Paederus littoralis GRAVENHORST, 1802

Assing, Volker, Schülke, Michael, Brachat, Volker & Meybohm, Heinrich, 2018, On the Staphylinidae of the Greek island Corfu (Insecta: Coleoptera), Beiträge Zur Entomologie = Contributions to Entomology (Beitr. Entomol.) 68 (1), pp. 31-67 : 55

Paederus littoralis GRAVENHORST, 1802

Paederus pelikani REITTER, 1884b: 44 f.; syn. nov.

In the original description of P. pelikani , which is based on an unspecified number of syntypes from Corfu, REITTER (1884b) compares the species with P. (Harpopaederus) baudii FAIRMAIRE, 1860 and P. (H.) brevipennis LACORDAIRE, 1835. Based on a study of “le type et und série de paratypes ” [sic], COIFFAIT (1982) provides a short redescription and illustrations of the aedeagus. In contrast to REITTER (1884b), however, he states that P. pelikani is closely allied to P. littoralis , a species currently assigned to the subgenus Poederomorphus GAUTIER DES COTTES, 1862 ( SCHÜLKE & SMETANA 2015). According to COIFFAIT (1982), P. pelikani is distinguished from P. littoralis only by shorter elytra of more trapezoid shape and by the apically truncate dorsal plate of the aedeagus, and it replaces P. littoralis in the Ionian Islands and is also found in Albania and the Pelopónnisos.

A study of material of P. littoralis and P. pelikani from Corfu, mainland Greece (from the north southwards to the Pelopónnisos), the Aegean Islands, Albania, and various other regions ( Spain, Italy, France, Germany, Austria, Hungary, Slovakia, Slovenia, Serbia, Turkey (numerous localities across the whole country), Israel, Georgia, Armenia, Azerbaijan, and Russia revealed considerable variation in elytral length and shape, as well as in other external characters. The specimens from Corfu and Albania are indeed at the lower end of the range of elytral length, and their elytra are of more trapezoid shape than those of material seen from other regions. On the other hand, intermediate conditions were observed in populations from the Pelopónnisos and Turkey. Moreover, significant differences in the morphology of the aedeagus were not found. There is, however, some variation in the shapes of the dorsoapical structures (the pair of sclerotized hook-shaped structures best visible in lateral view). They are stout and more or less distinctly angled (lateral view) in material from Corfu, stout and smoothly curved in material from the Caucasus region ( Georgia, Armenia, Azerbaijan, Russia, East and Northeast Anatolia (Erzurum, Van), and slender and smoothly curved in other regions. Intermediate forms were observed in material from the Pelopónnisos and from southwestern Anatolia (Antalya). These observations suggest that the variation is somewhat clinal, but unlikely to represent interspecific variation. There are numerous other examples of deviant elytral length in island populations (e.g., Othius lapidicola ( ASSING 1997b)) and of variation of aedeagal shape (e.g., species of Leptobium CASEY, 1905 ( ASSING 2005)). Therefore, based on currently available evidence, the populations from Corfu are regarded as conspecific with P. littoralis . Hence the synonymy proposed above.