Small Flies Research Articles

Evolution and development of Drosophila melanogaster under different thermal conditions affected cell sizes and sensitivity to paralyzing hypoxia

Environmental gradients cause evolutionary and developmental changes in the cellular composition of organisms, but the physiological consequences of these effects are not well understood. Here, we studied experimental populations of Drosophila melanogaster that had evolved in one of three selective regimes: constant 16 °C, constant 25 °C, or intergenerational shifts between 16 °C and 25 °C. Genotypes from each population were reared at three developmental temperatures (16 °C, 20.5 °C, and 25 °C). As adults, we measured thorax length and cell sizes in the Malpighian tubules and wing epithelia of flies from each combination of evolutionary and developmental temperatures. We also exposed flies from these treatments to a short period of nearly complete oxygen deprivation to measure hypoxia tolerance. For genotypes from any selective regime, development at a higher temperature resulted in smaller flies with smaller cells, regardless of the tissue. At every developmental temperature, genotypes from the warm selective regime had smaller bodies and smaller wing cells but had larger tubule cells than did genotypes from the cold selective regime. Genotypes from the fluctuating selective regime were similar in size to those from the cold selective regime, but their cells of either tissue were the smallest among the three regimes. Evolutionary and developmental treatments interactively affected a fly’s sensitivity to short-term paralyzing hypoxia. Genotypes from the cold selective regime were less sensitive to hypoxia after developing at a higher temperature. Genotypes from the other selective regimes were more sensitive to hypoxia after developing at a higher temperature. Our results show that thermal conditions can trigger evolutionary and developmental shifts in cell size, coupled with changes in body size and hypoxia tolerance. These patterns suggest links between the cellular composition of the body, levels of hypoxia within cells, and the energetic cost of tissue maintenance. However, the patterns can be only partially explained by existing theories about the role of cell size in tissue oxygenation and metabolic performance.

Effect of flyer diameters on the combustion characteristics of short pulse impact initiations

The flyer diameter is an important factor affecting short pulse impact. The impact initiation test of 1,3,5- Triamino-2,4,6- Trinitrobenzene (TATB) was carried out by changing the flyer diameter. By measuring the depth and diameter of the combustion pit, the combustion intensity of the sample propellant column under different flyers diameter was analyzed. The results show that under the condition of a small flyer diameter, changing the flyer diameter has little effect on the combustion intensity of PBXN-7. When the flyer diameter is large, because of the change in the fracture mode, the depth of the combustion pit generated by the TATB combustion initially increases and then decreases with an increasing flyer diameter; When PBXN-7 and TATB explode, the diameter of the accelerated chamber is reduced when the flyer diameter is less than 1.8 mm and 4.5 mm, respectively. When the flyer diameter is larger than 1.8 mm and 4.5 mm, the expansion of the bore diameter is accelerated. The intensity of the combustion is reflected by measuring the ablation range of the combustion. Under the influence of furrows in the combustion pit, the greater the combustion intensity of PBXN-7 is, the greater the ablation range.

Assessing Pollinator Assembly And Efficacy Across Species Ranges In The Genus Triodanis (Campanulaceae)

Plant-insect interactions are a key topic in evolutionary ecology, especially in the face of anthropogenic changes which threaten to disrupt these mutualisms. An in-depth pollinator survey for species in the genus Triodanis is performed here for the first time, with sampling covering four species and spanning a large portion of their geographic ranges (i.e., four U.S. states). All species in the genus exhibit dimorphic cleistogamy with variability in allocation to open (chasmogamous) flowers among populations and taxa. The genus Triodanis, therefore, provides an opportunity for understanding possible associations between pollinator assemblies and variation in species, breeding system, and geography. To assess these relationships, we sampled four species or subspecies of Triodanis at eight field sites in four states. Sampling encompassed a broad area across the Midwestern U.S. and Texas, and across a gradient of anthropogenically disturbed habitats. We found that for species of Triodanis: 1) small bee and fly generalist pollinators showed some floral constancy during feeding bouts but did not differentiate between species, 2) pollinator community was less diverse and abundant in highly degraded habitats, 3) while allocation to open flowers varied among species and populations, we found no association between breeding system (or species) on pollinator identity or abundance. This study represents the first in-depth survey of pollinator visitors of Triodanis and serves as foundational knowledge about the natural history of this group, provides resolution for members of Campanulaceae exhibiting floral traits of generalist hosts, and important documentation of plant-insect interactions in an era of ongoing anthropogenic changes.

