Calacalles (Nanoacalles) nataliae Astrin & Stüben, 2009

Astrin, Jonas J. & Stüben, Peter E., 2009, Molecular phylogeny in ' nano-weevils': description of a new subgenus Nanoacalles and two new species of Calacalles from the Macaronesian Islands (Curculionidae: Cryptorhynchinae), Zootaxa 2300, pp. 51-67 : 64-66

Calacalles (Nanoacalles) nataliae Astrin & Stüben sp.n.

( Figs. 4 , 5, 7 , 12 )

Type material. Holotype. 3: SPAIN, Canary Islands, La Gomera, SE Hermigua , near Casas del Palmar, thermophilous shrub forest, Sideritis / Gonospermum , N28°09'29" W17°09'37", 627 m, 8.10.2008, leg. Astrin & Stüben ("21"), coll. Curculio-Institute Mönchengladbach.

Paratypes. 13: SPAIN, Canary Islands, La Gomera, 7 km NW San Sebastián, Las Casetas, rock face, thermophilous shrub forest, N28°07'44" W17°09'17", 660 m, 31.12.2004, leg. Stüben ("25"), coll. Stüben; 13: SPAIN, Canary Islands, La Gomera, 2.5 km E Hermigua , thermophilous shrub forest, Sonchus hierrensis , N28°09'30" W17°09'46", 650 m, 31.12.2004, leg. Stüben ("27"), coll. Stüben; 93, 10Ƥ: data as for holotype, coll. Stüben (83, 9Ƥ) and coll. ZFMK (13, 1Ƥ).

Differential diagnosis. At the type locality on La Gomera, Calacalles nataliae lives syntopically with the new species Calacalles hermigua .

Calacalles nataliae is distinguished from Calacalles hermigua by: 1. The more parallel sides of the slender elytra which are 1.40x–1.62x as long as wide; apex acute-ovally rounded ( Fig. 4 ).

2. The shorter (at most 2.5x– 3x as long as wide) elytral bristles which are paddle-like (broadening towards the apex) in shape on the bright cross fascia of the elytral declivity.

3. The aedeagus with V -like structure of the internal sac ( Fig. 5 ).

Calacalles hermigua is distinguished from Calacalles nataliae by:

1*. The broader, laterally oblong-ovally rounded elytra which are 1.30x–1.47x as long as wide; apex more broadly rounded ( Fig. 4 ).

2*. The more slender (at least 4x–5x as long as wide) bristles of the elytra which are acuminate in shape on the bright cross fascia of the elytral declivity.

3*. The aedeagus with the structure of the internal sac like bulb peelings ( Fig. 6 ).

Calacalles nataliae shows considerable outward similarity to the species Calacalles exiguus Bahr, 2000 from the Anaga Mountains on Tenerife. C. exiguus also features a bar-shaped structure of the internal sac of the aedeagus; usually however, the two bars are arranged in parallel fashion ( Fig. 11 ) instead of forming an angle like in C. nataliae ( Fig. 12 ). Furthermore, the elytra of C. exiguus are more parallel-sided than those of C. nataliae and are much more coarsely punctuate.

In order to molecularly differentiate C. nataliae from other species of Calacalles , we here present DNA barcodes (GenBank accession numbers GQ332316 , GQ332317 , GQ332332 , GQ332333 , cf. Table 1).

Description ( Fig. 4 )

Length: 1.75–2.30 mm (without rostrum).

Head: Rostrum broader towards the apex; male rostrum with a dense cover of scales that continues also anterior to the insertion of the antennae, 3x as long as wide, finely and spaciously punctuated; female rostrum slender, nearly 4x as long as wide, more brilliant, but points not as fine as in male; antenna with 7 antennomeres; eyes large.

Pronotum: 1.04x–1.12x as long as wide, widest behind the middle, at the sides regularly rounded; with a weak lateral depression in front of the fore-margin; disc of the pronotum strongly arched in front of the base, and flattened in front of the fore-margin; circular and saucer-shaped scales completely adherent. If the scale cover is complete, the dense and fine punctures are not visible under the scales; disc of the pronotum with dark brown scales in front of the base, bright longitudinal fasciae or (very variable) beige-coloured/white spots at the sides and in front of the fore-margin. Fore-margin with corona of 14 to 16 dark, erect bristles; identical bristles isolated at the sides and also densely packed in the middle of the pronotum (forming a cross band of bristles).

Elytra: 1.40x–1.62x as long as wide, in the middle with sides parting towards the base nearly ‘parallelsided’ or weakly curved, towards the apex more acute-ovally rounded; in lateral view contour-line of elytra flatter behind the base, elytral declivity more steeply sloped. With round, adherent, mostly brown scales which completely cover the broad intervals; only the small, fine, bare elytral striae are visible. Single row of flattened, erect bristles, paddle-like (broadening towards the apex) and at most 2.5x– 3x as long as wide on bright cross fascia of elytral declivity; spaced about 2– 3 x bristle-length in front of the base and 1.5x bristlelength on the elytral declivity. Base of elytra concave, beyond this with bright, vague (poor in contrast) spots of scales; in the middle with broad, dark brown and diffusely delimited transverse fascia, towards the apex again with beige-coloured/white fascia. Lateral light longitudinal fasciae of pronotum continued as small spots on fourth and fifth intervals beyond elytral base; scutellum with light scales.

Legs: Front femora long and robust, reaching the fore margin of the pronotum, hind femora reaching the fourth segment of the abdomen; covered with light, widely-spaced and clubbed bristles. Tarsi and apex of tibiae light red.

Venter: First abdominal sternite at most as long as the three following sternites together. Second abdominal sternite as long as the very small sternites 3 and 4 together. All abdominal sternites with light, large and rounded scales and with far-scattered, long, light bristles.

Female genitalia: See Figure 7 .

Aedeagus: Internal sac of the aedeagus with V -like structure ( Fig. 5 ).

Ecology. The collecting locality can be found at an altitude of approx. 650 m, above Casas del Palmar ( Hermigua ) in the extreme north-east of La Gomera.

The specimens were collected in high numbers from dead or near-defoliated twigs of Gonospermum gomerae Bolle (Spanish "coronilla de la reina", Asteraceae ), but also of an unidentified species of Sideritis (Lamiaceae) on a slope of thermophilous shrub forest at the laurisilva edge. The slope was atypically dry for the season and largely affected by a land slide.

Distribution. This species is so far only known from the Canarian island of La Gomera.

Etymology. The epithet is a noun in the genitive case. The first author dedicates this species to his wonderful wife Natalia Astrin, who accompanied and helped him on the last ten field trips.

Figures

FIGURES 2 – 4. Habitus (dorsal / lateral view) of the two new Calacalles species in comparison with Calacalles seticollis (Wollaston, 1864).

FIGURES 5 – 8. Male (aedeagus, ventral / lateral view, Figs. 5, 6) and female genitalia (Figs. 7, 8) of the two new Calacalles species.

FIGURES 9 – 26. Comparison of the endophalli of all known Calacalles species.