Wing Beat Research Articles

GPS tracking insight into kittiwake muscle structure

‘Use it or lose it’, is the personal trainer's mantra. People and captive animals that exercise tend to have better developed muscles than those that prefer a more sedentary lifestyle. However, Kristen Lalla from McGill University, Canada, explains that the link was less clear for creatures in the wild. Although it would make sense that the most active animals would have the strongest muscles, few studies had put the theory to the test by directly comparing muscle fibre build with animal activity. Kittiwakes that nest in dense colonies on cliffs embark on foraging trips out at sea to feed their young. Given the birds’ epic exertions, Lalla, Kyle Elliott (also from McGill University), Scott Hatch (Institute for Seabird Research and Conservation, Anchorage, USA) and Ana Jimenez (Colgate University, USA) realised that a colony of the birds on Middleton Island, in the Gulf of Alaska, USA, were the ideal animals to investigate the link between muscle structure and an active lifestyle.‘Middleton Island has a field research station where kittiwakes breed on an abandoned radar tower’, says Lalla, explaining that Hatch has studied the birds for more than 30 years. ‘The tower has been modified with nesting platforms with one-way glass, so we can walk up into the tower and see hundreds of breeding kittiwakes up close’, she adds. But facilities at the site are also limited, with researchers having to bring everything they need, including equipment and food for several weeks, on the chartered flight from Anchorage. ‘If you forget a critical piece of equipment, there is no easy way to get a replacement’, says Lalla.Deploying GPS trackers with accelerometers – to capture the fine detail of the birds’ movements – on 37 of the tower's residents, Lalla and Shannon Whelan, also from McGill University, allowed the kittiwakes to come and go as they pleased before retrieving the data loggers 4 days later. ‘We spent many hours waiting for our study birds to come to their nests so that we could try to recapture them’, recalls Lalla, adding how they also collected a minute muscle sample from the pectoral muscle of 24 of the birds. ‘The options for storing samples, like muscle biopsies, are quite limited’, she explains, describing how they had no choice but to preserve the samples in formaldehyde prior to shipping them to Jimenez for analysis.Analysing the flight paths recorded on the GPS tracker, Lalla, Whelan and Allison Patterson (McGill University) were astonished to see how far some of the birds voyaged, with several round trips exceeding 250 km. And when Karl Brown (Colgate University) and Jimenez analysed the muscle samples, the team realised that the birds with the fastest wing beats had the thinnest muscle fibres, while the birds with the thickest muscle fibres beat their wings more slowly. ‘Kittiwakes with lower wing beat frequency are presumably not working as hard to maintain flight because thicker fibres are energetically cheaper to maintain than thinner fibres’, says Lalla. Finally, the team correlated the number of nuclei – which produce proteins to power flight – in the muscle cells with the birds’ flight speeds, discovering that the birds with the most nuclei tended to fly the fastest.‘Muscle fibre structure does affect movement in a wild bird, impacting their wing beat frequency and ability to sustain higher air speeds’, says Lalla, adding that it might be possible to predict muscle structure by tracking bird behaviour. The team is also keen to study the effects of warm and chilly climates on the birds’ muscles, to find out whether they are able to adapt their muscle to adjust to climate change.

Heinz Isler’s twin shell roof in Deitingen – preservation of a ‘timeless wing beat’

The Swiss shell pioneer Heinz Isler (1926–2009) fundamentally challenged established shell design methods by introducing original methods of form finding based on gravity. He realised elegant and pure shell forms in reinforced concrete, incarnating the perfect match of structural efficiency and form. With his shells, he gained acclamation of structural engineers and architects, and of the public. Heinz Isler’s more than 1400 built concrete shells are mostly located in Switzerland. The twin shell roof for the motorway rest area in Deitingen, Switzerland, and recent maintenance works to preserve this monument of structural art are described. After more than 50 years of use, the good condition and unaltered technical performance of the shells speak for Isler's excellent engineering work. The principle that well-designed structures are more durable is confirmed once again. Due to the non-invasive maintenance works carried out in 2016, the substance and aesthetics of the shells, which are one of the most successful and boldest engineering designs by Heinz Isler, are preserved for the shells to serve as a landmark on the motorway for decades.

