Generic limits and taxonomic features of some genera belonging to the tribe of Chrysogasterini (Diptera, Syrphidae) .1. Generic diagnosis and description of Riponnensia, Gen-Nov

Publication Type:Journal Article
Year of Publication:1994
Authors:A. Maibach, Detiefenau, P. G., Speight, M. C. D.
Journal:Annales de la Société Entomologique de France
Keywords:Chrysogasterini, Diptera, Orthonevra, Orthonevra argentina (Brethes), Orthonevra nobilis (Fallen), Orthonevra pictipennis (Loew), Syrphidae

A systematic review of the genera Lejogaster Rondani, Chrysogaster Meigen and Orthonevra Macquart is presented, based on both larval and adult criteria. This study allows us to check the morphological features characteristic of each taxon as well as to define some new features and leads to the following conclusions : - a) Lejogaster and Orthonevra are validly regarded as separate genera, rather than as subgenera of Chrysogaster, - b) Orthonevra, as recognised until now, comprises a polyphyletic group of species in Europe : Orthonevra sensu stricto and Riponnensia, gen. nov. Riponnensia includes four species, R. splendens (Meigen) [type species], R. daccordi (Claussen), R. insignis (Loew) and R. longicornis (Loew); - c) Chrysogaster sensu stricto comprises two distinct groups of species in Europe, that require recognition at generic level; the type species of the genus Chrysogaster, = C solstitialis (Fal.), belongs to the first group, while Rondani’s Melanogaster is available for the second group with M. nubilis Rondani as type species. The name nuda (Macquart) is established as the senior synonym of nubilis Rondani, to replace lucida (Scopoli), which is shown (Maibach et al., in press) to have been wrongly applied. A dichotomous key, providing with the separation of the five genera, both at immature stages and adults, completes this work.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith