Behavior Of Flies Research Articles

Convergent olfactory circuits for courtship in Drosophila revealed by ds-Tango.

Animals exhibit sex-specific behaviors that are governed by sexually dimorphic circuits. One such behavior in male Drosophila melanogaster, courtship, is regulated by various sensory modalities, including olfaction. Here, we reveal how sexually dimorphic olfactory pathways in male flies converge at the third-order, onto lateral horn output neurons, to regulate courtship. To achieve this, we developed ds-Tango, a modified version of the monosynaptic tracing and manipulation tool trans-Tango. In ds-Tango, two distinct configurations of trans-Tango are positioned in series, thus providing selective genetic access not only to the monosynaptic partners of starter neurons but also to their disynaptic connections. Using ds-Tango, we identified a node of convergence for three sexually dimorphic olfactory pathways. Silencing this node results in deficits in sex recognition of potential partners. Our results identify lateral horn output neurons required for proper courtship behavior in male flies and establish ds-Tango as a tool for disynaptic circuit tracing.

Pollination ecology of Dracula erythrochaete (Orchidaceae): brood-site imitation or food deception?

Abstract Pleurothallidinae is the most diverse Neotropical subtribe in Orchidaceae and is almost exclusively pollinated by insects of the order Diptera. Dracula, a genus of 138 species in the Pleurothallidinae, is known to attract Zygothrica (Drosophilidae) flies, common macrofungi visitors, by imitating fungal volatile compounds and lamellae. Interestingly, Dracula orchids do not appear to offer any rewards to their floral visitors. While brood-site imitation of macrofungi has been suggested as their pollination system, the exact behaviour of flies during their extended visits to the orchid flowers has yet to be confirmed. In this study, we document the pollination mechanism of Dracula erythrochaete. We characterize the floral structures involved in the mechanism using anatomical and morphological evidence. Additionally, through in situ observations and camera recordings, we describe the insect behaviour. We show that flowers of D. erythrochaete share the same group of visitors as nearby macrofungi, including different Zygothrica species, seven of which were determined as effective pollinators. Male and female flies were attracted to the flowers and displayed feeding behaviour. Accordingly, proteins were detected in high concentrations on the papillae at the base of the movable lip and in papillary trichomes of the sepals, near the column. The concept of brood-site imitation is debated, as no oviposition events were observed and no eggs were found on the flowers. Therefore, a mixed strategy of congregation/brood-site imitation and food reward is proposed for pollination.

Longitudinal activity monitoring and lifespan: quantifying the interface.

Understanding the relationship between activity over the entire lifespan and longevity is an important facet of aging research. We present a comprehensive framework for the statistical analysis of longitudinal activity and behavioral monitoring and their relationship with age-at-death at the individual level, highlighting the importance of advanced methodological approaches in aging research. The focus is on animal models, where continuous monitoring activity in terms of movement, reproduction and behaviors over the entire lifespan is feasible at the individual level. We specifically demonstrate the methodology with data on activity monitoring for Mediterranean fruit flies. Advanced statistical methodologies to explore the interface between activity and age-at-death include functional principal component analysis, concurrent regression, Fréchet regression and point processes. While the focus of this perspective is on relating age-at-death with data on movement, reproduction, behavior and nutrition of Mediterranean fruit flies, the methodology equally pertains to data from other species, including human data.

Navigating the landscape of fear: Fruit flies exhibit distinct antipredator and antiparasite defensive behaviors.

Most organisms are at risk of being consumed by a predator or getting infected by a parasite at some point in their life. Theoretical constructs such as the landscape of fear (perception of risk) and nonconsumptive effects (NCEs, costly responses sans predation or infection) have been proposed to describe and quantify antipredator and antiparasite responses. How prey/host species identify and respond to these risks determines their survival, reproductive success and, ultimately, fitness. Most studies to date have focused on either predator-prey or parasite-host interactions, yet habitats and ecosystems contain both parasitic and/or predatory species that represent a complex and heterogenous mosaic of risk factors. Here, we experimentally investigated the behavioral responses of a cactophilic fruit fly, Drosophila nigrospiracula, exposed to a range of species that include parasites (ectoparasitic mite), predators (jumping spiders), as well as harmless heterospecifics (nonparasitic mites, ants, and weevils). We demonstrate that D. nigrospiracula can differentiate between threat and non-threat species, increase erratic movements and decrease velocity in the presence of parasites, but decrease erratic movements and time spent grooming in the presence of predators. Of particular importance, flies could distinguish between parasitic female mites and nonparasitic male mites of the same species, and respond accordingly. We also show that the direction of these NCEs differs when exposed to parasitic mites (i.e., risk of infection) versus spiders (i.e., risk of predation). Given the opposing effects of predation versus infection risk on fly behavior, we discuss potential trade-offs between parasite and predator avoidance behaviors. Our findings illustrate the complexity of risk assessment in a landscape of fear and the fine-tuned NCEs that arise in response. Moreover, this study is the first to examine these behavioral NCEs in a terrestrial system.