Assessing the acoustic behaviour of Anopheles gambiae (s.l.) dsxF mutants: implications for vector control

BackgroundRelease of gene-drive mutants to suppress Anopheles mosquito reproduction is a promising method of malaria control. However, many scientific, regulatory and ethical questions remain before transgenic mosquitoes can be utilised in the field. At a behavioural level, gene-drive carrying mutants should be at least as sexually attractive as the wildtype populations they compete against, with a key element of Anopheles copulation being acoustic courtship. We analysed sound emissions and acoustic preference in a doublesex mutant previously used to collapse Anopheles gambiae (s.l.) cages.MethodsAnopheles rely on flight tones produced by the beating of their wings for acoustic mating communication. We assessed the impact of disrupting a female-specific isoform of the doublesex gene (dsxF) on the wing beat frequency (WBF; measured as flight tone) of males (XY) and females (XX) in homozygous dsxF− mutants (dsxF−/−), heterozygous dsxF− carriers (dsxF+/−) and G3 dsxF+ controls (dsxF+/+). To exclude non-genetic influences, we controlled for temperature and wing length. We used a phonotaxis assay to test the acoustic preferences of mutant and control mosquitoes.ResultsA previous study showed an altered phenotype only for dsxF−/− females, who appear intersex, suggesting that the female-specific dsxF allele is haplosufficient. We identified significant, dose-dependent increases in the WBF of both dsxF−/− and dsxF+/− females compared to dsxF+/+ females. All female WBFs remained significantly lower than male equivalents, though. Males showed stronger phonotactic responses to the WBFs of control dsxF+/+ females than to those of dsxF+/− and dsxF−/− females. We found no evidence of phonotaxis in any female genotype. No male genotypes displayed any deviations from controls.ConclusionsA prerequisite for anopheline copulation is the phonotactic attraction of males towards female flight tones within mating swarms. Reductions in mutant acoustic attractiveness diminish their mating efficiency and thus the efficacy of population control efforts. Caged population assessments may not successfully reproduce natural mating scenarios. We propose to amend existing testing protocols to better reflect competition between mutants and target populations. Our findings confirm that dsxF disruption has no effect on males; for some phenotypic traits, such as female WBFs, the effects of dsxF appear dose-dependent rather than haplosufficient.

<p class="ZootaxaTitle"><strong>New techniques for improving resolution and visual information on flight activity in Trichoptera</strong></p>

Earlier design and use of photographic rigs for recording insects in free flight, and the applications and shortcomings of those efforts are reviewed. Improvements included the following: Replacement of laser beams with infrared (IR) LED beam-emitters and IR phototransistor detectors; an array of nine intersection points to increase the possibility of capturing images; improved electronic circuitry to avoid multiple image capture; more energy-efficient and smaller UV light sources to attract insects; a more rigid aluminium frame to support the UV and IR LED transmitters and detectors; development of an ultra-high-speed flash system 5 μs, or faster, to produce even sharper images than those produced by the 25 μs standard speedlight flash units set at 1/128th power; and a transportable wooden box to house all the electronic components and mounts for cameras and speedlights. This paper describes the design features of the rig and its use in the field and illustrates and compares photographic results obtained using a variety of photographic techniques aimed at providing high quality, sharp, images of insects in free flight, continuous traces of the flight pattern of insects, strobe images, and combinations of these techniques. From these images reasonably accurate estimates of insect size, wing beat frequency, flight speed, and information on mechanics of flight can be obtained.

A comparison of supervised machine learning algorithms for mosquito identification from backscattered optical signals

