{"title":"Correction: Altitude alters how frogs keep their cool.","authors":"A. Palecek","doi":"10.1242/jeb.245014","DOIUrl":"https://doi.org/10.1242/jeb.245014","url":null,"abstract":"","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80888933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-23DOI: 10.1101/2023.06.20.545794
Chengpei Li, A. J. Xu, Eric Beery, S. Hsieh, S. Kane
How animals jump and land on a variety of surfaces is an ecologically important problem relevant to bioinspired robotics. We investigated this topic in the context of the jumping biomechanics of the planthopper Lycorma delicatula (the spotted lanternfly, SLF), an invasive insect in the US that jumps frequently for dispersal, locomotion, and predator evasion. High-speed video was used to analyze jumping by SLF nymphs from take-off to impact on compliant surfaces. These insects used rapid hindleg extensions to achieve high take-off speeds (2.7-3.4 m/s) and accelerations (800-1000 ms-2), with midair trajectories consistent with zero-drag ballistic motion without steering. Despite rotating rapidly (5-45 Hz) in the air about time-varying axes of rotation, they landed successfully in 58.9% of trials; they also attained the most successful impact orientation significantly more often than predicted by chance, consistent with their using attitude control. Notably, these insects were able to land successfully when impacting surfaces at all angles, pointing to the emerging importance of collisional recovery behaviors. To further understand their rotational dynamics, we created realistic 3D rendered models of SLFs and used them to compute their mechanical properties during jumping. Computer simulations based on these models and drag torques estimated from fits to tracked data successfully predicted several features of their measured rotational kinematics. This analysis showed that SLF nymphs are able to use posture changes and drag torques to control their angular velocity, and hence their orientation, thereby facilitating predominately successful landings when jumping. Summary High-speed video revealed that juvenile spotted lanternflies are adept at landing after tumbling rapidly midair during jumping. We present computer simulations and realistic 3D models to help explain these abilities.
{"title":"Putting a new spin on insect jumping performance using 3D modeling and computer simulations of spotted lanternfly nymphs","authors":"Chengpei Li, A. J. Xu, Eric Beery, S. Hsieh, S. Kane","doi":"10.1101/2023.06.20.545794","DOIUrl":"https://doi.org/10.1101/2023.06.20.545794","url":null,"abstract":"How animals jump and land on a variety of surfaces is an ecologically important problem relevant to bioinspired robotics. We investigated this topic in the context of the jumping biomechanics of the planthopper Lycorma delicatula (the spotted lanternfly, SLF), an invasive insect in the US that jumps frequently for dispersal, locomotion, and predator evasion. High-speed video was used to analyze jumping by SLF nymphs from take-off to impact on compliant surfaces. These insects used rapid hindleg extensions to achieve high take-off speeds (2.7-3.4 m/s) and accelerations (800-1000 ms-2), with midair trajectories consistent with zero-drag ballistic motion without steering. Despite rotating rapidly (5-45 Hz) in the air about time-varying axes of rotation, they landed successfully in 58.9% of trials; they also attained the most successful impact orientation significantly more often than predicted by chance, consistent with their using attitude control. Notably, these insects were able to land successfully when impacting surfaces at all angles, pointing to the emerging importance of collisional recovery behaviors. To further understand their rotational dynamics, we created realistic 3D rendered models of SLFs and used them to compute their mechanical properties during jumping. Computer simulations based on these models and drag torques estimated from fits to tracked data successfully predicted several features of their measured rotational kinematics. This analysis showed that SLF nymphs are able to use posture changes and drag torques to control their angular velocity, and hence their orientation, thereby facilitating predominately successful landings when jumping. Summary High-speed video revealed that juvenile spotted lanternflies are adept at landing after tumbling rapidly midair during jumping. We present computer simulations and realistic 3D models to help explain these abilities.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77428614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-25DOI: 10.1101/2022.09.28.509980
Frederik Püffel, F. Roces, D. Labonte
Atta leaf-cutter ants are the prime herbivore in the Neotropics: differently-sized foragers harvest plant material to grow a fungus as crop. Efficient foraging involves complex interactions between worker-size, task-preferences and plant-fungus-suitability; it is, however, ultimately constrained by the ability of differently-sized workers to generate forces large enough to cut vegetation. In order to quantify this ability, we measured bite forces of A. vollenweideri leaf-cutter ants spanning more than one order of magnitude in body mass. Maximum bite force scaled almost in direct proportion to mass; the largest workers generated peak bite forces 2.5 times higher than expected from isometry. This remarkable positive allometry can be explained via a biomechanical model that links bite forces with substantial size-specific changes in the morphology of the musculoskeletal bite apparatus. In addition to these morphological changes, we show that bite forces of smaller ants peak at larger mandibular opening angles, suggesting a size-dependent physiological adaptation, likely reflecting the need to cut leaves with a thickness that corresponds to a larger fraction of the maximum possible gape. Via direct comparison of maximum bite forces with leaf-mechanical properties, we demonstrate (i) that bite forces in leaf-cutter ants need to be exceptionally large compared to body mass to enable them to cut leaves; and (ii), that the positive allometry enables colonies to forage on a wider range of plant species without the need for extreme investment into even larger workers. Our results thus provide strong quantitative arguments for the adaptive value of a positively allometric bite force.
{"title":"Strong positive allometry of bite force in leaf-cutter ants increases the range of cuttable plant tissues","authors":"Frederik Püffel, F. Roces, D. Labonte","doi":"10.1101/2022.09.28.509980","DOIUrl":"https://doi.org/10.1101/2022.09.28.509980","url":null,"abstract":"Atta leaf-cutter ants are the prime herbivore in the Neotropics: differently-sized foragers harvest plant material to grow a fungus as crop. Efficient foraging involves complex interactions between worker-size, task-preferences and plant-fungus-suitability; it is, however, ultimately constrained by the ability of differently-sized workers to generate forces large enough to cut vegetation. In order to quantify this ability, we measured bite forces of A. vollenweideri leaf-cutter ants spanning more than one order of magnitude in body mass. Maximum bite force scaled almost in direct proportion to mass; the largest workers generated peak bite forces 2.5 times higher than expected from isometry. This remarkable positive allometry can be explained via a biomechanical model that links bite forces with substantial size-specific changes in the morphology of the musculoskeletal bite apparatus. In addition to these morphological changes, we show that bite forces of smaller ants peak at larger mandibular opening angles, suggesting a size-dependent physiological adaptation, likely reflecting the need to cut leaves with a thickness that corresponds to a larger fraction of the maximum possible gape. Via direct comparison of maximum bite forces with leaf-mechanical properties, we demonstrate (i) that bite forces in leaf-cutter ants need to be exceptionally large compared to body mass to enable them to cut leaves; and (ii), that the positive allometry enables colonies to forage on a wider range of plant species without the need for extreme investment into even larger workers. Our results thus provide strong quantitative arguments for the adaptive value of a positively allometric bite force.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74193202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-28DOI: 10.1101/2023.02.27.530217
Michael A. Calicchia, R. Mittal, J. Seo, R. Ni
Hydrodynamic pressure is a physical quantity that is utilized by fish and many other aquatic animals to generate thrust and sense the surrounding environment. To advance our understanding of how fish react to unsteady flows, it is necessary to intercept the pressure signals sensed by their lateral line system. In this study, the authors propose a new, non-invasive method for reconstructing the instantaneous pressure field around a swimming fish from 2D particle image velocimetry (PIV) measurements. The method uses a physics-informed neural network (PINN) to predict an optimized solution for the velocity and pressure fields that satisfy in an ℒ2 sense both the Navier Stokes equations and the constraints put forward by the measurements. The method was validated using a direct numerical simulation of a swimming mackerel, Scomber scombrus, and was applied to empirically obtained data of a turning zebrafish, Danio rerio. The results demonstrate that when compared to traditional methods that rely on directly integrating the pressure gradient field, the PINN is less sensitive to the spatio-temporal resolution of the velocity field measurements and provides a more accurate pressure reconstruction, particularly on the surface of the body.
{"title":"Reconstructing the pressure field around swimming fish using a physics-informed neural network","authors":"Michael A. Calicchia, R. Mittal, J. Seo, R. Ni","doi":"10.1101/2023.02.27.530217","DOIUrl":"https://doi.org/10.1101/2023.02.27.530217","url":null,"abstract":"Hydrodynamic pressure is a physical quantity that is utilized by fish and many other aquatic animals to generate thrust and sense the surrounding environment. To advance our understanding of how fish react to unsteady flows, it is necessary to intercept the pressure signals sensed by their lateral line system. In this study, the authors propose a new, non-invasive method for reconstructing the instantaneous pressure field around a swimming fish from 2D particle image velocimetry (PIV) measurements. The method uses a physics-informed neural network (PINN) to predict an optimized solution for the velocity and pressure fields that satisfy in an ℒ2 sense both the Navier Stokes equations and the constraints put forward by the measurements. The method was validated using a direct numerical simulation of a swimming mackerel, Scomber scombrus, and was applied to empirically obtained data of a turning zebrafish, Danio rerio. The results demonstrate that when compared to traditional methods that rely on directly integrating the pressure gradient field, the PINN is less sensitive to the spatio-temporal resolution of the velocity field measurements and provides a more accurate pressure reconstruction, particularly on the surface of the body.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84194847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-03DOI: 10.1101/2023.01.31.526545
Luke N. Jessup, L. Kelly, A. Cresswell, G. Lichtwark
Many models have been developed to predict metabolic energy expenditure based on biomechanical proxies of muscle function. However, current models may only perform well for select forms of locomotion, not only because the models are rarely rigorously tested across subtle and broad changes in locomotor task, but also because previous research has not adequately characterised different forms of locomotion to account for the potential variability in muscle function and thus metabolic energy expenditure. To help to address the latter point, the present study imposed frequency and height constraints to hopping and quantified gross metabolic power as well as the activation requirements of medial gastrocnemius, lateral gastrocnemius (GL), soleus (SOL), tibialis anterior, vastus lateralis (VL), rectus femoris (RF) and biceps femoris (BF), and the work requirements GL, SOL and VL. Gross metabolic power increased with a decrease in hop frequency and increase in hop height. There was no hop frequency or hop height effect on the mean electromyography (EMG) of ankle musculature, however, the mean EMG of VL and RF increased with a decrease in hop frequency and that of BF increased with an increase in hop height. With a reduction in hop frequency, GL, SOL and VL fascicle shortening, fascicle shortening velocity and fascicle to MTU shortening ratio increased, whereas with an increase in hop height, only SOL fascicle shortening velocity increased. Therefore, within the constraints that we imposed, decreases in hop frequency and increases in hop height resulted in increases in metabolic power that could be explained by increases in the activation requirements of knee musculature and/or increases in the work requirements of both knee and ankle musculature. Summary Statement This study directly measures activation and work requirements of lower-limb musculature and whole-body metabolic energy requirements across a wide variety of human hopping conditions, helping to guide biomechanical models of energy expenditure.
