[Occurrence of Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) on tobacco (Nicotiana tabacum L.) in Rio Grande do Sul, Brazil].

The occurrence of Rachiplusia nu (Guenée) is registered for the first time in tobacco [Nicotiana tabacum L. (Solanaceae)]. The specimens were collected in a Virginia tobacco field, in Venâncio Aires, State of Rio Grande do Sul. Caterpillars occurred in large infestations, causing important damage to tobacco leaves, and demanding chemical control to minimize losses. This occurrence indicates that this species can feed on Virginia tobacco, which corresponds to 80% of the tobacco area of Rio Grande do Sul, and so presents high risk to become an important pest in tobacco fields.