Adult Flies Research Articles

Bub1 and Bub3 regulate metabolic adaptation via macrolipophagy in Drosophila

Lipophagy, the process of selective catabolism of lipid droplets (LDs) by autophagy, maintains lipid homeostasis and provides cellular energy under metabolic adaptation, yet its underlying mechanism remains largely ambiguous. Here, we show that the Bub1-Bub3 complex, the crucial regulator involved in the whole process of chromosome alignment and separation during mitosis, controls the fasting-induced lipid catabolism in the fat body (FB) of Drosophila. Bidirectional deviations of the Bub1 or Bub3 level affect the consumption of triacylglycerol (TAG) of fat bodies and the survival rate of adult flies under starving. Moreover, Bub1 and Bub3 work together to attenuate lipid degradation via macrolipophagy upon fasting. Thus, we uncover physiological roles of the Bub1-Bub3 complex on metabolic adaptation and lipid metabolism beyond their canonical mitotic functions, providing insights into the invivo functions and molecular mechanisms of macrolipophagy during nutrient deprivation.

A quick and laidback way to detect the internal structure of the Drosophila eye: An alternative to cryosectioning

Immunofluorescence techniques have been a great tool to chase the structure, localization, and function of many proteins within a cell. Drosophila eye is widely used as a model to answer various questions. However, the complex sample preparation and visualization methods restrict its use only with an expert's hand. Thus, an easy and hassle-free method is in need to broaden the use of this model even with an amateur's hand. The current protocol describes an easy sample preparation method using DMSO to image the adult fly eye. The brief description of sample collection, preparation, dissection, staining, imaging, storage, and handling has been described over here. For readers, the possible problems that might arise during the execution of the experiment have been described with their possible reason and solutions. The overall protocol reduces the use of chemicals and shortens the sample preparation time to only 3h, which is significantly less in comparison to other protocols.

Additive Effect of Releasing Sterile Insects Plus Biocontrol Agents against Fruit Fly Pests (Diptera: Tephritidae) under Confined Conditions.

Pest control models integrating the use of the sterile insect technique (SIT) and augmentative biological control (ABC) have postulated that it is possible to obtain a synergistic effect from the joint use of these technologies. This synergistic effect is attributed to the simultaneous attack on two different biological stages of the pest (immature and adult flies), which would produce higher suppression on the pest populations. Here we evaluated the effect of the joint application of sterile males of A. ludens of the genetic sexing strain Tap-7 along with two parasitoid species at the field cage level. The parasitoids D. longicaudata and C. haywardi were used separately to determine their effect on the suppression of the fly populations. Our results showed that egg hatching percentage was different between treatments, with the highest percentage in the control treatment and a gradual reduction in the treatments with only parasitoids or only sterile males. The greatest induction of sterility (i.e., the lowest egg hatching percentage) occurred with the joint use of ABC and SIT, demonstrating that the earlier parasitism caused by each parasitoid species was important reaching high levels of sterility. Gross fertility rate decreased up to 15 and 6 times when sterile flies were combined with D. longicaudata and C. haywardi, respectively. The higher parasitism by D. longicaudata was determinant in the decrease of this parameter and had a stronger effect when combined with the SIT. We conclude that the joint use of ABC and SIT on the A. ludens population had a direct additive effect, but a synergistic effect was observed in the parameters of population dynamics throughout the periodic releases of both types of insects. This effect can be of crucial importance in the suppression or eradication of fruit fly populations, with the added advantage of the low ecological impact that characterizes both techniques.

Phenotypic and transcriptomic impact of expressing mammalian TET2 in the Drosophila melanogaster model

