Contributions to Zoology, 77 (4) - 2008Marco A. Bologna; Andrea Di Giulio: Revision of the genus Trichomeloe Reitter, with the description of new species and fi rst instarlarvae (Coleoptera: Meloidae)

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Introduction

The taxon Trichomeloe (Fig. 1) was described by Reitter (1911) as a subgenus of Meloe Linnaeus, 1758, a wingless and brachyelytrous genus of the tribe Meloini, largely distributed in the Holarctic, eastern and Southern Africa, and marginally in the Oriental Region. Reitter (1911) did not designate a type species and included in Trichomeloe five species, previously referred to Meloe by Escherich (1890) as the “behaarten Meloe-Arten” group, a polyphyletic assemblage, which almost completely belongs to Meloe, subgenus Eurymeloe Reitter, 1911.

FIG2

Fig. 1. Trichomeloe sericellus, male dorsal habitus (from Bologna, 1991). Scale bar = 5 mm.

Cros (1934) described the first instar larva of “Meloechrysocomus Miller, 1861, one of the species considered by Reitter (1911) as Trichomeloe, and noted its lyttine morphology, similar to that of “Meloemajalis Linnaeus, 1758, a Western Mediterranean species. Afterwards, Cros (1940) distinguished chrysocomus, majalis and affinis Lucas, 1849, another Maghrebian species, from typical Meloe because of larval characters, considering them as Lyttini but without description of a new taxon. This systematic opinion was adopted by MacSwain (1956), who separated these three species from Meloe, and formalized the new status of Trichomeloe by selecting Meloe chrysocomus as type species. Conversely, Pardo Alcaide (1952), Kaszab (1958, 1961, 1969) and Aksentjev (1988), conserved the traditional taxonomic arrangement and considered Trichomeloe as a subgenus of Meloe.

Recently, Bologna (1989) removed majalis from Trichomeloe and placed it in the new genus Berberomeloe based on adult and larval characters. Both genera were treated as Lyttini (see also Bologna, 1988, 1989, 1991). Selander (1991) also judged both genera as distinct and included them in the tribe Cerocomini, subtribe Lyttina. Placement in the tribe Lyttini was supported by Bologna and Pinto (2001, 2002), who noted considerable variability of larval morphology in the tribe and suggested its possible polyphyly (see also Bologna et al., 2008). A second species of Berberomeloe, B. insignis (Charpentier, 1818), endemic to southern Spain, was recently resurrected by Garcia-Paris (1998); this has been supported by molecular and larval evidence (Settanni et al., unpublished).

Following the literature (Escherich, 1890, pars; Reitter, 1911; Kaszab, 1958), Bologna (1988, 1989) referred six Meloe species to the genus Trichomeloe: T. chrysocomus Miller, 1861; T. conicicollis Reitter, 1907; T. deflexus Reitter, 1889; T. pubifer Heyden, 1887; T. sericellus Reiche, 1857; T. ottomanus Pliginskij, 1914. He also synonymized T. frivaldszkyi Kaszab, 1958 with T. ottomanus, and excluded T. affinis, referring it to Meloe (Eurymeloe). Afterwards, the same author (Bologna, 1991) excluded pubifer from Trichomeloe, referring also it to Meloe (Eurymeloe), after the examination of one syntype (MNHN: Reitter collection). In addition, Pripisnova (1987) described Meloe (Trichomeloe) ovatus from Tajikistan. The range of ovatus is isolated from that of other Trichomeloe, but some characters, figured in the short description, as the male genitalia (both parameres and aedeagus) and the pronotum shape, support the inclusion of T. ovatus in this genus. The range of the entire genus Trichomeloe appears consequently divided in two disjunct sub-ranges, respectively in the Eastern Mediterranean and Central Asia. At present, the following six species are referred to Trichomeloe: T. chrysocomus, T. conicicollis, T. deflexus, T. sericellus, T. ottomanus, T. ovatus.

Escherich (1890) and Reitter (1895) published partial keys to the Trichomeloe species, but mixed them with species actually belonging to Meloe (Eurymeloe). Several species are phenetically very similar and females are difficult to identify; for this reason an updated key was necessary.

Aims of this paper are to: (a) summarize adult and larval bionomics; (b) compare larval morphology of two species, one of which described for the first time and both figured by scanning electron microscopy photographs; (c) propose a classification of species and define natural groups; (d) construct an identification key to the species; (e) collect all taxonomic remarks and distributional information in an annotated catalogue; (f) describe two new species from Syria and Mesopotamia respectively.