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The species-specific and age-related autumn migration strategies of the sedge, reed and great reed warbler were investigated at stopover sites between central Europe and north-eastern Africa during autumn. Adult reed warblers accumulated larger fat reserves than juveniles and consequently were able to cover longer distances from most stopover sites. Juvenile sedge warblers, on the other hand, left Europe with significantly larger fat reserves than adults as opposed to the populations migrating along the western route. Both juvenile and adult great reed warblers were potentially able to make long flights without refuelling from the northern part of the Mediterranean region onwards. It was the proximity of large ecological barriers that had the most prominent influence on the potential flight distances of adult and juvenile Acrocephalus warblers during their southward migration. In reed and sedge warblers, the differences in mean flight distances covered by adults and juveniles were the largest (ca. 600 km) just before the crossing of the Mediterranean Sea, but smaller (ca. 200 and 400 km, respectively) in front of the Sahara Desert. Juvenile and adult great reed warblers were potentially able to cover 1660 km from Turkey, which was also supported by very low numbers of individuals caught at the Egyptian ringing sites. The results of this study carried out in the key regions of the eastern European–African flyway documented that migration strategies differed between adults and juveniles of three long-distance migrant species, yet this variation depended on the migration stage and the proximity of natural ecological barriers. [ABSTRACT FROM AUTHOR]

Flight range, endurance, maneuverability, and agility are the key elements that determine an aircraft's performance. Both conventional and morphing wing aircraft have been well studied and estimated in all aspects of performance. When considering the performance of morphing aircraft, most works address aspects of the aerodynamical performance such as L and D as well as flight envelopes for flight dynamics and control perspectives. However, the actual benefits of adopting morphing technologies in practical aspects such as aircraft operation, mission planning, and sustainability have not been addressed so far. Thus, this paper addresses the practical aspect of the benefits when adopting a camber morphing wing aircraft. Identical geometrical and computational conditions were applied to an already-existing aircraft: the RQ-7a Shadow. The wing structure was switched between a fixed wing and a camber morphing wing to generate conventional and morphing wing geometries. The fixed-wing cases had varying flap deflection angles, and the camber morphing wing cases had varying camber rates from 4% to 8%. Once the C L values of the fixed and morphing wing cases were matched up to two significant figures, the C D and C L / C D were analyzed for these matching cases to calculate the flight endurance, range, and improvement. When NACA 6410 is adopted, a 17% improvement in flight range and endurance average was expected. In the case of NACA 8410, an average 60% improvement was expected. [ABSTRACT FROM AUTHOR]

Estimating fuel load and potential flight ranges of migrant passerines are basic issues in understanding bird migration strategies. Thirteen sub-Saharan and three pre-Saharan migrant passerine species were analysed in this study. The birds were captured at the Tömörd Bird Ringing Station in the western part of the Carpathian Basin. A general linear model with body mass as the dependent variable and fat score, muscle score and wing length as independent variables were used to estimate lean body mass (body mass without fuel deposits) and fuel load. In ten of the species studied, models considering interactions between factors fit the data better than the main-effect models. Body mass was positively correlated with the fat score in all species, with muscle score in ten species and wing length in 14 species. During autumn, fuel load tended to be larger in the sub-Saharan migrants, especially in four species which pass over the Mediterranean Sea, Common Nightingale (Luscinia megarhynchos), Icterine Warbler (Hippolais icterina), Garden Warbler (Sylvia borin) and Barred Warbler (Curruca nisoria). Nine sub-Saharan migrants, Marsh Warbler (Acro- cephalus palustris), Sedge Warbler (A. schoenobaenus), Eurasian Reed Warbler (A. scirpaceus), European Pied Flycatcher (Ficedula hypoleuca), Spotted Flycatcher (Muscicapa striata), Wood Warbler (Phylloscopus sibilatrix), Willow Warbler (Ph. trochilus), Common Whitethroat (C. communis) and Lesser Whitethroat (C. curruca) had estimated flight ranges similar (<1300 km) to two pre-Saharans, European Robin (Erithacus rubecula) and Eurasian Blackap (S. atricapilla). The three short-distance migrants, including the Common Chiffchaff (Ph. col- lybita) with the shortest distance, had sufficient fuel load to reach their southern European wintering sites without needing to refuel at stopover sites. [ABSTRACT FROM AUTHOR]

