Diptera Research Articles

Machine Learning‐Based Wind Classification by Wing Deformation in Biomimetic Flapping Robots: Biomimetic Flexible Structures Improve Wind Sensing

Flying animals such as insects and birds have strain receptors on their wings. The functions and information processing capabilities of these strain receptors, however, are largely unknown. Herein, the potential ability of wing strain sensors to detect wind direction in flapping flight is experimentally explored. Seven strain gauges are attached to the biomimetic wing shafts of flexible wings. The wings flap through an electric mechanism emulating hovering flight in a wind tunnel with gentle wind, and a convolutional neural network model for wind direction classification is developed. The results show that with only one strain gauge, accurate wind classification is achieved using segmented data of ≈1 flapping cycle. Even with segmented data of only 0.2 flapping cycles, wind classification can be achieved with all seven strain gauges. Moreover, the use of wing shafts improves the classification accuracy, especially with shorter segmented data. Additional flapping phase information does not substantially improve classification performance. These results suggest that hovering animals determine the wind direction via strain sensing, which is useful for flight control. The implementation of wing strain sensors in flapping‐wing aerial robots may improve flight control ability.

Productive and morphological features of females and calves of domestic deer of the Evenk and Nenets breeds during the calving period

Purpose: to conduct a comparative description of the productive and morphological characteristics of domestic reindeer of the Nenets and Evenki breeds.Materials and methods. Study of the morphological, behavioral and reproductive characteristics of domestic reindeer of the Nenets and Evenki breeds, kept in various natural and climatic conditions of the tundra and northern taiga, during the calving and dairy periods. Experimental data were collected from clinically healthy animals. The research was carried out in accordance with the basic methods of zootechnical research (observation, examination). Their gender (visually) and age were determined (using ear tags and animal registration data, and, if necessary, based on the degree of tooth wear); An assessment of the exterior of the reindeer herd was carried out before the rut to select males and females for mating. Methods of visual assessment, linear measurements of animals, and field chronometry of calving were used.Results. The Evenki breed of deer is distinguished by its large size, height, high load-carrying capacity and endurance when transporting goods and people. It has been established that the dynamics of calving of domestic reindeer of the Evenki breed is identical to the dynamics of calving of Nenets reindeer, but there are some peculiarities. In the tundra zone, calving takes 3—5 days longer, and the initial phase begins (on average) 7-10 days earlier than in the taiga zone. The live weight of Evenki breed calves at birth is 0.8 kg higher than that of Nenets breed calves. The intensity of growth up to 3 months of age is higher in the early, mass and late periods of calving. It has been established that calves of the early calving period exceed in live weight at birth and its growth the calves of the mass period, and those, in turn, exceed the calves of the late calving period. This pattern can be traced up to 6 months of age. Calves of early and mass calving periods, having the potential for rapid growth, find themselves in more favorable nutritional conditions in the first months of life than late calves. This is expressed in the ability to receive green pasture food 15-25 days earlier and be stronger by the time the blood-sucking dipterous insects appear. Early calving Nenets calves are more active at night, since there is still a lot of snow in the tundra zone during this period and the temperature sometimes drops below 0ºC.

Gliding Performance of an Insect-Inspired Flapping-Wing Robot

Flying animals such as insects and birds use wing flapping for flight, occasionally pausing wing motion and transitioning into gliding to conserve energy for propulsion and achieve high flying efficiency. In this study, we have investigated the gliding performance of a gliding model based on a flapping-wing robot developed in a previous study, with the aim of developing a highly efficient flying robot that utilizes bio-inspired intermittent flight. Wind tunnel experiments with a gliding model have shown that the attitude of the wings has a strong influence on gliding performance and that a tail is effective in improving gliding performance. The results of this study provide important insights into the development of flying robots that can travel long distances with high efficiency.

