Socotrorhinus boswelliae, Skuhrovec & Kresl, 2014

Skuhrovec, Jiří & Kresl, Petr, 2014, A new genus and species of Rhinocartini (Coleoptera: Attelabidae: Rhynchitinae) from Socotra Island, Acta Entomologica Musei Nationalis Pragae 54, pp. 283-294 : 288-292

Socotrorhinus boswelliae sp. nov.

( Figs 1A, D–E ; 2A–M )

Type locality. Yemen, Socotra,Aloove area, 12°20ʹ58″N, 54°06ʹ39″E, 270–300 m a.s.l. (see BEZDĚK et al. 2012: 34). Material examined. HOLOTYPE: J, ‘ YEMEN, SOCOTRA Island / Zemhon area, 270–300 m / N 12°20ʹ58″, E 54°06ʹ39″ / 16.– 17.6.2010 / V.Hula leg. [printed label]’ ( NMPC). PARATYPES: 54 JJ 67 ♀♀, same data as holotype ( NMPC; 2 JJ 2 ♀♀ ARC; 2 JJ 2 ♀♀ BMNH; 2 JJ 2 ♀♀ IRSNB; 5 JJ 5 ♀♀ JSPC; 1 J 1 ♀ MNBE; 1 J 1 ♀ MZLU; 5 JJ 5 ♀♀ PKRC; 2 JJ 2 ♀♀ SMNS); ‘ YEMEN, SOCOTRA Island / Zemhon area, 270–350 m / N 12°30ʹ58″, E 54°06ʹ39″ / 3.–4.ii.2010 / L. Purchart & J. Vybíral lgt. [printed label]’ (1 J NMPC); ‘ YEMEN, SOCOTRA ISLAND / Dixam plateau 15.+ 22.vi.2012 / Wadi Dirhor, open woodland / with Boswellia ameero trees / 12°28.0ʹN, 54°00.5ʹE, 340 m // SOCOTRA expedition 2012 / J. Bezděk, J. Hájek, V. Hula, / P. Kment, I. Malenovský, / J. Niedobová & L. Purchart leg. [printed labels]’ (2 JJ 12 ♀♀ NMPC); ‘ YEMEN, SOCOTRA ISLAND / HOMHIL protected area / open woodland with Boswellia & / Dracaena trees; 10.–11.vi.2012 / 12°34.5ʹN, 54°18.5ʹE, 360–500 m // SOCOTRA expedition 2012 / J. Bezděk, J. Hájek, V. Hula, / P. Kment, I. Malenovský, / J. Niedobová & L. Purchart leg. [printed labels]’ (8 JJ 4 ♀♀ NMPC); ‘ YEMEN, Socotra Island / Aloove area, ALOOVE vill. env. / Jatropha unicostata shrubland; / with Boswellia elongata trees / 19.–20.vi.2012 / 12°31.2ʹN, 54°07.4ʹE, 221 m // SOCOTRA expedition 2012 / J. Bezděk, J. Hájek, V. Hula, / P. Kment, I. Malenovský, / J. Niedobová & L. Purchart leg. [printed labels]’ (13 JJ 8♀♀ NMPC). Specimens of the newly described species are provided with one printed red label:‘ Holotype [or Paratype] / Socotrorhinus / boswelliae sp. nov. / Jiří Skuhrovec & / Petr Kresl design.2014’.

Description ( Fig. 2A ). Coloration of body yellowish to pale brown, head, rostrum, scape and funicle antennomeres 1–2 and part of legs darker. Body sparsely setose with pale erect or suberect setae, rostrum subglabrous. Head with very short setae. Rostrum pale brown to reddish and brown. Antennae with short suberect setae; setae in funicle antennomeres II–VII and club approximately half of funicle segment length, in scapus and funicle antennomere I shorter. Pronotum with relatively long, anteriad directed, suberect setae. Elytral intervals with long erect setae (as long as claws). Apical third of elytra and shoulders with slightly longer setae, which are also slightly longer than claws. Scutellum glabrous. Femora yellowish to brown with pale long erect setae. Tibiae yellowish to pale brown with pale long erect setae. All tibiae bearing stout, yellowish bristles apically, slightly darker than erect setae, bristles oriented forward in the direction of tibial axis. Tarsi yellowish to pale brown with pale long erect setae. Tarsomeres I–III with sparse small projecting scales (‘soles’). Claws reddish to dark brown; inner teeth dark brown to black. Abdomen yellowish to pale brown with long erect setae.

