Insect pathogens are an excellent source of novel insecticidal agents with proven toxicity. In particular, bacteria
from the genera Photorhabdus and Xenorhabdus are proving to be a genomic goldmine, encoding a multitude of
insecticidal toxins. Some are highly specific in their target species, whilst others are more generalist, but all are of
potential use in crop protection against insect pests. These astounding bacterial species are also turning out to be equipped
to produce a vast range of anti-microbial compounds which could be of use to medical science. This review will cover the
current knowledge of the lifecycles of the two genera and the potential role of the toxins in their biology, before a more in
depth exploration of some of the best studied toxins and their potential use in agriculture.