Comparison of prey fauna in tropical red traps versus temperate whitish traps in carnivorous Drosera indica complex (Droseraceae)

AbstractCertain carnivorous plant species display geographical variation in trap coloration, which may impact interactions with prey. Our study focused on Drosera indica (Droseraceae) in tropical Thailand and its phylogenetically related species Drosera toyoakensis in temperate Japan. Drosera indica in Thailand has green leaf blades with red tentacles when flowering, making the entire trap appear red. In contrast, D. toyoakensis in Japan has green leaf blades with green‐white tentacles when flowering, and the entire trap appears white. Field observations revealed statistically significant differences in taxa and size of prey caught by D. indica and D. toyoakensis. Both species caught small flies, but D. toyoakensis additionally caught larger flies and butterflies, including pollinators. These differences in prey composition may reflect differences in trap coloration that evolved under different selection pressures for capturing prey. However, trap coloration and prey assemblages were influenced by various factors, and further research is required to elucidate their evolutionary significance.

Taxonomic review of the genus Aldrichiopa Guimares, 1971 (Diptera: Tachinidae) with notes on antennal morphology and description of a new species.

A redescription of the genus Aldrichiopa Aldrich, 1934 (Diptera: Tachinidae) is provided and a new species, Aldrichiopa serrata Torres-Domnguez & Mulieri sp. nov. is described from specimens collected in Argentina and Chile. A detailed morphological description of the egg, first instar larva, and adult male and female including terminalia are presented for the first time. Exhaustive photographic records, scanning electron microscopy images, morphological detail of antennal ultrastructure, and updated geographic distributions are provided for the two species of the genus, Aldrichiopa coracella (Aldrich) and A. serrata sp. nov. An identification key based on males is provided. The taxonomic placement of Aldrichiopa to subfamily and tribe is discussed and information on the hosts of this genus of small tachinid flies is compiled.

Study on the physical encapsulation mechanism of heavy metals in fly ash carbonation solidification based on synthetic pellets

The physical encapsulation mechanism prevents the leaching of heavy metals by forming calcium carbonate-encapsulated fly ash through the reaction of carbon dioxide and calcium oxide. However, current research in this area primarily involves qualitative analysis, focusing on various methods to enhance the fixation effect of heavy metals. There is a lack of quantitative description regarding how physical encapsulation solidifies heavy metals, and the solidification mechanism of heavy metals is challenging to verify through macroscopic experiments. In this paper, a method for synthesizing small fly ash particles into pellets is proposed to quantitatively study the mechanism of physically encapsulating heavy metals. The data from the carbonation reaction and leaching reaction are fitted using the shrinking core model. The depth of carbonation increases with the lengthening of carbonation time, and the physical encapsulation strengthens the immobilization of heavy metals. The leaching of heavy metals after carbonation can be categorized into three stages based on the shrinking core model: external diffusion, internal diffusion, and chemical reaction control. Synthetic pellets enhance all three stages, especially the external diffusion, which is not detectable with fly ash powder. The fitting results of the experimental data for the carbonation reaction of the enlarged synthetic pellets and the shrinking core model are both above 0.9. This indicates that the primary barrier to leaching of heavy metals is the physical encapsulation formed by the carbonation reaction following the shrinking core model. The physical encapsulation serves as the primary mechanism for the solidification of heavy metals during the carbonation process.

Taxonomic Morphology of Biting Midges (Diptera: Ceratopogonidae)

Ceratopogononidae is a family of small nematocerous flies ranging approximately 1 to 3mm in length. Ceratopogonidae which was previously categorised as a subfamily of Chironomidae is distinguised by the presence of its biting mouthparts. Ceratopogonids commonly known as biting midges are the vectors of numerous pathogens such as viruses, protozoans and nematodes. Hence its transmission has a great veterinary and medical importance. This family is divided into four subfamilies: Leptoconopinae, Forcipomyiinae, Dasyhilinae and Ceratopogoninae. The flies were collected with the help of aspirator, Diptera net and UV light trap. The collected specimens were preserved in the 70% ethanol and later dissected out with the help of Digital Motic Dissecting Binocular. Ceratopogonidae include widely diversified morphotaxanomic character describing various subgroups. This variable character which include colour pattern, sizes of the body, proportions of various morphological parts are not very reliable for taxonomic identification. The study found that the morphotaxanomic feature like external genitalia of male and female, armature and arrangement of wing venation are much more stable. There are several puzzling problems in the determination of disputed species, can be resolved on the basis of taxonomic characters of male and female genitalia. The present paper will resolve the problem related to plethora of taxonomic character with special reference to biting midges.

