Abstract

Surveying the biodiversity of entomopathogenic nematodes in Zulia and Falcon states, north-western Venezuela, two populations of a new Steinernema species were isolated from soil samples. Morphological, morphometric and molecular data indicate that the new species belong to the 'bicornutum-group' of Steinernema. The new species can be separated from the other species of the group due to the size and shape of their spicules, which are the shortest within the group, and the presence of prominent deirids in the male of both generations at basal bulb level. Lateral field with eight ridges at mid-body of which submarginal ridges are less distinct, but the third and sixth ridges eventually become wider posteriorly to form the last two ridges. Female possesses small but distinct double epiptygmata and anal swellings present in 50% of the specimens. Phylogenetic analyses of the bicornutum-group based on both ITS and D2-D3 regions showed a clear separation of the new species from all other species. We describe these two populations and designate them as Steinernema papillatum n. sp.