Abstract
A new entomopathogenic nematode, Steinernema colombiense n. sp., is described
from Colombia. Morphological, molecular (28S and ITS rDNA sequence data) and
cross-hybridisation studies were used for diagnostics and identification
purposes. In addition, 28S and ITS rDNA sequence data were used to assess
evolutionary relationships of the new species with other Steinernema spp.
Morphological diagnostic features for S. colombiense n. sp. include
morphometric features of the third-stage infective juvenile, including body
length of 636 (549-732) μm, narrow body diam. (31 (22-36) μm), position of
the excretory pore (35 (31-40) μm), tail length (41 (32-53) μm), D% = 29
(25-33) and E% = 205 (138-284). In addition, males of first and second
generations are characterised by the morphology of the spicules and
gubernaculum, the number and arrangement of the genital papillae and the
excretory pore position (at 67 (56-76) and 54 (46-63) μm, for first and
second generations, respectively). In addition to these traits, 28S and ITS
rDNA sequences analyses both showed this species to be a distinct and unique
entity.