A problem facing world commercial aviation is a provision of the flight range and an increase in the fuel efficiency of transport category airplanes using fuel trim transfer application, which allows for decreasing airplane trim drag at cruise flight. In the existing mathematical models, center-of-gravity position is usually assumed fixed, but with fuel usage, center-of-gravity shifts within the definite range of center-of-gravity positions. Until the fuel trim transfer was not used in airplanes, the center-of-gravity shift range was rather short, that allowed to use the specified assumption without any considerable mistakes. In case of fuel trim transfer use, center-of-gravity shifts can reach 15…20 % of mean aerodynamic chord, that requires considering the center-of-gravity actual position during the flight range calculation. Early made estimated calculations showed the necessity of following mathematical model improvement using accounting the real engine throttling characteristics. The goal of this publication is to develop a method of flight range calculation taking transport category airplane into account actual center-of-gravity position with fuel using and variation in engine-specific fuel consumption according to their throttling characteristics. On the basis of real data from engine maintenance manuals, formulas are obtained for approximation throttling characteristics of turbofan engines in the form of dimensionless specific fuel consumption (related to the specific fuel consumption at full thrust) dependence on the engine throttling coefficient. A mathematical model (algorithm and its program implementation using С language in Power Unit 11.7 R03 system) has been developed to calculate the airplane flight range accounting its actual center-of-gravity position shift with fuel usage and variation in specific fuel consumption according to engine throttling characteristics. Using comparison with known payload-range diagram, adequacy of developed mathematical model is shown. Recommendations to improve the mathematical model are also given.

Pollinator conservation is aided by knowledge of dispersal behavior, which shapes gene flow and population structure. In many bees, dispersal is thought to be male-biased, and males’ movements may be critical to maintaining gene flow in disturbed and fragmented habitats. Yet male bee movements are challenging to track directly and male dispersal ability remains poorly understood in most species. Here, we combine field manipulations and models to assess male dispersal ability in a stingless bee (Tetragonula carbonaria). We placed colonies with virgin queens at varying distances apart (1–48 km), genotyped the males that gathered at mating aggregations outside each colony, and used pairwise sibship assignment to determine the distribution of likely brothers across aggregations. We then compared simulations of male dispersal to our observed distributions and found best-fit models when males dispersed an average of 2–3 km (>2-fold female flight ranges), and maximum of 20 km (30-fold female flight ranges). Our data supports the view that male bee dispersal can facilitate gene flow over long-distances, and thus play a key role in bee populations’ resilience to habitat loss and fragmentation. In addition, we show that the number of families contributing to male aggregations can be used to estimate local stingless bee colony densities, allowing population monitoring of these important tropical pollinators.

The great reed warbler Acrocephalus arundinaceus is a common migrant through the Western Palearctic. However, its migration strategy, especially the spatiotemporal pattern of accumulation and utilisation of energy stores en route, is poorly known. Using ringing data collected at distant stopover sites located from Central Europe to Asia Minor, we observed that pattern in juvenile great reed warblers migrating along the eastern European flyway in autumn. We analysed body condition and stopover duration and estimated potential flight ranges for this species, taking into account two large ecological barriers – the Mediterranean Sea and the Sahara Desert – which it crosses during its southward migration. In Central and South-Eastern Europe the seasonal trends in body condition were similar and non-linear, with low values in August (i.e., during intensive migration of Acrocephalidae), and then a significant increase from the beginning of September until the end of the month. Estimated potential flight ranges showed that individuals migrating through Central and South-Eastern Europe might generally reach only the northern coast of the Mediterranean Sea. On the other hand, those flying from Asia Minor were able to reach the northern edge of the Sahel zone, crossing two large ecological barriers without refuelling. Therefore, it seems that great reed warblers change their autumn strategy en route: first, they migrate in short steps with low energy reserves through continental Europe; and then, after intensive refuelling before the Mediterranean Sea, they reach sub-Saharan Africa in a long flight. Based on the analysis of ringing data from several stopover sites, we show the complex pattern of how a long-distance migratory species accumulates and utilises its energy stores en route.

