The role of diet moisture content in the development and subsequent fecundity of Amyelois transitella

Navel orangeworm (NOW, Amyelois transitella (Walker), Lepidoptera: Pyralidae) requires accurate monitoring and timely management protocol in IPM-based systems. As a primary pest in almonds the fecundity of NOW ultimately determines potential damage, and the overwintering generation developmental time can influence subsequent management practices. Previous studies (Wade 1961, Kellen & Hoffman 1983), determined NOW fecundity and development parameters on different hosts under numerous temperatures and light regimens in the lab. However, results were not consistent and no studies documented these response variables with NOW reared from mummy host materials while controlling substrate moisture content as a limiting factor. The objective of this study was to measure male and female development and female fecundity from nearly wild-type NOW neonates reared on ’Nonpareil’ almonds under three moisture content regimes while controlling relative humidity, temperature, and lighting. Results from this research offer insight into NOW development and reproductive capacity in the overwintering generation and may facilitate more accurate management thresholds, timing, and sanitation practices for these cropping systems.