Dinas (Microspina) afonsoi, Skuhrovec & Batelka, 2014

Skuhrovec, JiĜí & Batelka, Jan, 2014, Taxonomy of the Cape Verde endemic weevil genus Dinas (Coleoptera: Curculionidae: Entiminae). Part I: Description of a new subgenus, and two new species from São Nicolau Island, Acta Entomologica Musei Nationalis Pragae 54 (1), pp. 315-336 : 321-325

Dinas (Microspina) afonsoi sp. nov.

( Figs 2A, 2C, 2G , 3A–B, 3E–I , 7A–C )

Type locality. Cape Verde Isl., E of São Nicolau, Tope de Chuva, 16°36ƍ6.05ƎN, 24°7ƍ26.8ƎW.

Material examined. HOLOTYPE: 3: ‘ON FLOWERS OF / EUPHORBIA / TUCKEYANA // CAPE VERDE Isl. / SAO NICOLAU, E, Tope / de Chuva, 10.xi.2011, / 16°36ƍ6.05ƎN, 24°7ƍ26.8ƎW / J. Batelka & J. Straka lgt. [printed label]’ ( SMNS). PARATYPES: 22 3319 ♀♀, same as holotype (all SMNS; 2 332 ♀♀ JSKC). Specimens of the newly described species are provided with one red printed label: ‘ Holotype [or Paratype] / DINAS (MICROSPINA) / AFONSOI sp. nov. / JiĜí Skuhrovec & / Jan Batelka design. 2013’.

Description ( Figs 2A, 2C, 2G , 3A–B ). Body dark reddish, brown to black, antennae, tibiae and all tarsi light reddish to brownish. Head, rostrum and antennae with sparse pale very short erect setae. Club dark reddish with dense pale short adjacent setae. Head and rostrum except epistome with circular small whitish scales with feeble green or brown lustre.

Pronotal vestiture dark reddish, brown to black with pale very short erect setae (distinctly shorter than claws) and circular small whitish scales with feeble green or brown lustre. Elytral vestiture black (brown) covered with small circular to slightly oval scales. Scales present on whole elytra, sometimes varying in color (from white with feeble green or brown lustre to brown or black), highly variable and without any distinct pattern on whole elytra except the basal third of interval 1 and part of interval 2, where they are always dark or absent. Elytral intervals with pale, short, slightly erect setae (shorter than claws). Apical third of elytra with pale, stout, distinctly erect setae, which are distinctly longer than claws. Scutellum bald. Femora black with pale setae and circular small whitish scales with feeble green or brown lustre. Tibiae reddish to brownish with pale setae and circular small whitish scales. Tibiae bearing stout, yellowish bristles apically. Tarsi light reddish with pale setae. First three segments on all tarsi with sparse small projecting scales (“soles”). Claws reddish.

Abdomen black to brownish covered with circular whitish scales sometimes with feeble green lustre.

Head ( Fig. 2A ). Eyes elliptical to oval; distinctly convex; ventral apex narrower than dorsal. Narrowest vertex distance slightly narrower or as wide as width of rostrum base. Rostrum as wide as length (ratio = 0.95–1.05), enlarged anteriad, tapered to medial part and than enlarged posteriad. Epistome small, but distinct; epistomial keel slightly developed, but visible. Frons not separated from epifrons by any distinct carina, but only with almost unrecognizable protuberances. Epifrons narrowest in medial part; with median longitudinal shallow furrow along almost whole epifrons; area along shallow longitudinal furrow flat without any striae. Scrobes distinct and deep; in dorsal view visible for more than two third of length, well visible in whole length; in lateral view curved, enlarged posteriad, dorsal border directed towards below eyes and not reaching them; ventral border directed below eyes; in front of antennal insertion broad, short and well visible. Occiput distinct, behind eyes almost unrecognizable shallow striae.

Antennae inserted one-third of rostrum from rostrum apex. Scape narrow and elongated (ratio to funicle = 1; ratio to funicle and club together = 1.5), distinctly extended behind posterior margin of eyes, slightly sinuous and abruptly widened apically. Funicle as long as scape; ¿rst funicle segment longer than second, funicle segments 1 and 2 twice as long as 3 and 4; 3 and 4 one and half as long as 5 to 7; 5 to 7 having approximately equal lengths and widths. Club elongated.

Pronotum ( Fig. 2C ) as wide as its length (ratio = 0.9–1.1), widest near middle; anterior margin nearly straight in dorsal view; sides slightly rounded; posterior margin showing equal width to anterior margin; basal constriction noticeable, lacking distinct protuberances, markedly bent, not flat and well visible from lateral and dorsal views; distinct punctures on whole surface, and slightly noticeable shallow furrow in middle.

Elytra ( Fig. 2G ) elongate and slightly oval, distinctly longer than wide (ratio = 1.35–1.75, see Sexual dimorphism) with base that slightly wider than widest part of pronotum, without humeral angle; convex sides. Elytral striae distinct and well recognizable; slightly deep punctures, striae in well distinct row. Elytral intervals slightly prominent, and slightly wider than striae.

Legs. All femora with distinct spina. All tibiae apically widened. Tarsi with ¿rst tarsal segment distinctly longer than second, third distinctly bilobed, ¿fth twice as long as ¿rst.