Head ( Figs 1D–E , 2A–G ). Eyes elliptical to oval; strongly convex and bulging; ventral apex narrower than dorsal. Temples distinctly widened backwards, shorter than longitudinal eye diameter. Head (vertex, temples and frons) dotted; punctation deep and distinct; punctures slightly oval, almost touching each other. Rostrum distinctly longer than its basal width (ratio = 2.75–4.88, see Sexual dimorphism); curved in dorsal view, most at antennal base, then only slightly; bent, not flat, well visible in lateral and dorsal views; in lateral view, rostrum pointed towards apex. Rostrum shiny with very fine punctation, punctures smaller and less deep than on head. Scrobes indistinct and shallow; not visible in dorsal view; poorly visible in lateral view as longitudinal furrow along whole length of rostrum on its lower side.

Antennae ( Figs 1D–E , 2A–G ). Scape club-shaped, more than twice as long as wide; funicle antennomere I oval, about half length of scape, 1.5 times longer than wide; funicle antennomeres II–VI slender, slightly widened at apex, longer than funicle antennomere I but shorter than scape; funicle antennomere VII similar in shape to funicle antennomeres II–VI, only more widened at apex; club three-segmented, basal two segments triangular, approximately 1.75 times longer than wide, apical segment broadly oval, slightly longer than wide.

Pronotum ( Figs 2A–G ) slightly narrower than its length (ratio = 1.1–1.4), widest near middle; anterior margin nearly straight in dorsal view; behind anterior margin slightly but distinctly choked; sides slightly rounded; posterior margin 1.4 times longer than anterior margin; only slightly bent, almost flat in lateral view; shiny, distinct punctures more coarse than on vertex; punctures sparser in middle part.

Elytra ( Figs 1A , 2A–G ) almost rectangular, distinctly longer than wide (ratio = 1.35–1.61, see Sexual dimorphism), with base distinctly wider than the widest part of pronotum, with distinct humeral angle; basal margin slightly bent; almost parallel-sided; apically broadly rounded. Elytral striae form 10 distinct rows; one shortened line of 5–6 elytral striae inserted between first and second rows, beginning near scutellum and reaching about basal fifth of elytra; disordered short line inserted between seventh and eighth rows in middle of elytra. Elytral intervals slightly prominent, as wide as or slightly narrower than striae.

Legs. Femora slightly inflated in middle. Meso- and metatibiae straight, protibiae slightly curved outwards. All tarsi similar; tarsomere I elongated, about 3 times longer than its width, slightly widened at apex; tarsomere II distinctly triangular, as long as wide; tarsomere III triangular, distinctly bilobed almost to base; tarsomere V as long as tarsomere I, slightly widened at apex. Claws thick, wide sickle-shaped; at inner margin before apex split up and forming two teeth: narrower, sharp and longer tooth on outer edge, and wider, shorter one on inner edge.

Abdomen. Abdominal ventrites decreasing in length; abdominal ventrites I and II fused, slightly visible small sinuosity in midlength; ventrites I and II thrice longer than ventrite III, and as long as ventrites III–V together. Suture between abdominal ventrites I and II still slightly visible as sinuosity; sutures between other ventrites straight, deeply incised.

Sexual dimorphism. Rostrum distinctly longer than its base width in females (ratio = 4.00–4.88, median 4.5; Fig. 2F ), less so in males (ratio = 2.75–3.50, median 3.30; Fig. 2E ), and males have more flattened rostrum than females ( Figs 2E–F ). Females are larger with more oval elytra (elytral length to width ratio = 1.40) than males (ratio = 1.50). Protibiae incurved in males and nearly straight in females.Abdominal ventrite I with distinct depression in males but not in females. Abdominal ventrite V with shallow medial impression in males. No differences in ratios of pronotal length and width.

Male genitalia. Penis ( Fig. 2H ) in dorsal view gradually slightly narrowed from base to basal 1/4, then parallel-sided. Ventral plate triangularly narrowed towards top. Apodemes of penis more than twice as long as median lobe. Penis slightly curved ( Fig. 2H ) in basal third in lateral view. Tegmen ( Fig. 2I ) stick-shaped up to midlength; tegmen without fenestrae, tegminal plate elongated and tapered apically, with 2 long setae. Spiculum gastrale ( Fig. 2J ) stick-shaped, slightly curved and of half length of penis; basal plate triangular.