How African Ungulates Respond to Tourist Vehicles in Kruger National Park

ABSTRACTManagers of protected areas need to balance how they use or preserve their resources, especially regarding ‘road ecology’. This study focuses on Kruger National Park's (KNP) common ungulates’ response to tourist vehicles. We answered the following questions for impala, zebra, giraffe, blue wildebeest, greater kudu and steenbok: What mediates animal flight and flight distance from a vehicle? How much of KNP is affected by roads? Are ungulates using or avoiding roads? We sampled 55.9% of KNP's tourist roads, where we approached animals and determined whether and how far they fled. We georeferenced sightings and estimated the amount of land area along KNP's tourist roads where animals would be expected to flee from vehicles. Of 517 animal sightings, Impala were sighted most (263) and steenbok least (32). Impala had the highest flight propensity (42.6%) and wildebeest lowest (13%). Steenbok were found closest to the road (22.13 m) and wildebeest furthest (77.6 m). Impala had the closest tolerance distance (16.63 m), with zebra furthest (44.74 m). Impala fled the least distance (9.93 m) and zebra fled furthest (24.52 m). Binary logistic regressions (BLRs) showed that all species fled more consistently when closer to the road. The amount of KNP affected by animal flight based on BLRs was largest for zebra (2.32% of the park) and smallest for kudu (0.84%). Impala used the first 10 m of the roadside more than expected and 10–20 m from the road less. KNP's ungulates are habituated to vehicles since flight propensity was low, distribution analysis showed no‐road avoidance, flight distance was short, and animals > 50 m from the road generally do not flee. Given the amount of KNP that is already affected by vehicle traffic, as tourism increases, the land solely devoted to wildlife will necessarily decrease. This study aims to provide information for the best management of roads and traffic in KNP.

Chromosome-scale genome of the polyphagous pest Anastrepha ludens (Diptera: Tephritidae) provides insights on sex chromosome evolution in Anastrepha.

The Mexican fruit fly, Anastrepha ludens, is a polyphagous true fruit fly (Diptera: Tephritidae) considered one of the most serious insect pests in Central and North America to various economically relevant fruits. Despite its agricultural relevance, a high-quality genome assembly has not been reported. Here, we described the generation of a chromosome-level genome for the A. ludens using a combination of PacBio high fidelity long-reads and chromatin conformation capture sequencing data. The final assembly consisted of 140 scaffolds (821 Mb, N50 = 131 Mb), containing 99.27% complete conserved orthologs (BUSCO) for Diptera. We identified the sex chromosomes using three strategies: 1) visual inspection of Hi-C contact map and coverage analysis using the HiFi reads, 2) synteny with Drosophila melanogaster, and 3) the difference in the average read depth of autosomal versus sex chromosomal scaffolds. The X chromosome was found in one major scaffold (100 Mb) and eight smaller contigs (1.8 Mb), and the Y chromosome was recovered in one large scaffold (6.1 Mb) and 35 smaller contigs (4.3 Mb). Sex chromosomes and autosomes showed considerable differences of transposable elements and gene content. Moreover, evolutionary rates of orthologs of A. ludens and Anastrepha obliqua revealed a faster evolution of X-linked, compared to autosome-linked, genes, consistent with the faster-X effect, leading us to new insights on the evolution of sex chromosomes in this diverse group of flies. This genome assembly provides a valuable resource for future evolutionary, genetic, and genomic translational research supporting the management of this important agricultural pest.

A DNA barcode reference library for the Tipulidae (Insecta, Diptera) of Germany.

