Mortality of Immature Stages of the Navel Orangeworm Stored at 3.5°C1

Abstract

When immature stages of Amyelois transitella (Walker) were exposed to 3.5°C for 2, 4, 7, 14, 21, or 28 days, the time to 50 and 95% mortality was determined. Mature larvae and pupae proved to be more tolerant to cold; eggs and young larvae were more susceptible. The most tolerant stage tested was the pupa at 28 days from oviposition, with LT50 and LT95 values of 11 and 21 days, respectively. However, cold storage at 3.5°C for 28 days resulted in 100% mortality of all stages and is a promising method for controlling navel orangeworms if the infested commodity is stored 28 days or more after reaching 3.5°.