G. it. Ent., 3 (12): 1-165
April 30, 1986
A revision of the Old World species
of the genus Diastictus Muls. and its allies
(Platytomus Muls., Pleurophorus Muls., Afrodiastictus n. gen., Bordatius n. gen.)
(Coleoptera, Aphodiidae, Psammodiini)
by
RICCARDO PITTINO & GIOVANNI MARIANI
Abstract - After defining the diagnosis and status of the tribe Psammodiini and proposing its subdivision in 2 subtribes (Psammodiina and Rhyssemina) a revision of the Old World species of 5 genera - Diastictus Muls. Platytomus Muls., Pleurophorus Muls., Afrodiastictus n. gen., Bordatius n. gen. - is hereby provided. This work is based on the examination of 11613 specimens from Europe, Asia and Africa, of which 480 are type specimens of already known species (17 holotypes, 1 neotype and 1 lectotype, both previously designated, 7 lectotypes hereby selected), as well as 325 additional specimens from both the Western Hemisphere and the Australian Region. 48 valid species are dealt with in all with respective synonyms, two new genera (Afrodiastictus and Bordatius) and 25 new species are described, 6 new synonymies pointed out, 2 already known synonymies verified, 8 new combinations proposed, one species (Plerophorus torretassoi) and genus (Platytomus) are hereby validated. For each genus bibliographic references, diagnosis and status, discussion and distribution are given, for the polyspecific ones a key to species is also provided. For each species bibliographic references, types localities and locations of types, description, discussion, as well as known and verified distributions are presented. The main results are as follows: 1) The genus Diastictus, monospecific (D. vulneratus) with a NW Palaearctic distribution, appears to hold a peculiar position within the subtribe Psammodiina hereby defined. 2) The genus Platytomus, usually incorrectly regarded as synonymous with Diastictus, is here validated. It belongs to the subtribe Rhyssemina, consequently phyletically distant from Diastictus, has an almost cosmopolitan distribution and is polyspecific, containing 10 Old World species, 3 of which new to science: 4 Palaearctic (P. tibialis, P. laevistriatus, P. variolosus, P. mongolicus), 3 Oriental (P. indicus, P. nathani n. sp., P. nagporensis n. sp.), and 3 from sub-Saharan Africa (P. pumilio, P. ashantii, P. gomyi n. sp.). 3) The genus Pleurophorus (Rhyssemina), closely allied to Platytomus, is almost exclusively found in the Old World, with one species (P. caesus) also occurring in the Western Hemisphere. It is polyspecific, with 29 species, 18 of which new to science, ranged into 3 different species groups, as follows: A) "caesus" species group, with 13 species in all, 5 of which new to science: 9 Palaearctic (P. caesus, P. anatolicus, P. arabicus n. sp., P. pannonicus, P. mediterranicus n. sp., P. opacus, P. torretassoi, P. maghrebinicus n. sp., P. apicipennis) and 4 Ethiopian (P. villiersi, P. madagassus n. sp., P. africanus, P. raffrayi n. sp.); B) "impressicollis" species group, with 15 species, 12 of which new to science: one Palaearctic (P. ledouxi n. sp.) and 14 Oriental (P. impressicollis, P. cracens, P. tonkinensis, P. beccarii n. sp., P. cambeforti n. sp., P. banksi n. sp., P. laticollis n. sp., P. formosanus n. sp., P. dinajpurensis n. sp., P. thailandicus n. sp., P. schereri n. sp., P. setosus n. sp., P. bengalensis n. sp., P. besucheti n. sp.); C) "nepalensis" species group, with one Oriental new species (P. nepalensis n. sp.). 4) The genus Afrodiastictus n. gen. is herein created for 5 Afrotropical species, one new (A. apterus n. sp.) and 4 formerly ranged into Diastictus and/or Pleurophorus (A. carinatus, A. ceratus, A. insularis, A. endroedyyoungai). 5) The genus Bordatius n. gen. is described for 3 new species of the subtribe Rhyssemina, one Palaearctic (B. tingitanus n. sp.), two S African (B. capensis n. sp., B. australis n. sp.). Finally, 5 species are removed from the genus Pleurophorus and from the tribe: P. caesoides, P. capicola, P. natalensis, P. chopardi, P. edithae. This study proves that both male and female (spermatheca) genitalia have a high taxonomic value, often being indispensable to a correct identification of species, anyhow always usefully complementing the quite homogeneous external morphology. The epipharynx, on the contrary, seems to have a superspecific value, but its actual meaning is still poorly known. The work is completed with numerous original drawings and distributional maps, as well as many bibliographic references and an index of Latin nouns quoted throughout the text.