Abstract Background Understanding the dispersal dynamics of invasive mosquito species is fundamental to improve vector surveillance and to target control efforts. Aedes albopictus has been deemed a poor flyer as its range of active dispersal is generally assumed to be limited to a few hundred metres, while laboratory studies suggest this mosquito could actually fly several kilometres. The discrepancy may be due to differences in the local environment or to the methodological approach. In Switzerland, Ae. albopictus has been present since 2003 and has since then expanded its range. While passive dispersal is a key driver, it remains unclear how far this mosquito spreads through active flight and what the age structure and size of the local population are, all important parameters for vector surveillance and control. Method We investigated the active dispersal, daily survival rate and population size of Ae. albopictus in mark-release-recapture studies in Coldrerio and Lugano, two areas of intensive control in Switzerland. To mark mosquitoes emerging from breeding sites, we used self-marking units with fluorescent pigment that have minimal impact on mosquito survival and behaviour. We recaptured the adult mosquitoes with BG-Sentinel traps within a radius of 1 km from the marking units over 22 consecutive days. Results We found that 77.5% of the recaptured Ae. albopictus individuals flew further than 250 m, the limit that is usually deemed sufficient for vector containment. The average age of females and males was 8.6 days and 7.8 days in Coldrerio and Lugano, respectively, while the estimated mosquito population densities were 134 mosquitoes/ha in Coldrerio and 767 mosquitoes/ha in Lugano. Conclusions Self-marking units are an effective tool to mark wild mosquitoes. Using this approach, we found that mosquitoes survive long enough to potentially transmit arboviral disease in our study area and that host-seeking Ae. albopictus females may travel further than previously assumed for European mosquito populations. This finding has direct implications for vector control as emergency treatments around positive cases, as well as surveillance and control around detections of new infestations, might need to be extended beyond the usual recommended range of just a few hundred metres.

ABSTRACT The aim of the study was to investigate the flight range and foraging behavior of the stingless bee Plebeia aff. flavocincta, as well as testing its attraction to different sugar syrup concentrations within different distances to the colony. Foraging pattern along the day, preference of bees for sugar concentration in nectar and their relationship with distance from the colony were assessed by the means of manipulating those parameters with artificial flowers containing different sugar syrup concentrations and displayed at varying distances. The bees P. aff. flavocincta foraged from 6 a. m. to 5:30 p. m., with a foraging peak from 9 a. m. to 11:30 a. m. and showed preference for higher syrup concentrations (60% and 70%) though have foraged indiscriminately in all tested sugar concentrations and varying distances. We have concluded that due to its small body size, this species needs higher temperatures to forage when compared to large-body species, and shows preference for more concentrated sugar sources, but also explores the food source with lower sugar concentrations within their flight range. Such strategy may help to understand how a small-sized and short-flight bee such as P. aff. flavocincta achieved a vast geographic distribution in the country and is well succeeded in colonizing highly anthropized areas where natural sources of nectar are usually scarce within short distances.

Copyright of Transactions on Aerospace Research is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bee flight capacity determines the area that a colony can exploit, and this knowledge is essential to formulate management and conservation strategies for each species. In this study, we evaluated the flight capacity of Melipona seminigra using radio frequency identification (RFID). Three questions were addressed: Do the RFID tags affect the flight of M. seminigra workers? What is the effect of the landscape on foraging activity? Does the time since the colony was re-established affect the flight range of foragers? Our results indicate that the RFID tag used does not affect the flight ability of M. seminigra. Bees marked with nontoxic paint vs. RFID tags had the same return ratio and return time to the colony of origin. Flight capacity was affected by the landscape, because the return rate to the colonies was higher from the tested vegetated area than from the sterile area. The time elapsed since the bee colony re-establishment also affected the flight range because the return rate increased with time since the colony was relocated in the new site. We estimate that M. seminigra workers make foraging flights of approximately 1000 m from the colony and that the maximum flight range is 5000 m. Colonies of this species take more than 1 or 2 months to be able to fully exploit a landscape. [ABSTRACT FROM AUTHOR]

