Insect Flight Behavior Research Articles

Temperature Dependency of Insect's Wingbeat Frequencies: An Empirical Approach to Temperature Correction.

This study examines the relationship between the wingbeat frequency of flying insects and ambient temperature, leveraging data from over 302,000 insect observations obtained using a near-infrared optical sensor during an eight-month field experiment. By measuring the wingbeat frequency as well as wing and body optical cross-sections of each insect in conjunction with the ambient temperature, we identified five clusters of insects and analyzed how their average wingbeat frequencies evolved over temperatures ranging from 10 °C to 38 °C. Our findings reveal a positive correlation between temperature and wingbeat frequency, with a more pronounced increase observed at higher wingbeat frequencies. Frequencies increased on average by 2.02 Hz/°C at 50 Hz, and up to 9.63 Hz/°C at 525 Hz, and a general model is proposed. This model offers a valuable tool for correcting wingbeat frequencies with temperature, enhancing the accuracy of insect clustering by optical and acoustic sensors. While this approach does not account for species-specific responses to temperature changes, our research provides a general insight, based on all species present during the field experiment, into the intricate dynamics of insect flight behavior in relation to environmental factors.

Arduino‐integrated flight mill: A cost‐effective approach to studying insect flight behavior

AbstractIn recent years, the study of insect flight behavior has gained prominence, offering insights into their dispersal strategies, habitat preferences, and potential migration patterns. Recognizing the need for a precise tool to capture insect flight, we developed an Arduino‐integrated flight mill that offers researchers affordability, accuracy, and adaptability. Our flight mill was rigorously tested on two insect species, Protaetia brevitarsis seulensis and Polygonia c‐aureum, and proved effective in recording their unique flight patterns. Key to the precision of our flight mill is the integration of advanced materials, such as polytetrafluoroethylene, which reduces friction, and the incorporation of magnetic sensing for meticulous data capture. These design choices ensure that the natural flight speed of the insect is replicated with minimal disturbance. Additionally, the implementation of a dedicated R script for data analysis provides researchers with a comprehensive platform, allowing them to delve deeply into various metrics, visualize patterns, and make informed conclusions. However, our flight mill is not without challenges. Mastery of the Arduino platform and R programming environment is essential for optimal use, which could pose barriers for those unfamiliar with these platforms. Moreover, although carefully designed, the mounting mechanism may still influence the natural behavior of the insect. Despite these challenges, the potential applications of our flight mill are myriad. From basic entomological research to practical applications in pest management and conservation, its versatility is evident. The adaptability of the tool also makes it an excellent resource in educational settings, offering students hands‐on experience in studying insect behavior.

A simple computerized Arduino-based control system for insect rotary flight mills.

Flight mills are widely used to investigate insect flight behavior. As technology advances, the means to build a computerized control system for a flight mill has become more accessible in terms of both price and availability of components. However, the specialized electronics and programming knowledge required to build such a system can still present an obstacle to interested parties. Here, we describe a simple and inexpensive flight mill control system that can be easily assembled and operated without specialized experience. The hardware and software components are built around an Arduino single-board microcontroller, which outputs raw data in the form of timestamped detections of rotations of the flight mill arm. This control system is suitable both as the basis for new flight mills and for replacing outdated computer controls on existing flight mills. Additionally, it can be used with any rotary flight mill design that uses an electronic sensor to count rotations.

Comparing Drosophila suzukii flight behavior using free‐flight and tethered flight assays

AbstractTethered flight mills and free‐flight studies are two common approaches for examining insect flight behavior in the laboratory. Flight behavior studies are significant because they provide information with understanding dispersal and range expansion. Each approach has advantages and drawbacks and can influence the flight behavior of the study organism. However, tethered and untethered flight studies are rarely performed simultaneously to determine whether one technique is better suited for a particular species. Here, we conducted a tethered and untethered flight study to determine the limitations, benefits, and effects the two methods could have on assessing an insect's flight capacity. We focused the study on the global invasive pest, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Propensity of flight and flight duration, distance, and velocity were examined for (1) females and males, and (2) summer and winter morphs, as the two morphs differ significantly in body and wing size. The study showed that summer morphs were more likely to fly when untethered than when tethered to a flight mill. Additionally, when comparing the length of time of flight for first take‐off, D. suzukii flew longer when untethered. Outcomes from this study provide information on D. suzukii flight behavior, which could assist with future research on this economically important fruit pest that is rapidly expanding its range. The results also suggest that the flight apparatus can affect D. suzukii flight behaviors, such that future laboratory flight research should be considerate of the flight technique utilized.

