Heterorhabditis safricana n. sp. (Rhabditida: Heterorhabditidae) : a new entomopathogenic nematode from South Africa
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.