Baezia bimbache García and López, 2007

García, Rafael, López, Heriberto & Oromí, Pedro, 2007, Additional data to the genus Baezia with description of a new species from a cave on El Hierro, Canary Islands (Coleoptera, Curculionidae, Molytinae), Zootaxa 1631, pp. 47-55 : 48-52

Baezia bimbache García and López n. sp.

Figures: 1–6

Studied material. Holotype male: (code no. HI-CU/ 2931-CO) Cueva de La Curva (400 m a.s.l., UTM 28R0206798-3066660), El Pinar, Frontera, El Hierro, Canary Islands, eclosion from roots 15-2-2005, H. López leg. Deposited in the entomological collection of the Department of Animal Biology (Zoology), University of La Laguna ( DZUL).

Paratypes: 9ɗ, 5Ψ and 3 indet. (HI-CU/ 2932-CO to HI-CU/ 2948-CO), same data as holotype; 4ɗ, 5Ψ and 1 indet. (HI-CU/ 2949-CO, HI-CU/ 2951-CO to HI-CU/ 2959-CO), same locality as holotype, eclosion from roots 4-X-2005, H. López & Oromí leg.; 1ɗ (HI-CU/ 2960-CO), same locality as holotype, eclosion from roots 10-VI-2004, Oromí & H. López leg. 12 paratypes are deposited in the collection of the Department of Animal Biology ( DZUL), 4 in the Museo de Ciencias Naturales de Tenerife ( MCNT), and 4 in H. López, 4 in P. Oromí, 4 in R. García private collections.

Description. General colour bright reddish-brown (fig. 6); the head, rostrum and pronotum covered with testaceous to yellowish erect setae, and the elytra with a short, fine vestiture on the whole surface.

Total length (including rostrum) ranging from 2.7 to 3.2 mm in males (mean 2.9) and from 2.9 to 3.1 in females (mean 3.0); sine capite et rostro length (pronotum + elytra) from 2.0 to 2.4 mm in males (mean 2.2), and from 2.3 to 2.5 mm in females (mean 2.4).

Rostrum obtuse, similar in both sexes, widest at the antennal insertion, 2.1 × as long as the width at the antennal insertion, and 0.9 × as long as pronotum. In lateral view the lower margin concave, and the upper one almost straight except near the apex where it is more declivous. Scrobes deep, their apical third visible from above; the apex smooth, shiny, with testaceous, erect setae. Rostrum slightly more depressed than forehead, with dorsal surface irregular with longitudinal sulci separated by fine keels; ventral surface smooth. Head microreticulated with fine, sparse punctuation. Eyes absent.

Antennae. Scape straight, increasingly widened towards the apex, 5.7 × as long as wide and 0.8 × as long as funicule, covered with small erect setae. Pedicel conical, 2x as long as wide, as long as the next three desmomeres together; 2nd to 7th desmomeres obconical, transverse, altogether as long as club; the latter oval, 1.7 × as long as wide.

Pronotum slightly transverse, sides almost straight, parallel, constricted behind apex, sometimes with a small concavity at middle, apex 0.9 × as wide as base. Surface smooth and shiny, with traces of microreticulation around the punctures, these clearly marked; setae decumbent and spread, a little more erect towards the edges. Scutellum small, triangular.

Elytra elongate, 1.7 × as long as wide and 2.4 × as long as pronotum, with the base wider than the base of pronotum; maximum width at middle, 0.6 × as wide as the base. Surface chagrinated and shiny, interstriae smooth, striae very fine, weekly marked by aligned punctures coinciding with small, erect setae. Humeral calli absent. Metathoracic wings absent.

Ventral surface with integument shiny, microreticulate, distinctly punctured, punctures separated from 0.6 × to 1.0 × their diameter, each including a fine, short seta. Procoxae close to each other. Mesocoxae separated by 0.8 × their diameter. Posterior half of 2nd and anterior half of 3rd sternites slightly depressed in their median zone, very faintly more concave in males than in females; the remaining sternites slightly convex, a little but increasingly elevated towards the apex and suddenly cut down at the end, giving a stair-like appearance. 5th sternite 2.4 × as wide as long.

Legs moderately elongate, with shiny surface, microreticulate with abundant semierect setae. Femora clavate at middle, strongly narrowed towards the apex; profemora and mesofemora 2.9 × as long as wide; metafemora 3.6 × as long as wide. Tibiae almost straight, widened at middle of the ventral side, provided at the apex by a spiny short comb; pro- and mesotibiae 5 × as long as wide; metatibiae 5.5 × as long as wide. Protarsi with tarsomeres 1 ×, 0.5 ×, 0.8 × and 3.0 × as long as wide respectively, the 3rd clearly bilobed, bearing two free simple claws; soles with long sparse hyaline hairs.

Male genitalia. Penis in dorsal view almost symmetrical, with straight, apically slightly diverging sides, apex slightly acute (fig. 1); in side view markedly curved, with apex acute, thin (fig. 2). Internal sac with abundant, dense teeth and spicules, appearing as a single group close to the ostium, and with two short semicylindrical pieces. Tegmen very similar to that of the species from La Palma (fig. 3).

