How does a quiescent symbiont of a nematode worm know when to turn nasty? Metabolic analysis and genetic knockouts confirm that model insect pathogens can sense L-proline in insect blood. This not only serves as a wake-up call, activating secondary metabolite virulence factors, but also provides an energy source for a metabolic shift appropriate for adaptation to the host environment.

The greater wax moth Galleria mellonella has been widely used as a heterologous host for a number of fungal pathogens including Candida albicans and Cryptococcus neoformans. A positive correlation in pathogenicity of these yeasts in this insect model and animal models has been observed. However, very few studies have evaluated the possibility of applying this heterologous insect model to invest...

Jenny S. Cory* and Judith H. Myers Molecular Ecology and Biocontrol Group, NERC Centre for Ecology and Hydrology, Mansfield Road, Oxford OX1 3SR, UK Department of Zoology and Faculty of Agricultural Sciences, Centre for Biodiversity Research, University of British Columbia, 6270 University Boulevard, Vancouver, Canada *Correspondence and present address: Jenny S. Cory, Laboratory of Virology, W...

Xenorhabdus nematophila is an insect pathogen and produces protein toxins which kill the larval host. Previously, we characterized an orally toxic, large, outer membrane-associated protein complex from the culture medium of X. nematophila. Here, we describe the cloning, expression, and characterization of a 17-kDa pilin subunit of X. nematophila isolated from that protein complex. The gene was ...

Cyclic outbreaks of defoliating insects devastate forests, but their causes are poorly understood. Outbreak cycles are often assumed to be driven by density-dependent mortality due to natural enemies, because pathogens and predators cause high mortality and because natural-enemy models reproduce fluctuations in defoliation data. The role of induced defenses is in contrast often dismissed, becau...

Immunological memory in vertebrates, conferring lasting specific protection after an initial pathogen exposure, has implications for a broad spectrum of evolutionary, epidemiological, and medical phenomena . However, the existence of specificity in protection upon secondary pathogen exposure in invertebrates remains controversial . To separate this functional phenomenon from a particular mechan...

1. Studies of variability in host resistance to disease generally emphasize variability in susceptibility given exposure, neglecting the possibility that hosts may vary in behaviours that affect the risk of exposure. 2. In many insects, horizontal transmission of baculoviruses occurs when larvae consume foliage contaminated by the cadavers of virus-infected conspecific larvae; so, host behaviou...

Transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. Pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. Experiments were conducted to understand how a plant pathogenic bacterium, Candidatus Liberibacter asiaticus (Las)...