ABSTRACT Ten-Eleven Translocation (TET) proteins have recently come to light as important epigenetic regulators conserved in multicellular organisms. TET knockdown studies in rodents have highlighted the critical role of these proteins for proper brain development and function. Mutations in mammalian mTET proteins and mTET2 specifically are frequent and deregulated in leukaemia and glioma respectively. Accordingly, we examined the role of mTET2 in tumorigenesis in larval haemocytes and adult heads in Drosophila melanogaster. Our findings showed that expression of mutant and wild type mTET2 resulted in general phenotypic defects in adult flies and accumulation of abdominal melanotic masses. Notably, flies with mTET2-R43G mutation at the N-terminus of mTET2 exhibited locomotor and circadian behavioural deficits, as well as reduced lifespan. Flies with mTET2-R1261C mutation in the catalytic domain, a common mutation in acute myeloid leukaemia (AML), displayed alterations affecting haemocyte haemostasis. Using transcriptomic approach, we identified upregulated immune genes in fly heads that were not exclusive to TET2 mutants but also found in wild type mTET2 flies. Furthermore, inhibiting expression of genes that were found to be deregulated in mTET2 mutants, such as those involved in immune pathways, autophagy, and transcriptional regulation, led to a rescue in fly survival, behaviour, and hemocyte number. This study identifies the transcriptomic profile of wild type mTET2 versus mTET2 mutants (catalytic versus non-catalytic) with indications of TET2 role in normal central nervous system (CNS) function and innate immunity.

Wing Morphometrics of Forensic Important Fly Species in Kelantan, Malaysia

This research discusses the possibility of determining the species and sex of necrophagous flies by examining their wing morphology. Fresh beef meat (500 g) was placed in both rural and urban areas of Kelantan, Malaysia, and third instar maggots were collected for rearing from the third to the seventh day. Adult flies were killed with chloroform and their species and sexual status were determined using standard procedures. After detaching their wings, the morphology was documented using a Leica MC 170HD digital camera attached to a Leica stereo microscope. Thirteen wing landmarks were chosen for geometric morphometric analysis. Principal Component Analysis (PCA), canonical variate analysis (CVA), centroid size variation, and the unweighted pair-group method with arithmetic averages (UPGMA) were used to analyse the wing morphology of Chyrsomya megacephala (Fabricius, 1794), Chrysomya rufifacies (Macquart, 1843), and Sarcophaga ruficornis (Fabricius, 1794) The results indicate that sex and fly species can be distinguished based on wing morphology, and that CVA is more effective at species differentiation than sex grouping using Malahanobis distances, with a P value of 0.0001. When comparing different species and sexes of the fly, CVA demonstrates distinct clustering. Identification of necrophagous fly wings is a useful alternative tool for fly classification.

Assessment of Chemical Toxicity in Adult Drosophila Melanogaster.

Human industries generate hundreds of thousands of chemicals, many of which have not been adequately studied for environmental safety or effects on human health. This deficit of chemical safety information is exacerbated by current testing methods in mammals that are expensive, labor-intensive, and time-consuming. Recently, scientists and regulators have been working to develop new approach methodologies (NAMs) for chemical safety testing that are cheaper, more rapid, and reduce animal suffering. One of the key NAMs to emerge is the use of invertebrate organisms as replacements for mammalian models to elucidate conserved chemical modes of action across distantly related species, including humans. To advance these efforts, here, we describe a method that uses the fruit fly, Drosophila melanogaster,to assess chemical safety. The protocol describes a simple, rapid, and inexpensive procedure to measure the viability and feeding behavior of exposed adult flies. In addition, the protocol can be easily adapted to generate samples for genomic and metabolomic approaches. Overall, the protocol represents an important step forward in establishing Drosophila as a standard model for use in precision toxicology.

Ascending neurons convey behavioral state to integrative sensory and action selection brain regions

Knowing one’s own behavioral state has long been theorized as critical for contextualizing dynamic sensory cues and identifying appropriate future behaviors. Ascending neurons (ANs) in the motor system that project to the brain are well positioned to provide such behavioral state signals. However, what ANs encode and where they convey these signals remains largely unknown. Here, through large-scale functional imaging in behaving animals and morphological quantification, we report the behavioral encoding and brain targeting of hundreds of genetically identifiable ANs in the adult fly, Drosophila melanogaster. We reveal that ANs encode behavioral states, specifically conveying self-motion to the anterior ventrolateral protocerebrum, an integrative sensory hub, as well as discrete actions to the gnathal ganglia, a locus for action selection. Additionally, AN projection patterns within the motor system are predictive of their encoding. Thus, ascending populations are well poised to inform distinct brain hubs of self-motion and ongoing behaviors and may provide an important substrate for computations that are required for adaptive behavior.

