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1. Wind effects on individual male and female Bactrocera jarvisi (Diptera: Tephritidae) tracked using harmonic radar

   https://doi.org/10.1093/ee/nvae108  

   Welty_Peachey, Allysen M; Moses, Ethan R; Johnson, Adesola J; Lehman, Meredith_G M; Yoder, James M; De_Faveri, Stefano G; Cheesman, Jodie; Manoukis, Nicholas C; Siderhurst, Matthew S (October 2024, Environmental Entomology)

   Cha, Dong H (Ed.)

   Abstract Wind affects the movement of most volant insects. While the effects of wind on dispersal are relatively well understood at the population level, how wind influences the movement parameters of individual insects in the wild is less clear. Tephritid fruit flies, such as Bactrocera jarvisi, are major horticultural pests worldwide and while most tephritids are nondispersive when host plants are plentiful, records exist for potentially wind-assisted movements up to 200 km. In this study, harmonic radar (HR) was used to track the movements of both male and female lab-reared B. jarvisi in a papaya field. Overall flight directions were found to be correlated with wind direction, as were the subset of between-tree movements, while within-tree movements were not. Furthermore, the effect of wind direction on fly trajectories varied by step-distance but not strongly with wind speed. Mean path distance, step distance, flight direction, turning angle, and flight propensity did not vary by sex. Both male and female movements are well fit by 2-state hidden Markov models further supporting the observation that B. jarvisi move differently within (short steps with random direction) and between (longer more directional steps) trees. Data on flight directionality and step-distances determined in this study provide parameters for models 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. 

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2. Tracking and modeling the movement of Queensland fruit flies, Bactrocera tryoni, using harmonic radar in papaya fields

   https://doi.org/10.1038/s41598-024-67372-4  

   Hurst, Anika L; O′Brien, Allison L; Miller, Nicole D; Peachey, Allysen_M Welty; Yoder, James M; De_Faveri, Stefano G; Cheesman, Jodie; Manoukis, Nicholas C; Siderhurst, Matthew S (December 2024, Scientific Reports)

   Abstract Determining movement parameters for pest insects such as tephritid fruit flies is critical to developing models which can be used to increase the effectiveness of surveillance and control strategies. In this study, harmonic radar was used to track wild-caught male Queensland fruit flies (Qflies),Bactrocera tryoni,in papaya fields. Experiment 1 continuously tracked single flies which were prodded to induce movement. Qfly movements from this experiment showed greater mean squared displacement than predicted by both a simple random walk (RW) or a correlated random walk (CRW) model, suggesting that movement parameters derived from the entire data set do not adequately describe the movement of individual Qfly at all spatial scales or for all behavioral states. This conclusion is supported by both fractal and hidden Markov model (HMM) analysis. Lower fractal dimensions (straighter movement paths) were observed at larger spatial scales (> 2.5 m) suggesting that Qflies have qualitatively distinct movement at different scales. Further, a two-state HMM fit the observed movement data better than the CRW or RW models. Experiment 2 identified individual landing locations, twice a day, for groups of released Qflies, demonstrating that flies could be tracked over longer periods of time. 

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3. The long-distance flight behavior of Drosophila supports an agent-based model for wind-assisted dispersal in insects

   https://doi.org/10.1073/pnas.2013342118  

   Leitch, Katherine J.; Ponce, Francesca V.; Dickson, William B.; van Breugel, Floris; Dickinson, Michael H. (April 2021, Proceedings of the National Academy of Sciences)

   null (Ed.)

   Despite the ecological importance of long-distance dispersal in insects, its mechanistic basis is poorly understood in genetic model species, in which advanced molecular tools are readily available. One critical question is how insects interact with the wind to detect attractive odor plumes and increase their travel distance as they disperse. To gain insight into dispersal, we conducted release-and-recapture experiments in the Mojave Desert using the fruit fly, Drosophila melanogaster . We deployed chemically baited traps in a 1 km radius ring around the release site, equipped with cameras that captured the arrival times of flies as they landed. In each experiment, we released between 30,000 and 200,000 flies. By repeating the experiments under a variety of conditions, we were able to quantify the influence of wind on flies’ dispersal behavior. Our results confirm that even tiny fruit flies could disperse ∼12 km in a single flight in still air and might travel many times that distance in a moderate wind. The dispersal behavior of the flies is well explained by an agent-based model in which animals maintain a fixed body orientation relative to celestial cues, actively regulate groundspeed along their body axis, and allow the wind to advect them sideways. The model accounts for the observation that flies actively fan out in all directions in still air but are increasingly advected downwind as winds intensify. Our results suggest that dispersing insects may strike a balance between the need to cover large distances while still maintaining the chance of intercepting odor plumes from upwind sources. 