The great reed warbler Acrocephalus arundinaceus is a common migrant through the Western Palearctic. However, its migration strategy, especially the spatiotemporal pattern of accumulation and utilisation of energy stores en route, is poorly known. Using ringing data collected at distant stopover sites located from Central Europe to Asia Minor, we observed that pattern in juvenile great reed warblers migrating along the eastern European flyway in autumn. We analysed body condition and stopover duration and estimated potential flight ranges for this species, taking into account two large ecological barriers – the Mediterranean Sea and the Sahara Desert – which it crosses during its southward migration. In Central and South-Eastern Europe the seasonal trends in body condition were similar and non-linear, with low values in August (i.e., during intensive migration of Acrocephalidae), and then a significant increase from the beginning of September until the end of the month. Estimated potential flight ranges showed that individuals migrating through Central and South-Eastern Europe might generally reach only the northern coast of the Mediterranean Sea. On the other hand, those flying from Asia Minor were able to reach the northern edge of the Sahel zone, crossing two large ecological barriers without refuelling. Therefore, it seems that great reed warblers change their autumn strategy en route: first, they migrate in short steps with low energy reserves through continental Europe; and then, after intensive refuelling before the Mediterranean Sea, they reach sub-Saharan Africa in a long flight. Based on the analysis of ringing data from several stopover sites, we show the complex pattern of how a long-distance migratory species accumulates and utilises its energy stores en route. [ABSTRACT FROM AUTHOR]

For five consecutive years (2001–2005), during a one-month period in August–September, we studied the turnover of juvenile Ruddy Turnstones Arenaria interpres at a tidal area along the Dutch coast, by colour-marking cohorts of migrants. Taking turnover into account revealed that 1.8–2.4 times as many juvenile birds used the area during their southward migration, compared to the numbers based on maximum counts. This larger estimate amounts to 35% of the number at which the 1% criterion of the Ramsar Convention is met, whereupon a wetland is designated as internationally important, with significant implications for conservation commitments. Presuming adult birds had the same turnover factor, adult birds contributed almost 70% to the 1% criterion during the same period. Autumn migration of juvenile Ruddy Turnstones was rapid, with more than 50% of individuals leaving within 4 days (95%-CI: 3.4–4.6). The mean mass at departure, as derived from median staging duration and mean body mass gain from recaptured birds (1.1 g/d), was 104.3 g (±10.3 SD). The mean potential flight range as calculated using the aerodynamic approach by Pennycuick was 1981 km (±717 SD), which suggests that juvenile birds that leave the area can cover short to medium distances at most. The fuel loads are sufficient to reach one of the four key wintering sites along the coast of France, but not the Banc d'Arguin in Mauretania, which is the first key wintering site in West Africa. By early October, 80% of the birds had left the study area. Our study shows the importance of a small tidal area during autumn migration and raises the question of whether a considerable number of comparable small stopover sites along the coast of Western Europe and West Africa are needed. More attention to the designation and the protection of such sites and the achievement of a network would have the potential to greatly support juvenile birds on their first journey south. [ABSTRACT FROM AUTHOR]

For migratory landbird species, large expanses of open water or inhospitable areas provide unique challenges during migration. Research on the strategies that species use to navigate barriers can yield insights into the factors shaping the evolution of migration and facilitate the identification of critical staging areas prior to barrier crossing. One such barrier, the Caribbean Sea, has received little study but must be negotiated by 50 migratory landbirds as they fly from South America to North America in spring. Recent discoveries from the gray-cheeked thrush Catharus minimus, which undertakes non-stop flights >3000 km across the Caribbean Sea, raises the possibility that the breadth of potential strategies has been unappreciated thus far. We calculated fuel load and potential flight range in 9985 individuals of 16 species captured over 10 years at two stopover sites in northern Colombia to 1) evaluate the likely migratory strategy of these species as they depart northern Colombia in spring, and 2) evaluate the influence of family, diet, morphology and migratory distance on potential flight range. We found considerable variation in flight ranges and therefore strategies for crossing the Caribbean Sea/Gulf of Mexico barrier complex. In addition to gray-cheeked thrush, non-stop flights >2500 km were possible in yellow-billed cuckoo Coccyzus americanus, yellow warbler Setophaga petechia and northern waterthrush Parkesia noveboracensis. The remaining species were either capable of over-water flights to the Yucatan Peninsula/Cuba (>1800 km) or shorter flights to middle Central America (>1000 km) and likely required one or more stopovers to reach North America. Predicted flight ranges were influenced by morphology but not by distance, diet or taxonomic group, providing a novel insight into the evolution of migratory strategies. Our study confirms the vital role northern Colombia performs in providing energy for migratory birds and highlights the Caribbean as a key migratory barrier for many species. [ABSTRACT FROM AUTHOR]