Fishing for flies: testing the efficacy of “stink stations” for promoting blow flies as pollinators in mango orchards

Pollinator communities are composed of diverse groups of insects, with radically different life histories and resource needs. Blow flies are known to visit a variety of economically important crop plants. Larval blow flies develop by feeding on decaying animals. Some fruit growers are known to place carrion on farms during the flowering season to attract adult blow flies (Calliphoridae). However, the efficacy of these “stink stations” has not been tested. We conducted a series of experiments to determine: 1) if stink stations promote the abundance of blow flies in mango orchards (Mangifera indica L.), 2) if any increases in the abundance of flies acts to promote pollination and fruit set in Australian mango orchards. Farms with stink stations had approximately three times more flies than control farms. However, the increased abundance of blow flies did not result in increased fruit set. Although stink stations increased the abundance of blow flies, we found no evidence that their use improves mango yield. This may be due to pollination saturation by a highly abundant native hover fly, Mesembrius bengalensis (Syrphidae), during our study. We hypothesize that stink stations may only be beneficial in years or regions where other pollinators are less abundant.

Stress‐sensitive dynamics of miRNAs and Elba1 in Drosophila embryogenesis

Early‐life stress can result in life‐long effects that impact adult health and disease risk, but little is known about how such programming is established and maintained. Here, we show that such epigenetic memories can be initiated in the Drosophila embryo before the major wave of zygotic transcription, and higher‐order chromatin structures are established. An early short heat shock results in elevated levels of maternal miRNA and reduced levels of a subgroup of zygotic genes in stage 5 embryos. Using a Dicer‐1 mutant, we show that the stress‐induced decrease in one of these genes, the insulator‐binding factor Elba1, is dependent on functional miRNA biogenesis. Reduction in Elba1 correlates with the upregulation of early developmental genes and promotes a sustained weakening of heterochromatin in the adult fly as indicated by an increased expression of the PEV wm4h reporter. We propose that maternal miRNAs, retained in response to an early embryonic heat shock, shape the subsequent de novo heterochromatin establishment that occurs during early development via direct or indirect regulation of some of the earliest expressed genes, including Elba1.

Aggregation pheromones have a non-linear effect on oviposition behavior in Drosophila melanogaster

Female fruit flies (Drosophila melanogaster) oviposit at communal sites where the larvae may cooperate or compete for resources depending on group size. This offers a model system to determine how females assess quantitative social information. We show that the concentration of pheromones found on a substrate increases linearly with the number of adult flies that have visited that site. Females prefer oviposition sites with pheromone concentrations corresponding to an intermediate number of previous visitors, whereas sites with low or high concentrations are unattractive. This dose-dependent decision is based on a blend of 11-cis-Vaccenyl Acetate (cVA) indicating the number of previous visitors and heptanal (a novel pheromone deriving from the oxidation of 7-Tricosene), which acts as a dose-independent co-factor. This response is mediated by detection of cVA by odorant receptor neurons Or67d and Or65a, and at least five different odorant receptor neurons for heptanal. Our results identify a mechanism allowing individuals to transform a linear increase of pheromones into a non-linear behavioral response.

The effect of postmortem penetrative trauma on oviposition behavior of Calliphora vicina

Flies in the family Calliphoridae are purported to demonstrate a strong attraction to and preferential colonization of wounds when present on human corpses or carrion. This well-circulated concept in Forensic Entomology is based on surprisingly few empirical studies that have examined the oviposition behavior of necrophagous Diptera toward wounds of vertebrate animals. In the present study, the oviposition behavior of Calliphora vicina toward piglets inflicted with postmortem sharp force trauma was examined during a 10-h test period under controlled laboratory conditions and in an outdoor urban environment. Three species of flies (C. vicina, C. livida and Cynomya cadaverina) deposited eggs on wounded and non-wound piglets during the field studies, although more than 80% of all eggs laid were by C. vicina regardless of wound status. For all species, oviposition occurred predominately on the head, including in eyes, ears, nose and mouth, and less frequently in other locations on the body. Eggs were never found in or near wounds. Similar oviposition patterns were displayed by C. vicina under laboratory conditions, with the exception for limited egg deposition in wounds under overcrowded conditions. In this latter scenario, egg deposition represented only 0.14% of the total reproductive output of adult flies. The findings do not support the contention that calliphorids preferentially oviposit in wounds resulting from sharp force penetrating trauma.

