First report of an entomopathogenic nematode, Steinernema kraussei (Rhabditida, Steinernematidae) from Iran

Abstract

During conduction a survey of entomopathogenic nematodes throughout Arasbaran forests and rangelands, north west of Iran in 2007-2008, an entomopathogenic nematode was isolated using Galleria baiting method from soil samples collected from rangelands, near Chichakloo, Varzeghan, East Azarbaijan. It was identified as Steinernema kraussei (Steiner, 1923) Travassos, 1927 based on morphology and morphometric characters, cross breeding test, as well as molecular data. This species can be separated from other members of the genus by medium body length of infective juvenile (818 μm), lateral field with eight ridges in which the central pair is less distinct than others, head smooth, long cephalic papillae, secretory-excretory pore located at the level of middle of esophagus and anterior to the nerve ring; broad, slightly yellowish and short spicules, low D% value and tail with fine mucron in males. The analysis of ITS-rDNA sequence placed Iranian population of S. kraussei in the ‘feltiae - kraussei - oregonense’ group in the clade that containing different isolates of the species. It has some morphological and morphometric differences such as long cephalic papillae of IJ, more curvature of spicules and absence of mucron in some males as compared with type species. The mentioned differences are considered as intraspecific variations, and the described population from Iran is another isolate of S. kraussei. This is the first record of S. kraussei from Iran.

Keywords

• arasbaran
• iran
• entomopathogenic nematodes
• morphology
• morphometrics
• steinernema kraussei