The article considers several solid ethinyl derivatives (actually existing diethinylbenzene and a number of compounds not yet synthesized) as potential dispersants of fuels for direct-flow rocket engines. The density and enthalpy of the formation of the considered hypothetical ethinyl derivatives are estimated. Some of important parameters are studied characterizing their effectiveness as dispersants. The calculation and parametric studies of the effectiveness of the compounds as fuel components for direct-flow rocket engines of specific atmospheric aircraft of the Meteor-type are carried out, the results of which confirm their efficiency. [ABSTRACT FROM AUTHOR]

Determining bee flight capacity is crucial for developing management strategies for bee conservation and/or crop pollination and purposes. In this study, we determined the flight distance of the stingless bee Melipona fasciculata using the radiofrequency identification (RFID) technology. For this, we conducted two translocation experiments using workers equipped with RFID microsensors: (1) release of bees at seven distances between 100 and 3000 m from experimental colonies in Belém, Brazil, and (2) at six distances between 1500 and 10,000 m at Carajás National Forest Reserve. Return rates of workers were negatively correlated to release distance, with typical flight distances of 2 km, but a maximum homing distance of 10 km. Use of RFID tags revealed how past experiments may have greatly underestimated homing abilities of stingless bees. [ABSTRACT FROM AUTHOR]

Migration theory has largely overlooked the role of overwintering grounds and yet many migratory animals spend most of the annual cycle there. High winter site familiarity could confer considerable advantages on animals preparing for subsequent migration phases, enabling them to maximize migration speed and minimise the use of unknown stopover sites. Despite this, quantitative studies of the magnitude of fuel stores attained at such sites are lacking. To evaluate the energetic contribution of an overwintering site to spring migration, we used manual and automated telemetry to estimate departure date, departure fuel load, flight range and breeding destination of blackpoll warblers (Setophaga striata) wintering in Colombia. Relative to overwinter mass, warblers increased body mass (a surrogate for fuel stores) by an average of 59% prior to departure from the overwintering site. Flight range (mean 2710 km, range 2110–3380 km, N = 16) and detections at automated telemetry stations in North America suggest movements to Cuba/southeastern US, before refuelling and then continuing towards breeding grounds in eastern Canada (total duration ∼ 30 days). Total migration length was ∼ 5350 km and energy acquired at the overwintering site was sufficient to cover 39–63% (mean = 50%), demonstrating the major contribution tropical wintering grounds can make to migration. It follows that varying the extent of fuelling prior to departing overwintering sites may provide animals with a mechanism for balancing their exposure to risk during migration, while simultaneously allowing for flexibility in migratory schedules in a changing world. • Optimal migration theory has largely overlooked the function of wintering sites. • Extensive fuelling at such sites could maximize migration speed and reduce risk. • Blackpoll warblers stored enough energy at a tropical wintering site to fly 2710 km. • Mean flight range was equivalent to 50% of the total migratory journey. • Wintering sites can have an intrinsic role in shaping migratory strategies. [ABSTRACT FROM AUTHOR]

Short-tailed shearwaters Puffinus tenuirostris migrate annually from breeding areas in southeast Australia and Tasmania to the Bering Sea to feed on abundant prey aggregations, mainly euphausiids. Occasionally thousands of shearwaters die of starvation en route, within, or on return from the Bering Sea. Collection of live and dead shearwaters in the southeastern Bering Sea in 1997, 1998, and 1999 allowed us to measure seasonal changes in energy reserves during a major mortality event. As birds lost body mass, lipid mass initially decreased faster than that of pectoralis muscle, but loss of pectoralis mass increased markedly at a body mass around 500 g when lipids were almost depleted (∼33 g remaining). Death occurred as body mass approached 426 g. Individuals near this body mass had lipid values permitting estimated flight ranges of 140 to 400 km, a range less than that potentially covered in 1 d by shearwaters searching for prey (440 to 1124 km d-1). Seasonal differences in body composition were most striking among body and bone marrow lipid contents, with the lowest values occurring during the die-off in fall 1997 and in fall 1998. The lack of shearwater mortality in fall 1998 may have resulted from more consistent winds that decreased flight costs and from greater availability of alternative fish prey. Our data allow estimates of usable energy stores and flight ranges based on lipid reserves in short-tailed shearwaters. Estimated flight ranges suggest that if feeding conditions are poor near Japan or near other termination points of the transequatorial migration routes shearwaters may have few reserves available to support foraging for food and starvation events may occur. Our findings suggest how their energetic strategies and migration are shaped by seasonal and annual variability of prey during transglobal movements of short-tailed shearwaters between oceanic regions.

