The Morphology of Lateral Fields of Infective Juveniles of Entomogenous Nematodes of the Family Steinernematidae (Rhabditida)

Abstract

Approximately 1000 specimens representing more than 30 species and strains of the family Steinernematidae, from Australia, North and South America and Europe were investigated by scanning electron microscopy to determine the structure of the lateral field of the infective juveniles. Although fixation and critical point drying may cause distortion of the ridges of the lateral field, three basic types of arrangement could be observed. Six ridges were present on Steinernema affinis and S. intermedia; seven ridges were present in most species and strains from forest-ecosystems (i.e. S. kraussei) and eight ridges were present in species and strains from agroecosystems (i.e. S. bibionis and S. carpocapsae).

Phylogenetic relationships of Steinernema Travassos, 1927 (Nematoda: Cephalobina: Steinernematidae) based on nuclear, mitochondrial and morphological data

“…Morphological character-states were based on our observations and measurements, except for IJ lateral-field pattern (Mra´cek & Bednarek, 1991;Tallosi et al, 1994;Elawad et al, 1997;Nguyen & Smart, 1997;Waturu et al, 1997;Stock et al, 1998) morphology of the gubernaculum cuneus Nguyen & Smart, 1997;Stock et al, 1998), and the presence of horn-like structures in juveniles (Tallosi et al, 1994;Nguyen & Adams, 2003). Of 22 morphological characters, six were binary and 16 were multi-state (Table 2); four missing values were coded as ''?…”