The surveillance of mosquito populations is paramount in the fight against mosquito-borne diseases that affect millions of people every year. Evaluating the efficiency of mitigation methods requires extensive and long-term surveys which can be costly and time consuming. The recent development of optical sensors give access to alternative methods for entomological monitoring but require efficient classification algorithms to be successful. In this contribution, supervised machine learning algorithms such as Linear Discriminant Analysis, Decision Trees, Support Vector Machine, K-Nearest Neighbors and Naïve Bayes are compared for the identification of mosquitoes through optical signals. Based on predictor variables derived from the wing beat frequency and optical cross section of mosquitoes, these algorithms were trained to perform different classification tasks: the identification of species, sex and/or gravidity of mosquitoes present in New Jersey, USA. Results shows that the most polyvalent machine learning algorithm for mosquito identification is Support Vector Machine that performs on average over all tasks between 0.65 and 7.3% better than other algorithms. Moreover, Support Vector Machine is the algorithm that best performed for the most complex tasks, more than 2% above the second best, it is therefore the most suited for real-world study where several species of mosquito can be expected at a single location. A close second is Linear Discriminant Analysis that is only outperformed by Support Vector Machine by 0.65% over all tasks and is the most performant when studying mosquito gravidity. Finally, Decision Trees algorithm has reached almost perfection in identifying the sex of a single mosquito species with 99.9% accuracy which is 1.3% more than the second best performing algorithm on this task. These results demonstrate that optical sensors, coupled with machine learning, can be a viable alternative or complementary methodology for the monitoring of mosquito populations. Furthermore, this methodology can perform non-intrusive, automatic, time-resolved measurements of insect population dynamics over extended periods of time without the need for laboratory analysis of captured specimens as in most traditional survey methods.

Coping with the commute: behavioural responses to wind conditions in a foraging seabird

Movement is a necessary yet energetically expensive process for motile animals. Yet how individuals modify their behaviour to take advantage of environmental conditions and hence optimise energetic costs during movement remains poorly understood. This is especially true for animals that move through environments where they cannot easily be observed. We examined the behaviour during commuting flights of black‐legged kittiwakes Rissa tridactyla breeding on Middleton Island, Alaska in relation to wind conditions they face. By simultaneously deploying GPS and accelerometer devices on incubating birds we were able to quantify the timing, destination, course and speed of flights during commutes to foraging patches, as well as how wing beat frequency and strength relate to flight speeds. We found that kittiwakes did not preferentially fly in certain wind conditions. However, once in the air they exhibited plasticity through modulation of effort by increasing air speed (the speed at which they fly relative to the wind) when travelling into headwinds and decreasing their air speed when flying with tailwinds. Moreover, we identified a biomechanical link behind this behaviour: that to achieve these changes in flight speeds, kittiwakes altered their wing beat strength, but not wing beat frequency. Using this information, we demonstrate that the cost of flying into a headwind outweighs the energy saving benefit of flying with a tailwind of equivalent speed; therefore, exploiting a tailwind when commuting to a foraging patch would not be beneficial if having to return in the same direction with the same conditions. Our findings suggest that extrinsic factors, such as prey availability, have a more influential role in determining when and where kittiwakes fly during foraging trips than do wind conditions. However, once flying, kittiwakes exhibit behavioural plasticity to minimise transport costs.

Impact of the quality of food sources on the wing beating of honey bee dancers

The waggle dances of honey bees provide information about the location of food sources and their quality. This study aimed to investigate how the quality of food sources affects different components of the dance. For the first time, we analysed in detail both the waggle phase and the return phase of the dance using a high-speed camera. The frequency of wing beats in the waggle phase and the frequency of wing-beating pulses in the return phase were significantly higher in foragers collecting more concentrated honey compared with foragers collecting less-concentrated honey, whereas the duration of the return phase was significantly shorter. Discriminant function analysis allowed correct classification of 88.1% of dances as referring to 60 or 40% honey concentration. In conclusion, information about the quality of food sources can be contained both in the waggle phase and in the return phase; however, the return phase appears to transfer more information about the quality of food sources.

Dual functions of insect wings in an odor-guided aeronautic navigation.

Insects can detect and locate distant odor sources (food, mate, etc.) by tracking odor plumes, which is key to their survival. During an odor-guided navigation, flapping wings have been speculated to actively draw odorants to the antennae and enhance olfactory sensitivity. Utilizing an in-house computational fluid dynamics solver, we have quantified the odor plume structures of a fruit fly in a forward flight motion and have confirmed that the flapping wings induce a strong vortex flow over the insect's head, thereby enhancing the odor mass flux around the antennae (by ~1.8 times). To further understand the function of different wing area in terms of aerodynamics and olfaction, we designed an altered fruit fly wing by removing its trailing-edge portion; subsequent simulations showed that this altered wing has an improved lift production but with significantly reduction of the induced odor mass flux. Contrary to the common belief that the wing shapes of an insect are optimized only for aerodynamic performance, our results suggest that, because both aerodynamic and olfactory functions are indispensable during the odor-guided navigation, insects may sacrifice some aerodynamic potential to enhance olfactory detection; and the shape and size of the wing may be a balance between the two functions. Furthermore, we found that higher wing beat frequency and wing reversal phase induce higher odor mass flux, while lower beat frequency and downstroke phase produce better lift coefficient, which indicates another balance between the two functions.

