Platyderus casalei Guéorguiev, 2009, new species

Platyderus casalei new species

(Figs. 1, 7, 11, 16, Table 1)

Type material. HOLOTYPE: male, labelled “Calabria Sta. Eufemia d’Aspromonte 1905 Paganetti” / “coll. Leonhard” / “Tausch von Dahlem 4.1935” / “F. van Emden Bequest. B.M. 1960–129.” (BMNH).

Type locality. Italy, Calabria Region, province of Reggio Calabria, Santa Eufemia.

Diagnosis. This species is distinct from any other one from the Apennines by frontal impressions of head relatively deep, basal impressions of pronotum foveate (not linear), elytral striae irregularly but finely punctate, each elytron usually with 4 dorsal SP and situation of second dorsal SP in middle of interval 2 (equidistantly from striae 2 and 3), medial lobe of aedeagus laterally curved, with twin-peaked apex sharply bent downwards and lobes twisted ventrally (Figs. 1, 7, 11), copulatory piece with prominent medial lobe in front (Fig. 11). In addition, P. casalei sp. n. is distinct from P. paganettii sp. n. in the non-overlapping values of the ratios PW/HW, PW/PL, and EW/PW.

Description. A micropterous Platyderus species, with microsculpture of tegument isodiametric, distinct on labrum, vertex and elytra. Colour dark brown, antennomeres, palpomeres and legs paler. Values for sizes and ratios are shown in Table 1.

Head round, dorsal surface impunctate. Eyes moderately big, flat, moderately prominent. Labrum slightly emarginate anteriorly. Mandibles shorter than half length of head (with mandibles). Antennae pubescent from article 4 (articles 10–11 of left antennomere and articles 3–11 of right antennomere missing). Disc smooth, frontal impressions moderately deep, foveate, obliquely situated. Pronotum subrectangular, widest near middle. Lateral, anterior (excluding medial tip) and posterior margins beaded. Sides convex towards both apex and base; anterior margin slightly emarginate; posterior margin convex near angles, emarginate in middle. Basal impressions foveate, relatively deep, subround. Hind angles small, distinct. Disc moderately vaulted anteriorly, midline distinct, not reaching anterior and posterior margin; basal part notched longitudinally in middle including area of basal impressions; punctuation around hind angles indistinct. Elytra moderately vaulted, coalesced in anterior half, widest after middle and narrower at apical third. Shoulders obtusely angulate, not denticulate. Basal bead complete; scutellar striae and scutellar SP present; elytral striae finely punctate, all striae reaching basal margin; intervals flat, without punctuation. Hind wings reduced. Promeso- and metasternum smooth; anterior and internal margins of metaepisternae of equal length. Abdomen smooth. Legs relatively long and slender.

Male genitalia: Median lobe of aedeagus in lateral view regularly curved, equally wide in base and in middle, apex sharply bent downwards, beak-shaped (Figs. 1, 7); same ventrally short, apically twin-peaked with lobes twisted ventrally (Fig. 11); same in dorsal view widest before middle, with apex visible from above (Fig. 16). Copulatory piece convex laterally, ventrally with prominent medial lobe in front (Figs. 1, 11).

Chaetotaxy: interval 3 of each elytron with 4 SP (first SP situated in stria 3 at first third of elytron, second SP laying in middle of interval 3, at middle of elytron, and last two SP situated in stria 2, in last third of elytron (third SP situated closer to forth SP than to second SP).

Etymology. Dedicated to Prof. Dr. Achille Casale for his important contributions to the systematics and taxonomy of the Italian and European Carabidae.

Notes. The significant differences in the external structure of the male genitalia between P. casalei sp. n. and P. paganettii sp. n., as well the state of several external special features (foveae of head; basal impression of pronotum) and non-overlapping ratios (PW/HW, PW/PL, EW/PW) could be the effect of rapid sympatric isolation of these related taxa.