Tipulidae, commonly known as true crane flies, represent one of the most species-rich dipteran families, boasting approximately 4,500 known species globally. Their larvae serve as vital decomposers across diverse ecosystems, prompting their frequent and close observation in biomonitoring programs. However, traditional morphological identification methods are laborious and time-consuming, underscoring the need for a comprehensive DNA barcode reference library to speed up species determination. In this study, we present the outcomes of the German Barcode of Life initiative focused on Tipulidae. Our DNA barcode library comprises 824 high-quality cytochrome c oxidase I (COI) barcodes encompassing 76 crane fly species, counting for ca. 54% of the German tipulid fauna. Our results significantly increased the number of European tipulid species available in the Barcode of Life Data System (BOLD) by 14%. Additionally, the number of barcodes from European tipulid specimens more than doubled, with an increase of 118%, bolstering the DNA resource for future identification inquiries. Employing diverse species delimitation algorithms - including the multi-rate Poisson tree processes model (mPTP), Barcode Index Number assignments (BIN), Assemble Species by Automatic Partitioning (ASAP), and the TaxCI R-script - we successfully match 76-86% of the morphologically identified species. Further validation through neighbor-joining tree topology analysis and comparison with 712 additional European tipulid barcodes yield a remarkable 89% success rate for the species identification of German tipulids based on COI barcodes. This comprehensive DNA barcode dataset not only enhances species identification accuracy but also serves as a pivotal resource for ecological and biomonitoring studies, fostering a deeper understanding of crane fly diversity and distribution across terrestrial landscapes.

The contractile efficiency of the mantle muscle of European common cuttlefish (Sepia officinalis) during cyclical contractions.

Escape jet propulsion swimming in cuttlefish (Sepia officinalis) is powered by the circular muscles surrounding the mantle cavity. This mode of locomotion is energetically costly compared with undulatory swimming. The energetic cost of swimming is determined by the mechanical power requirements and the efficiency with which chemical energy is transferred into useful mechanical work. One step in this energy transduction process is the transfer of energy from ATP hydrolysis into mechanical work by the muscles. Here, we determined the efficiency of this step, termed the contractile efficiency. Muscle preparations from the circular muscles of the mantle cavity were subjected to sinusoidal length changes at different cycle frequencies, and stimulated with a phase and duration that maximised initial net work. Changes in ATP, arginine phosphate and octopine content between control and exercised muscles were determined and used to calculate the energy released from ATP hydrolysis (Emet). The maximum contractile efficiency (the ratio of net work to Emet) was 0.37, occurring at the same cycle frequency at which mechanical power was maximal and that was used during jet propulsion swimming, suggesting that cuttlefish muscle is adapted to generate muscular power efficiently. The overall efficiency of cuttlefish jet propulsion swimming was estimated to be 0.17, which is broadly comparable to that measured during animal flight and human-powered pedalled locomotion, indicating the high energetic costs of jet propulsion swimming are not due to inefficient locomotion per se; instead, they result from the relatively high mechanical power requirements.

Three-dimensional evaluation of the responses of two species of flies (Diptera) to an indoor light trap

Abstract We used the Photonic Fence Monitoring Device (PFMD) to evaluate orientation by Musca domestica L. (Diptera: Muscidae), and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) to the Zevo Flying Insect Trap Model 3. The PFMD’s dual cameras record infrared light (IR) reflected from a wavelength-specific fabric; insects do not reflect IR at the same wavelength and are tracked in 3 dimensions as moving objects. The plug-in trap emits ultraviolet and blue light from behind an opaque shield; attracted insects enter the space between the shield and the wall and are trapped on a sticky cartridge facing the wall. An experiment (N = 10) with replicates of approximately 40, 1- to 7-day-old mixed-sex flies of each species was conducted in a 6.1 m3 arena. Prior to turning the trap on, the fly movement was not directed toward the trap on the back wall of the arena, regardless of whether the overhead light was on or off. When the overhead light was off, the mean first catch of both species occurred within 5 min after the trap was turned on, and 33.1% and 41.8% of M. domestica and C. vicina, respectively, were caught. House flies flew toward the trap, many approaching from below, while C. vicina apparently walked or flew outside the field of view of the PFMD until they appeared on the vertical reflective surface, and then walked toward the trap from all directions. Our results show that the Zevo Trap attracts and catches flies, and that the PFMD can be used to track flying and walking flies.