Protective Role of Hsp27 in the Nonylphenol-Induced Locomotory and Longevity Toxicity

Abstract Background Gut health is directly proportional to an organism's fitness. Our recent study showed a functional link between oxidative stress and heat shock protein 27 (Hsp27, a stress protein) in the Drosophila larval gut, which coordinates the nonylphenol (an endocrine disruptor) allied sub-cellular and developmental adversities. Objective In continuation with the prior study, the present study aimed to explore the association of Hsp27 with locomotory and survival against nonylphenol-induced toxicity in the Drosophila gut. Methods and Methodology The freshly emerged adult flies were exposed to nonylphenol (5.0 µg/mL) for 10 to 40 days, and their locomotory performance (climbing activity) and survivability were assessed. ANOVA was used to evaluate the statistical significance of the mean values in control and treated flies. Results Nonylphenol exposure markedly influenced locomotory activity and survivability after 30 to 40 days. For instance, ∼76% (40 days) declined locomotor behavior, and ∼35% (40 days) reduced survivability was observed. While the overexpression of Hsp27 in the organism's gut showed improvement in locomotory performance and survivability after 30 to 40 days. No significant alteration in locomotory performance and survivability was observed after 10 to 20 days of nonylphenol exposure. Conclusion The present study illustrates that Hsp27 overexpression in the Drosophila gut improves the locomotory performance and survivability in the nonylphenol exposed Drosophila. This also indicates the possible connection between the gut and organismal fitness.

Decomposition and insect succession of pig cadavers in tents versus outdoors – A preliminary study

The pattern of insect succession and the species composition on cadavers can be influenced by several parameters, one of which is concealment. It has been previously shown for cadavers inside containers (e.g. suitcases or vehicles) or various indoor situations, that concealment can lead to a delayed arrival, altered species composition and decreased number of taxa present at the cadaver. As no data is yet available for the specific environment of tents on these processes, we placed five pig cadavers inside closed two-person tents during the summer of 2021 in a mixed forest in Germany. Five control cadavers were freely accessible for insects. To minimize disturbances, tents were only opened every fifth day over a period of 25 days for estimating the temperature profiles, insect diversity and quantification of the cadavers’ decomposition using the total body score (TBS).The temperature inside the tents was only slightly elevated compared to the ambient temperature during the study. Although the tents prevented direct access of adult flies and beetles, the cadavers were colonized because the flies oviposited on the zippers and fly screens of the inner tents. However, the resulting infestation of the cadavers by fly larvae was reduced and delayed, compared to the exposed cadavers. The dominant fly species on both the tent and exposed cadavers was the blow fly Lucilia caesar. Open cadavers showed the expected decomposition patterns with large larval masses. 25 days after placement, only bones and hair remained from the exposed pigs (TBS = 32), while most of the tissue of the cadavers inside the tents was still present (TBS = 22.5) and post feeding larvae were not able to leave the tents. Regarding the attraction of beetles to both treatments, open cadavers were predominately colonized by the silphid Oiceoptoma thoracicum, while the silphid Necrodes littoralis was the most dominant species in the pitfall traps surrounding the tents. Considering the prolonged pre-appearance interval of fly larvae colonizing the cadavers inside tents, the entomological evidence of forensic cases dealing with concealed bodies should be handled with caution, since the post mortem interval might be significantly underestimated.

Distribution of Biting Flies Associated with Swine Production Facilities in the Southeastern United States

High populations of pest flies on swine facilities can be detrimental to the animals and producers. The purpose of this study was to identify the distribution pattern and the influence of habitats on distribution of adult biting flies surrounding commercial swine production barns in North Carolina. In this study, fly surveillance was conducted on four swine facilities in Bladen County, North Carolina, U.S.A., from January to October 2019. Biting flies typically associated with livestock were passively collected weekly on sticky traps, which were placed in three concentric circles surrounding swine barns, and then counted and identified. Stable flies [Stomoxys calcitrans (L.); Diptera: Muscidae] were most abundant on swine facilities that were mixed-use with pastured beef cattle. However, swine producers with no pastured cattle should be aware of the potential for stable flies to disperse from off-property larval development sites. Therefore, adult fly management may be necessary if populations reach nuisance levels. Horse and deer fly (Diptera: Tabanidae) captures were not related to trap proximity to water. Differences in horse and deer fly trap captures was likely less of a reflection of differences in potential fly development habitat quality (e.g., water) and more related to adult fly habitat selection.

