Comparison of transportation methods’ effect on flight performance of navel orangeworm for sterile insect technique

Navel orangeworm (NOW) (Pyralidae: Amyelois transitella) is a key pest of almonds, pistachios and walnuts in California. The moths directly infest nuts which leads to reduced crop yield and quality. Moth infestation can also predispose nuts to fungal pathogens that produce aflatoxins. While several integrated pest management strategies have been developed for this insect, studies have recently been initiated to explore the use of sterile insect technique (SIT) as an additional control tool. Currently, NOW are shipped overnight via airplane (flown) from Phoenix, AZ to central California for pilot SIT field release studies. However, previous studies have shown male NOW flight performance is reduced by one or more aspects of the mass-rearing process (e.g., transportation). Thus, initial protocols have been developed and implemented to transport NOW via car (driven) as an alternative transportation method in order to improve NOW fitness, including flight and dispersal. In this study, flight mills were used to measure distance and duration of flown and driven NOW males and females relative to local conspecifics. No significant differecnes were found between treatments in terms of distance, duration, and velocity. However, mass-reared NOW that were driven from Arizonia to California engaged in significantly more flights per night. Findings from this study provide new information on the effects of mass-rearing and transportation on NOW quality, which is critical to the development of an effective SIT program for this important pest.