Nematodes are one of the most abundant animals on earth, and bacteria comprise the most biologically and phylogenetically diverse domains of organisms. On at least two separate occasions a soil dwelling nematode and a bacterium have entered into a mutualistic, insecticidal association. From such origins arose two distinct lineages of nematode–bacterium entomopathogens, Steinernema–Xenorhabdus a...

Larvae, pupae, and adults of the carrot weevil (Listronotus oregonensis) were infected and killed by the three entomophagous nematodes (Steinernema feltiae, S. bibionis, and Heterorhabditis heliothidis) under controlled conditions. Third-stage larvae were more susceptible than pupae or adults. S. feltiae and S. bibionis were the most aggressive nematode species, causing larval mortality after 2...

Frozen hydrated specimens of Pratylenchus agilis and dauer larvae of Steinernema carpocapsae were observed with low-temperature field emission scanning electron microscopy. This new technique provides information about the surface features of nematodes and also allows specimens to be fractured to reveal their internal structure. Furthermore, both halves of fractured specimens can be retained, e...

Entomopathogenic nematodes are used for biological control of insect pests. A method for improved cryopreservation of infective juvenile stage nematodes has been developed using Steinernema carpocapsae and Heterorhabditis bacteriophora. Optimum survival for both species was achieved with 12,000 infective juveniles/ml in glycerol and 7,500/ml in Ringer's solution. For S. carpocapsae, maximum sur...

Entomopathogenic nematodes are generally considered beneficial organisms. However, they can affect beneficial insects such as parasitoids. The interaction between the entomopathogenic nematodes Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) and Steinernema carpocapsae Weiser, and the parasitoid Microplitis rufiventris Kokujev (Hymenoptera: Braconidae) was investigated in t...

Virulence and development of the insect-parasitic nematode, Steinernema carpocapsae (Weiser) (Mexican strain), were evaluated for the immature stages of the western corn rootworm, Diabrotica virgifera virgifera LeConte. Third instar rootworm larvae were five times more susceptible to nematode infection than second instar larvae and 75 times more susceptible than first instar larvae and pupae, b...