Field studies of synthetic food-based attractants for detecting invasive fruit flies (Diptera: Tephritidae)

True fruit fly species (Diptera: Tephritidae) threaten the production and international trade of many fruit and vegetable crops. Many fruit fly-free regions operate trapping programs for the detection of these invasive pests, and food baits are an important component of detection trapping. A torula yeast-borax (TYB) solution has been widely used as a food bait, but it has a relatively short field longevity and is generally replaced every 1–2 weeks. Dry synthetic food-based attractants, consisting of ammonium acetate, putrescine, and trimethylamine, have been developed and appear to be effective for several months. Initially, the three components were presented in individual sachets within a trap, but to ease handling ‘all-in-one’ dispensers have been developed that contain all three components. While a logistical improvement, there are few data that compare captures between the standard TYB solution and these combination dispensers. This study presents the results of field experiments assessing the relative effectiveness of three ‘all-in-one’ dispensers of synthetic food-based attractants (i.e., Scentry food cones, Suterra Unipaks, and Susbin Difusors) in trapping three major pest species of tephritid fruit flies in Hawaii. The data presented here indicate that, with respect to C. capitata, the Difusor lures performed as well as TYB, while the Unipaks and food cones were significantly less attractive than TYB. With respect to B. dorsalis and Z. cucurbitae, none of the synthetic baits tested was as effective as TYB. Thus, among the baits studied here, TYB was most effective in attracting all three of the target species.

Of flippers and wings: The locomotor environment as a driver of the evolution of forelimb morphological diversity in mammals

Abstract The early diversification of tetrapods into terrestrial environments involved adaptations of their locomotor apparatus that allowed for weight support and propulsion on heterogeneous surfaces. Many lineages subsequently returned to the water, while others conquered the aerial environment, further diversifying under the physical constraints of locomoting through continuous fluid media. While many studies have explored the relationship between locomotion in continuous fluids and body mass, none have focused on how continuous fluid media have impacted the macroevolutionary patterns of limb shape diversity. We investigated whether mammals that left terrestrial environments to use air and water as their main locomotor environment experienced constraints on the morphological evolution of their forelimb, assessing their degree of morphological disparity and convergence. We gathered a comprehensive sample of more than 800 species that cover the extant family‐level diversity of mammals, using linear measurements of the forelimb skeleton to determine its shape and size. Among mammals, fully aquatic groups have the most disparate forelimb shapes, possibly due to the many different functional roles performed by flippers or the relaxation of constraints on within‐flipper bone proportions. Air‐based locomotion, in contrast, is linked to restricted forelimb shape diversity. Bats and gliding mammals exhibit similar morphological patterns that have resulted in partial phenotypic convergence, mostly involving the elongation of the proximal forelimb segments. Thus, whereas aquatic locomotion drives forelimb shape diversification, aerial locomotion constrains forelimb diversity. These results demonstrate that locomotion in continuous fluid media can either facilitate or limit morphological diversity and more broadly that locomotor environments have fostered the morphological and functional evolution of mammalian forelimbs. Read the free Plain Language Summary for this article on the Journal blog.

Consistent differences in tissue oxygen levels across 15 insect species reflect a balance between oxygen supply and demand and highlight a hitherto unknown adaptation for extracting sufficient oxygen from water

Animals, including insects, need oxygen for aerobic respiration and eventually asphyxiate without it. Aerobic respiration, however, produces reactive oxygen species (ROS), which contribute to dysfunction and aging. Animals appear to balance risks of asphyxiation and ROS by regulating internal oxygen relatively low and stable, but sufficient levels. How much do levels vary among species, and how does variation depend on environment and life history? We predicted that lower internal oxygen levels occur in insects with either limited access to environmental oxygen (i.e., insects dependent on aquatic respiration, where low internal levels facilitate diffusive oxygen uptake, and reduce asphyxiation risks) or consistently low metabolic rates (i.e., inactive insects, requiring limited internal oxygen stores). Alternatively, we predicted insects with long life-stage durations would have internal oxygen levels > 1 kPa (preventing high ROS levels that are believed to occur under tissue hypoxia). We tested these predictions by measuring partial pressures of oxygen (PO2) in tissues from juvenile and adult stages across 15 species comprising nine insect orders. Tissue PO2 varied greatly (from 0 to 18.8 kPa) and variation across species and life stages was significantly related to differences in habitat, activity level, and life stage duration. Individuals with aquatic respiration sustained remarkably low PO2 (mean = 0.88 kPa) across all species from Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies), and Diptera (true flies), possibly reflecting a widespread, but hitherto unknown, adaptation for extracting sufficient oxygen from water. For Odonata (dragonflies), aquatic juveniles had higher PO2 levels (mean = 6.12 kPa), but these were still lower compared to terrestrial adults (mean = 13.3 kPa). Follow-up tests in juvenile stoneflies showed that tissue PO2 remained low even when exposed to hyperoxia, suggesting that levels were down-regulated. This was further corroborated since levels could be modulated by ambient oxygen levels in dead individuals. In addition, tissue PO2 was positively related to activity levels of insect life stages across all species and was highest in stages with short durations. Combined, our results support the idea that internal PO2 is an evolutionarily labile trait that reflects the balance between oxygen supply and demand within the context of the environment and life-history of an insect.