Female genitalia. Apodeme of sternite VIII relatively long, without distinct lateral arms; plate starting near apical fifth of apodeme ( Fig. 2K ); plate spacious and cordiform, with apical margin bearing several distinct setae, weakly sclerotised. Ovipositor short and wide, tapered apicad ( Fig. 2M ); styli relatively long, cylindrical and well sclerotized, apex with 4–7 erect setae. Spermatheca C-shaped with short and stout cornu; apex of cornu sharp; nodulus and ramus short, ramus slightly wider and as long as nodulus ( Fig. 2L ).

Intraspecific variation. Body length: 2.8 to 4.2 mm (length of the holotype 3.5 mm). Coloration of the head, pronotum and elytra from yellowish to pale brown. Specimens from the locality Wadi Dirhor, associated with Boswellia ameero trees show greatest color variation. The variation in coloration compared to the standard (see Description, Fig. 2A ) is as follows ( Figs 2B–G ): (1) temples behind eyes reddish brown to dark brown; (2) pronotum with reddish brown to dark brown longitudinal lateral stripes of different widths; and (3) elytra reddish brown to dark brown in various patterns: from (a) differently colored small dots on basal fifth of interval I and II ( Fig. 2C ); through (b) differently colored intervals I–IV from base to basal third, then narrowed only to interval I–II and continuing to elytral apex with the exception of apical third where narrow projection expands to sides up to interval V ( Fig. 2D ); and finally (c) differently colored almost entire elytra except interval VIII–IX, partly VII (from basal third to apical third) and short spot in interval III to IV from basal third to half of elytra ( Fig. 2G ). Coloration patterns on elytra (a–c) are the only connecting link between the known coloration states (see Figs 2A–G ).

Differential diagnosis. See the same chapter in generic description.

Etymology. The name refers to the frankincense tree genus, Boswellia (Burseraceae) , which is the most likely host plant of this attelabid.

Bionomics. Adults are macropterous, and all specimens from the series collected in early spring (June) 2010 were collected at light. In early spring (June) 2012, several specimens were collected also on the twigs and young leaves of Boswellia elongata Balf. f. (localities Aloove area, Figs 3A–B and Homhil, Figs 3C–D ) and B. ameero Balf. f. (locality Wadi Dirhor; Figs 3E–F ). Both tree species had only fresh young leaves on twigs and also fresh fruits. Boswellia species flower from January to April, and then have fruits in May–June which ripen during summer (P. Maděra, pers. comm.).

Distribution. Socotra Island ( Yemen).

Figures

Fig. 1. Differential diagnosis of the new genus and the tribes of Rhinocartitae according to the characters used by LEGALOV (2007): Socotrorhinus gen. nov. (S. boswelliae sp. nov.): A – elytra; D – head with rostrum and antennae, male; E – head with rostrum and antennae, female; Vossicartini (Vossicartus tanzanensis Legalov, 2007): B – elytra; F – head with rostrum and antennae, male; Rhinocartini: (Rhinocartus tessmanni Voss, 1922): C – elytra; G – head with rostrum and antennae, male.

Fig. 2. Socotrorhinus boswelliae sp. nov. Holotype, male (A, H–J), female (K–M): A – habitus, dorsal view; B–G – variation in coloration, dorsal view; H – aedeagus, dorsal and lateral view; I – tegmen; J – spiculum gastrale; K – female sternite VIII; L – spermatheca; M – ovipositor. Scales: 1 mm, scale with * = 2 mm, scale with ** = 0.2 mm.

Fig. 3. Habitats of Socotrorhinus boswelliae sp. nov.: A–B – Jatropha unicostata shrubland of Aloove area with Boswellia elongata trees; C – open woodland with Boswellia elongata and Dracaena cinnabarina trees in Homhil protected area; D – Boswellia elongata tree in Homhil protected area; E – Boswellia ameero tree in open woodland in Wadi Dirhor area; F – open woodland in Wadi Dirhor area. (Photos by Jiří Hájek (A–C) & Petr Kment (D–F)).