Laparocerus exiguus, Machado, Antonio, 2007

Machado, Antonio, 2007, New species of Laparocerus Schönherr, 1834 from La Gomera, Canary Islands (Coleoptera, Curculionidae, Entiminae), Zootaxa 1643, pp. 1-38 : 11-12

Laparocerus exiguus n. sp.

(Figs. 2B, 14A–B, 15D, 18D)

Dimensions, holotype (ɗ). Length: total (without rostrum) 3.40 mm, head 0.72 mm, rostrum 0.38 mm, scape 0.74, mm, funicle 0.70 mm, segments (1st/ 2nd/ 3rd/ 4th) 0.16 /0.14 /0.9 / 0.9 mm, club 0.30 mm, eyes 0.22 pronotum 0.78 mm, elytra 2.45 mm, tibiae (pro- /meso- /meta-) 0.80 /0.68 / 0.90 mm. Width: head (with eyes) 0.79 mm, head (between eyes) 0.44 mm, rostrum (with pterygia) 0.42 mm, rostrum (minimum dorsal /ventral) 0.30 / 0.39 mm, rostrum (base) 0.42 mm, scape 0.09 mm, club 0,13 mm, pronotum (anterior /maximum /posterior) 0.68 /1.08/ 0.96 mm, elytra (maximum) 1.64 mm. Height: abdomen 1.24 mm.

Male. Length 3.2–3.6 mm, short-oblong, subparallel. Integument piceous, densely covered with linear, decumbent scales of testaceous and dark colour, arranged in mosaic pattern on elytra, and protruding, curved, short, dark, recurved setae; legs ferrugineous. Antenna short; scape hardly longer than pronotum, sinuate, heavily capitate at apical third; funicle slightly shorter than scape, segments 1–2 elongated, subequal, 3–4 much shorter but still longer than broad, 5–7 globular; club large, oval, twice as thick as funicle, longer than three previous segments combined. Head subconical, with broad base; rostrum short, dorsally fairly trapezoidal and slightly canaliculate; prorostrum weakly delimited; epistomal carina poorly marked; pterygia small, hardly protruding; frons depressed, with long and fine median impression. Eyes prominent, almost hemispherical (convexity 40%); close to but not reaching frontal border; peri-ocular sulcus noticeable. Scrobes slightly curved downwards. Integument at vertex more or less strongly rugose and punctate, on prorostrum uneven, microreticulated, with a few punctures, devoid of scales. Pronotum subconvex, transverse (L/W ratio 0.70), not rimmed; sides strongly curved except at base and apex; widest at or slightly behind middle; densely covered with large, deep, almost coalescent, but sharply impressed punctures and short, decumbent, fulvescent, hair-like scales, with some intermixed setae. Scutellum small, acute, covered by adjacent scales. Elytra oblong, 3.1 × longer and 1.5 × broader than pronotum, laterally weakly curved, widest and subparallel in middle portion, apex blunt, shoulders not marked; striae with large deep separated punctures (larger than on pronotum); intervals noticeably convex, with row of short, curved, brown, recurved setae protruding from dense vestiture of loose moderate-sized linear decumbent scales of flavescent or dark colour (in patches); 10th interval not narrowing at metacoxal level; scales 1–1.5 × diameter of a strial puncture in length, setae twice as long. Legs without brushes; protibia straight, hardly emarginate, apex externally rounded off, internally expanded into an acute point bearing a strong sharp mucro flanked on either side by an incrassate fringing seta; meso- and metatibia with smaller mucro. Ven t er. Vestiture of thinner and larger hair-like scales very sparse; intermesocoxal keel short and low; last ventrite uniformly rounded, as in females. Abdominal convexity 76%. Aedeagus (fig. 14A–B) with median lobe curved; apical plate evenly narrowing, with blunt tip; internal sac short, with a few large sclerotized denticles.

Female. As male but broader, more quadrangular (length 3.2 – 4.1 mm). Elytral L/W ratio 1.3 (instead of 1.5); intervals less convex; protibia with smaller mucro but apex hardly expanded internally; mesotibial mucro small, metatibial mucro tiny. Last ventrite rounded. Sternite VIII as in fig. 15D, with triangular-pointed plate, spermatheca as in fig. 18D.

Etymology. The specific epithet refers to the small size of the species.

Remarks. Laparocerus exiguus is the smallest Laparocerus species with eyes known from La Gomera, easy to recognize by its size, small, protruding, hemispherical eyes, trapezoidal rostrum, internally expanded and mucronate protibial apex, large antennal club, globular funicle segments 5–7, densely and sharply punctate pronotum and the subconvex elytral intervals, beset with strong curved setae protruding above the scale vestiture. The Gomeran species most similar in size is L. puncticollis indutus Wollaston, 1865 , which has a strongly emarginate male protibia, elevated pronotal base in the female and soft, elongate, suberect, elytral hairs. Similar in appearance and often even smaller in size is L. tenellus Wollaston, 1864 from Tenerife, which, however, has a narrower, squarer snout, smaller and more appressed scales and funicular segments 3–4 also globular, in addition to 5–7. Laparocerus exiguus belongs to the group of L. mendicus Wollaston, 1864 . Its closest relative is an undescribed vicariant species from the summit region of La Palma (unpublished molecular data), which is similar in appearance but much larger and with marked shoulders.

Material examined. Holotype: La Gomera: Laguna Grande, 1250 m (UTM = 28R 0 27830 311330), 6- 12-2002, leg. A. Machado, 1 ɗ ( TFMC, reg. CO-15512). Paratypes: same locality and collector, 6-12-2002, 52 exx.; 2-1-2005, 2 exx. ( AMC, TFMC, MNCN, NHM); same locality, 31-10-2002, 2 exx.; Pajarito, 1360 m, 20-10-2001, leg. P. Oromí, 4 exx. (POM); same locality, 6-12-2002, leg. R. García, 58 exx. (RGB). Other specimens: Las Hayas N, 800 m, 5-12-2002, leg. A. Machado, 2 exx. ( AMC); Cruce las Hayas, 6-12-2006, leg. R. García, 2 exx. (RGB); Pinar del Infierno [Infante?], 1200 m, 19-3-1985, leg. A. Vigna ( MZUR), El Cedro, 7-1-1983, leg. P. Oromí, 1 ex. (POM).

Distribution and ecology. An endemic species of La Gomera, occurring in the high central parts of the island. It has been found in numbers under small stones and sticks in an open grassy spot and was occasionally beaten at night from bushy vegetation of Adenocarpus and Cistus . It appears to be associated with very lowgrowing plants.