Guaranteed cost control for a class of composite hybrid aerial/terrestrial precise manipulator with stochastic switching payloads

AbstractThis article investigates the modeling and attitude control of a class of composite hybrid aerial/terrestrial precise manipulator (Chat‐PM) with stochastic switching payloads when attaching to a vertical surface. The dynamics of the Chat‐PM for aerial locomotion are modeled by transferring the force and moment of the end‐effector to the body based on the recursive Newton–Euler equations. Furthermore, the attitude dynamics of the Chat‐PM under the wall‐attachment condition is obtained by limiting the attitude angle/angular velocity and introducing the friction torque acting on the passive wheels for the first time. Taking into consideration the complexity of the task and the stochastic nature of environmental changes, the payload attached to the end‐effector is modeled as a continuous‐time Markov process with mode‐dependent fixed sojourn time in this study. The proposed guaranteed cost controller results in the Chat‐PM capable of stably attaching to a wall under random switching loads, while guaranteeing the quadratic performance cost with an attainable upper bound. Additionally, a convex‐optimization‐based guaranteed cost controller is proposed to optimize the performance cost in the random switching part. Finally, the effectiveness of the proposed guaranteed cost controllers is demonstrated by illustrative examples.

Flies tune the activity of their multifunctional gyroscope

Members of the order Diptera, the true flies, are among the most maneuverable flying animals. These aerial capabilities are partially attributed to flies' possession of halteres, tiny club-shaped structures that evolved from the hindwings and play a crucial role in flight control. Halteres are renowned for acting as biological gyroscopes that rapidly detect rotational perturbations and help flies maintain a stable flight posture. Additionally, halteres provide rhythmic input to the wing steering system that can be indirectly modulated by the visual system. The multifunctional capacity of the haltere is thought to depend on arrays of embedded mechanosensors called campaniform sensilla that are arranged in distinct groups on the haltere's dorsal and ventral surfaces. Although longstanding hypotheses suggest that each array provides different information relevant to the flight control circuitry, we know little about how the haltere campaniforms are functionally organized. Here, we use invivo calcium imaging during tethered flight to obtain population-level recordings of the haltere sensory afferents in specific fields of sensilla. We find that haltere feedback from both dorsal fields is continuously active, modulated under closed-loop flight conditions, and recruited during saccades to help flies actively maneuver. We also find that the haltere's multifaceted role may arise from the steering muscles of the haltere itself, regulating haltere stroke amplitude to modulate campaniform activity. Taken together, our results underscore the crucial role of efferent control in regulating sensor activity and provide insight into how the sensory and motor systems of flies coevolved.