{"title":"Linking muscle mechanics to the metabolic cost of human hopping","authors":"Luke N. Jessup, L. Kelly, A. Cresswell, G. Lichtwark","doi":"10.1101/2023.01.31.526545","DOIUrl":"https://doi.org/10.1101/2023.01.31.526545","url":null,"abstract":"Many models have been developed to predict metabolic energy expenditure based on biomechanical proxies of muscle function. However, current models may only perform well for select forms of locomotion, not only because the models are rarely rigorously tested across subtle and broad changes in locomotor task, but also because previous research has not adequately characterised different forms of locomotion to account for the potential variability in muscle function and thus metabolic energy expenditure. To help to address the latter point, the present study imposed frequency and height constraints to hopping and quantified gross metabolic power as well as the activation requirements of medial gastrocnemius, lateral gastrocnemius (GL), soleus (SOL), tibialis anterior, vastus lateralis (VL), rectus femoris (RF) and biceps femoris (BF), and the work requirements GL, SOL and VL. Gross metabolic power increased with a decrease in hop frequency and increase in hop height. There was no hop frequency or hop height effect on the mean electromyography (EMG) of ankle musculature, however, the mean EMG of VL and RF increased with a decrease in hop frequency and that of BF increased with an increase in hop height. With a reduction in hop frequency, GL, SOL and VL fascicle shortening, fascicle shortening velocity and fascicle to MTU shortening ratio increased, whereas with an increase in hop height, only SOL fascicle shortening velocity increased. Therefore, within the constraints that we imposed, decreases in hop frequency and increases in hop height resulted in increases in metabolic power that could be explained by increases in the activation requirements of knee musculature and/or increases in the work requirements of both knee and ankle musculature. Summary Statement This study directly measures activation and work requirements of lower-limb musculature and whole-body metabolic energy requirements across a wide variety of human hopping conditions, helping to guide biomechanical models of energy expenditure.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81742046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-16DOI: 10.1101/2023.01.16.524323
Emmet M. Power, Dharshini Ganeshan, Karl J. Iremonger
Corticotropin-releasing hormone (CRH) neurons are the primary neural population controlling the hypothalamic–pituitary–adrenal (HPA) axis and the secretion of adrenal stress hormones. Previous work has demonstrated that stress hormone secretion can be regulated by circulating levels of estradiol. However, the effect of estradiol on CRH neuron excitability is less clear. Here we show that chronic estradiol replacement following ovariectomy increases two types of potassium channel currents in CRH neurons; fast inactivating voltage-gated A-type K+ channel (IA) currents and non-inactivating M-type K+ currents (IM). Despite the increase in K+ currents following estradiol replacement, there was no overall change in CRH neuron spiking excitability assessed with either frequency-current curves or current ramps. Together, these data reveal a complex picture whereby ovariectomy and estradiol replacement differentially modulate distinct aspects of CRH neuron and HPA axis function. Summary statement Chronic estradiol replacement in ovariectomised mice influences voltage-gated potassium channel function.
{"title":"Estradiol regulates voltage-gated potassium currents in corticotropin-releasing hormone neurons","authors":"Emmet M. Power, Dharshini Ganeshan, Karl J. Iremonger","doi":"10.1101/2023.01.16.524323","DOIUrl":"https://doi.org/10.1101/2023.01.16.524323","url":null,"abstract":"Corticotropin-releasing hormone (CRH) neurons are the primary neural population controlling the hypothalamic–pituitary–adrenal (HPA) axis and the secretion of adrenal stress hormones. Previous work has demonstrated that stress hormone secretion can be regulated by circulating levels of estradiol. However, the effect of estradiol on CRH neuron excitability is less clear. Here we show that chronic estradiol replacement following ovariectomy increases two types of potassium channel currents in CRH neurons; fast inactivating voltage-gated A-type K+ channel (IA) currents and non-inactivating M-type K+ currents (IM). Despite the increase in K+ currents following estradiol replacement, there was no overall change in CRH neuron spiking excitability assessed with either frequency-current curves or current ramps. Together, these data reveal a complex picture whereby ovariectomy and estradiol replacement differentially modulate distinct aspects of CRH neuron and HPA axis function. Summary statement Chronic estradiol replacement in ovariectomised mice influences voltage-gated potassium channel function.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89010313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-12DOI: 10.1101/2022.12.09.519768
J. Troscianko
