Following Diachasmimorpha longicaudata (Hymenoptera: Braconidae) movements with harmonic radar: Flight testing, cage studies, and field tracking

Authors: Siderhurst, Matthew; Hurst, Anika

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2026
Publication Date: 3/24/2026
Citation: Siderhurst, M.S., Hurst, A.L. 2026. Following Diachasmimorpha longicaudata (Hymenoptera: Braconidae) movements with harmonic radar: Flight testing, cage studies, and field tracking. Journal of Economic Entomology. 119(3):1774-1783. https://doi.org/10.1093/jee/toag067.
DOI: https://doi.org/10.1093/jee/toag067

Interpretive Summary: Biocontrol of insects, using an organism to control an insect pest, is a promising if somewhat underutilized method of reducing pest impacts in an environmentally safe manner. One specific form of biocontrol is known as augmentative biological control (ABC) in which additional biocontrol agents are released into an area to boost the control of an insect pest(s). Understanding the behavior of insect parasitoids, which are often used as biological control agents, is critical to implementing effective ABC management measures. This study used tiny harmonic radar tags to track the movements of individual Diachasmimorpha longicaudata parasitoid wasps in large outdoor cages and in a coffee field. Wasps with tags attached were observed to be largely sedentary in both the cage and field experiments. In the coffee field, all tagged wasp observations were made within 5 m from the release tree. This study demonstrates the feasibility of using harmonic radar to track small parasitoid wasps thus opening up new ways to study the behavior of these important components of biological control.

Technical Abstract: Increasing our understanding of parasitoid behavioral movement dynamics is critical to improving biological control strategies. The development of miniature harmonic radar (HR) tags, made with superelastic nitinol wire antennas, means tracking parasitoid wasps may now be possible. This study assessed the suitability of using HR tags (weighing ~135 µg) for tracking individual Diachasmimorpha longicaudata wasps. These braconid wasps are endoparasitoids of the larvae of many agriculturally important tephritid fruit fly species. HR tagged female D. longicaudata were found to be flight capable, but a laboratory flight bioassay showed some potential adverse effects of tagging, including slightly decreased cage landing heights and a numerical decrease in flight times. Flight tests in a large outdoor screen cage showed that D. longicaudata had biased landing distributions favoring a darker colored wall. Additionally, an attempt to observe wasp attraction to fruit was not successful. A multi-day experiment conducted in a coffee field demonstrated the feasibility of successfully following tagged wasp movements over time. Tagged D. longicaudata were found to be largely sedentary with the longest recorded movements paths (sum of all observed moves) remaining under 10 m over a three-day period. Mean observed movement distance was 2.7 ± 0.4 m with a mean movement rate of 0.11 ± 0.03 m/h (both values exclude wasps that remained in the release tree). This tracking approach is promising for future studies on parasitoid dispersal, chemical ecology, and parasitoid/predator/prey interactions in natural habitats thus potentially enhancing the efficiency of biological control using D. longicaudata.