A comparative evaluation of the use of various metals and nonmetals as fuel components of a solid propellant containing ammonium perchlorate as an oxidizer and rubber as a binder was performed using the flight range criterion of a rocket-ramjet aircraft taking into account the expected completeness of combustion of individual components. The influence of the energetic properties of the propellant on the technical and economic characteristics and flight performance of the aircraft was also taken into account. The aircraft flight range was calculated by numerical integration of flight dynamics equations. Based on the results, it is recommended that a number of fuel components should be studied in more detail, in particular, for the purpose of the full or partial replacement of boron currently used in solid propellants for rocket-ramjet engines. [ABSTRACT FROM AUTHOR]

In contrast to the rapidly growing body of knowledge on migratory routes, wintering grounds and timing of annual life cycle events of migratory birds, knowledge on how migratory songbirds refuel at stopover sites along the Asian–Australasian flyway has increased only slowly, despite the fact that migrant birds show declining trends along it. We analysed the amount and variation of energy stores between species, variation of energy stores within the day and within the season, and estimated flight ranges of ten closely related warbler species (genera Acrocephalus, Arundinax, Locustella and Phylloscopus), captured at a stopover site in the Russian Far East during the autumn migration. We found significant differences in the species' energy stores, with Pallas's Leaf Warbler Phylloscopus proregulus having by far the highest. All species increased their energy stores within the day, and eight species increased their energy stores within the season. Individuals with the highest estimated flight ranges were able to cover a distance of 470 km during one nocturnal flight bout, which would have resulted in a minimum of nine stopovers before the birds reached their wintering grounds. We assume that a combination of factors determines the variation in energy stores between these species. We discuss the potential for these birds to exploit different habitats and refuelling strategies according to the distribution of species-specific refuelling habitats, and a variety of food resources, along the migratory route. This study is the first to provide information on energy stores, refuelling strategies and flight ranges for a set of closely related songbird species migrating along the Asian–Australasian flyway. [ABSTRACT FROM AUTHOR]

Background: Understanding the dispersal dynamics of invasive mosquito species is fundamental to improve vector surveillance and to target control efforts. Aedes albopictus has been deemed a poor flyer as its range of active dispersal is generally assumed to be limited to a few hundred metres, while laboratory studies suggest this mosquito could actually fly several kilometres. The discrepancy may be due to differences in the local environment or to the methodological approach. In Switzerland, Ae. albopictus has been present since 2003 and has since then expanded its range. While passive dispersal is a key driver, it remains unclear how far this mosquito spreads through active flight and what the age structure and size of the local population are, all important parameters for vector surveillance and control. Method: We investigated the active dispersal, daily survival rate and population size of Ae. albopictus in mark-release-recapture studies in Coldrerio and Lugano, two areas of intensive control in Switzerland. To mark mosquitoes emerging from breeding sites, we used self-marking units with fluorescent pigment that have minimal impact on mosquito survival and behaviour. We recaptured the adult mosquitoes with BG-Sentinel traps within a radius of 1 km from the marking units over 22 consecutive days. Results: We found that 77.5% of the recaptured Ae. albopictus individuals flew further than 250 m, the limit that is usually deemed sufficient for vector containment. The average age of females and males was 8.6 days and 7.8 days in Coldrerio and Lugano, respectively, while the estimated mosquito population densities were 134 mosquitoes/ha in Coldrerio and 767 mosquitoes/ha in Lugano. Conclusions: Self-marking units are an effective tool to mark wild mosquitoes. Using this approach, we found that mosquitoes survive long enough to potentially transmit arboviral disease in our study area and that host-seeking Ae. albopictus females may travel further than previously assumed for European mosquito populations. This finding has direct implications for vector control as emergency treatments around positive cases, as well as surveillance and control around detections of new infestations, might need to be extended beyond the usual recommended range of just a few hundred metres. [ABSTRACT FROM AUTHOR]

