Animals were either infected for four days as asynchronous populations or for two days as synchronous populations. Infections of asynchronous populations were performed as in 5 (link). Briefly, two L4 hermaphrodites were distributed in each 50 mm plates and, on the next day, 20 µl of viral filtrate was spread on the plates. Animals were harvested (for viral load measurement) or observed under a Leica M165 FC fluorescent microscope (for scoring of the viral stress sensor) four days post-infection (4 dpi). This method was typically used for the characterization of the Ovid screen isolates. For the infection of synchronous populations, 200 animals at the larval stage L1 were deposited on each 50 mm plate. On the next day, L2 animals were infected with 20 µl of viral filtrate homogeneously spread on the plate. Plates were kept up-side-up for 24 hrs. Animals were harvested for viral load measurement at 2 dpi. This method was used to measure the viral load in cde-1 mutants, as indicated in the figure legends.