Rapid acceleration in Odonata flight: highly inclined and in-phase wing beating

Acceleration manoeuvres in free flight in nature of five damselfly (Zygoptera) and four dragonfly (Anisoptera) species were analysed by means of slow motion filming. Changes in stroke frequencies, ...

Measuring the effect of wing tears on flight in common pipistrelle bats (Pipistrellus pipistrellus)

Bat wings are susceptible to tearing. Many bats are admitted to care with wing tears and their flight is subjectively measured prior to release. This study presents a new method to objectively measure the effect of bat wing tears on the flight of common pipistrelle bats, Pipistrellus pipistrellus. Bats were filmed and their wing movements and body positions tracked using freely available software. Results found that bats with bilateral tears moved their wings with smaller movements, and with more wing beats per second. Bats with wing tears tended to tilt their whole body towards the healthier wing – which is the wing with no or smaller wing tears. Differences in wing movements and body positioning suggest that flight might be affected in bats with wing tears, and future work should assess whether foraging and survival are also affected in these animals.

Echolocation and foraging ecology of the bristle-faced free-tailed bat, Setirostris eleryi, in central Australia

We document the spectral characteristics of echolocation sequences of Setirostris eleryi recorded from riparian zones in the Central Ranges in Western Australia, near Warakurna. These are the first records of this species in Western Australia. The sequences are comparable to reference S. eleryi sequences from near Alice Springs, as well as to sequences from a nearby vouchered specimen locality (Hull River in the Northern Territory), yet distinct from Scotorepens greyii sequences from Western Australia, including locations in the Central Ranges. The central Australian S. eleryi sequences average 3kHz higher in frequency than reference S. eleryi recordings from eastern Australia. We deduce the species’ foraging strategy, microhabitat, wing beat frequency and flight speed from the echolocation sequences, then show that these deductions are consistent with calculations based on an airframe analysis of museum specimens, and with available field observations. The echolocation recordings provided a quick, passive, cost-effective characterisation of foraging niche, useful for conservation planning.

Accelerometry predicts muscle ultrastructure and flight capabilities in a wild bird.

Muscle ultrastructure is closely linked with athletic performance in humans and lab animals, and presumably plays an important role in the movement ecology of wild animals. Movement is critical for wild animals to forage, escape predators and reproduce. However, little evidence directly links muscle condition to locomotion in the wild. We used GPS-accelerometers to examine flight behaviour and muscle biopsies to assess muscle ultrastructure in breeding black-legged kittiwakes (Rissa tridactyla). Biopsied kittiwakes showed similar reproductive success and subsequent over-winter survival to non-biopsied kittiwakes, suggesting that our study method did not greatly impact foraging ability. Muscle fibre diameter was negatively associated with wing beat frequency, likely because larger muscle fibres facilitate powered flight. The number of nuclei per fibre was positively associated with average air speed, likely because higher power output needed by faster-flying birds required plasticity for muscle fibre recruitment. These results suggest the potential for flight behaviour to predict muscle ultrastructure.

Mechanism and scaling of wing tone generation in mosquitoes

The generation of sound from flapping (i.e. wing tones) of mosquito (Culex) wings is investigated using computational modeling. The flow field around the wing is simulated by solving the incompressible Navier–Stokes equations using a sharp-interface immersed boundary method, and the aeroacoustic sound is predicted by the Ffowcs Williams and Hawkings equation using data from the aerodynamic simulations. In addition to the aerodynamics, the characteristics of mosquito’s wing tone, spectral directivity patterns, and generation mechanisms are investigated. The effects of wing-beat frequency and stroke amplitude are also studied, and scaling analysis for the mean lift, mechanical power, and overall wing tone sound power are performed to understand the effects of the wing shape and kinematics parameters. The analysis shows that the high wing aspect-ratio, high wing beat frequency, and small stroke amplitude adopted by mosquitoes enable efficient generation of high-intensity wing-tones for acoustic communications. The present findings may also apply to the optimized noise control in the flapping-wing micro air vehicles (FWMAV).

