Morphology and ultrastructure of the bacterial receptacle in Steinernema nematodes (Nematoda: Steinernematidae).

Infective juveniles of entomopathogenic nematodes in the genus Steinernema harbor symbiotic bacteria, Xenorhabdus spp., in a discrete structure located in the anterior portion of the intestine known as the 'bacterial receptacle' (formerly known as the bacterial or intestinal vesicle). The receptacle itself is a structured environment in which the bacteria are spatially restricted.

The rectal glands of Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae) hermaphrodites and their role in symbiont transmission.

Differential interference contrast, transmission electron and epifluorescence microscopy techniques were employed to examine the ultrastructure of the rectal glands in Heterorhabditis bacteriophora hermaphrodites, with special attention to the location of Photorhabdus bacteria symbionts within these structures. Three rectal glands were clearly visualized in all examined specimens, with two glands positioned sub-ventrally and another gland located dorsally. The dorsal rectal gland in all examined specimens is larger than the subventral ones.

Heterorhabditis sonorensis n. sp. (Nematoda: Heterorhabditidae), a natural pathogen of the seasonal cicada Diceroprocta ornea (Walker) (Homoptera: Cicadidae) in the Sonoran desert.

A new Heterorhabditis species was isolated from nymphal stages of the seasonal cicada Diceroprocta ornea (Walker) in an asparagus field in the state of Sonora, Mexico. Concomitantly, another isolate of the same nematode species was also collected from an oak woodland habitat in the Chiricahua mountain range in southeastern Arizona. Morphological and molecular studies together with cross-hybridization tests indicate these two isolates are conspecific and represent a new undescribed Heterorhabditis sp.

New insights into the colonization and release processes of Xenorhabdus nematophila and the morphology and ultrastructure of the bacterial receptacle of its nematode host, Steinernema carpocapsae.

We present results from epifluorescence, differential interference contrast, and transmission electron microscopy showing that Xenorhabdus nematophila colonizes a receptacle in the anterior intestine of the infective juvenile (IJ) stage of Steinernema carpocapsae. This region is connected to the esophagus at the esophagointestinal junction. The process by which X.

Influence of nematode age and culture conditions on morphological and physiological parameters in the bacterial vesicle of Steinernema carpocapsae (Nematoda: Steinernematidae).

Steinernema spp. third-stage infective juveniles (IJs) play a key role in the symbiotic partnership between these entomopathogenic nematodes and Xenorhabdus bacteria. Recent studies suggest that Steinernema carpocapsae IJs contribute to the nutrition and growth of their symbionts in the colonization site (vesicle) [Martens, E.