Using harmonic radar to compare movement behavior between Bactrocera dorsalis and Ceratitis capitata (Diptera: Tephritidae)

Authors: Siderhurst, Matthew; Hurst, Anika; Ladizinsky, Nicolas; Aldebron, Charlotte

Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/4/2025
Publication Date: 10/6/2025
Citation: Siderhurst, M.S., Hurst, A.L., Ladizinsky, N., Aldebron, C. 2025. Using harmonic radar to compare movement behavior between Bactrocera dorsalis and Ceratitis capitata (Diptera: Tephritidae). Journal of Insect Science. 25(5). https://doi.org/10.1093/jisesa/ieaf078.
DOI: https://doi.org/10.1093/jisesa/ieaf078

Interpretive Summary: Fruit flies are major horticultural pests throughout the tropics and subtropics. Recent advances have made it possible to track individual fruit flies as they move around farms, urban areas, and other habitats. Tracking fruit flies allows us to better understand their biology and therefore how to better control them. For example, understanding how fruit flies move on farms will allow the optimization of trap placement or kill sprays. Information on how flies move in different environments under different conditions will allow more effective responses to pest fly invasions and outbreaks. This paper compared how two different fruit flies moved around a coffee field and in a large outdoor cage. Data on flight behavior determined in this study provide parameters that may help enhance current surveillance, control, and eradication methods, such as optimizing trap placements and pesticide applications, determining release sites for parasitoids, and setting quarantine boundaries after incursions.

Technical Abstract: Behavioral differences between related insects may inform how pest management strategies or conservation efforts are tailored to specific species. Movement behavior is particularly important, but few studies have undertaken head-to-head comparisons to evaluate interspecific movement parameter differences. This study used harmonic radar tags to simultaneously track two agriculturally important tephritid fruit fly species, Bactrocera dorsalis and Ceratitis capitata, in an outdoor-cage (Experiment 1) and a coffee field (Experiments 2-3) to assess fly directional movement, distance, and speed parameters. In general, both fly species have similar movement parameters. However, Experiment 2 showed B. dorsalis to be more active with fewer induced movements and less time needed to record the target number of movement steps. This was supported by a laboratory bioassay (Experiment 4) that confirmed B. dorsalis were more active. Mean step distances only differed in Experiment 2 and were longer for C. capitata. Experiment 3 tracked tagged flies over time with two B. dorsalis located after 3 days post release while no C. capitata were located after 48 h. Both species generally move with the prevailing wind. While this study found some differences in movement behaviors between these two pest