Recovering from a tumble and roosting bat style

Evolution has had some fun with the limbs that we call arms. From weight-bearing forelimbs, to fins and flippers, the same skeletal structures keep turning up; albeit somewhat modified. When David Boerma from Brown University, USA, gazes at the wings of a bat, he says that he literally sees himself; ‘from an anatomical perspective their wings aren't very different from my own arms and hands’, he smiles. Having traded in their manual dexterity, bats mastered an airborne lifestyle, but Boerma wondered how the mammal's elegantly elongated limbs might contribute as they navigate natural gusts and squalls. Knowing that bat wings are relatively heavy, Boerma wondered whether the mammals could capitalize on the limbs’ apparent weighty inertia to stabilise their manoeuvres when knocked off course by a gust of wind.Working with Tim Treskatis, an intern from Westphalian University of Applied Sciences, Germany, to build a laser-triggered blast of air that would unbalance Seba's short-tailed bats (Carollia perspicillata) as they flew along a narrow corridor in the lab, Boerma filmed the bats’ recoveries in 3D to reconstruct their manoeuvres. Remarkably, when Boerma, Treskatis, Kenneth Breuer and Sharon Swartz analysed the bats’ movements they were amazed that the animals were able to recover from being thrust off course within a single wing beat.Focusing on the bats that had been pitched upward when the 2.5× bodyweight puff of air hit their back end, the bats flung their wings wide at a point in the wing beat when they would normally pull them in; with the result that their wings were thrust forward, to counteract the jet of air and tip the body back down. However, when the jet glanced off one of the bats’ wings – forcing it down and sending the animal into a spin – the bats swiftly extended the unperturbed wing as it rolled upward in a bid to counteract the rotation. Then they swept the perturbed wing all the way under the body as the bat righted itself ready to resume normal wing beats. ‘By just shifting the weight of their wings around, bats can generate forces that rapidly reorient their bodies when recovering from aerial stumbles, similar to the way a gymnast or diver moves their arms and legs to spin in mid-air’, says Boerma.By this point, Boerma's appetite for research had been whetted; ‘the experience left me yearning to work with bats in the field, where I might see first-hand the kinds of environmental challenges they face and learn how they respond’, he recalls. Explaining that Spix's disk-winged bats (Thyroptera tricolor), which roost head-up inside furled Heliconia leaves in the rainforest, have evolved unconventional suction cups at the base of the thumb and at the ankle for attachment to smooth leaves, Boerma was curious how the minute mammals manage their inbound trajectory when coming in to land.Travelling to the Hacienda Baru Biological Research Station, Costa Rica, and teaming up with José Pablo Barrantes from the Universidad de Costa Rica, the duo spent two weeks tracking down the tiny mammals in their rainforest home. Returning with them briefly to the research station, the pair quickly trained the bats to land on a force plate disguised as a leaf while filming the manoeuvre. And Boerma recalls how the bats were equally happy to land on the researchers as they were on the force plate: ‘At one point José Pablo left the enclosure and I kept training the bat on my own. It flew around and then landed on my back where I couldn't reach it’, he laughs. Analysing movies of the bats landing on the force plate and within furled leaves, with the help of high-school student Charles Chung, Boerma realised that the bats fine-tune their approach by subtly adjusting their wing beats until just above the landing site. Then they pull in their wings, going into freefall as they reach forward with their thumb suction pads to latch onto the surface. Evaluating the force exerted on the force plate as the bat made contact, the duo also realised that the suction pad snaps into place as soon as it contacts the leaf.‘These kinds of studies help us to begin to apply what we learn about bat flight in the lab to understand the more complex flight they perform in their natural habitats’, says Boerma. He is now eager to understand how reeling bats coordinate their deft manoeuvres; in addition to looking for connections between the landing styles of other species to learn how the mammals have adapted to roost sites ranging from tightly furled leaves to caves and trees.

Vibrational behavior of psyllids (Hemiptera: Psylloidea): Functional morphology and mechanisms.