The applicability of 1,4-diethynylbenzene (DEB) as a dispersant of solid fuels was studied. The atmospheric flight ranges of an aircraft with a rocket ramjet engine operating on fuels with DEB dispersant and wth high-enthalpy dispersants containing not only carbon and hydrogen, but also nitrogen and oxygen, were compared. Fuels with DEB are much more efficient in terms of this performance characteristic. The regularities of gasification of solid propellants comprising DEB, a binder, and ammonium perchlorate were studied experimentally. 1,4-Diethynylbenzene containing no oxidizing elements in the molecule can burn by itself due to the high enthalpy of formation (ΔH°f) in the 2–6 MPa pressure range. The dependences of the combustion rate on the pressure and on binder and ammonium perchlorate contents were elucidated. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of habitat choice on fuelling behaviour and the organization of migration in birds has rarely been examined, despite the potential impact of widespread anthropogenic transformation of stopover regions. High energetic requirements in migrating birds mean that resource abundance, through its influence on fuel deposition rates (FDR), is expected to be the main determinant of stopover and migration strategy. We examined the spring stopover of Tennessee Warblers (Oreothlypis peregrina) in northern Colombia, evaluating how diet, FDR, stopover duration, departure mass and estimated flight range varied between two commonly used stopover habitats: shade coffee plantations and pre-montane forests. Diet included insects in both habitats, but fruit was only consumed in pre-montane forest, where FDR was highest (FDR forest = 2.4% LBM/day; coffee = 0.5% LBM/day). Three different estimates of stopover duration suggested longer stays in coffee but lengthier durations did not result in equivalent departure mass between habitats, such that estimated flight range was twice as long for birds departing forest (2000 km) relative to coffee (1088 km). We conclude that stopover performance differed between habitats, likely influencing the subsequent temporal and spatial organization of spring migration. On the basis of flight ranges, stopovers in shade coffee may also increase the risks of trans-Caribbean flights, suggesting a mechanism by which stopover habitat could directly influence survival. Given that fruit consumption in forest probably explains these differences, we recommend the identification of appropriate fruiting trees for Neotropical agroforestry systems that can tolerate a variety of conditions and increase the quality of these anthropogenic habitats for migratory and other frugivorous birds. [ABSTRACT FROM AUTHOR]

The possibility of replacing the currently widely used ammonium perchlorate as an oxidizing agent (dispersant) in the composition of solid boron-containing fuels for aircraft with rocket ramjet engine was considered by dispersants with reduced nitrogen and oxygen content with a high enthalpy of formation (more than 2 MJ kg−1) and capable of gasifying solid fuels. The efficiency of fuels with high enthalpy dispersants was evaluated in an optimization setting according to the flight range criterion of the aircraft taking into account the complete combustion of fuel in the afterburner chamber. A number of the most effective dispersants were recommended for further study. [ABSTRACT FROM AUTHOR]

The efficacy of natural enemies in controlling pests under field conditions is largely correlated with their capacity to spread within infested crops. In this study the spatial dispersal of the California red scale parasitoid Aphytis melinus DeBach (Hymenoptera: Aphelinidae) was evaluated in the field after augmentative releases. The experiment was conducted in 2007 in six 1-ha plots in a Sicilian citrus orchard under integrated pest management. A total of 180,000 A. melinus adults was released in each of three plots and the other plots were left as untreated control. The flight range of the parasitoid was evaluated, for 35 days after the release, on 16 trees per each plot, located at 20 and 40 m from the central release point using yellow sticky traps activated with Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae) sexual pheromone and by monitoring the percentage parasitism of the scale on fruits and twigs. The effects of the distance from the release point and density of susceptible stages of host on parasitoid dispersal were evaluated. The number of wasps captured during the whole trial was greater in the traps located 20 m from the release point than in those at 40 m and in the control plots. Aphytis melinus dispersed over distances less than 40 m based on both the lower percentage parasitism and numbers captured recorded at distances of 40 m. The results are discussed in the context of the biological control of California red scale in citrus orchards by means of wasp releases. In particular, the release points should be no more than 40 m apart for a quick and homogeneous colonization of the area treated.

