Rasilinus bifasciatus, Mazur, 2017

Mazur, Miłosz A., 2017, Notes on the genus Rasilinus Mazur, 2016 (Curculionidae: Curculioninae, Eugnomini), with the description of a new species from New Caledonia, Zootaxa 4318 (1), pp. 195-200 : 196-199

Rasilinus bifasciatus sp. n.

Etymology. The specific epithet is based on the Latin prefix bi— (double) and fascia (stripe)—and refers to two stripes composed of the yellowish-white scales on the elytra.

Diagnosis. Species with characteristics stripes of yellowish-white scales at middle of elytra. Ventral part of head distinctly covered with white scales, except two, suboval, bare areas medially. Apex of aedeagal pedon strongly narrow, truncate. Parameroid lobes of tegmen completely separated.

Description. Body length without rostrum 3.10–3.20 mm.

Body colour and vestiture ( Figs 9, 10 , 18 ).

Head and rostrum dark brown with white, elongate, adjoining and erect scales. Scape dark orange, darkening to apex; funicle and club dark. Pronotum and elytra blackish. Elytra medially with stripe of white scales from third to ninth interval; each interval with single line of protruding, elongate scales in two colours—blackish, from base to approximately four-fifths of length and whitish at apical part. Ventral part of head covered with white, suboval scales with two suboval, asetose areas. Ventral part of body reddish with short stripe composed of white scales near hind coxae. Legs uniformly brown; femora covered with elongate, dark brown, protruding scales; tibiae with whitish, elongate, protruding scales from one third of length. Apical part of fore tibiae with recumbent, elongate scales with the same colour as protruding scales. Tarsi with the same colour as tibiae.

Head, rostrum and antennae ( Figs 7–11 ). Head capsule quadrate (hw/hl 1.00). Forehead between eyes flat; eyes distinctly protruding above. Vertex flat with sparse punctation, space between punctures glabrous, shining. Eyes rounded, strongly convex, distinctly protruding beyond head outline; almost as long as half length of head (eyl/hl 0.45). Rostrum weakly curved, longer than wide at apex (rl/arw 1.50), shorter than head (rl/hl 0.80). Funicle slightly longer than scape; 1 st segment elongate, constricted basally; 2nd elongate, slightly shorter than 1st, constricted basally; 3–7 subquadrate. Club elongate, 2.0 times as long as wide, slightly longer than last five segments.

Pronotum ( Figs 1, 2 ). Slightly wider than long (mpw/pl 1.15–1.23), dorsally slightly rounded, strongly narrowed at apical part, slightly narrowed at base. Apical margin slightly rounded, basal margin slightly bisinuate. In lateral view pronotal disc slightly convex near midlength. Surface with distinctive and dense punctation, scabrous; space between punctures matte.

Elytra ( Figs 1, 2 ). Widest near midlength, elongate (el/mew 1.50–1.57). Striae shallow with suboval punctures, at apical part of elytra punctures evanescent, forming indistinct line. Intervals flat, glabrous, shining.

Legs ( Figs 3–5 , 12, 13 ). Front and middle legs robust; fore tibiae straight, middle slightly bisinuate, both slender (ptbl/ptbmw 7.50); hind tibiae slightly narrowed before apex. Femora with scabrous surface and distinct, transverse corrugation. Femora slender, fore and middle unarmed; hind with distinct tooth (mth/mith 2.0) almost as high as half of maximum width of femur. Front and middle tarsi short, first segment almost as long as 2+3; hind tarsi elongate, first segment longer than 2+3. Claws regularly curved, distinctly broadened near base.

Abdomen ( Figs 6 , 14 ). Distinctly narrowed, longer than maximal wide at base. First suture medially evanescent, invisible; sutures between ventrites 2–5 wide, strongly depressed. Last ventrite distinctly wider than long; apical part with wide, slightly shallow depression and pair of elongate, protruding setae; apical margin widely rounded. Entirely covered with sparse punctures, bearing elongate seta, surface between glabrous, shining. Pygidium of male longer than wide, dorsal surface with sparse punctures; ventrally with narrow, elongate processes.

Male terminalia ( Figs. 15–17 ). Aedeagal pedon longer than apodemes with maximal width at base, slightly narrowed to apex, apically strongly constricted with truncate apex; basal part of pedon completely sclerotised. In lateral view distinctly curved at base and apically, middle part straight. Endophallus everted with complex apparatus composed with pairs of G -shaped, suboval, irregular sclerites. Tegmen with tegminal apodeme broadened apically; parameroid lobes shorter than apodeme, weakly sclerotised, completely separated. Spiculum gastrale with basal part and apex arrow-shaped; in lateral view small, protruding process near middle of length. Hemisternites on sternite IX irregular, well visible.

Female. Unknown

Biology. Unknown

Measurements. Holotype, male: apw 0.60; arw 0.30; bew 1.25–1.30; bpw 0.70–0.75; el 2.10–2.20; eyl 0.25; frw 0.15; hl 0.55; hw 0.55; lb 3.10–3.20; mew 1.40; mith 0.20; mpw 0.75–0.80; mth 0.40; pl 0.65; ptbl 0.75; ptbmw 0.10; rl 0.45; scl 0.55.

Type material. Holotype, 1♂– New Caledonia (N); -21.1739/165.3116; Auopinié , 700– 800 m. ; near Goipin Rd jct; 20.11.2010; leg. M. Wanat & R. Ruta (MNHN). Paratype, 1♂– same data as holotype ( MNHW). Distribution. New Caledonia (main island) ( Fig. 18 ).

Remarks. This new species can be easily distinguished from other members of the genus by the characteristic, yellowish-white stripes on the elytra. Other species are glabrous except R. bicolor Mazur, 2016 and R. bimaculatus Mazur, 2016 which have pair of whitish spots on the elytra. This species is also distinct by having the ventral part of head with two suboval glabrous areas and by the terminal structures (apex of aedeagus rounded— R. bicolor , or truncate and widely rounded— R. bimaculatus ; both species have parameroid lobes of tegmen fused basally, unlike in R. bifasciatus which has parameroid lobes completely separated ( Fig. 16 ); see Figs. 100, 102, 114, 116 in Mazur 2016). The new species is similar to R. subgemellus Mazur, 2016 in having the fore and middle femora glabrous, without medial teeth. It can be, however, distinguished by having a pair of small nodules at the middle of the first ventrite of male (absent in R. bifasciatus sp. nov.), shortened parameroid lobes of tegmen (elongate in R. bifasciatus sp. nov.), R. subgemellus has also glabrous elytra, without stripes or spots.

Figures

FIGURE 18. Rasilinus bifasciatus sp. nov., dorsal habitus colour photograph; distribution map.

FIGURES 9 – 17. Rasilinus bifasciatus sp. nov.: 9 — head, lateral view, scales arrangement, 10 — head, ventral view, 11 — antenna, 12 — front tarsus, 13 — hind tarsus, 14 — male pygidium, ventral view, 15 — spiculum gastrale, male, 16 — male tegmen, 17 — aedeagus, dorsal and lateral view.

FIGURES 1 – 8. Rasilinus bifasciatus sp. nov.: 1 — elytra and pronotum, dorsal view, 2 — elytra and pronotum, lateral view, 3 — front femur, 4 — middle femur, 5 — hind leg and tarsal claw, 6 — abdominal sternites and apical setae, 7 — head, dorsal view, 8 — head, lateral view.