Laparocerus depressus, 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 : 7-9

Laparocerus depressus n. sp.

( Figs. 3 A, 10D–E, 15A, 18E)

Dimensions, holotype (ɗ). Length: total (without rostrum) 6.50 mm, head 1.44 mm, rostrum 0.66 mm, scape 1.44, mm, funicle 1.96 mm, segments (1st/ 2nd/ 3rd/ 4th) 0.40 /0.50 /0.23 / 0.24 mm, club 0.58 mm, eyes 0.44, pronotum 1.45 mm, elytra 4.80 mm, tibiae (fore /mid /hind) 1.86 /1.72 / 2.10 mm. Width: head (with eyes) 1.14 mm, head (between eyes) 0.64 mm, rostrum (with pterygia) 0.78 mm, rostrum (minimum dorsal /ventral) 0.56 mm / 0.68 mm, rostrum (base) 0.66 mm, scape (maximum) 0.16 mm, club 0.12 mm, pronotum (anterior /maximum /posterior) 1.25 /1.70 / 1.57 mm, elytra (maximum) 3.05 mm. Height: abdomen 2.35 mm.

Male. Length 5.6 – 6.9 mm, oblong, depressed. Integument shiny, piceous; vestiture composed of dense, separate, small, linear, recumbent, hyaline or whitish scales with glaucous or coppery tint, arranged in mosaic pattern on elytra; only few curved setae at apex. Legs paler or testaceous. Antenna slender; scape clavate, slightly sinuate, shorter than pronotum, much shorter than funicle (0.74×); funicle long, second segment slightly longer than first (1.25×) and 3rd + 4th; club fusiform, narrow, not broader than scape, slightly longer than three previous segments together. Head normal, rostrum short (L/ W 1.2 ×), dorsally somewhat convergent apicad, not canaliculate; prorostrum well delimited, epistomal keel complete, convex; pterygia small, hardly protruding; frons noticeably depressed between eyes, median fovea large, deep, rarely extended. Eyes hardly prominent, evenly convex (convexity 23%), reaching border of frons. Integument obscurely punctate, with scales, except glabrous on prorostrum. Pronotum transverse (L/W ratio 0.85), moderately convex, not rimmed, more constricted at front than at base; maximum width at middle; prebasal collar feebly developed. Integument somewhat rough, micropunctures shallow, densely distributed, macropunctures small, sparse, precise, irregular, occasionally with faint median line. Scutellum very small, punctate. Elytra long, elliptical, truncated at base (L/W ratio 1.7), 3.2 × longer than pronotum and much wider (1.7 ×), sides evenly curved, widest at middle; shoulders not marked, declivous (scutellar area elevated); disc flattened. Striae with deep precise punctures (larger than on pronotum), obsolescent in distal half; intervals flat or clearly subconvex, devoid of punctures. Integument shiny; finely rugose; with linear recumbent scales 8–10 across intervals, separated but overlapping longitudinally, in mosaic pattern; very small arcuate dark setae, hardly projecting but visible in profile, longer and noticeably protruding only at apex. Legs normal; tibiae not carinate externally; protibia with apical angle externally blunt, internally slightly expanded, angular, with small mucro, smoothly emarginate in apical third, internal edge of excavation incrassate and black, grooming mat on internal face little developed; meso- and metatibia with tiny mucro. Ve n t e r. Ventrites with whitish scales and intermixed longer hair-like scales; no special tufts on coxae; inter-mesocoxal keel long and low; last ventrite apically clearly truncated. Abdominal convexity 72 %. Aedeagus (fig. 10D–E) with slender, fairly flat, hardly arcuate median lobe (0.60× length of elytra); apical plate smoothly tapering, evenly blunt; apodemes half the length of median lobe; internal sac with two long parallel fields of strong denticles and another much smaller isolated one at the end of the sac; muscular sheath covered with fine denticles.

Female. As male but larger (length 5.3–7.4 mm) and broader; elytra more strongly depressed on disc, maximum width in basal third; slightly impressed on flanks at 2/3 from base; irregular dark protruding setae on dorsum twice as long as in male, very conspicuous in apical third. Last ventrite apically rounded. All tibiae unarmed; protibia straight, not emarginate. Sternite VIII (fig. 15A) with broad, blunt plate, spermatheca as in fig. 18E.

Etymology. The specific epithet refers to the depressed disc of the elytra, which is characteristic of this species, particularly in the females.

Remarks. The species is easy to distinguish from other Laparocerus species on La Gomera by its depressed elytra, particularly in the female where the maximum width is in front of the middle. The slight impression on the flanks of the female is noteworthy, as this character is strongly developed in L. subopacus Wollaston, 1865 , a species that also belongs to the gracilis group. Closely related species are L. spinimanus (see below) and L. gracilis Wollaston, 1864 . The genetic distance of the latter species is minimal (unpublished data), but the morphological differences are too significant to not recognise L. depressus as a distinct species. L. gracilis is much narrower and more convex, particularly the males having a subcylindrical appearance and the females with elytra less convex than in the males but not depressed and without a ventrolateral impression, and the elytral vestiture consists of longer and denser scales without additional setae on the dorsum but, conversely, with much longer ones on the apex in females, and the ventrites show only a single type of scale. The rostrum is shorter and square, the frontal fovea is narrower and often extending as a line forwards and backwards, the smooth shiny integument of the prorostrum extends much more onto the metarostrum, the eyes are proportionally much larger, the antennae more strongly curved, the pronotum more distinctly punctate, etc. Moreover, the aedeagus of L. gracilis has a pointed apical plate and the basal aperture of the median lobe is situated more apically.

Material examined. Holotype: Vegaipala, 870 m (UTM = 28R 0 283745 3109002), 3-1-2005, leg. A. Machado, 1 ɗ ( TFMC, reg. CO-15509). Paratypes: same locality and collector, 17-2-2004, 3 exx.; 3-1-2005, 125 exx. ( AMC, MNCN, NHM, ZMUH); same locality, 25-1-2003, leg. H. López, 6 exx. (HLH), 14-2-2003, leg. P. Oromí, 7 exx.; 15-2-2003, leg. P. Oromí, 8 exx. (POM, TFMC); 7-12-2006, leg. R. García, 14 exx. (RGB). Other specimens: Bco. de la Villa, Las Casetas, 10-2-2006, leg. A. Machado, 10 exx. ( AMC).

Distribution and ecology. A species endemic to La Gomera, occurring at median altitudes (400–800 m) on the north-eastern mountain slopes of the island, in open habitat dominated by Euphorbia and Cistus scrub. It has been collected abundantly on Kleinia neerifolia but also feeding on Lavandula multifolia and Pancratium canariense . It is nocturnal, with a short activity period in the winter months.

Figures

FIGURE 3. New Laparocerus species from La Gomera, holotypes: (A) L. depressus n. sp. (B) L. spinimanus. Scale = 2 mm