Stealth Worms May Improve Insect Pest Control | Science Blog:
Known as entomopathogenic nematodes (EPN), the juvenile stage of these tiny worms travels with bacteria in its intestine that specifically kill certain insect species. Nematodes in the family Steinernematidae are associated with Xenorhabdus bacteria; those in the family Heterorhabditidae harbor Photorhabdus bacteria. Both types of EPN operate in similar ways.
Scientists work hard to make families monophyletic (all the descendants from a common ancestor). The similarities between the two families indicates common ancestry. Understanding how different members of the families evolved to kill specific insects will help scientists tailor insecticides to pest species without killing predatory insects and pollinators.