Pachybrachis (Pachybrachis) sassii Montagna,

Montagna, Matteo, 2011, Pachybrachis sassii, a new species from the Mediterranean Giglio Island (Italy) (Coleoptera, Chrysomelidae, Cryptocephalinae), ZooKeys 155, pp. 51-60 : 53-57

Pachybrachis (Pachybrachis) sassii Montagna, sp. n. Figs 136

Type-locality.

Italy, Tuscany: Grosseto, Giglio island, Giglio Campese.

Material examined.

Type-specimens:Holotype male, pinned, with genitalia on a separate card board. Original label: "Italy, Grosseto, Isola del Giglio, Giglio Campese, 42°21.90'N, 10°52.59'E, ca. 30 m a.s.l., 14 Jun 2010, M. Montagna & F. Castiglioni leg. [printed label], "HOLOTYPUS / Pachybrachis sassii / Montagna M. des. [red handwritten label] (MSNM). Paratypes: 5 females and 5 males pinned. Three females and 3 males, original label: "Italy, Grosseto, Isola del Giglio, Via della Cabulgina, 42°22.97'N, 10°53.89'E, ca. 60 m a.s.l., 13 Jun 2010, M. Montagna & F. Castiglioni leg." [printed label], "PARATYPE / Pachybrachis sassii / Montagna M. des. [red handwritten label]; 2 males and 2 females (MMPC), 1 male and 1 female (DSPC). Two males and 2 females, original label: "Italy, Grosseto, Isola del Giglio, Giglio Campese, 42°21.01'N, 10°52.26'E, ca. 30 m a.s.l., 14 Jun 2010, M. Montagna and F. Castiglioni leg. [printed label], "PARATYPE / Pachybrachis sassii / Montagna M. des. [red handwritten label] (MMPC).

Diagnosis.

The new species belongs to the subgenus Pachybrachis s.str. The external morphological characters, general habitus, size, black and yellow pattern of elytra and pronotum prompt the ascription of Pachybrachis sassii sp. n. to the fifth artificial group suggested by Burlini (1968) and adopted in the most recent revision of the subgenus by Warchalowsky (2008). Species belonging to this group are longer than 3 mm, have black elytra with yellow raised spots, mesoepimera completely black or sometimes with an indistinct yellow spot, pronotum with irregular and deep punctation.

Description.

Male and female measurements are reported in Table 1.

Body relatively robust, dorsally black with yellow raised spots (Fig. 1), black/yellow ratio variable in male and female (female usually darker than male). Ventral side black, mesoepimera with yellow sometimes evanescent spot. Pygidium black. Vertex, frons, clypeus and upper labrum yellow. Antennal insertions, median longitudinal line on frons (in female wider and triangular in shape) and upper internal margin of eyes black. Vertex with black transverse line. First three antennomeres pale with blackish upper part, from IV to XI blackish to completely black. Pronotum with black/yellow pattern and narrow blackish outline, entirely black in some female. Two large lateral and irregular black spots reach pronotal base at corners, sometimes contact with anterior border in female. Lateral and anterior edges yellow, absent in some female. Evanescent yellow mark present within lateral black spot. Central black “V” -shaped spot connected to lateral spots. Scutellum black, shiny. Elytron with yellow shiny edge extending from humeral callus to suture surrounding scutellum. Humeral callus shiny, proximally yellow, distally black, completely black in some specimens. Suture black. Epipleura yellow with black outline. Apical lunula yellow, covered with evident black punctures in middle, inner and outer yellow branches extending up to half of suture and below humeral calli respectively. Legs brownish, upper part of femora black in male. Mid and hind femora with distinct yellow spots and black knees. Frons flat, interocular furrow fairly impressed and punctured, evanescent in female. Eyes at upper edge with impressed and punctured median line. Head with strong and diffuse punctation, denser in middle and close to internal margins of eyes, evanescent on clypeus. First antennomere swollen, as long as third, second antennomere roundish and shorter than half of third. Eyes prominent, distance between upper lobes smaller than distance between antennal sockets.

Pronotum with maximum width slightly posterior to middle. Longitudinal edge curved in middle, anteriorly not completely visible from above. Posterior edge sinuous in middle, slightly rimmed and bordered by line of punctures. Punctation evanescent on central disc close to median yellow spot, gradually coarser on sides and towards posterior margin, absent on tiny yellow raised ridge surrounding pronotum. Posterior margin of pronotum with single row of punctures. At bottom, two transverse impressions separated from edge by slightly raised area, less evident than in Pachybrachis salfii . Scutellum wide, rectangular, slightly convex, covered with short setae. Elytra slightly wider than pronotum at base, flattened on top. Elytral punctation located mainly on black markings, well impressed and placed in irregular rows anteriorly, starting from median spot becomes almost regular and less impressed. Humeral callus prominent, externally delimited by grooves. Base of elytra, proximally to margin, with evident carina originating at humeral calli and extending along anterior margin up to suture surrounding scutellum. Epipleura narrowly raised. Internal margin of apical lunula evenly cut, puncture clusters separate two inner appendices. Pygidium evenly convex, punctated and pubescent. Urosternite with evident microsculpture and fine whitish pubescence. In male external margin of VII urosternite with row of short and dense setae. Anal sternite with shiny median impression in male, rectangular and not deeply engraved fovea in female. Legs without diagnostic characters, first tarsomere enlarged in male. Median lobe of aedeagus well sclerotized. Phallotreme with sinuous edges, tiny truncated tip surrounded by visible setae, central frenulum with long basal stem expanded anteriorly (Fig. 3a). In lateral view (Fig. 3b) apex sinuous, not curved apically as in Pachybrachis salfii (Figs 4, 5); frenuli narrow with right angle in distal part, not obtuse as in Pachybrachis salfii (Figs 4, 5). Ventral side with evident triangular carina harboring two small cristae at base, apex with robust setae on each side and hairless tip (Fig. 3c). Spermatheca (Fig. 6a) sickle-shaped, wider on curve, slender anteriorly to fine tip, slightly recurved at base; ductus sclerotized and smooth throughout its length, at base robust junction with spermatheca, distal end forming a subtriangular pigmented diverticulum; accessory gland joining spermatheca at base in slightly sclerotized junction opposite to ductus. Ventral sclerites of kotpresse (Fig. 6b) triangular, lateral apices with three spicules each, anterior margin with prominent central carina, posterior margin sinuous and convex in middle; dorsal sclerite strongly transverse (Fig. 6c), two narrow lateral wings and two well sclerotized vertical processes.

Etimology.

The species is dedicated to Dr. Davide Sassi, a friend and well-known specialist in Chrysomelidae .

Ecology.

Pachybrachis sassii inhabits plant geoseries of Cyclamino repandi-Querco ilicis sigmetum ( De Dominicis et al. 2010) that are composed by fragmented bush vegetation close to sea reef. Specimens of Pachybrachis sassii were observed and collected on Erica arborea Linné and on Cistus incanus Linné. The mating male and female were observed on Cistus incanus . Adults were active in sunny days from mid-morning until mid-afternoon, when the temperature is the highest.