Context-dependent impact of the dietary non-essential amino acid tyrosine on Drosophila physiology and longevity.

Dietary protein intake modulates growth, reproduction, and longevity by stimulating amino acid (AA)-sensing pathways. Essential AAs are often considered as limiting nutrients during protein scarcity, and the role of dietary non-essential AAs (NEAAs) is less explored. Although tyrosine has been reported to be crucial for sensing protein restriction in Drosophila larvae, its effect on adult physiology and longevity remains unclear. Here, using a synthetic diet, we perform a systematic investigation of the effect of single NEAA deprivation on nutrient-sensing pathways, reproductive ability, starvation resistance, feeding behavior, and life span in adult female flies. Specifically, dietary tyrosine deprivation decreases internal tyrosine levels and fecundity, influences AA-sensing machineries, and extends life span. These nutritional responses are not observed under higher total AA intake or in infertile female flies, suggesting a context-dependent influence of dietary tyrosine. Our findings highlight the unique role of tyrosine as a potentially limiting nutrient, underscoring its value for dietary interventions aimed at enhancing health span.

A comprehensive review of long‐distance hover fly migration (Diptera: Syrphidae)

Abstract Hover flies (Diptera: Syrphidae) are a group of insects containing many migratory species that provide critical ecosystem services including pollination, decomposition and biological control. Their migratory behaviour remains largely overlooked and unacknowledged, but an influx of contemporary research is beginning to shift this. The goal of this review is to summarise and synthesise the past 150+ years of global hover fly migration research from over 50 papers in multiple languages. Here, we provide comprehensive evidence for hover fly migration through the lens of the methodologies used for studying these phenomena, the biological mechanisms for migration and the associated ecological and economic impacts. We also include an inventory of all recognised migratory species and discuss taxonomic patterns. In total, we compiled accounts of 46 species that are considered migratory, most of which were sourced from Europe. Recent reports, however, have also described hover fly migration in North America, Asia, the Middle East and Australia. Approximately 70% of these species are from the subfamily Syrphinae, which are important biological control agents. The migratory behaviour of hover flies has substantial impacts on ecosystem services and may be linked to long‐distance gene flow for many angiosperms via pollen transportation. These insects are also likely redistributing biological control services at a continental scale on an annual basis, which has major repercussions for the management of crop pests such as aphids. The sensitivity of hover fly migration to anthropogenic impacts is not well known, but shifting climatic conditions, pollution and increased habitat fragmentation are likely impactful and should be further explored. Despite recent advances and increased interest in the subject, hover fly migration remains understudied and many major knowledge gaps continue to persist.

Methyl eugenol regulates mating behavior in oriental fruit flies by enhancing lek attractiveness

Methyl eugenol regulates mating behavior in oriental fruit flies by enhancing lek attractiveness

Microbiomes of Two Pest Fly Species of Pennsylvania Mushroom Houses.

Mushroom cultivation vastly improves the yield of mushrooms under optimized, controlled conditions, but may be susceptible to opportunistic colonization by pest species that can establish themselves, as well as the pathogens and pests they may transmit. Here, we describe our investigation into the bacterial communities of adult Lycoriella ingenua (Diptera: Sciaridae) and Megaselia halterata (Diptera: Phoridae) collected from button mushroom (Agaricus bisporus) production houses in Pennsylvania. We collected adult flies and sequenced the hypervariable v4 region of the bacterial 16S rRNA using the Illumina MiSeq. The most abundant bacterial genus detected in both species was Wolbachia, but phylogenetic analysis revealed that the infections are from different clades. Future studies include the characterization of Wolbachia infections on fly behavior and biology, comparison of microbial diversity of fly species colonizing wild mushrooms, and other microbiota that may contribute to the success of certain pest fly species.