Female very similar to male, difficult to distinguish without extraction of genitalia. Small differences are: protibiae 5.5 × and metatibiae 6 × as long as wide, and the elytra 2.7 × as long as the pronotum.

Female genitalia. Ovipositor short, with styles very short, cylindrical and bearing four apical macrochaetae (fig. 4); ovipositor hemisternites with a longitudinal sulcus in latero-dorsal view. Spiculum ventrale (fig. 5) with the median unsclerotized area fine, and with a submarginal row of macrochaetae; manubrium very short, with two divergent apical apophyses giving an V-shape. Spermatheca sclerotized, similar to that of Oromia hephaestos .

Etymology. The specific epithet is a noun in apposition for the aboriginal people inhabiting El Hierro before the colonization by Europeans. Though this word is erroneously used according to Corrales et al. (1992), it is very frequent in chronicles and books on the history of the Canaries.

Comparative notes. According to its morphology, the new species is closer to Baezia martini (fig. 7). However, B. bimbache n. sp. differs by several characters: the pronotum is more transverse, the widening at the middle of the inner side of femora and tibiae is less marked and smoother, the general surface is more shiny and the vestiture less abundant, the elytra are proportionally shorter, the tibiae much longer than wide, the aedeagus has a more curved profile, and the female spiculum ventrale has a distinct V-shape.

It differs from B. vulcania (fig. 8) by its squared pronotum clearly constricted behind apex, its shorter, decumbent, not claviform hairs, its shorter elytra and longer tibiae, its aedeagus more acute with straight sides and without apical prominence, and the V-shaped spiculum ventrale.

B. litoralis (fig. 9) differs from the new species by the subsphaeric pronotum of the former, without apical constriction, the inner face of femora and tibiae not thickened, the aedeagus more rounded with more convex sides and less curved profile, and the spiculum ventrale almost T-shaped.

Biology and ecology. All the specimens were obtained in the laboratory from dead roots gathered in the cave. Some immediately emerged as adults, and some did it later along 16 months (10-VI-2004 to 4-X-2005), which indicates that probably they were collected at the larval or pupal stages. The roots assembled in the cave were always dead. They were not identified at the species level, but most probably they belonged to Rumex lunaria L., since the other big bushes upon the surface were Euphorbia lamarckii Sweet , easy to recognize by their latex in stems and roots. The cave is a lava tube located at 600 m a.s.l., in a rather dry area on the southern slope of the island. The abundant volcanic cinder covering most of the terrain provides a good isolation to the underground, keeping the moisture much better than in other dry places. The cave has two superposed tubes, the upper passage of about 20 m and the lower one of 110 m long. According to Oromí et al. (2001) temperature was similar in both passages (20.3ºC and 20.4 ºC respectively in winter; 22ºC and 22.2ºC in the fall), as well as relative humidity (100% and 100% in the winter; 88.7% and 96.7% in the fall). However, the upper passage has more abundant dropping water and roots, and the fauna is richer than in the lower passage (see Hoch and Asche 1993; Oromí et al. 2001). In this upper passage temporary tender roots and germinating seeds grow abundantly on the floor in the humid seasons, especially on the accumulations of cinder that enter through a fissure at the rear part of the cave. The permanent thicker roots are attached to the walls or hanging from the ceiling, being found all along the cave except in a part of the lower passage which is under a paved road. The tender roots hold an interesting fauna including the planthoppers Cixius ariadne Hoch and Asche, 1993 and Meenoplus charon Hoch and Asche, 1993 , which are found exclusively in this cave. Other troglobitic insects like the thread-legged bug Collartida anophthalma Español and Ribes, 1983 and the cockroach Loboptera ombriosa Martín and Izquierdo, 1987 do not feed directly on tender roots, but are attracted to these rich spots. However, Baezia bimbache n. sp. was not found on the cave floor close to tender roots but in the older roots hanging from the ceiling and walls. Unlike Baezia vulcania and B. martini from caves in La Palma ( Alonso-Zarazaga and García 2002; García 2003), the new species has never been collected in baited pitfall traps or seeving the soil, in spite of our repeated samplings in Cueva de la Curva using these techniques ( Oromí et al. 2001). Only in one occasion the abdomen and elytra of a dead specimen were found in a pitfall trap, probably falling in together with soil.

The concentration of cave-adapted fauna in such a reduced space is remarkable, since almost all individuals were found in the rear part of the 20 m long upper passage. Still more interesting is the exclusivity of this fauna, four of the species being known only from this cave. Moreover, the two endemic planthoppers have vicariant species ( Meenoplus cancavus Remane and Hoch, 1988 and Cixius nycticolus Hoch and Asche, 1993 respectively) occurring in Cueva de Don Justo and Cueva Roja, other lava tubes located a few kilometers away, but at lower altitude (see Hernández et al. 1992; Hoch and Asche 1993; Oromí et al. 2001). Sampling in dead roots of these caves would be interesting to check whether also Baezia bimbache n. sp. is there or maybe a vicariant, different species of this genus.