Small flies with high conservation value: first reliable record of Hyperoscelis veternosa (Diptera, Canthyloscelidae) from Romania supported by DNA barcode data

Here we present the first reliable record of the rare Hyperoscelis veternosa Mamaev and Krivosheina, 1969 from the headwaters area of the Someșul River, Apuseni Natural Park, Romania. Species level identification was made by detailed examination of the single female genitalia, supported by DNA barcode data. The new finding confirms the presence of the species in Romania, whereas a very old, single and doubtful record from the Bucharest area dates back to 1900 needs further confirmation. The presence of the second species of genus Hyperoscelis from Romania is of high conservation value, and confirm the persistence of a relict biodiversity of an old-growth forests-spot in the Carpathians.

A Compact Planar Wi-Fi Antenna with Optimized Radiation Patterns for Small UAV Applications

This paper proposes a compact planar Wi-Fi antenna with optimized radiation patterns for small uncrewed aerial vehicle (UAV) applications in both urban and open areas. It is suitable for mounting on the outermost side of the non-metallic wing of small UAVs. It has small dimensions of 16.5 mm (L) by 30.3 mm (W) by 1.6 mm (h), and the measured results of its prototype are in agreement with simulated data. Its impedance bandwidths over the two frequency ranges are 2.11 to 2.58 GHz and 5.06 to 7.5 GHz (S11≤-10 dB). At 5.8 GHz, it has stronger radiation below the small UAV to reduce interference from rare-use directions. Its maximum radiations, the directions of the maximum radiation in each elevation plane, are below the UAV and between 14° and 29° from the horizontal plane. At 2.4 GHz, it has quasi-omnidirectional radiation to ensure a stable link in all directions, and its maximum radiations are near the horizontal plane. The optimized radiation patterns at 5.8 and 2.4 GHz can provide more antenna gain when the small UAV flies farther in urban and open areas, respectively. In addition, it has good vertically polarized radiation for long-distance applications.

Population assemblage of the small fruit flies (Diptera, Drosophilidae) in the North Western Ghats of Karnataka (India) with special report on the dominant species

Population assemblage of the small fruit flies (Diptera, Drosophilidae) in the North Western Ghats of Karnataka (India) with special report on the dominant species

Survey of conceptual and taxonomic characteristics of the Families Acartophthalmidae, Canacidae and Carnidae (Insecta: Diptera)

The Acartophthalmidae family includes tiny to small dark flies with hyaline or infuscate wings along the coast. Adults live in the forest, where they are associated with decaying substances such as wood, fungi, carrion, excrement and rotten meat. The Canacidae are found along the sea coasts, on the surface of small bodies of water, saline and fresh, in places protected from the wind. They feed on infusoria and other tiny organisms. In Carnidae, the larvae are saprophagous or coprophagous (they live in the litter of birds' nests). Pupae are enclosed within a puparium and bird nests are micro-ecosystems with diverse communities of invertebrates, from ectoparasitoids to commensal species. The objective of this manuscript was to carry out a survey of the Families Acartophthalmidae, Canacidae and Carnidae regarding their biology, ecology, geographic distribution, and taxonomy. The systematized bibliographic study, of the descriptive and exploratory type of the Families Acartophthalmidae and Canacidae. The bibliographic search included the LILACS databases at: http://www.bireme.br/, in electronic journals available at the SciELO and USP databases: http: //www.usp.br/ and in theoretical books, these banks, university dissertations, national and international scientific articles, scientific journals, documents. The main terms used were: Diptera, flies, Acartophthalmidae, Canacidae and Carnidae.