Keypoint-MoSeq: parsing behavior by linking point tracking to pose dynamics

Keypoint tracking algorithms can flexibly quantify animal movement from videos obtained in a wide variety of settings. However, it remains unclear how to parse continuous keypoint data into discrete actions. This challenge is particularly acute because keypoint data are susceptible to high-frequency jitter that clustering algorithms can mistake for transitions between actions. Here we present keypoint-MoSeq, a machine learning-based platform for identifying behavioral modules (‘syllables’) from keypoint data without human supervision. Keypoint-MoSeq uses a generative model to distinguish keypoint noise from behavior, enabling it to identify syllables whose boundaries correspond to natural sub-second discontinuities in pose dynamics. Keypoint-MoSeq outperforms commonly used alternative clustering methods at identifying these transitions, at capturing correlations between neural activity and behavior and at classifying either solitary or social behaviors in accordance with human annotations. Keypoint-MoSeq also works in multiple species and generalizes beyond the syllable timescale, identifying fast sniff-aligned movements in mice and a spectrum of oscillatory behaviors in fruit flies. Keypoint-MoSeq, therefore, renders accessible the modular structure of behavior through standard video recordings.

Carbonation behavior of aged alkali-activated fly ash/slag binder modified by MgO with different reactivities

Carbonation behavior of aged alkali-activated fly ash/slag binder modified by MgO with different reactivities

Carbon Dioxide, Methane, and Synthetic Cattle Breath Volatiles Attract Host-Seeking Stable Flies, Stomoxys calcitrans.

Stable flies, Stomoxys calcitrans (L.), are blood-feeding ectoparasites of cattle. Host-seeking stable flies respond to various cattle host cues, but a potential role of cattle breath gases [carbon dioxide (CO2), methane (CH4)] and cattle breath volatiles (acetone, isoprene, 2-butanone, 2-propanol, propionic acid, 3-methyl butyric acid, phenol), alone or in combination, on host-seeking behavior of stable flies has not yet been comprehensively investigated. In laboratory and greenhouse experiments, we tested the hypotheses that (1) CO2 and CH4 interactively attract stable flies, (2) CO2 'gates' attraction of stable flies to CH4, and (3) breath volatiles on their own, or in combination with both CO2 and CH4, attract stable flies. In Y-tube olfactometer experiments, the blend of CH4 (0.5%) and CO2 (1%) in breathing air ('b-air') attracted significantly more female flies than CH4, or CO2, in b-air. The flies' responses to CH4 were contingent upon their prior or concurrent exposure to CO2. In two-choice experiments in a large greenhouse compartment, significantly more flies landed on the host-look-alike barrel that disseminated a blend of CO2 and CH4 in b-air (CO2/CH4/b-air) than on the barrel disseminating either b-air or CO2. Moreover, significantly more flies landed on the barrel that disseminated synthetic breath volatiles (SBVs) than on the barrel disseminating b-air. The blend of CO2/CH4/b-air and SBVs elicited more fly landings on barrels than CO2/CH4/b-air but not than SBVs. SBVs, possibly combined with both CH4 and CO2, could be developed as a lure to enhance trap captures of stable flies in livestock production facilities.

A review of Musca sorbens (Diptera: Muscidae) and Musca domestica behavior and responses to chemical and visual cues.

Musca flies (Diptera: Muscidae) have been found culpable in the mechanical transmission of several infectious agents, including viruses, bacteria, protozoans, and helminths, particularly in low-income settings in tropical regions. In large numbers, these flies can negatively impact the health of communities and their livestock through the transmission of pathogens. In some parts of the world, Musca sorbens is of particular importance because it has been linked with the transmission of trachoma, a leading cause of preventable and irreversible blindness or visual impairment caused by Chlamydia trachomatis, but the contribution these flies make to trachoma transmission has not been quantified and even less is known for other pathogens. Current tools for control and monitoring of house flies remain fairly rudimentary and have focused on the use of environmental management, insecticides, traps, and sticky papers. Given that the behaviors of flies are triggered by chemical cues from their environment, monitoring approaches may be improved by focusing on those activities that are associated with nuisance behaviors or with potential pathogen transmission, and there are opportunities to improve fly control by exploiting behaviors toward semiochemicals that act as attractants or repellents. We review current knowledge on the odor and visual cues that affect the behavior of M. sorbens and Musca domestica, with the aim of better understanding how these can be exploited to support disease monitoring and guide the development of more effective control strategies.

Sand Fly larvae are capable of positive chemotaxis: a proof of concept study using Phlebotomus papatasi (Diptera: Psychodidae) as a model species.