Spectroradiometery is a vital tool in a wide range of biological, physical, astronomical and medical fields, yet its cost and accessibility are frequent barriers to use. Research into the effects of artificial light at night (ALAN) further compounds these difficulties with requirements for sensitivity to extremely low light levels across the ultraviolet to human-visible spectrum. Here I present a open-source spectroradiometry (OSpRad) system that meets the design challenges of typical ALAN research. The system utilises an affordable miniature spectrometer chip: the Hamamatsu C12880MA, and combines it with an automated shutter and cosine-corrector, microprocessor controller, and graphical user interface “app” that can be used with smartphones or desktop computers. The system is designed to be user-friendly, adaptable, and suitable for automation/data-logging. All code and 3D printed parts are made available open-source. I constructed 5 units and tested their linearity, spectral sensitivity, cosine-corrector performance, and low-light performance. There were modest unit-specific differences in spectral sensitivity, implying calibration is required for maximal accuracy. However, depending on the application, it may be acceptable to use a default calibration template together with careful experimental design considerations to mitigate unit-specific differences. All other performance characteristics were highly consistent. The OSpRad system was able to measure spectral irradiance down to around 0.005 lx, and spectral radiance down to 0.001 cd.m-2, meaning it would be able to measure night-time lighting under the vast majority of real-world conditions. The OSpRad system’s low cost and high sensitivity make it well suited to a range of spectrometry tasks in general, and ALAN research in particular. The project is hosted on GitHub here: https://github.com/troscianko/OSpRad
{"title":"OSpRad: an open-source, low-cost, high-sensitivity spectroradiometer","authors":"J. Troscianko","doi":"10.1101/2022.12.09.519768","DOIUrl":"https://doi.org/10.1101/2022.12.09.519768","url":null,"abstract":"Spectroradiometery is a vital tool in a wide range of biological, physical, astronomical and medical fields, yet its cost and accessibility are frequent barriers to use. Research into the effects of artificial light at night (ALAN) further compounds these difficulties with requirements for sensitivity to extremely low light levels across the ultraviolet to human-visible spectrum. Here I present a open-source spectroradiometry (OSpRad) system that meets the design challenges of typical ALAN research. The system utilises an affordable miniature spectrometer chip: the Hamamatsu C12880MA, and combines it with an automated shutter and cosine-corrector, microprocessor controller, and graphical user interface “app” that can be used with smartphones or desktop computers. The system is designed to be user-friendly, adaptable, and suitable for automation/data-logging. All code and 3D printed parts are made available open-source. I constructed 5 units and tested their linearity, spectral sensitivity, cosine-corrector performance, and low-light performance. There were modest unit-specific differences in spectral sensitivity, implying calibration is required for maximal accuracy. However, depending on the application, it may be acceptable to use a default calibration template together with careful experimental design considerations to mitigate unit-specific differences. All other performance characteristics were highly consistent. The OSpRad system was able to measure spectral irradiance down to around 0.005 lx, and spectral radiance down to 0.001 cd.m-2, meaning it would be able to measure night-time lighting under the vast majority of real-world conditions. The OSpRad system’s low cost and high sensitivity make it well suited to a range of spectrometry tasks in general, and ALAN research in particular. The project is hosted on GitHub here: https://github.com/troscianko/OSpRad","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90556043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-09DOI: 10.1101/2022.07.27.501787
Malin Thyselius, Yuri Ogawa, Richard Leibbrandt, T. Wardill, P. Gonzalez-Bellido, Karin Nordström
The ability to visualize small moving objects is vital for the survival of many animals, as these could represent predators or prey. For example, predatory insects, including dragonflies, robber flies and killer flies, perform elegant, high-speed pursuits of both biological and artificial targets. Many non-predatory insects, including male hoverflies and blowflies, also pursue targets during territorial or courtship interactions. To date, most hoverfly pursuits were studied outdoors. To investigate naturalistic hoverfly (Eristalis tenax) pursuits under more controlled settings, we constructed an indoor arena that was large enough to encourage naturalistic behavior. We presented artificial beads of different sizes, moving at different speeds, and filmed pursuits with two cameras, allowing subsequent 3D reconstruction of the hoverfly and bead position as a function of time. We show that male E. tenax hoverflies are unlikely to use strict heuristic rules based on angular size or speed to determine when to start pursuit, at least in our indoor setting. We found that hoverflies pursued faster beads when the trajectory involved flying downwards towards the bead. Furthermore, we show that target pursuit behavior can be broken down into two stages. In the first stage the hoverfly attempts to rapidly decreases the distance to the target by intercepting it at high speed. During the second stage the hoverfly’s forward speed is correlated with the speed of the bead, so that the hoverfly remains close, but without catching it. This may be similar to dragonfly shadowing behavior, previously coined ‘motion camouflage’.