Abdomen. Suture between abdominal ventrites 1 and 2 slightly but distinctly sinuose and shallow; next sutures straight and deep. Abdominal ventrites 1–2 approximately of the same width, but twice the length of each abdominal ventrites 3 and 4.

Sexual dimorphism. Females are distinctly larger with more oval elytra (♀ = 1.35–1.55) than males (3 = 1.55–1.75). Protibiae incurved in males and nearly straight in females. Abdominal ventrite 1 bears distinct depression in males but not in females. Last abdominal ventrite with shallow medial impression in males. No differences in the ratios of rostral and pronotal lengths.

Male genitalia. Penis ( Fig. 3E ) in dorsal view gradually slightly narrowed from base to basal 1/4, then parallel-sided. Ventral plate distinctly and triangularly narrowed towards top. Apodeme of penis slightly longer than median lobe. Penis in lateral view strongly curved in basal third, then less strongly curved until subapically ( Fig. 3E ). Spiculum gastrale ( Fig. 3F ) stick-formed, curved and of subequal length as median lobe of penis.

Female genitalia. Apodeme of sternite VIII relatively long, lateral arms and plate starting near apical ¿fth of apodeme, in termination Y-shaped ( Fig. 3G ); plate short, not very well sclerotized and bearing a few short setae. Ovipositor long and slender, tapered apicad ( Fig. 3H ); styli long, cylindrical and well sclerotized, apex bears 3–5 erect setae. Spermatheca Cshaped with long and slender cornu; apex of cornu sharp; nodulus and ramus relatively short, ramus slightly wider and as long as nodulus ( Fig. 3I ).

Variation. Dinas afonsoi sp. nov. is variable in body length: 4.6–6.0 mm. Coloration of the scales on the pronotum and elytra vary mainly in luster (see Description). The elytral coloration varies as in other Dinas (Microspina) species, and could not be used for differential diagnosis. Erect setae on the apical third of the elytra also vary in their thickness, but are ever distinct. Differential diagnosis. The species belongs to the subgenus Microspina . Dinas afonsoi sp. nov. has narrow and elongate elytra in the male, much wider and more oval elytra in the female; and the rostrum is distinctly narrowed in the middle ( Fig. 2A ), in which it differs from the Microspina species from the Southern Chain ( Table 2). The body length is 4.6 to 6.0 mm ( Fig. 3A ) (in contrast to D. obsita Wollaston, 1867 and D. angustula Wollaston, 1867 which are smaller than 4.5 mm). Dinas afonsoi sp. nov. has stout, apically pointed, not flattened, long erect setae only on the apical third of the elytra ( Fig. 3B ) (in contrast to D. sitonaeformis and D. pallipes Roudier, 1957 which lack erect setae ( Fig. 3C ), and to D. angusticeps in which more stout, apically widened and flattened, long setae are present on the whole elytra ( Fig. 3D )).

Etymology. The new species is named after Diogo Afonso, the Portuguese sailor and navigator, and discoverer of all islands belonging to the Northern Chain of the Cape Verde Islands.

Bionomics. Dinas afonsoi sp. nov., from Tope de Chuva, was collected exclusively on flowers of Euphorbia tuckeyana (species endemic to Cape Verde) ( Figs 6 , 7A–C ). Specimens were observed eating flowers and pollen grains, so inflicted plant damage could be easily seen upon ¿rst inspection and presence of the beetles could be expected.

Distribution. Cape Verde Islands – São Nicolau (eastern part), circa 550–600 m a.s.l.

Figures

Fig. 2. Differential diagnosis of the subgenera of Dinas: Dinas (Microspina) afonsoi sp. nov.:A – head, dorsal view; C – pronotum; G – elytra, dorsal view; Dinas (Microspina) sitonaeformis Wollaston, 1867: E – spina on profemora; Dinas (s. str.) strakai sp. nov.: B – variability of rostrum of Dinas (s. str.) strakai sp. nov., dorsal view; D – pronotum; F – spina on profemora; H – elytra, male, dorsal view.

Fig. 3. Dinas (Microspina) afonsoi sp. nov., holotype, male (A–B, E–F), female (G–I): A – habitus, dorsal view; B – elytra, lateral view; C – elytra of Dinas (Microspina) sitonaeformis Wollaston, 1867, lateral view; D – elytra of Dinas (Microspina) angusticeps Roudier, 1957, lateral view; E – aedeagus, dorsal and lateral view; F – spiculum gastrale; G – female sternite VIII; H – ovipositor; I – spermatheca. Scales: 1 mm, scale with ‘*’=2 mm, scale with ‘**’=0.5 mm.

Fig. 7. Habitats and biology of Dinas species: A–C – Dinas (Microspina) afonsoi sp. nov. on flowers of Euphorbia tuckeyana; D – Dinas sitonaeformis Wollaston, 1867 on twig of Periploca laevigata chevalieri in Chã de Caldeira; E – grassy slopes of Chã de Caldeira, São Nicolau with scattered Periploca laevigata chevalieri – locality of Dinas sitonaeformis. (Photos by Jakub Straka).

Fig. 6. Habitat of Dinas species: Summit of Tope de Chuva, São Nicolau – the type locality of Dinas (s. str.) strakai sp. nov. and Dinas (Microspina) afonsoi sp. nov.