Observations on a Pasteuria isolate parasitic on Hoplolaimus galeatus in Peru

A Pasteuria isolate associated with a population of the lance nematode Hopl olaimus galeatus was discovered in Peru. The infective propagules adhered t o adult stages and juveniles and were found filling the bodies of males and females. The endospore and central core diameters measured 4.5 +/- 0.4 mu m and 1.9 +/- 0.2 mu m, respectively, which differed from those reported fo r other Pasteuria isolates found in North America on the same host. Examina tions of endospore ultrastructure with scanning electron microscopy showed the presence of a thin layer of parasporal fibers surrounding the central c ore, a thin reduced layer of parasporal fibers in contact with the host's c uticle, and a putative basal core ring.