Dual stereo-digital image correlation system for simultaneous measurement of overlapped wings with a polarization RGB camera and fluorescent speckle patterns.

Simultaneous monitoring of overlapped multi-wing structure by stereo-digital image correlation (stereo-DIC) may be used to quantify insect motion and deformation. We propose a dual stereo-DIC system based on multispectral imaging with a polarization RGB camera. Different fluorescent speckle patterns were fabricated on wings, which emit red and blue spectra under ultraviolet light that were imaged and separated using a polarization RGB camera and auxiliary optical splitting components. The resulting dual stereo-DIC system was validated through translation experiments with transparent sheets and reconstructed overlapped insect wings (cicadas). Dynamic measurements of the Ruban artificial flier indicate the efficacy of this approach to determining real insect flight behavior.

Overseas immigration of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), invading Korea and Japan in 2019.

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), spread rapidly in Africa and Asia recently, causing huge economic losses in crop production. Fall armyworm caterpillars were first detected in South Korea and Japan in June 2019. Here, the migration timing and path for FAW into the countries were estimated by a trajectory simulation approach implementing the insect's flight behavior. The result showed that FAWs found in both South Korea and Japan were estimated to have come from eastern China by crossing the Yellow Sea or the East China Sea in 10–36 h in three series of migrations. In the first series, FAW moths that arrived on Jeju Island during 22–24 May were estimated to be from Zhejiang, Anhui and Fujian Provinces after 1–2 nights’ flights. In the second series, it was estimated that FAW moths landed in southern Korea and Kyushu region of Japan simultaneously or successively during 5–9 June, and these moths mostly came from Guangdong and Fujian Provinces. The FAW moths in the third series were estimated to have immigrated from Taiwan Province onto Okinawa Islands during 19–24 June. During these migrations, southwesterly low‐level jets extending from eastern China to southern Korea and/or Japan were observed in the northwestern periphery of the western Pacific Subtropical High. These results, for the first time, suggested that the overseas FAW immigrants invading Korea and Japan came from eastern and southern China. This study is helpful for future monitoring, early warning and the source control of this pest in the two countries.

Autonomous Flying With Neuromorphic Sensing.

Autonomous flight for large aircraft appears to be within our reach. However, launching autonomous systems for everyday missions still requires an immense interdisciplinary research effort supported by pointed policies and funding. We believe that concerted endeavors in the fields of neuroscience, mathematics, sensor physics, robotics, and computer science are needed to address remaining crucial scientific challenges. In this paper, we argue for a bio-inspired approach to solve autonomous flying challenges, outline the frontier of sensing, data processing, and flight control within a neuromorphic paradigm, and chart directions of research needed to achieve operational capabilities comparable to those we observe in nature. One central problem of neuromorphic computing is learning. In biological systems, learning is achieved by adaptive and relativistic information acquisition characterized by near-continuous information retrieval with variable rates and sparsity. This results in both energy and computational resource savings being an inspiration for autonomous systems. We consider pertinent features of insect, bat and bird flight behavior as examples to address various vital aspects of autonomous flight. Insects exhibit sophisticated flight dynamics with comparatively reduced complexity of the brain. They represent excellent objects for the study of navigation and flight control. Bats and birds enable more complex models of attention and point to the importance of active sensing for conducting more complex missions. The implementation of neuromorphic paradigms for autonomous flight will require fundamental changes in both traditional hardware and software. We provide recommendations for sensor hardware and processing algorithm development to enable energy efficient and computationally effective flight control.

