GENERIC LIMITS AND TAXONOMIC FEATURES OF SOME GENERA BELONGING TO THETRIBE OF CHRYSOGASTERINI (DIPTERA, SYRPHIDAE) .3. DESCRIPTION OF IMMATURE STAGES OF SOME WEST PALEARCTIC SPECIES

Following the recent revision of the generic limits of the genera Lejo gaster Rondani, Chrysogaster Meigen and Orthonevra Macquart, with the revalidation of Melanogaster Rondani and the creation of a new genus R iponnensia (Maibach et al. 1994a), we present a morphological synthesi s of all the immature stages of these genera known, at present, in the west palaearctic region. Besides the re-description of larvae and pup aria of Chrysogaster solstitialis (Fallen), Lejogaster metallina (Fabr icius), L. tarsata (Megerle in Meigen). Melanogaster hirtella (Loew), M. nuda (Macquart), Orthonevra brevicornis (Loew) and Riponnensia sple ndens (Meigen), we describe for the first time the immature stages of Melanogaster aerosa (Loew), Orthonevra nobilis (Fallen) and O. onytes (Seguy). Biological notes on the developmental stages are included, as well as a key to the identification of the presently known European l arvae and puparia of the concerned genera.