Abstract The effects of a granulosis virus from Sesamia nonagrioides were established in the larval, pupal, and adult stages. Different ages of larvae were compared as to their survival rates. Pupae deriving from diseased larvae had a sex ratio that deviated from the expected 1:1; in some of these pupae an incomplete pigmentation was noticed in abdominal segments. Adults deriving from inoculated larvae were less fertile, as measured by oviposition and by hatching rate. Offspring of inoculated parents had a greater incidence of the granulosis virus disease than did offspring of uninoculated parents.