Rice caseworm moth, Nymphula spp., population dynamics in irrigated rice

Abstract

The population dynamics of the rice caseworm moth, Nymphula spp. (Lepidoptera: Pyralidae), in irrigated rice,
in Santa Catarina State, Brazil, is still unknown. This makes it difficult for the development and practice of new strategies of
integrated pest management, as well as the timing of insecticide application for pest control. The aim of this study was to
monitor the rice caseworm moth occurence to know its population dynamics and its periods of movement in the rice fields.
Three light traps, model “Luiz de Queiroz”, were set in a irrigated rice field at Epagri Experimental Station, in Itajaí, SC. From
August 2008 to April 2013 the light traps were turned on, from 16pm to 9am once a week, except from May to August of
each year when a fortnight schedule was follow. The Nymphula spp. adult population growth starts to be continuous from the
second 10 days of September, decaying only between February and March. The Nymphula moths occur with more intensity in
rice fields from December to February.