Flight behavior of four species of Holotrichia chafer (Coleoptera: Scarabaeidae) with different habitat use

Insect flight behavior varies among species and selective pressures underlying the diversification of flight performance remain to be fully elucidated. Comparisons of flight behavior among congeners with differing ecologies can contribute to gaining a better understanding of the mechanisms underlying the diversification of insect flight behavior. In this study, we compared the laboratory arena flight performance of four species of nocturnal Holotrichia black chafers (Coleoptera: Scarabaeidae) based on three-dimensional reconstructions of flight trajectories. Principal component analysis was applied to six kinematic parameters to summarize the flight performance of each species. We found that the flight of H. parallela, which feeds on the leaves of hardwood species, was faster and higher than that of the other three species (H. kiotonensis, H. picea, and H. convexopyga), which typically feed on herbaceous plants. However, maneuverability (rotational component) did not differ significantly among the four species. We further compared the flight velocities of H. parallela and H. kiotonensis using a tethered flight mill system. Similar to the free-flight observations, the velocity of H. parallela flights was significantly greater than that of H. kiotonensis. The interspecific difference in velocities may be associated with differences in spatial distribution of their host plants.

Longitudinal Actuated Abdomen Control for Energy Efficient Flight of Insects

The actuated abdomens of insects such as dragonflies have long been suggested to play a role in optimisation and control of flight. We have examined the effect of this type of actuation in the simplified case of a small fixed wing aircraft to determine whether energetic advantages exist in normal flight when compared to the cost of actuation using aerodynamic control surfaces. We explore the benefits the abdomen/tail might provide to balance level flight against trim changes. We also consider the transient advantage of using alternative longitudinal control effectors in a pull up flight maneuver. Results show that the articulated abdomen significantly reduces energy consumption and increase performance in isolated manoeuvres. The results also indicate a design feature that could be incorporated into small unmanned aircraft under particular circumstances. We aim to highlight behaviours that would increase flight efficiency to inform designers of micro aerial vehicles and to aid the analysis of insect flight behaviour and energetics.

Strong impacts of smoke polluted air demonstrated on the flight behaviour of the painted lady butterfly (Vanessa cardui L.)

1. A major component of biomass burning smoke is fine particulate matter (PM2.5), which has been shown to generate impacts on insect population dynamics and development. However, little is known about its effect on insect flight behaviour, even though this will influence insect dispersal and distribution, and potentially migration and ecosystem services such as pollination.2. Here we use a tethered flight mill setup to examine the behaviour of adult painted lady butterflies (Vanessa cardui L.) flying in different levels of combustion‐generated airborne PM2.5, comparison this to TFM flying under ‘clean air’ conditions.3. Descriptive statistics and paired sample t‐tests indicate that the smoke had a significantly deleterious impact on flight behaviour, with for example total flight distance covered declining by 65% during the first 20 min of flying in the least smoke contaminated air compared to ‘clean air’ control conditions, whilst average speed declined by 54% and flight duration by 32%. A strongly negative and highly significant linear correlation between flight speed and PM2.5 concentration was also observed.4. This study represents the first time that smoke effects on insect flight behaviour have been experimentally tested, and the longer the butterflies were exposed to the elevated PM2.5 concentrations the more obviously their flight behaviour declined. We conclude that the month(s)‐long episodes of air pollution often associated with agricultural burning and deforestation fires in the tropics may well be significantly affecting the behaviour of the flying insects living in those regions and/or who migrate through them.

Neural conduction, visual motion detection, and insect flight behaviour are disrupted by low doses of imidacloprid and its metabolites

While neonicotinoid insecticides impair visually guided behaviours, the effects of their metabolites are unknown and measurements of environmental concentrations of neonicotinoids, typically lower than those required to elicit toxic effects, tend to exclude metabolites. Here we examined the contributions of imidacloprid and two of its metabolites, imidacloprid-olefin and 5-hydroxy-imidacloprid, on neural conduction velocity, visual motion detection and flight in the locust (Locusta migratoria) using a combination of electrophysiological and behavioural assays. We show reduced visual motion detection and impaired flight behaviour following treatment of metabolite concentrations equal to sublethal doses of the parent compound. Additionally, we show for the first time that imidacloprid and its metabolites result in a decrease in conduction velocity along an unmyelinated axon. We suggest that secondary effects of the insecticide on the biophysical properties of the axon may result in decreased neural conduction. As these metabolites display neurotoxicity similar to the parent compound they should be considered when quantifying environmental concentrations.

