1542 © The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. Ecology and Behavior Evaluating Flight Performance of Mass-Reared and Irradiated Navel Orangeworm (Lepidoptera: Pyralidae) for Sterile Insect Technique Joshua Reger, 1,3,4, Jacob A. Wenger, 1 Gurreet Brar, 1 Charles Burks, 2 and Houston Wilson 3, 1 Department of Plant Science, California State University, Fresno, 2415 E San Ramon, Fresno, CA 93740, USA, 2 USDA-ARS, San Joaquin Valley Agricultural Sciences Center, 9611 S Riverbend Avenue, Parlier, CA 93648, USA, 3 Department of Entomology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA, and 4 Corresponding author, e-mail: joshua. reger@ucr.edu Disclaimer: Mention of trade names or commercial products in this publication is solely for the purpose of providing specifc information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer. Subject Editor: Lisa Neven Received 16 February 2021; Editorial decision 13 May 2021 Abstract Navel orangeworm (Pyralidae: Amyelois transitella) is a key pest of almonds and pistachios in California. Moths directly infest nuts which leads to reduced crop yield and quality, and infestation can predispose nuts to fungal pathogens that produce aflatoxins. While several integrated pest management strategies have been devel- oped for A. transitella, studies have recently been initiated to explore the use of sterile insect technique (SIT) as an additional control tool. Mass-rearing, sterilization, and transportation methods originally developed for Pectinophora gossypiella (Lepidoptera: Gelechiidae) are currently being used for production of A. transitella in a mass-rearing facility, but the impacts of these processes on performance of A. transitella remain unclear. In this study, computerized flight mills were used to evaluate multiple flight parameters of mass-reared and irradi- ated A. transitella males and females relative to non-irradiated mass-reared moths and two strains of locally reared moths which were neither mass-reared nor irradiated. Mass-reared non-irradiated females performed similarly to both strains of locally reared females, flying a mean 9.4–11.8 km per night, whereas mass-reared and irradiated males and mass-reared non-irradiated males all flew shorter distances, in the range of 3.0–6.7 km per night. All of the mass-reared moths compared to locally reared moths had significantly more non-fliers that did not engage in more than two minutes of continuous flight. Findings from this study suggest that mass-rearing conditions reduce A. transitella flight capacity, while irradiation interacts with moths in a sex-specific manner. Key words: sterile insect technique, fight mill, Amyelois transitella, almonds, pistachios Sterile insect technique (SIT) involves the mass production, ster- ilization, and area-wide release of sterile organisms that sub- sequently mate with wild conspecifcs, which can lead to the reduction of target populations over time (Knipling 1955). SIT has been successfully implemented in many different regions glo- bally to eradicate or suppress pests that affect agriculture, human health, and natural ecosystems (Dyck et al. 2021). Successful agri- cultural SIT programs have been developed for various species of Diptera (Baumhover et al. 1955, Dowell et al. 2000, Vreysen et al. 2000), Coleoptera (Kohama et al. 2003), and Lepidoptera (Walters et al. 2000, Hight et al. 2005, Nepgen et al. 2015, Thistlewood and Judd 2019). The success of any SIT program hinges on the competitive abilities of the sterile insects relative to wild conspecifcs. This competitiveness is associated with copula- tion because the mating of sterile insects with wild conspecifcs re- sults in sterile or no offspring which drives down wild populations Journal of Economic Entomology, 114(4), 2021, 1542–1548 doi: 10.1093/jee/toab114 Advance Access Publication Date 9 June 2021 Research Downloaded from https://academic.oup.com/jee/article/114/4/1542/6295457 by guest on 06 July 2022