New material of Paleopsychoda jarzembowskii Azar & Maksoud, 2022 from Bqaatouta amber outcrop, showing the importance of insect fossils in biostratigraphy

The family Psychodidae Newman, 1834 comprises about 3,000 living species of small hairy nematoceran flies (Azar & Maksoud, 2022). To date, seven psychodid subfamilies are recognized within this family, namely Bruchomyiinae Alexander, 1921; extinct Datziinae Stebner, Solórzano Kraemer, Ibáñez-Bernal & Wagner, 2015; Horaiellinae Enderlein, 1937; Phlebotominae Rondani, 1840; Psychodinae Newman, 1834; Sycoracinae Rondani, 1856; and Trichomyiinae Tonnoir, 1922 (Azar & Maksoud, 2022). Some authors consider the psychodid group to consist of two families, i.e., Psychodidae and Phlebotomidae (Williams, 1993; Azar et al., 1999). This taxonomic treatment is based only on the hematophagous and medically important aspects of the phlebotomines. Nevertheless it is unfounded, because the phylogenetic relationships between the psychodid subfamilies remain unresolved, even if there is a possible sister-group relationship between the Phlebotominae and Psychodinae (Curler & Moulton, 2012). We consider that recognising phlebotomines as a separate family would necessitate also giving separate familial rank to all the currently recognised subfamilies, which is not adopted here.

Beat frequency extraction method of high speed and high noise Doppler signal based on double correction

When detecting ultrahigh speed micro targets, because the photon Doppler signal will be seriously interfered with by high-frequency noise, it is difficult to accurately extract the beat frequency information, resulting in serious speed demodulation error. Therefore, we propose a beat frequency extraction method for high-speed and high-noise Doppler signals based on double correction, which can accurately correct the beat frequency signals of high-frequency noise interference. First, the ratio correction method is used for the first spectrum correction to screen out the normalized spectrum of high-frequency noise interference; then, according to the degree of noise interference, the energy barycenter correction method or linear interpolation method is used for the second spectrum correction. Numerical simulation results show that this method can reduce the spectral error by 1.6% to 2.1%. We used this method to process the Doppler signal from the detonation small flyer experiment in Initiating explosive device testing. The results show that it can reduce the beat frequency error by 1.83 times at most under high-frequency noise interfered, equivalent to the instantaneous velocity error of 1955 m/s can be decreased after velocity demodulation. Therefore, the beat frequency extraction method based on double correction has good noise resistance and reliability. We corrected the different regions’ frequency spectrums according to the noise interference intensity, which provides an idea for the beat frequency extraction of high-speed and high-noise Doppler signals.

What Can Fruit Flies Tell Us About an Environment?

Fruit flies are very small flies. When people find them in their kitchens, they are often annoyed. However, fruit flies can tell us about what is happening in nature. Some fruit flies are native to an area, whereas others have been introduced by people. When a place is in its natural state, native species of fruit flies are abundant. When a place has been changed, for example, by the construction of lots of buildings, invasive species of fruit flies are found. Fruit flies are an indicator species that can tell us about how land use has changed.

Comparison of Edge Vortices from Normal and Elliptic Flapping Flat Plates

Computational analysis of elliptic and normal flat plate geometries, sized to wings of small fliers and in a two-dimensional plunging–pitching–flapping motion resulting in hover, is conducted to investigate circulation growth at the leading-edge vortex (LEV) and trailing-edge vortex (TEV). The models are sized to the same aspect ratio, and a Reynolds number of 225 is chosen as it is similar to that observed in small fliers in hover. Results show similar LEV growth and lift production trends for both cases but with differing energy flux mechanisms. A vorticity transport analysis is done to quantify these energy fluxes. The LEV growth and shearing is closely related to the TEV growth and shearing, and the plunging–pitching profile, while the geometry plays a role in the magnitude of vortex creation and intensity of spanwise fluxes only.