Assessing Insect Flight Behavior in the Laboratory: A Primer on Flight Mill Methodology and What Can Be Learned

Dispersal is a key component in the population ecology and dynamics of insects and remains one of the most difficult and intractable ecological processes to study in the field. As a consequence, many researchers have looked to laboratory methods for investigating the myriad factors that govern and impact an insect’s ability to move within its environment. A key tool in this effort since at least the early 1950s has been the insect flight mill. Nearly 260 studies have been published using flight mills covering 214 species in 61 families and 9 orders. This review explores the methodology and technology of tethered flight in insects using flight mills. The goal is to provide the reader with a historical context of the approach, an understanding of the available tools and technology, background on how best to apply these tools through a comparative lens, and to summarize the wide breadth of factors that have been explored to further our knowledge of insect flight behavior. Overall, it is hoped that the interested reader will understand the limits and benefits of flight mills and will know where to find the resources, and perhaps collaborators, to pursue this line of study.

The tethered flight technique as a tool for studying life-history strategies associated with migration in insects.

1. Every year billions of insects engage in long‐distance, seasonal mass migrations which have major consequences for agriculture, ecosystem services and insect‐vectored diseases. Tracking this movement in the field is difficult, with mass migrations often occurring at high altitudes and over large spatial scales.2. As such, tethered flight provides a valuable tool for studying the flight behaviour of insects, giving insights into flight propensity (e.g. distance, duration and velocity) and orientation under controlled laboratory settings. By experimentally manipulating a variety of environmental and physiological traits, numerous studies have used this technology to study the flight behaviour of migratory insects ranging in size from aphids to butterflies. Advances in functional genomics promise to extend this to the identification of genetic factors associated with flight. Tethered flight techniques have been used to study migratory flight characteristics in insects for more than 50 years, but have never been reviewed.3. This study summarises the key findings of this technology, which has been employed in studies of species from six Orders. By providing detailed descriptions of the tethered flight systems, the present study also aims to further the understanding of how tethered flight studies support field observations, the situations under which the technology is useful and how it might be used in future studies.4. The aim is to contextualise the available tethered flight studies within the broader knowledge of insect migration and to describe the significant contribution these systems have made to the literature.

Assessing Aquatic Insect Flight Behavior with Sticky Traps

Assessing Aquatic Insect Flight Behavior with Sticky Traps

Effects of Light Intensity on the Flight Behaviour of Adult Tirumala limniace (Cramer) (Lepidoptera: Nymphalidae: Danainae)

Light intensity significantly affects insect flight behaviour. Mating of butterflies is significantly associated with flight frequency. However, no research has elucidated the effects of light intensity on butterfly flight. Thus, a clear understanding of the effects of light intensity on flight has significant theoretical implications for the cultivation and utilization of butterflies. We observed the flight behaviour of adult Tirumala limniace (Cramer) exposed to light intensities from 243 to 2240 lx and measured the frequency of flight, take-off rhythm, thoracic temperature excess (△T) when perching and flying, and the tendency for thoracic temperature to increase. Results showed that high-intensity light significantly increased flight activity, and males were more active than females under similar light intensities; strong light (1280–2240 lx) resulted in female and male butterflies taking flight earlier compared with weak light (243–864 lx); and a similar pattern was observed for flight duration, with flights by males being significantly longer than those by females at 864–2240 lx; △T of adults flying in strong light was significantly higher than in weak light, whereas the thoracic temperature of perching adults was similar to the air temperature. Compared with other light intensities, the equilibrium thoracic temperature of adults exposed to 2240 lx was higher, and the time to reach it was shorter; in addition, the △T and rate of thoracic temperature increase were higher and achieved more quickly, respectively. Thus, of the 243–2240 lx range, 2240 lx was the most optimal light intensity for adult T. limniace flight and captive rearing.

