MICROMORPHOLOGY OF THE OVIPOSITOR IN HYME NOPTERA AND EVOLUTION FROM PHYTOPHAGOUS SYMPHYTA TO PARASITOIDS APOCRITA

The ovipositor of 1 Symphyta and 12 primitive parasitoid Apocrita belo nging of the family of Ichneumonidae has been studied With the scannin g electron microscope (SEM) and for 2 species, semi-thin sections were used. The study shows the presence of closed trachea in the 3 pairs o f valvulae and a secretory system in the 2 pairs of valvulae interlock ed into a piercing stylus. We discuss the role of trachea and a secret ory system leading to excretory pores an the lancets of valvulae which occupy very precisely the site of sensory chemoreceptors known in mor e advanced species lacking this secretory system. The micromorphologic al data support the phylogeny within Hymenoptera, from Symphyta to pri mitive parasitoid Apocrita.