Impacts of harmonic radar tagging on the flight ability of male Bactrocera tryoni and B. jarvisi (Diptera, Tephritidae)

Authors: TOMERINI, JOHN - Conservation Partners; DE FAVERI, MATTHEW - University Of Queensland; DE FAVERI, STEFANO - Department Of Agriculture And Fisheries; WRIGHT, CAROLE - Department Of Agriculture And Fisheries; Siderhurst, Matthew

Submitted to: Austral Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2024
Publication Date: 1/19/2024
Citation: Tomerini, J.M., De Faveri, M.G., De Faveri, S.G., Wright, C., Siderhurst, M.S. 2024. Impacts of harmonic radar tagging on the flight ability of male Bactrocera tryoni and B. jarvisi (Diptera, Tephritidae). Austral Entomology. 64(1),312728. https://doi.org/10.1111.aen.12728.
DOI: https://doi.org/10.1111/aen.12728

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. While multiple field studies using fruit fly tracking have already been conducted, how fly behavior in effected by having tracking tags attached is not well understood. This study focused on quantifying the effects of tag attachment on two fruit flies in Australia. In general, flies were easily able to take off and fly with tags attached. However, the time to take off and the time spent flying varied between the groups of tested flies.

Technical Abstract: The Queensland fruit fly, Bactrocera tryoni is a major horticultural pest in the Northern Territory and east coast of Australia. Jarvis's fruit fly, B. jarvisi is one of the lesser Australian fruit fly species, with distribution from Broome in Western Australia to the Northern Territory, into Queensland and down as far as Sydney in New South Wales. Understanding the movement dynamics of fruit flies is critical to both surveillance and control strategies with much of what is known coming from mark-release-recapture or flight mill studies. However, recent studies have demonstrated the feasibility of field-tracking fruit flies using harmonic radar (HR). In this study, the effects of attaching HR tags to B. tryoni and B. jarvisi were assessed in large indoor cages with both cultured and wild flies. Three flight-associated behavioural parameters were recorded: 1) flight success (proportion of flies that flew), 2) time to flight (period from release to take-off), and 3) time of flight (period from take-off to landing). Untagged flies were more likely to fly and also took flight more quickly than tagged flies with this result holding across fly species and fly origin (wild or cultured). Similarly, wild flies were more likely to fly than cultured flies, but no differences were observed between the flight success of the two fruit fly species. For all tagged flies, mean time to flight increased with successive flight trials while untagged flies mean time to flight over time varied with species and fly origin. The effect of tagging on time of flight varied by species (tagged > untagged for B. tryoni, tagged < untagged for B. jarvisi) but not by fly origin with species. Together these results quantify the significant negative effects of HR tagging on B. tryoni and B. jarvisi flight behaviours that should be taken into account when interpreting the biological relevance of HR tracking studies. These results also suggest that HR tracking of fruit flies might benefit from the further development of smaller and lighter tags.