Vibrational behavior of psyllids was first documented more than six decades ago. Over the years, workers have postulated as to what the exact signal producing mechanisms of psyllids might be but the exact mechanism has remained elusive. The aim of this study is to determine the specific signal producing structures and mechanisms of the psyllids. Here we examine six hypotheses of signal producing mechanisms from both previous and current studies that include: wingbeat, wing-wing friction, wing-thorax friction, wing-leg friction, leg-abdomen friction, and axillary sclerite-thorax friction. Through selective removal of possible signal producing structures and measuring wing beat frequency with high speed videos, six hypotheses were tested. Extensive experiments were implemented on the species Macrohomotoma gladiata Kuwayama, while other species belonging to different families, i.e., Trioza sozanica (Boselli), Mesohomotoma camphorae Kuwayama, Cacopsylla oluanpiensis (Yang), and Cacopsylla tobirae (Miyatake) were also examined to determine the potential prevalence of each signal producing mechanism within the Psylloidea. Further, scanning electron microscope (SEM) was used to examine possible rubbing structures. The result of high speed video recordings showed that wingbeat frequency did not match the dominant frequency of vibrational signals, resulting in the rejection of wingbeat hypothesis. As for the selective removal experiments, the axillary sclerite-thorax friction hypothesis is accepted and wing-thorax friction hypothesis is supported partially, while others are rejected. The SEM showed that the secondary axillary sclerite of the forewing bears many protuberances that would be suitable for stridulation. In conclusion, the signal producing mechanism of psyllids may involve two sets of morphological structures. The first is stridulation between the axillary sclerite of the forewing and the mesothorax. The second is stridulation between the axillary cord and anal area of the forewing.

A Novel Methodology For Recording Wing Beat Frequencies of Untethered Male and Female Aedes aegypti.

Aedes aegypti is a vector of many significant arboviruses worldwide, including dengue, Zika, chikungunya, and yellow fever viruses. With vector control methodology pivoting toward rearing and releasing large numbers of insects for either population suppression or virus-blocking, economical remote (sentinel) surveillance methods for release tracking become increasingly necessary. Recent steps in this direction include advances in optical sensors that identify and classify insects based on their wing beat frequency (WBF). As these traps are being developed, there is a strong need to better understand the environmental and biological factors influencing mosquito WBFs. Here, we developed new untethered-subject methodology to detect changes in WBFs of male and female Ae. aegypti. This new methodology involves directing an ultrasonic transducer at a free-flying subject and measuring the Doppler shift of the reflected ultrasonic continuous wave signal. This system's utility was assessed by determining its ability to confirm previous reports on the effect of temperature, body size, and age on the WBFs generated from acoustic or optical-based experiments. The presented ultrasonic method successfully detected expected trends for each factor for both male and female Ae. aegypti without the need for subject manipulation and potential impediment of natural flight dynamics due to tethering. As a result, this ultrasonic methodology provides a new method for understanding the environmental and physiological determinants of male and female WBFs that can inform the design of remote mosquito surveillance systems.

Numerical Simulation of a Bat Wing at a Wing Beat

Numerical Simulation of a Bat Wing at a Wing Beat

Precopulatory acoustic interactions of the New World malaria vector Anopheles albimanus (Diptera: Culicidae)