Complex temporal trends in biomass and abundance of Diptera communities driven by the impact of agricultural intensity

Abstract Insect biodiversity and abundance declines have been reported widely and are expected to alter ecosystem functions and processes. Land use change has been recognised as a major cause of such declines. However, variation in local environmental drivers and the scale of available monitoring data have left large knowledge gaps in which taxa are declining, where declines are the greatest, and how these declines will impact ecosystems. We used 11 years (2006–2016) of monitoring data on 40 farms distributed over ~10,000 km2 in southern Québec, Canada, to quantify the impact of agricultural intensity on temporal trends in abundance and biomass of Diptera (true flies). There was a large difference in temporal trends between farms, which we found to be driven by agricultural landcover. Contrary to expectation, increases in Diptera abundance over time were greater in areas with higher agricultural intensity, especially with an increase in cereal crops. In contrast, declines in biomass were steeper in areas of higher agricultural intensity, although only with greater maize and soy production rather than cereals such as wheat. Variation in forest cover around farms had the least effect on trends. We found steeper declines in biomass per total number of Diptera with increasing agricultural intensive cover, suggesting the presence of community turnover towards smaller bodied flies with lower individual biomass. Our results imply that land use may not only alter abundance and species composition of insect species assemblages but also the distribution of key functional traits such as body size.

Field longevity of methyl eugenol and cue-lure plugs and associated insecticidal strips: captures of Bactrocera dorsalis and Zeugodacus cucurbitae (Diptera: Tephritidae) in Hawaii.

Certain species of true fruit flies (Diptera: Tephritidae) cause tremendous damage to commercially important fruits and vegetables, and many countries operate continuous trapping programs which rely on male-specific lures such as trimedlure (TML), methyl eugenol (ME), and cue-lure (CL). Traditionally, these attractants have been applied as liquids to cotton wicks inside traps, although this results in high evaporative loss of the lure. Slow-release, polymeric plugs have been widely adopted for TML, but such devices are not widely used for ME or CL. Recent data, however, suggest that ME and CL plugs may be attractive for as long as 12 wk in the field. The present study investigates whether ME and CL plugs weathered for 18 or 24 wk are effective in capturing males of Bactrocera dorsalis (Hendel) and Zeugodacus cucurbitae (Coquillett), respectively. For B. dorsalis, 6 g ME plugs were as effective as the control treatment (fresh liquid on a wick) after 12 wk of weathering but not after 18 or 24 wk. For Z. cucurbitae, 3 g CL plugs were as effective as the control treatment (fresh CL plugs) after 12 and 18 wk of weathering but not after 24 wk. The residual content and release rate of the 2 lures were also measured over time, but, with the exception of the residual content of ME, we did not find a direct correlation between these parameters and numbers of flies captured.

Benthic invertebrate fauna of a forest spring on the Muravyov- Amursky Peninsula (Primorsky Krai, Southern Russian Far East)

The fi rst data on spring macroinvertebrate fauna of the Southern Russian Far East are presented. Macrobenthos of a small forest spring classifi ed as helocrene includes at least 21 species from 20 genera and 17 families in Arthropoda and Platyhelminthes. Main groups of benthic organisms are amphipods, planarians, larvae of dipterous insects, caddisfl ies, stonefl ies and mayfl ies, small water beetles. The following invertebrates are defi ned to the species level: planaria Phagocata sibirica, stonefl y Skwala compacta, caddisfl y Glossosoma angarensis, aquatic beetles Hydraena riparia (imago) and Heterlimnius gapyeongensis (larvae), amphipods Gammarus koreanus and hypogean Procrangonyx primoryensis. The macrobenthos of the spring is also ecologically diverse. Here, rheo- and stagnophiles, highly specialized stygo- and crenobionts, and species with wide ecological niches, sharply diff ering in their preferences, closely coexist.

Motion Control of a Hybrid Quadruped-Quadrotor Robot

Multimodal motion capability is an emerging topic in the robotics field, and this paper presents a hybrid robot system maneuvering in both terrestrial and aerial environments. Firstly, a micro quadruped–quadrotor robot with onboard sensing and computing is developed. This robot incorporates both the high mobility of unmanned aerial vehicles and the long endurance of mobile robots on the ground. A coordinated motion control scheme is then exploited for adaptive terrestrial–aerial motion transition. In this scheme, a bio-inspired terrestrial locomotion controller is proposed to generate various quadruped locomotions, and a model-based aerial locomotion controller is proposed to generate various quadrotor configurations. Then, an unified motion controller for the two subsystems which dynamically adjusts crawling and flying motion in a complicated environment is presented. Consequently, several practical trials are conducted to demonstrate the adaptability and the robustness of the proposed system.