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4. Wind, waves, wing loading and the flight energetics of giant petrels

   https://doi.org/10.1111/1365-2435.70352  

   Hallet, Madeline E; Phillips, Richard A; Maywar, Ian J; Thorne, Lesley H (May 2026, Functional Ecology)

   Abstract Wind is a major factor driving seabird movement and energetics, the effects of which are modulated by morphology. Developments in tagging technology now make it possible to test predictions from aerodynamic theory about the effects of wind on flight performance in free‐ranging birds. Waves are also thought to have a strong influence on seabird movement but have received less attention.We investigated the interplay between wind, waves, and morphology and tested predictions of flight theory in giant petrels (Macronectesspp.), which show greater sexual size dimorphism than any other seabird. We quantified flapping rates as a proxy of energy expenditure using accelerometers deployed on northern giant petrels (M. halli;n = 45) and southern giant petrels (M. giganteus;n = 48) breeding at Bird Island, South Georgia in 2022 and 2023. Wind and waves experienced by birds tracked with Global Positioning System (GPS) loggers were integrated with ERA5 reanalysis data to assess how flapping rates and ground speeds, respectively, were influenced by wind and waves. Using generalized additive mixed models, we predicted the spatial distribution of suitable habitat for soaring based on wind and wave conditions.Both wind and waves strongly influenced flight energetics; flapping rates decreased with increasing wind speed and swell height in all species and sexes. Together, wind and waves allowed giant petrels to reduce flapping rates by 76% to 91%. Wind also influenced the speed of travel; ground speed increased with wind speed in tail‐ and crosswinds, but generally decreased with wind speed in headwinds.Male giant petrels had higher wing loadings, and as predicted by flight theory, required higher air speeds for soaring flight and had higher flapping rates than females. Potential soaring habitat was much more limited for male than for female giant petrels, suggesting that differences in flight energetics between sexes may contribute to sexual segregation in foraging areas.Our results demonstrate how morphology, wind and waves combine to influence the flight energetics of giant petrels. Understanding the interactions among these factors is central to understanding environmental drivers of seabird distribution and to predicting responses to continued climate change. Read the freePlain Language Summaryfor this article on the Journal blog. 

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5. Takeoff diversity in Diptera

   https://doi.org/10.1098/rspb.2020.2375  

   Yarger, Alexandra M; Jordan, Katherine A; Smith, Alexa J; Fox, Jessica L (January 2021, Proceedings of the Royal Society B: Biological Sciences)

   The order Diptera (true flies) are named for their two wings because their hindwings have evolved into specialized mechanosensory organs called halteres. Flies use halteres to detect body rotations and maintain stability during flight and other behaviours. The most recently diverged dipteran monophyletic subsection, the Calyptratae, is highly successful, accounting for approximately 12% of dipteran diversity, and includes common families like house flies. These flies move their halteres independently from their wings and oscillate their halteres during walking. Here, we demonstrate that this subsection of flies uses their halteres to stabilize their bodies during takeoff, whereas non-Calyptratae flies do not. We find that flies of the Calyptratae are able to take off more rapidly than non-Calyptratae flies without sacrificing stability. Haltere removal decreased both velocity and stability in the takeoffs of Calyptratae, but not other flies. The loss of takeoff velocity following haltere removal in Calyptratae (but not other flies) is a direct result of a decrease in leg extension speed. A closely related non-Calyptratae species (D. melanogaster) also has a rapid takeoff, but takeoff duration and stability are unaffected by haltere removal. Haltere use thus allows for greater speed and stability during fast escapes, but only in the Calyptratae clade. 

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