BackgroundAnopheles albimanus is a malaria vector in Central America, northern South America and the Caribbean. Although a public health threat, An. albimanus precopulatory mating behaviors are unknown. Acoustics play important roles in mosquito communication, where flight tones allow males to detect and attract potential mates. The importance of sound in precopulatory interactions has been demonstrated in Toxorhynchites brevipalpis, Aedes aegypti, Culex quinquefasciatus and Anopheles gambiae; convergence in a shared harmonic of the wing beat frequency (WBF) during courtship is thought to increase the chance of copulation. To our knowledge, An. albimanus precopulatory acoustic behaviors have not been described to date. Here, we characterized An. albimanus (i) male and female flight tones; (ii) male–female precopulatory acoustic interactions under tethered and free flight conditions; and (iii) male-male acoustic interactions during free flight.ResultsWe found significant increases in the WBFs of both sexes in free flight compared to when tethered. We observed harmonic convergence between 79% of tethered couples. In free flight, we identified a female-specific behavior that predicts mate rejection during male mating attempts: females increase their WBFs significantly faster during mate rejection compared to a successful copulation. This behavior consistently occurred during mate rejection regardless of prior mating attempts (from the same or differing male). During group flight, males of An. albimanus displayed two distinct flying behaviors: random flight and a swarm-like, patterned flight, each associated with distinct acoustic characteristics. In the transition from random to patterned flight, males converged their WBFs and significantly decreased flight area, male-male proximity and the periodicity of their trajectories.ConclusionsWe show that tethering of An. albimanus results in major acoustic differences compared to free flight. We identify a female-specific behavior that predicts mate rejection during male mating attempts in this species and show that male groups in free flight display distinct flying patterns with unique audio and visual characteristics. This study shows that An. albimanus display acoustic features identified in other mosquito species, further suggesting that acoustic interactions provide worthwhile targets for mosquito intervention strategies. Our results provide compelling evidence for swarming in this species and suggests that acoustic signaling is important for this behavior.

Desenvolvimento neuropsicomotor de crianças com cardiopatias congênitas

INTRODUÇÃO: Especula-se que as cardiopatias congênitas (CC) podem afetar o desenvolvimento neuropsicomotor. No entanto, ainda se faz necessários estudos que visem avaliar esse desenvolvimento nas crianças com CC. OBJETIVO: Avaliar o desenvolvimento neuropsicomotor de crianças com cardiopatias congênitas. MÉTODOS: Estudo observacional de corte transversal, conduzido no Hospital do Coração de Alagoas (Maceió – AL, Brasil), no período de junho a outubro de 2016. Foram incluídas crianças internadas para a realização de cirurgias eletivas no referido hospital, com idade entre 1 e 72 meses, e excluídas aquelas que apresentassem algum sinal de desconforto (dispneia, taquicardia, cianose, batimento de asa de nariz e uso da musculatura acessória), baixa capacidade para responder aos comandos verbais e/ou doenças/síndromes associadas que levassem ao atraso no desenvolvimento neuropsicomotor. O desenvolvimento neuropsicomotor (DNPM) foi avaliado por meio do teste de triagem do desenvolvimento Denver II, aplicado no momento pré-cirúrgico. RESULTADOS: Foram avaliadas 20 crianças, com idade entre 1-72 meses, das quais 05 foram excluídas. As 15 restantes tiveram média de idade de 16,12 (±15,56) meses, 7 meninos (46,66%) e 8 meninas (53,33%). Oitenta por cento das crianças apresentaram atraso no DNPM, sendo o domínio motor fino-adaptativo o mais comprometido, no qual as crianças realizaram apenas 48% das tarefas propostas. A maioria das crianças com o atraso, apresentavam persistência do canal arterial (41,66%), seguida de comunicação interatrial-CIA (16,66) e coexistência de CIA e comunicação interventricular (16,66). CONCLUSÃO: Conclui-se que as crianças com CC apresentam o DNPM não compatível com a sua idade. Evidenciando a necessidade de diagnóstico e estimulação precoce das mesmas.

Identification of gravid mosquitoes from changes in spectral and polarimetric backscatter cross sections.

Improving the survey of mosquito populations is of the utmost importance to further enhance mitigation techniques that protect human populations from mosquito‐borne diseases. While mosquito populations are generally studied using physical traps, stand‐off optical sensors allow to study insect ecosystems with potentially better spatial and temporal resolution. This can be greatly beneficial to eco‐epidemiological models and various mosquito control programs. In this contribution, we demonstrate that the gravidity of female mosquitoes can be identified from changes in their spectral and polarimetric backscatter cross sections. Among other predictive variables, the wing beat frequency and the depolarization ratio of the mosquito body allows for the identification of gravid females with a precision and recall of 86% and 87%, respectively. Since female mosquitoes need a blood meal to become gravid, statistics on gravidity is of prime importance as only females that have been gravid might carry infectious diseases. In addition, it allows to detect possible breeding habitat, predict a potential increase in the mosquito population and provide a better overall understanding of the ecosystem dynamics. As a result, targeted and localized mitigation techniques can be used, reducing the cost and improving the efficiency of mosquito population control.