Phlebotomine sand flies are important vectors of medical and veterinary importance, transmitting pathogens, such as the Leishmania parasites, responsible for 700,000 to 1 million new cases of leishmaniasis every year. The vast majority of the current sand fly surveillance and control tools are tailored against the adult stages, due to the limited knowledge on the ecology of the larval stages. Since vector control is primarily an ecological problem, an in-depth understanding of the behavior of the target insect pests across all the different life stages of their development is required prior to the development of effective control strategies. It is well known that chemical cues play an important role in insect behavior. While there are numerous studies investigating the behavior of adult sand flies in response to chemical sources, there is currently no information available on the response of their larval stages. In this study, novel bioassays were constructed to investigate the effect of chemical cues (gustatory and olfactory) on the behavior of Phlebotomus papatasi (Scopoli) sand fly larvae. The larvae exhibited a clear food preference within a few hours of exposure in a 2-choice bioassay, while, also, demonstrated positive chemotaxis in response to volatile stimuli emitted from their preferred food source. Identification of the specific chemical compounds (or the combination thereof) eliciting attractance response to sand fly immature stages could lead to the development of innovative, and targeted (larval-specific) tools for the surveillance, and management of these important public health pests.

Future avenues in Drosophila mushroom body research.

How does the brain translate sensory information into complex behaviors? With relatively small neuronal numbers, readable behavioral outputs, and an unparalleled genetic toolkit, the Drosophila mushroom body (MB) offers an excellent model to address this question in the context of associative learning and memory. Recent technological breakthroughs, such as the freshly completed full-brain connectome, multiomics approaches, CRISPR-mediated gene editing, and machine learning techniques, led to major advancements in our understanding of the MB circuit at the molecular, structural, physiological, and functional levels. Despite significant progress in individual MB areas, the field still faces the fundamental challenge of resolving how these different levels combine and interact to ultimately control the behavior of an individual fly. In this review, we discuss various aspects of MB research, with a focus on the current knowledge gaps, and an outlook on the future methodological developments required to reach an overall view of the neurobiological basis of learning and memory.

Improvement of sleep duration and quality through GABAA receptor by whey protein hydrolysate containing DIQK as the main active compound

This study characterized the sleep activity, sleep mechanism, and active peptides of whey protein hydrolysates selected through behavioral analysis of fruit flies (Drosophila melanogaster). Sleep-inducing whey protein (WP) hydrolysate was selected through fruit fly behavior analysis, and sleep activity was measured using a pentobarbital model and electroencephalographic analysis. The mechanism of action was confirmed using a γ-aminobutyric acid (GABA) receptor antagonist, and the active peptide was identified using liquid chromatography-mass spectrometry. Whey protein hydrolysate, prepared using Alcalase and Prozyme (WP-AP), increased sleep time in a dose-dependent manner. The WP-AP significantly increased not only sleep time but also slow-wave sleep and showed an insomnia-alleviating effect in a caffeine-induced insomnia mouse model. In addition, the gene and protein expression levels of GABA subtype A receptors increased in the brains of mice orally administered with WP-AP. Through peptide analysis, the mixture of DIQK, VPPF peptide, and GABA contained in WP-AP was estimated to exhibit sleep activity, and due to its high content, DIQK was speculated to be the main sleep-inducing ingredient. These results indicate that WP-AP has the potential to be used as a new ingredient to improve sleep quality.

Effect of the electric field generated from high voltage power lines on the biology and behavior of the fruit fly, Drosophila melanogaster

Effect of the electric field generated from high voltage power lines on the biology and behavior of the fruit fly, Drosophila melanogaster

Ghosts of parasites past influence current non-consumptive effects in Drosophila nigrospiracula

Parasites can indirectly impact hosts through non-consumptive effects (NCEs) via changes in behaviour, morphology, and/or physiology. These responses can be understood in terms of the ecology of fear (ectoparasites) or the ecology of disgust (endoparasites) framework. We tested the hypothesis that NCEs of parasite exposure (e.g., parasite avoidance and defense) trade off with other important behaviours such as feeding and resting. We predicted that when exposed to parasites (without infection), hosts will increase their defensive behaviors at the expense of feeding. We also posited that history of exposure (without infection), or previous infection would impact the expression of these NCEs. The study system involves a cactophilic fruit fly (Drosophila nigrospiracula) and a naturally occurring parasitic mite (Macrocheles subbadius). First, we assessed how prior mite exposure affected fly behaviour in response to current parasite exposure. Mite presence resulted in increased grooming and movement, but exposure history did not affect these behaviours. However, the interaction between previous and current exposure influenced host feeding and resting behaviours. We found that previously exposed flies increased feeding and decreased resting upon a secondary mite exposure. In a second experiment, we tested the role of infection history on current parasite exposure. Compared with naïve flies, previously infected flies were expected to increase defensive behaviours upon secondary exposure. Flies increased defensive and ambulatory behaviour in the presence of mites, and consequently less time was spent resting but feeding was unaffected. None of the behaviours measured were affected by previous infection status. In general, current parasite exposure resulted in NCEs. Moreover, our results showed that previous exposure (without infection) to parasites may have an even stronger effect upon secondary exposure than infection history. Our study highlights the importance of the ecology of fear and the role that exposure and infection history plays in generating NCEs of parasitism.

