Vertical transmission of nucleopolyhedrovirus in insects.

A review of the literature on transmission studies of nucleopolyhedroviruses showed that low levels of viral infection were common among studies of pupae of insects but rarer in adults. Virus could be transmitted from parent to progeny and could be found in caterpillars reared from surface-decontaminated eggs. Persistent low levels of infection were observed in many of the studies considered. These could contribute to the persistence of virus in low-density populations, but the dominant source of virus among generations is probably through environmental contamination.