; width of eye clearly less than interocular width; clypeus smooth and convex, in lateral view about as high as or slightly higher than lora and slightly surpassing lora anteriorly; lora swollen, with a small, but distinct dorsal nodule, usually bearing few sparse, long, pale setae along dorsal side. Antenna ( Fig. 4A ): finger-like projection of second antennal segment very short, about 0.2× the length of third segment.

Thorax: Prothorax in lateral view distinctly longer than fore coxa (about 1.5–1.6× the length of fore coxa) and subequal to or slightly shorter than fore femur (0.92–0.99× the length of fore femur); anterior lobe about 1.7–1.9× as long as posterior lobe; anterior collar of pronotum distinctly raised when viewed laterally; ratio of posterior width / anterior width 1.25–1.36; posterior lobe with humeri broadly rounded, on each sublateral side with two swellings separated by a longitudinal groove ( Fig. 4B, C ). Scutellum with length ca. 1.8–2.1× width, usually swollen at midpoint followed by a transverse depression before posterior third, apex pointed. Prosternum with paired broad, shallow longitudinal depressions separated by low and blunt median carina; median carina rather indistinct in posterior half. Mesosternum with slightly raised anterolateral margin, posterior projection between middle coxae truncate, weakly grooved along midline. Metasternum with anterior part grooved along midline, posterior part distinctly raised along midline and grooved sublaterally, posterior margin angularly emarginated ( Fig. 4F ). Space between middle coxae about same as or slightly greater than that between hind coxae. Hemelytra: membrane only reaching mid-length of abdominal tergum VI.

Legs: Fore femur ( Fig. 4D, E ): in both sexes relatively thick (ratio of length / maximum width of femur: 9.8–11.0, holotype 10.4), widest at basal part, distal part nearly as wide as basal part, ratio in males: 1.13–1.17 (holotype 1.17), in females: 1.13–1.19; flexor side with a median carina bearing dense, short setae and a tooth on mesal (anterior) surface situated distally to median carina; distal part with a pair of small teeth on lateral (posterior) surface flexor side, proximal to sinuous pre-apical ventral margin; distal teeth slightly longer than surrounding setae on flexor side of femur (more prominent in female); ratio of width of femur across median tooth (excluding tuft of setae) / width of femur at basal part: 1.07–1.14 (holotype 1.07); ratio of width of femur across median carina (excluding setae, on proximal side of median tooth) / width of femur at basal part: 0.97–1.02 (holotype: 1.00). Middle femur slightly shorter than hind femur; hind femur, when folded back parallel to body only reaching to anterior third of abdominal sternum VI (in males) or slightly surpassing anterior margin of sternum VI (in females). Middle tibia shorter than middle femur; hind tibia longer than hind femur; middle and hind tibiae both bearing dense fringes of long hairs on posterior margins along their distal two-thirds. Abdomen: Operculum of male slightly shorter than connexivum, medially keeled, apex pointed. Sternum VI of female with median keel distinctly raised on posterior half. Operculum of female clearly longer than connexivum, surpassing the apex of connexivum of about one third the length of operculum. Respiratory siphon clearly shorter (0.70–0.82×) than the length of sterna III–V combined, with sparse long, thin hairs along its length, more on apical part.

Male genitalia: Paramere ( Fig. 4G–I ): thickest at basal third, constricted at distal quarter; ventral margin gradually tapering from middle part towards the constricted part, then followed by a large sub-triangular process bearing tuft of setae; on inner face, pre-apical process bearing a pointed projection slightly shorter than tuft of setae; apical hook long, slender with narrow, rounded tip; dorsal margin of paramere almost straight, slightly concave at same section with ventral, pre-apical process (ca. at distal fifth). Phallotheca strongly sclerotised.

Etymology. This new species is dedicated to the entomologist and curator Mr. Fidel E. Bendanillo MSc from the University of San Carlos (Cebu City) who collected the holotype.

Remarks. For comparative notes, see Remarks under R. pangantihoni , new species.

Distribution. Philippines: Greater Visayas region: Negros and Masbate.

Figures

Fig. 1. Habitus of Ranatra spp., all males. A, R. stali Montandon, 1905; B, R. bisaya, new species; C, R. bendanilloi, new species; D, R. brevicauda, new species; E, R. pangantihoni, new species (all of same scale).

Fig. 4. Ranatra bendanilloi, new species, male. A, antenna; B, C, head and prothorax, lateral and dorsal views; D, E, fore femur, lateral and mesal views; F, metasternum; G, paramere, lateral view; H, I, apical part of paramere, sub-caudal and inner views. (B, C same scale; D, E same scale; G–I same scale).