Pachybrachis holerorum Montagna & Sassi

Montagna, Matteo, Sassi, Davide & Giorgi, Annamaria, 2013, Pachybrachis holerorum (Coleoptera: Chrysomelidae: Cryptocephalinae), a new species from the Apennines, Italy, identified by integration of morphological and molecular data, Zootaxa 3741 (2), pp. 243-253 : 248-252

Pachybrachis holerorum Montagna & Sassi , new species

(figure 3)

Material examined. Holotype. Male, deposited in MSNM. Original label: Emilia-Romagna, Parma, Passo del Pellizzone, 1000 m, 8.VI.2011, Montagna & Sassi leg., 44°40'48.84"N 9°44'42.66" E [white label, printed] / Pachybrachis holerorum n. sp. holotypus Montagna & Sassi des. [red, printed]. DNA extracted to perform the amplification through PCRs of the genes: cox1, rbcL and trnL.

Paratypes. 46 specimens: Emilia-Romagna, Parma, Passo del Pellizzone, 1000 m, Montagna & Sassi leg., 44°40'48.84"N 9°44'42.66" E [white labels, printed], 8♂ and 19 ♀, DNA extracted from 4♂ (gene cox1) and 2♀ (genes: cox1, rbcL and trnL); Lombardia, PV, dint. Brallo di Pregola, Cima Colletta, 1366 m, 16. VI. 2011, Sassi leg., 44°42'37.59"N 9°15'36.55"E [white labels, printed], 3♂ and 1♀; Em. Romagna, MO, Nirano, Salse di Nirano, 30.V.2007, D. Sassi leg. [white label, handwritten], 1♂ and 2 ♀; LOMB. Emilia, Lago di Trebecco, 11.6.1997, leg. D. Sassi, [white label, printed], 2♂; Lombardia, PV, R, de' Giorgi, 16.6.1990, D. Sassi, 3♂ and 6 ♀ [white label, printed]; Em. Romagna, MO, Sassatella, 800 m, 30.V.2007, D. Sassi leg., [white label, printed], 1♂. All paratypes with our label: Pachybrachis holerorum n. sp. paratypus Montagna & Sassi des. [red, printed]. Paratypes in MSNM, DSPC, MMPC, MSPC, MDPC.

Etymology. The name is genitive plural of holus, used by the Roman poet Lucilius to indicate leguminous forbs.

Description of male. Total length: male = 2.9± 0.1 mm. Head yellow except vertex, a median longitudinal stripe with bifurcated apex along frons, antennae sockets, anterior margin of clypeus black. Frons shining, covered with fairly impressed punctation, denser on clypeus and above insertion of antennae, sparser on frons. Antennae filiform, brownish, segments 1–5 partly yellowish.

Pronotum black with yellow bands along anterior and lateral borders; anterior band lightly thickened at anterior angles and with short median posteriorly directed vitta; two anteriorly directed yellow lines from basal margin at sides of scutellum, 1.5 times wider than long, regularly curved at sides, with maximum width at about middle; punctation deep, denser at sides, slightly sparser on disc. Scutellum elevated, black, minutely punctate, apically truncate. Elytra coarsely punctured, partially arranged in striae; interstices raised, black with yellow pattern slightly raised from black surface, arranged as follows (spots and vittae may be interrupted or absent): narrow bands and vittae along anterior, lateral and posterior margins; narrow vitta along posterior half of sutural margin; two elongated spots near suture, plus one behind scutellum and one larger, in median position; longitudinal vitta on anterior margin lateral to humeral callus; post-median spot on disc; several smaller spots variously arranged on elytral surface. Epipleura black in posterior half, partly yellow anteriorly, with one or two series of irregularly aligned punctures on edges. Venter black, mesepimera with yellow spot, sometimes indistinct. Abdominal ventrites sparsely punctured and covered with rather sparse, long whitish hairs; ventrite 5 with shallow depression, glabrous.

Legs yellow, fore femora blackish along posterior edge; median and hind femora largely darkened along basal half, fore tibiae yellow; meso and metatibiae darkened at apex; tarsi mostly yellow, more or less darkened towards apex. First protarsomere moderately broadened, as wide as apex of tibia.

Apex of aedeagal median lobe (figure 4) acute, lateroventrally with row of white hairs, shaft thin and elongated, slightly careened along ventral surface, venter straight in lateral view.

