Heterorhabditis safricana Malan, Nguyen, De Waal & Tiedt, 2008
Summary – During a survey for
entomopathogenic nematodes in the Western Cape Province of South Africa, a new
species in the genus Heterorhabditis was collected from a peach orchard. The nematode was trapped by
the insect-baiting technique using last instar larvae of Galleria mellonella. The infective
juvenile of the new species differs from the morphologically closest species, H. marelatus, in shorter body length
600 (550-676) vs 685 (588-700) μm and the shorter tail of 93 (86-108) vs 107 (99-117) μm. It differs from all other species in the
vulva pattern of hermaphroditic female. The genital papillae of the male H. safricana n. sp. are typical for
species in the megidis-group
(three papillae in terminal group). The average length of the gubernaculum is
longer than that of all other species (24 vs 19-23 μm) and the
gubernaculum length as a percentage of spicule length (53.9) is less than that
of H. mexicana (56), similar to that of H. floridensis
(53.8), but larger than that of all others
(51 or less). For molecular characterisation, the species closest to H. safricana n. sp. is H. marelatus. The length of the ITS
rDNA sequence of the new species is characterised by 995 base pairs, identical
to that of H. marelatus, but differs from this species by 25 aligned positions, seven of
which are unambiguous autapomorphies. Phylogenetic trees show further evidence
of a separate species status for H. safricana n. sp.