Proboscidea and Dicyphini: An example of spontaneous mutualism by a population of predatory bugs inhabiting a sticky plant

A population of the mirid-bug Dicyphus errans (Miridae) a species occurring in Europe, colonized a group of Devil’s Claw (Proboscidea louisianica subsp. fragrans (Martyniaceae)) native to the USA and cultivated in a garden in Germany. More than 20 individuals of these predatory bugs have been found living and moving freely on these sticky plants, feeding on stuck victims, while garden ants (Lasius spp. (Hymenoptera)) trying to place aphids for “sugar farming” became captured together with their “productive livestock”, as do small flies and bees. The observations on this spontaneous mutualism between the American Devil’s Claw and a small mosquito-like European mirid-bug has been recorded on video (Hartmeyer 2022). This constitutes an additional example for the adaptation of these ubiquitous predatory bugs to feed on the prey of sticky plants that would usually capture small-sized insects. The American Frank Obregon (2017), who found native mirid-bugs on his cultivated Roridula (Roridulaceae) in California, called the phenomenon assisted carnivory, which fits quite nicely. Proboscidea as well as Roridula do not produce digestive enzymes, so they cannot benefit directly from their diverse captured prey. But as soon as predatory bugs colonize the plants and feed on the sticking prey, their droppings provide a suitable fertilizer to be absorbed by the stomata of the leaf. A perfect mutualism. In addition, some historic facts on bug-plant interaction are provided.

Frequency-Modulated Control for Insect-Scale Flapping-Wing Vehicles

Many insects utilize both amplitude and frequency modulation of their wingstrokes to control flight, a combination with potential advantages for flapping-wing micro-aerial vehicle (FWMAV) flight control as we attempt to mimic the agility of small biological fliers. However, frequency-modulated control is uncommon in insect-scale FWMAVs, and these vehicles have not yet demonstrated graceful, mid-wingstroke frequency transitions in flight. We propose a method to allow active frequency control as a primary control variable, and describe a method to achieve smooth frequency transitions in flight. We demonstrate that frequency, in combination with other flapping parameters, may be used to generate arbitrary, time-varying forces and torques. Additionally, we explore the advantages of frequency modulation in FWMAV flight, applying a frequency-based method to control the Harvard RoboBee during hovering flight.

THE MEMS-BASED BAROMETRIC ALTIMETER INACCURACY AND DRIFT PHENOMENON

MEMS technology has made sensors for measuring barometric pressure and altitude above sea level very cheap and widely used in many consumer electronic devices. This paper presents a theoretical analysis of the sources and types of errors in the barometric altimeter using the standard atmosphere model (ISA). Methods for correcting principal errors caused by non-standard sea level conditions are described and compared. A method of correcting errors in the case of altimeter horizontal movement to the air column and total pressure measurement was proposed. It was compared with another method known from the literature. In the numerical experiment, data recorded by a bicycle computer equipped with a MEMS-based barometric altimeter was analyzed. As the GPS data of the route covered was also known, it was possible to compare the recorded altimeter data with the heights determined from the digital terrain model (DTM), which in this case were considered accurate. The error of the measured altitude calculated in this way was tried to be divided into the principal error, the external error caused by the sensor movement, and the barometer drift. Hence, a numerical experiment was carried out in which, based on the recorded data, an attempt was made to reconstruct non-standard sea level conditions and the impact of speed on the sensor measurements. Furthermore, a method of solving such a reverse problem was proposed. The results of the presented studies can be used in the design of systems correcting the indications of barometric altimeters. The accuracy of the altitude measurement is especially important for small controlled flying objects (UAH) and when recording the route of vehicles moving on the ground.

A chemical reaction insight of shock initiation criterion

Shock initiation criteria are essential to the shock initiation process and applications in modern pyrotechnics. The most commonly used shock initiation criteria are Walker and James criterion, which can very well describe the threshold data of the impactor with sufficient size. However, the criteria were also found not to provide a good fit to the data of thin, curve, or small flyers. By comparing the wave structure of the shock process with the stable detonation wave structure, a shock initiation criterion is developed based on the concept of the chemical reactions during the impact, focusing more on the properties of the explosives. Furthermore, a desktop micro-flyer initiating system was designed for the initiation of the thin metal flyer. The obtained data and classical historical data were analyzed with the proposed criterion, producing an excellent fit, with R2 values greater than 0.96. Compared to the existing criteria, the proposed criterion can weaken the influence of the interfacial properties of the impact and collapse the threshold velocity data with different impactor types to a single curve. The shock sensitivities of various explosives are also discussed based on the criterion. A denser impactor or the incorporation of impurities may contribute to the generation of the hot spot during the impact, leading to an increase in the sensitivity. The proposed criterion provides insight into the development of the shock initiation criteria and may help to understand the mechanism of shock initiations.

Moman's Secret Agenda

Moman's Secret Agenda