41st Annual Meeting of the Society for Invertebrate Pathology
and 9th International Conference on Bacillus thuringiensis

Lepidoptera are attacked by numerous virus strains, but in many cases do not show obvious signs of infection. Molecular techniques now allow the monitoring of viruses in wild populations without overt disease, and this has revealed a surprising diversity of pathogens. Baculoviruses were traditionally known for their lethal impact on hosts but are now known to also form persistent, almost symptomless infections, first detected in Mamestra brassicae. Such hidden infections may be vertically transmitted over many generations, be vectored by pathogens, have major to minimal impacts on host fitness and may interact with other invading pathogens. We report the detection of covert infections caused by baculoviruses and cypoviruses in a range of species, and explore their ecological significance.