{"title":"Hoverfly (Eristalis tenax) pursuit of artificial targets","authors":"Malin Thyselius, Yuri Ogawa, Richard Leibbrandt, T. Wardill, P. Gonzalez-Bellido, Karin Nordström","doi":"10.1101/2022.07.27.501787","DOIUrl":"https://doi.org/10.1101/2022.07.27.501787","url":null,"abstract":"The ability to visualize small moving objects is vital for the survival of many animals, as these could represent predators or prey. For example, predatory insects, including dragonflies, robber flies and killer flies, perform elegant, high-speed pursuits of both biological and artificial targets. Many non-predatory insects, including male hoverflies and blowflies, also pursue targets during territorial or courtship interactions. To date, most hoverfly pursuits were studied outdoors. To investigate naturalistic hoverfly (Eristalis tenax) pursuits under more controlled settings, we constructed an indoor arena that was large enough to encourage naturalistic behavior. We presented artificial beads of different sizes, moving at different speeds, and filmed pursuits with two cameras, allowing subsequent 3D reconstruction of the hoverfly and bead position as a function of time. We show that male E. tenax hoverflies are unlikely to use strict heuristic rules based on angular size or speed to determine when to start pursuit, at least in our indoor setting. We found that hoverflies pursued faster beads when the trajectory involved flying downwards towards the bead. Furthermore, we show that target pursuit behavior can be broken down into two stages. In the first stage the hoverfly attempts to rapidly decreases the distance to the target by intercepting it at high speed. During the second stage the hoverfly’s forward speed is correlated with the speed of the bead, so that the hoverfly remains close, but without catching it. This may be similar to dragonfly shadowing behavior, previously coined ‘motion camouflage’.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90251591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-04DOI: 10.1101/2022.11.04.515210
T. Collett, T. Robert, E. Frasnelli, A. Philippides, N. Hempel de Ibarra
The start of a bumblebee’s first learning flight from its nest provides an opportunity to examine the bee’s learning behaviour on its initial view of the nest’s unfamiliar surroundings. Bumblebees like many other ants, bees and wasps learn views of their nest surroundings while facing their nest. A bumblebee’s first fixation of the nest is a coordinated manoeuvre in which the insect faces the nest with its body oriented towards a particular visual feature within its surroundings. The manoeuvre’s utility is that during return flights after foraging bees, when close to the nest, adopt the same preferred body-orientation (Hempel de Ibarra et al., 2009; Robert et al., 2018). A translational scan oriented orthogonally to the bee’s body-orientation helps the bee reach the preferred conjunction of nest-fixation and body-orientation. How does a bee, unacquainted with its surroundings, know when it is facing its nest? The details of nest-fixation argue that, like desert ants (Fleischmann et al., 2018), the bee relies on path integration. Path integration gives bees continuously updated information about the current direction of their nest and enables them to fixate the nest when the body points in the appropriate direction. We relate the three components of the coordinated manoeuvre to events in the central complex, noting that nest fixation is in egocentric coordinates, whereas body orientation and flight direction within the visual surroundings of the nest are in geocentric coordinates.