Female differs from male in: larger and stouter body (length 3.3± 0.1 mm); frons broader and, as result, eyes more separated; generally reduced yellow pattern; first protarsomeres significantly narrower than tibiae apically; rectal apparatus (figure 5a,b) with two dorsal and one ventral sclerites; dorsal sclerites short and narrow, slightly wider than rectum, transverse connection across dorsal fold not perceptible, so sclerites essentially reduced to the apodemes only; ventral sclerite ribbon-like, evenly pigmented in the middle, with large and rounded apodemes at both ends, wider than rectum; dorsal and ventral sclerotizations of lateral fold present; spermatheca (figure 5c) sickle-shaped, lightly pigmented, basal part not swollen; base reflexed, with gland and duct insertions well sclerotized, so that it seems bifurcated; duct not coiled, quite short, its insertion on bursa copulatrix not enlarged and only feebly and briefly pigmented.

Diagnosis. Pachybrachis of medium-small size, characterized by elytral pattern, with marginal yellow stripe from anterior edge, to and around posterior margin, then along apical half of suture. This stripe interrupted only at humeral callus. Similar elytral marginal stripes are present in P. karamani Weise and P. fimbriolatus Suffrian , with which the new species forms a group, based on morphology. In P. karamani , the elytral yellow spots are generally smaller, and the irregularly distributed small spots that characterize P. holerorum are almost entirely missing. Pachybrachis fimbriolatus is distinguished from the new species by: less transverse and more minutely and densely punctured pronotum, reduced elytral yellow spotting, particularly, postmedian dot nearly always absent. The new species clearly differs from the all Pachybrachis species in the shape of the median lobe of aedeagus (figures 4 and 6).

Distribution. The new species is endemic to Northern Apennines, Italy. The type locality is Emilia Romagna, Piacenza Prov., Passo del Pellizzone (also written “Pelizzone”) (44°40'48.84"N 9°44'42.66"E).

Remarks. The biology of P. holerorum is poorly known. At Passo del Pellizzone it was collected in early June on Lotus herbaceus . This possible host was confirmed by the gut analysis of plant DNA from specimens at this locality. The preference of many species of the genus Pachybrachis for Fabaceae is well known (Jolivet and Hawkeswood 1995).

Pachybrachis holerorum is restricted to the north and west Apennines and P. k a r a m a n i is on the Adriatic slopes of North and Central Apennines (Sassi 2006). Molecular and morphological evidence show that Pachybrachis holerorum and P. karamani are recently diverged sister species in adjacent allopatric ranges, suggesting vicariant origin for the two species.

We take the opportunity here to designate a lectotype for P. karamani , to fix the identity of this species which is similar to P. holerorum . The syntypic series of P. k a r a m a n i consists of five specimens. We designate a male as lectotype, labelled as follows: Spalato (handwritten, white label) / Typus (printed, red label) / karamani Ws. (handwritten, white label) / Zool. Mus. Berlin (printed, yellow label) / Sintypus (printed, red label) / Pachybrachis karamani Weise, 1893 labelled by MNHUB 2012 (printed, red label). Pachybrachis karamani Weise, 1893 LECTOTYPUS Montagna & Sassi des. (Printed / red label). The remaining paralectotypes are labelled as follows: 2 ♂, 1 ♀: Spalato (handwritten, white label) / Typus (printed, red label) / Zool. Mus. Berlin (printed, yellow label) / Sintypus (printed, red label) / Pachybrachis karamani Weise, 1893 labelled by MNHUB 2012 (printed, red label). Pachybrachis karamani Weise, 1893 PARALECTOTYPUS Montagna & Sassi des. (Printed / red label). Female: Spalato Karam (handwritten, white label) / Karamani det. Burlini 1968 (partly printed, white label) / Zool. Mus. Berlin (printed, yellow label) / Karamani (handwritten, white label) / Typus (printed, red label) / Pachybrachis karamani Weise, 1893 labelled by MNHUB 2012 (printed, red label). Pachybrachis karamani Weise, 1893 PARALECTOTYPUS Montagna & Sassi des. (Printed / red label).

Concluding remarks

In our study of these Pachybrachis populations, the combination of three different approaches (morphological features of the aedeagus, nucleotide distance values and a method delimiting species based on single-locus molecular data), has provided evidence for a new species and its sister taxon.

The results contained in this work strongly confirm the urgent need to increase efforts to uncover the real biodiversity of the European fauna, in particular the Mediterranean region.

Acknowledgements

We cordially thank Dr. Johannes Frisch and Joachim Willers of the Museum für Naturkunde (Berlin) which give us the opportunity to study the type series of P. k a r a m a n i Weise, 1893. Moreover we thank Dr. Matthias Schöller (Berlin) for the helpful comments, Michele Zilioli of the Museo civico di Storia naturale di Milano for the SEM support, Loris Colacurcio (Bologna) for his precious help during the collecting campaigns, the Editor and two anonymous reviewers for their comments and suggestions to the preliminary version of the manuscript.

This work was partially supported by "Accordo di Programma, affermazione in Edolo del Centro di Eccellenza Università della Montagna" MIUR-Università degli Studi di Milano, prot. n. 1293- 05/08/2011.