Laparocerus oromii, Machado, 2008

Machado, Antonio, 2008, Three new endogean species of Laparocerus Schönherr, 1834 from the Canary Islands (Coleoptera, Curculionidae), Journal of Natural History 42 (17 - 18), pp. 1277-1288 : 1282-1285

Laparocerus oromii n.sp.

( Figures 3 and 4 )

Measurements of holotype (♂)

Length. Total 3.10 mm, head 0.70 mm, rostrum 0.36 mm, scape 0.59 mm, funicle 0.64 mm, articles (1 st /2 nd /3 rd /4 th) 0.16/0.12/0.07/ 0.07 mm, club 0.31 mm, eyes 0.13, pronotum 0.74 mm, elytra 2.10 mm, tibiae (pro-/meso-/meta-) 0.58/0.74/ 0.66 mm.

Width. Head (at eye level) 0.44 mm, frons 0.34 mm, rostrum (with pterygia) 0.38 mm, rostrum (minimum dorsal/ventral) 0.26/ 0.33 mm, rostrum (base) 0.32 mm, scape 0.09 mm, club 0.13 mm, pronotum (anterior/maximum/posterior) 0.58/0.76/ 0.66 mm and elytra (maximum) 1.10 mm.

Height. Abdomen 0.72 mm.

Description of male

A very small Laparocerus (length without rostrum: 2.9–3.2 mm), of oblong-elongate shape. Integument uniformly reddish-brown, brilliant, devoid of scale cover and with dispersed short flavescent pilosity all over. Antennae: scape robust, slightly sinuate at base, a little longer than pronotum, capitate at apex (1/3 of length); funicle longer than scape, first article longer than second, third and fourth short, subglobular; club oval, thick, longer than the three previous articles combined. Head cone-shaped, without eyes (with only a vestigial scar). Rostrum short, subparallel convergent apicad (minimum dorsal width before the insertion of the antennae); prorostrum and epistomal keel badly defined; pterygia large and salient; frontal furrow broad and shallow, extending along whole metarostrum; surface with large separate punctures and small suberect hairy scales, except vertex (almost smooth, shiny). Pronotum almost as long as broad (L/ W=0.95), 0.33×length of elytra, sides moderately curved, widest at middle, not rimmed at base; integument smooth, shiny, with separate foveiform punctures, each beset with a suberect hairy scale; usually a long median impunctate line (slightly cariniform). Scutellum small, acute, smooth with two tiny piliferous punctures. Elytra elongated with rounded apex (L/ W=1.9), in profile evenly flattened (like pronotum) and apical declivity short; shoulders obsolete, sides weakly but evenly curved, maximum width at middle. Striae marked by big round punctures, obliterated apicad; intervals flat, shiny, with some irregular wrinkles and rows of emergent short flavescent setae pointing backwards. Ventral parts: mesosternal declivity not pronounced; inter-mesocoxal process poorly developed (often granule-ended); with a wide median fovea at posterior margin of metasternum. Metasternum and first ventrite depressed, with strong transverse wrinkles. Ventrites shiny, with very shallow large separate punctures, pilosity shorter and more disperse. Last ventrite truncated, briefly scoped at middle. Abdominal convexity 65%. Legs short, (tibiae shorter than length of pronotum), protibiae straight, slightly excavated apicad, briefly curved inwards at apex; outer apical angle blunt, inner angle acute, expanded, with a very strong and large mucro. Meso- and metatibiae with strong but shorter mucro. First tarsomere short, transversal. Genitalia ( Figures 4A–B ). Aedeagus weakly curved, broad apical plate with apex curved upwards. Parameres strongly broadened at end, very short (1/4 of median lobe). Internal sac short, with two median fields of teeth and a y-shaped piece (visible dorsally).

Description of female

Length 2.8–3.5 mm. Same as male, but more elongate (Elytra/pronotum L ratio=3.0×instead of 2.8) and elytra broader, less parallel. Preapical internal sinuosity of protibiae less marked; promucro shorter, meso- and metamucro reduced to a tiny triangular blade. Last ventrite round-ended. Sternite VIII ( Figure 4C ). Styli of valves long ( Figure 4D ).

Etymology

The species is dedicated to its discoverer, Dr Pedro Oromı´, a good friend and professor of Entomology at the University of La Laguna.

Diagnostic remarks

This is the most morphologically endogean adapted Laparocerus and the only known without eyes. Its very small size, linear form, unpigmented integument (ferruginous colour) and extended pilosity are also very characteristic. Although the species has the pro-tibiae externally round at the apex, it is related to the sculptus - excavatus group (unpublished DNA data), which has some representatives in the island where it lives.

Material examined

Holotype. La Gomera : El Cedro – Los Acebiños , 940 m (N28 ° 08'20' W17 ° 13'40') 1 ♂ 30-12-2004 leg. P. Stüben (TFMC, reg. CO- 15538) .

Paratypes. Same locality and collector, 10 exx (6 PS, 4 AMC); same locality 30-12-2004, leg. Ch. Germann, 7 exx (4 CG, 2 AMC, 1 POM). El Cedro: Reventón Oscuro , 1 ♀ 20-9-2002 leg. P. Oromí (POM), 1 ex 6-9-2003 leg. P. Oromí (AMC, in alcohol) .

Distribution and ecology

Laparocerus oromii n. sp. is endemic to the island of La Gomera. It has been collected with traps in the mesocavernous shallow substratum (MSS) and by washing earth with small roots beneath an Apollonias tree in Los Acebiños cloud forest, near a small stream. In the latter case several individuals were collected, as well as many dead specimens and remnants. It seems to be a very hygrophilous insect.

Figures

Figure 3. Male of Laparocerus oromii n. sp.

Figure 4. Laparocerus oromii n. sp. (A) Aedeagus, (B) apex of aedeagus, (C) female sternite VIII, (D) hemisternites of ovipositor, (E) head in lateral view.