The first data on the biology of Ips stebbingi Strohmeyer, 1908 (coleoptera: curculionidae: Scolytinae), a pest of himalayan blue pine

ABSTRACT This paper deals with the studies on the biology and development of the bark beetle Ips stebbingi Strohmeyer, 1908 (Coleoptera: Curculionidae: Scolytinae), a pest of Himalayan blue pine Pinus wallichiana A.B.Jacks. in Kashmir Himalaya. This pest is an aggressive and notorious one, but little is known of its biology. This beetle pest overwinters in adult stage under the bark of host trees P. wallichiana. After emergence, the adults fly to suitable trees and undergo maturation feeding for 4–6 days. Reproduction is polygamous type; two to six females join a male in his nuptial chamber. After mating, each of the females makes one gallery with an average length of 10.76 (±3.30 standard deviation [SD]) cm. The female lays 23.16 (±7.03 SD) eggs on an average. The eggs hatch in 8–18 days. The larvae have five instars and complete their development in 30–45 days constructing larval galleries of 3.83 (±0.63 SD) cm in length. The larvae pupate for 18–28 days and finally the adults emerge to attack new suitable trees. The adults live for 45–70 days, and the total lifespan of this species ranges from 101 to 156 days. The seasonal distribution of various life stages and the number of generations were also recorded.

Sexual size and shape dimorphism, and allometric scaling in the pupal and adult traits of Eristalis tenax.

The patterns and amount of variation in size, shape, and/or life history traits between females and males are fundamentally important to gain the comprehensive understanding of the evolution of phenotypic diversity. In addition, the covariation of phenotypic traits can significantly contribute to morphological diversification and sexual dimorphism (SD). Using linear and geometric morphometrics, 237 Eristalis tenax specimens sampled from five populations were, therefore, comparatively assessed for the variation in sexual size dimorphism (SSD), sexual shape dimorphism (SShD), and life history traits, as well as for trait covariation (ontogenetic and static allometry). Pupal body, adult wing, and body mass traits were analyzed. Female-biased SSD was observed for pupal length, width, and centroid size, adult wing centroid size, mass, wing loading, and wing area. Conversely, pupal length/width ratio, developmental time, and mass were not found to be sexually dimorphic. Next, wing SShD, but not pupal body SShD was revealed, while allometry was found to be an important "determinant of SD" at the adult stage, with only a minor impact at the pupal stage. By comparing the patterns of covariance (based on allometric slope and intercept) between respective body mass and morphometric traits of pupae and adults, greater variation in allometric slopes was found in adult traits, while static allometries of the two stages significantly differed, as well. Finally, the results indicate that changes in the allometric intercept could be an important source of intraspecific variation and SD in drone fly adults.

Adult Emergence and Morphometrics of Chinese Citrus Fly, Bactrocera minax (Enderlein) (Diptera: Tephritidae) in Nepal

Chinese citrus fly, Bactrocera minax is a destructive and univoltine pest of citrus fruits. Geographical altitudinal gradients as well as prevailing climate affect the biology and ecology of insect. Hence, this study aimed to ascertain the effect of altitude on the adult emergence and morphological variations in various ecological settings of Ramechhap district of Nepal from February to June 2021 in citrus orchard. Six altitude ranges were selected in 50 m distance from 1200 to 1500 m above sea level (masl), ranging from 1201-1250 masl, 1251-1300 masl, 1301-1350 masl, 1351-1400 masl, 1401-1450 masl and 1451-1500 masl. The peak adult emergence periods were the 2nd, 3rd, 4th week of April in 1201-1250 masl, 1251-1300 masl, 1301-1350 masl, respectively, followed by 1st, 2nd and 3rd week of May in 1351-1400 masl, 1401-1450 masl, 1451-1500 masl, respectively. Morphometrics of Chinese citrus fly such as weight, length and width of pupa and adult were almost similar to the species collected in various altitudes. The average body length of male Chinese citrus fly adult was 11.58± 0.112 mm while female was 15.57± 0.076 mm. The average wingspan of male was 20.71± 0.285 mm while that of female was 23.14± 0.156 mm. The longevity of adult Chinese citrus fly species increased with increase in altitude. This information could be useful to design an appropriate management plan of Chinese citrus fly in various altitudinal gradients of Nepal.

