Morphology of the immature stages of the hoverfly Paragus (Paragus) hyalopteri Marcos-García & Rojo, 1994 (Diptera, Syrphidae), predator of the mealy plum aphid Hyalopterus pruni (Hemiptera, Aphididae)

The genus Paragus Latreille, 1804 with over 100 species of hoverflies (Diptera: Syrphidae) is widely distributed except for Antarctica. The larval biology of these hoverflies is well known since they develop in aphid colonies, which are often of economic importance. However, the immature stages of only 9 of the 27 known larvae of genus Paragus are described. Paragus (Paragus) hyalopteri Marcos-García & Rojo, 1994, is a Palaearctic species described from Spain. Its larva has only been found preying on the aphid Hyalopterus pruni (Geoffroy, 1762) (Hemiptera: Aphididae), on several species of fruit trees and on leaves of Arundo donax L., and Phragmites spp. Here for the first time the full life cycle of a Paragus hoverfly is described including egg, all three larval stages and the puparium. Eggs, larvae and pupae of P. hyalopteri were collected on leaves of Phragmites australis (Cav.) among aphid colonies of H. pruni, and their morphology analyzed and described in detail using stereomicroscope and Scanning Electron Microscope techniques. To facilitate the diagnosis of Paragus larvae, a key to all known larvae of Paragus is provided.