Tissue tropism and viral levels of Acheta domesticus densovirus throughout the house cricket production

The house cricket, <i>Acheta domesticus,</i> is commonly reared for food and feed purposes and is often infected with the Acheta domesticus densovirus (AdDV). This single-stranded DNA virus can cause high mortality in crickets resulting in colony collapse. AdDV disease outbreaks in cricket mass-rearing can be prevented by either obtaining virus-free crickets or by reducing virus spread. Therefore, insight into viral levels in cricket developmental stages and into viral transmission routes is needed. Viral levels were monitored using quantitative PCR on samples collected 1) simultaneously from different life stages present in the rearing room and 2) weekly from a single rearing container during the successive developmental stages. To study viral tissue tropism and to infer the route of virus transmission, viral levels were measured in cricket tissues and in mated and non-mated adult crickets. Results showed that viral levels increased when developing from nymphs into adults and that unmated individuals had significantly lower viral levels than mated individuals. Furthermore, AdDV was present in every tested tissue and the gut and ovaries of females showed the highest viral levels. Our results suggest that AdDV is both horizontally and vertically transmitted among house crickets and provide relevant information to establish virus-free cricket lines.