Brightness cues affect gap negotiation behaviours in zebra finches flying between perches.

Flying animals have had to evolve robust and effective guidance strategies for dealing with habitat clutter. Birds and insects use optic flow expansion cues to sense and avoid obstacles, but orchid bees have also been shown to use brightness cues during gap negotiation. Such brightness cues might therefore be of general importance in structuring visually guided flight behaviours. To test the hypothesis that brightness cues also affect gap negotiation behaviours in birds, we presented captive zebra finches Taeniopygia guttata with a symmetric or asymmetric background brightness distribution on the other side of a tunnel. The background brightness conditions influenced both the birds' decision to enter the tunnel aperture, and their flight direction upon exit. Zebra finches were more likely to initiate flight through the tunnel if they could see a bright background through it; they were also more likely to fly to the bright side upon exiting. We found no evidence of the centring response that would be expected if optic flow cues were balanced bilaterally during gap negotiation. Instead, the birds entered the tunnel by targeting a clearance of approximately one wing length from its near edge. Brightness cues therefore affect how zebra finches structure their flight when negotiating gaps in enclosed environments.

Asynchronous haltere input drives specific wing and head movements in Drosophila.

Halteres are multifunctional mechanosensory organs unique to the true flies (Diptera). A set of reduced hindwings, the halteres beat at the same frequency as the lift-generating forewings and sense inertial forces via mechanosensory campaniform sensilla. Though haltere ablation makes stable flight impossible, the specific role of wing-synchronous input has not been established. Using small iron filings attached to the halteres of tethered flies and an alternating electromagnetic field, we experimentally decoupled the wings and halteres of flying Drosophila and observed the resulting changes in wingbeat amplitude and head orientation. We find that asynchronous haltere input results in fast amplitude changes in the wing (hitches), but does not appreciably move the head. In multi-modal experiments, we find that wing and gaze optomotor responses are disrupted differently by asynchronous input. These effects of wing-asynchronous haltere input suggest that specific sensory information is necessary for maintaining wing amplitude stability and adaptive gaze control.

The pattern of the follicle cell diversification in ovarian follicles of the true fruit flies, Tephritidae.

In flies (Diptera), the ovary displays several distinct patterns of the follicular epithelium formation and diversification. Two main patterns have been identified in the true flies or Brachycera, namely the Rhagio type and the Drosophila type. These patterns align with the traditional division of Brachycera into Orthorrhapha and Cyclorrhapha. However, studies of the follicular epithelium morphogenesis in cyclorrhaphans other than Drosophila are scarce. We characterise the developmental changes associated with the emergence of follicle cell (FC) diversity in two cyclorrhaphans belonging to the family Tephritidae (Brachycera, Cyclorrhapha). Our analysis revealed that the diversification of FCs in these species shows characteristics of both the Rhagio and Drosophila types. First, a distinct cluster of FCs, consisting of polar cells and border-like cells, differentiates at the posterior pole of the ovarian follicle. This feature is unique to the Rhagio type and has only been reported in species representing the Orthorrhapha group. Second, morphological criteria have identified a significantly smaller number of subpopulations of FCs than in Drosophila. Furthermore, while the general pattern of FC migration is similar to that of Drosophila, the distinctive migration of the anterior-dorsal FCs is absent. In the studied tephritids, the migration of the anterior polar cell/border cell cluster towards the anterior pole of the oocyte is followed by the posterior migration of the main body cuboidal FCs to cover the expanding oocyte. Finally, during the onset of vitellogenesis, a distinct subset of FCs migrates towards the centre of the ovarian follicle to cover the oocyte's anterior pole. Our study also highlights specific actions of some FCs that accompany the migration process, which has not been previously documented in cyclorrhaphans. These results support the hypothesis that the posterior and centripetal migrations of morphologically unique FC subsets arose in the common ancestor of Cyclorrhapha. These events appear to have occurred fairly recently in the evolutionary timeline of Diptera.