Polysaccharides from Bletilla striata protect against mercury-induced gastrointestinal toxicology in adult Drosophila melanogaster via modulation of sestrin

Oxidative stress was one of the major causes of heavy metal-induced toxicity in organisms. The polysaccharide from Bletilla striata (Orchidaceae) (BSP) has been recently recognized as a novel player in the management of oxidative stress response in organisms. Here, we took the midgut of adult Drosophila melanogaster (Diptera: Drosophilidae) (D. melanogaster), a functional equivalent to the mammalian intestine and stomach, as a model to evaluate the protective effects of BSP (50 μg/mL) on mercuric chloride-induced gastrointestinal toxicology in insects. As a result, BSP exposure significantly improved the survival rates and climbing ability of adult flies exposed to mercury. Further study demonstrated that BSP significantly alleviated the mercury-induced oxidative injury to midgut epithelium, at least partly, through increasing antioxidant enzyme activity (glutathione-S-transferase and superoxide dismutase), decreasing reactive oxidative species production, inhibiting cell death, restoring intestinal epithelial barrier and regulating intestinal stem cell-mediated tissue regeneration. Additionally, sestrin, an oxidative-stress gene, was required in mediating the protection of BSP against mercury-induced oxidative damage to midgut. This study suggested that BSP has great potential for future application in the treatment and prevention of heavy metal-induced gastrointestinal adversities in mammals.

A Simple Technique to Assay Locomotor Activity in Drosophila.

Drosophila melanogaster is an ideal model organism for studying various diseases due to its abundance of advanced genetic manipulation techniques and diverse behavioral features. Identifying behavioral deficiency in animal models is a crucial measure of disease severity, for example, in neurodegenerative diseases where patients often experience impairments in motor function. However, with the availability of various systems to track and assess motor deficits in fly models, such as drug-treated or transgenic individuals, an economical and user-friendly system for precise evaluation from multiple angles is still lacking. A method based on the AnimalTracker application programming interface (API) is developed here, which is compatible with the Fiji image processing program, to systematically evaluate the movement activities of both adult and larval individuals from recorded video, thus allowing for the analysis of their tracking behavior. This method requires only a high-definition camera and a computer peripheral hardware integration to record and analyze behavior, making it an affordable and effective approach for screening fly models with transgenic or environmental behavioral deficiencies. Examples of behavioral tests using pharmacologically treated flies are given to show how the techniques can detect behavioral changes in both adult flies and larvae in a highly repeatable manner.

Toxicity of Insecticides in the Adult and Larva Olive Fruit Fly, after Estimation of the Dislodgeable Foliar and Fruit Residues in Olive Trees by LC-MS/MS and GC-MS/MS

“Can systemic insecticides be used in bait spots in order to kill the adult olive fly?” Effort was directed toward providing an answer to that question. Both field and laboratory tests were implemented to detect the dislodgeable residues of dimethoate, phosmet and b-cyfluthrin in olive leaves and fruit using the LC-MS/MS and GC-MS/MS chromatographic techniques. Residues of dimethoate declined more over time than those of phosmet, while levels of beta-cyfluthrin remained almost stable, both in leaves and fruit. Additionally, significantly higher and faster toxicity of dimethoate and beta-cyfluthrin (>92%) compared to phosmet (80%) to fly adults was shown, which was reduced significantly after a two-week period. Conversely, 100% mortality of the larval stages within olive flesh was observed at the 2nd day for dimethoate and at the 7th day for phosmet. Although phosmet was not expected to contribute to preventing larval development, its application in bait sprays presented similar toxicity to that of dimethoate. However, no larval toxicity was recorded in beta-cyfluthrin. As a primary conclusion, we recommend the avoidance of the use of systemic insecticides in bait sprays.