Reduced geomagnetic field may affect positive phototaxis and flight capacity of a migratory rice planthopper

The geomagnetic field (GMF) is not constant but changes over space and time. In addition to the current slow decay of GMF, sudden GMF anomalies, mainly characterized by reduced field intensity, and variation in GMF strength between the migration origin and destination areas of migratory animals have attracted growing attention from researchers. We investigated magnetic field effects (MFEs) triggered by the near-zero magnetic field (NZMF), to some extent a proxy for the reduced GMF, on the positive phototaxis and flight capacity of the adult migratory white-backed planthopper, Sogatella furcifera. For the first time, we report the significant enhancement of adult positive phototaxis by the NZMF compared with the GMF. Compared with the GMF, NZMF also affected the flight capacity of adults (with significantly lower body weights) in a sexually dimorphic way. We further found that expression patterns of the multifunctional cryptochromes (genes CRY1 and CRY2) as circadian photoreceptor and magnetoreceptor, along with the genes AKH and AKHR in the adipokinetic hormone (AKH)/AKH receptor (AKHR) signalling system which is related to energy metabolism and antioxidative stress reactions, correlated with phenotypic changes in positive phototaxis and flight endurance of adults. Therefore, potentially acting through an antioxidative stress-related CRYs–circadian clock–AKH/AKHR signalling pathway, we suggest that a reduced field intensity, and even just variation in GMF, may influence positive phototaxis and flight (migratory) behaviour of insects. Our study presents a feasible link between the probable mechanisms underlying MFEs, including cryptochrome-mediated light-dependent magnetosensitivity, cryptochrome-mediated light-dependent magnetosensitivity of the circadian clock and magnetic field-triggered oxidative stress, and provides new insights into the complexity of potential MFEs induced by variation in GMF.

A Simple Flight Mill for the Study of Tethered Flight in Insects.

Flight in insects can be long-range migratory flights, intermediate-range dispersal flights, or short-range host-seeking flights. Previous studies have shown that flight mills are valuable tools for the experimental study of insect flight behavior, allowing researchers to examine how factors such as age, host plants, or population source can influence an insects' propensity to disperse. Flight mills allow researchers to measure components of flight such as speed and distance flown. Lack of detailed information about how to build such a device can make their construction appear to be prohibitively complex. We present a simple and relatively inexpensive flight mill for the study of tethered flight in insects. Experimental insects can be tethered with non-toxic adhesives and revolve around an axis by means of a very low friction magnetic bearing. The mill is designed for the study of flight in controlled conditions as it can be used inside an incubator or environmental chamber. The strongest points are the very simple electronic circuitry, the design that allows sixteen insects to fly simultaneously allowing the collection and analysis of a large number of samples in a short time and the potential to use the device in a very limited workspace. This design is extremely flexible, and we have adjusted the mill to accommodate different species of insects of various sizes.

A Simple Flight Mill for the Study of Tethered Flight in Insects

Flight in insects can be long-range migratory flights, intermediate-range dispersal flights, or short-range host-seeking flights. Previous studies have shown that flight mills are valuable tools for the experimental study of insect flight behavior, allowing researchers to examine how factors such as age, host plants, or population source can influence an insects' propensity to disperse. Flight mills allow researchers to measure components of flight such as speed and distance flown. Lack of detailed information about how to build such a device can make their construction appear to be prohibitively complex. We present a simple and relatively inexpensive flight mill for the study of tethered flight in insects. Experimental insects can be tethered with non-toxic adhesives and revolve around an axis by means of a very low friction magnetic bearing. The mill is designed for the study of flight in controlled conditions as it can be used inside an incubator or environmental chamber. The strongest points are the very simple electronic circuitry, the design that allows sixteen insects to fly simultaneously allowing the collection and analysis of a large number of samples in a short time and the potential to use the device in a very limited workspace. This design is extremely flexible, and we have adjusted the mill to accommodate different species of insects of various sizes.

次世代照明が不快昆虫の飛翔行動に及ぼす影響

次世代照明が不快昆虫の飛翔行動に及ぼす影響

Flying insect detection and classification with inexpensive sensors.

An inexpensive, noninvasive system that could accurately classify flying insects would have important implications for entomological research, and allow for the development of many useful applications in vector and pest control for both medical and agricultural entomology. Given this, the last sixty years have seen many research efforts devoted to this task. To date, however, none of this research has had a lasting impact. In this work, we show that pseudo-acoustic optical sensors can produce superior data; that additional features, both intrinsic and extrinsic to the insect's flight behavior, can be exploited to improve insect classification; that a Bayesian classification approach allows to efficiently learn classification models that are very robust to over-fitting, and a general classification framework allows to easily incorporate arbitrary number of features. We demonstrate the findings with large-scale experiments that dwarf all previous works combined, as measured by the number of insects and the number of species considered.