A review on natural phenylbutanoid attractants: Occurrence, distribution, and role in nature, especially in relation to Dacini fruit fly behavior and pollination.

The natural occurrence, distribution (within a plant) and roles of four phenylbutanoid compounds (anisyl acetone, cue-lure, raspberry ketone and zingerone) are elucidated for the Asia-Pacific and Oceania regions. These phenylbutanoids may act individually or in combination to attract true fruit fly males belonging to a tribe Dacini of subfamily Dacinae (Diptera: Tepritidae). Of special interest are the mutualistic interactions between the Dacini fruit fly males and the tropical daciniphilous (attracting exclusively Dacini fruit flies) orchids - leading to cross pollination for the orchids and enchanced mating success for the flies. When offered to male flies, anisyl acetone and cue-lure are generally converted to raspberry ketone. Upon consumption, raspberry ketone and zingerone are individually sequestered in the male rectal (pheromonal) gland unchanged. Attracted male flies readily imbibe the phenylbutanoid(s) in the floral synomone to compliment the endogenously synthesized male sex pheromonal components - to enhance attraction of conspecific females during courtship as well as attract conspecific males to form 'leks'. The phenylbutanoid(s) may also act as an allomone to deter vertebrate predators, especially geckos, besides possessing antimicrobial and antioxidant activities. Cue-lure, raspberry ketone and zingerone are important attractants/lures used in pest surveillance and mass trapping under the integrated pest management (IPM) program against quarantine Dacini fruit fly pest species, particularly Bactrocera tryoni and Zeugodacus cucurbitae.

Intelligent Deep Adaptive Intuitionistic Fuzzy Classifier Based Dyslexia Prediction Among Children at its Early Stage

The inability of standard linear research to clearly define the role of cognitive abilities in reading difficulties is most likely due to the fact that reading and the components that are related to reading are both part of a system of factors. There are numerous interrelated and mitigating elements that conventional statistical models are unable to deal effectively. This work aims to increase dyslexia prediction accuracy by introducing two stage non-linear methodology which incorporate both deep learning and uncertainty theory. In the first stage, the pattern of dyslexic symptoms is learned by introducing deep adaptive neural network. During the training phase, the hyperparameters weight and learning rate are optimized using a metaheuristic algorithm called the fruit fly optimization algorithm. This algorithm imitates the behavior of fruit flies to search for the best set of values. The acquired knowledge is infused in the uncertainty inference model known as intuitionistic inference classifier. Each characteristic that defines an instance as dyslexic or non-dyslexic is represented in tristate degrees to precisely address the inconsistent or vague instance which neither or nor exhibit dyslexic symptoms by introducing the hesitancy factor. The simulation results support the proposed intuitionistic fuzzy rules prominently improves the accuracy rate of dyslexia prediction compared to the other existing state of arts.

Megaselia scalaris (Diptera: Phoridae) development and behaviour under fluoxetine effect and Calliphora vicina (Diptera: Calliphoridae) presence

Megaselia scalaris Loew (Diptera: Phoridae) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) are species of medical and forensic interest. Scuttle flies can eat carrion but also behave as a facultative parasitoid of other organisms. This study evaluated the effect of fluoxetine on the development of M. scalaris, and also the feeding behavior of the scuttle flies. For this, these flies were reared on artificial fodder with 2000 mg/kg of fluoxetine and also larvae of blue bottle flies on third stage were added. A control was used for each analysis. Daily observations were performed from the beginning to the end of the experiments. The duration of life cycle, body length, grosso modo external morphology and sex ratio were evaluated. Results indicated that development of M. scalaris was not affected by fluoxetine. The duration of stages, body length and external morphology did not show differences between fluoxetine and control groups. In addition, scuttle flies did not behave as parasites of blue bottle flies in their larval advanced stage and their presence did not interference on the development of M. scalaris. In conclusion, no alteration was observed on the development of M. scalaris at the dose of fluoxetine used and scuttle flies presence did not necessarily imply predation or parasitism of C. vicina larvae. Therefore, the current study provides data that could be applied in forensic entomological research or in forensic expertise.