大黄蜂第一次从巢中学习飞行的开始，提供了一个机会来检查蜜蜂在蜂巢不熟悉环境的初始视图中的学习行为。像许多其他蚂蚁、蜜蜂和黄蜂一样，大黄蜂在面对它们的巢穴时，可以看到周围的环境。大黄蜂对巢的第一次固定是一种协调的动作，在这种动作中，昆虫面对巢，身体朝向周围环境中特定的视觉特征。这种机动的效用在于，当蜜蜂觅食后返回飞行时，当靠近巢穴时，会采用相同的首选身体方向(Hempel de Ibarra et al.， 2009;Robert et al.， 2018)。垂直于蜜蜂身体取向的平移扫描有助于蜜蜂达到固定巢和身体取向的首选结合。一只不熟悉周围环境的蜜蜂怎么知道它什么时候面对着它的巢呢?固巢的细节表明，像沙漠蚂蚁一样(Fleischmann et al.， 2018)，蜜蜂依赖于路径整合。路径整合为蜜蜂提供了关于蜂巢当前方向的持续更新信息，并使它们能够在身体指向适当方向时固定蜂巢。我们将协调机动的三个组成部分与中心复合体中的事件联系起来，注意到巢固定是在自我中心坐标中，而巢的视觉环境中的身体方向和飞行方向是在地心坐标中。
{"title":"How bumblebees coordinate path integration and body orientation at the start of their first learning flight","authors":"T. Collett, T. Robert, E. Frasnelli, A. Philippides, N. Hempel de Ibarra","doi":"10.1101/2022.11.04.515210","DOIUrl":"https://doi.org/10.1101/2022.11.04.515210","url":null,"abstract":"The start of a bumblebee’s first learning flight from its nest provides an opportunity to examine the bee’s learning behaviour on its initial view of the nest’s unfamiliar surroundings. Bumblebees like many other ants, bees and wasps learn views of their nest surroundings while facing their nest. A bumblebee’s first fixation of the nest is a coordinated manoeuvre in which the insect faces the nest with its body oriented towards a particular visual feature within its surroundings. The manoeuvre’s utility is that during return flights after foraging bees, when close to the nest, adopt the same preferred body-orientation (Hempel de Ibarra et al., 2009; Robert et al., 2018). A translational scan oriented orthogonally to the bee’s body-orientation helps the bee reach the preferred conjunction of nest-fixation and body-orientation. How does a bee, unacquainted with its surroundings, know when it is facing its nest? The details of nest-fixation argue that, like desert ants (Fleischmann et al., 2018), the bee relies on path integration. Path integration gives bees continuously updated information about the current direction of their nest and enables them to fixate the nest when the body points in the appropriate direction. We relate the three components of the coordinated manoeuvre to events in the central complex, noting that nest fixation is in egocentric coordinates, whereas body orientation and flight direction within the visual surroundings of the nest are in geocentric coordinates.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85767820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-24DOI: 10.1101/2022.10.21.513269
Nicholas P. Burnett, S. Combes
Flying insects often forage among cluttered vegetation that forms a series of obstacles in their flight path. Recent studies have focused on behaviors needed to navigate clutter while avoiding all physical contact, and as a result, we know little about flight behaviors that do involve encounters with obstacles. Here, we challenged carpenter bees (Xylocopa varipuncta) to fly through narrow gaps in an obstacle course to determine the kinds of obstacle encounters they experience, as well as the consequences for flight performance. We observed three kinds of encounters: leg, body, and wing collisions. Wing collisions occurred most frequently (in about 40% of flights, up to 25 times per flight) but these had little effect on flight speed or body orientation. In contrast, body and leg collisions, which each occurred in about 20% of flights (1-2 times per flight), resulted in decreased flight speeds and increased rates of body rotation (yaw). Wing and body collisions, but not leg collisions, were more likely to occur in wind versus still air. Thus, physical encounters with obstacles may be a frequent occurrence for insects flying in some environments, and the immediate effects of these encounters on flight performance depends on the body part involved.
{"title":"Close encounters of three kinds: impacts of leg, wing and body collisions on flight performance in carpenter bees","authors":"Nicholas P. Burnett, S. Combes","doi":"10.1101/2022.10.21.513269","DOIUrl":"https://doi.org/10.1101/2022.10.21.513269","url":null,"abstract":"Flying insects often forage among cluttered vegetation that forms a series of obstacles in their flight path. Recent studies have focused on behaviors needed to navigate clutter while avoiding all physical contact, and as a result, we know little about flight behaviors that do involve encounters with obstacles. Here, we challenged carpenter bees (Xylocopa varipuncta) to fly through narrow gaps in an obstacle course to determine the kinds of obstacle encounters they experience, as well as the consequences for flight performance. We observed three kinds of encounters: leg, body, and wing collisions. Wing collisions occurred most frequently (in about 40% of flights, up to 25 times per flight) but these had little effect on flight speed or body orientation. In contrast, body and leg collisions, which each occurred in about 20% of flights (1-2 times per flight), resulted in decreased flight speeds and increased rates of body rotation (yaw). Wing and body collisions, but not leg collisions, were more likely to occur in wind versus still air. Thus, physical encounters with obstacles may be a frequent occurrence for insects flying in some environments, and the immediate effects of these encounters on flight performance depends on the body part involved.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87342960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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