The genus Euscelidia Westwood, 1850 is with 68 recognised species one of the most speciose of the presently 17 valid Leptogastrinae genera.
The distribution of species of Euscelidia is centred on the African continent (including Madagascar) where major speciation events have taken place – 55 of 68 known species occur here. The remaining species are distributed in the Oriental (11 species, India to the Philippines) and Palaearctic regions (4 species; Egypt, Greece to Turkmenistan, and China; E. bishariensis Efflatoun, 1937 and E. nitida (Wiedemann, 1828) are probably distributed in both the Afrotropical and Palaearctic regions).
Westwood (1850) erected the genus on the basis of the strongly swollen metathoracic femora of the type species E. rapax. This feature is not an autapomorphy, but found in many other species of Leptogastrinae and is not useful in delimiting Euscelidia. The only autapomorphic feature for the genus appears to be the postpronotal peg. The postpronotal peg (see picture), situated on the postpronotum anterior to the mesonotal apodeme, is not a complex structure that presents entirely satisfying support for the monophyly of Euscelidia. The size and shape vary within Euscelidia, but when it is present it is easily seen.
Altogether some 1485 specimens have been examined during the revision and the description of 40 new species and numerous new combinations are the result of this extensive research project. More detailed information on the taxonomic history and status of Euscelidia can be found in Dikow (2003). |