Head and Cuticular Structures of Some Species in the Family Steinernematidae (Nematoda)

Head and cuticular structures of the Steinernematidae: Steinernema kraussei, Neoaplectana glaseri, N. carpocapsae and N. bibionis were compared by scanning electron microscopy. In both genera and all species studied one ring of six labial papillae and one of four cephalic papillae were clearly visible, which shows that Steinernema and Neoaplectana cannot be separated on the number of head papillae alone. Details of the morphology of the lips, openings of secretory organs and of the surface of the cuticle are given. Invasive juveniles have only one ring of four cephalic papillae.