Stingless bee males (Hymenoptera: Apidae) aggregate themselves for reproductive purposes. The knowledge of relatedness among the males attending the aggregations and the distance that they disperse from their natal nests to aggregations may provide important data to effectively conserve these bees. Here, we estimated these properties for Tetragonisca angustula (Latreille, 1811) males. Microsatellite molecular markers were used to genotype bees sampled from local nests and in mating swarms in order to identify the nests of origin of males and maternal genotypes of concerning queens. The distances from assigned nests to the mating swarms allowed us to estimate the distances travelled by males. A genetic relationship analysis was conducted to verify whether T. angustula males were closely related to nests where they aggregated. A pairwise relatedness analysis was also performed among all T. angustula males in each mating swarm. Our results demonstrated that T. angustula mating swarms received dozens to hundreds of males from several colonies (up to 70). Only two of the five mating swarms contained any males that were closely related to the bees from the new nests in construction. The relatedness among males was also extremely low. Yet, dispersal distance of T. angustula males ranged hundreds of meters up to 1.6 km, with evidence of reaching 2.25 km according to their flight radius obtained from their foraging area for locality. These data indicate a highly efficient mating system with minimal inbreeding in this bee species, with a great dispersal capability not previously found for stingless bee males. [ABSTRACT FROM AUTHOR]

The article is dedicated to the substantiation of the complex parameter that characterizes the technical level of an unmanned aerial vehicle (UAV). This parameter includes the maximum lift-to-drag ratio, propeller efficiency, specific fuel consumption, and other components, on which the main flight characteristics, such as flight range and flight duration, depend. To make a comparative assessment of UAVs of different types, a special scale is developed. First published online: 14 January 2016

The distance a bee can fly is quite relevant, among other aspects, for successful pollination. The objectives of this study were to verify the maximum distance a forager of Meliponamandacaia can flyand whether experience is relevant for it. Five colonies were used to collect foragers, which were marked and released from and each 100m, up to a maximum distance on which there would be no bee returning. To evaluate the influence of experience, after being marked, bees were put back into colonies, collected again after eight days, and released in five distances only (500m-2,500m). In both experiments as the distance increased, the returning success decreased significantly. The maximum distance a translocated bee returned to its hive was 2,700m. The percentage of success was very high for bees released at 500 and 1,000m (100% and 77%, respectively), suggesting this is the common flight range for the species. In most cases, average percentage of success was significantly higher for experienced bees than for the other bees reinforcing that experience is quite important for returning to the nest.

The article is dedicated to the substantiation of the complex parameter that characterizes the technical level of an unmanned aerial vehicle (UAV). This parameter includes the maximum lift-to-drag ratio, propeller efficiency, specific fuel consumption, and other components, on which the main flight characteristics, such as flight range and flight duration, depend. To make a comparative assessment of UAVs of different types, a special scale is developed. [ABSTRACT FROM AUTHOR]

Preliminary investigations were carried out to determine the insect behavior of Tuta absoluta towards different factors. Observations showed that the moth is nocturnal in habits. It is most active at dusk and dawn and rest among leaves of the host plant during the day, showing greater morning-crepuscular activity. It prefers to infest leaves of its host plants followed by sepals, leaf neck and stem. Also, the apical part of the tested plants showed to be more attractive to the females‘ oviposition compared to the median and basal parts. The best time for mating started in the morning. The insect can discriminate between different host plants. It showed more preference to tomato followed by black nightshade, eggplant, potato and pepper. The larvae are sensitive to light and it prefers the dark zones. The larvae with its taste receptors are able to discriminate between host plants and other chemicals. For instance, it showed great sensitivity to various sugars in varying degrees. The flight range of the moth was determined and it showed the ability to fly for a distance of 0.4 km overnight. [ABSTRACT FROM AUTHOR]

Africanized honeybees from five colonies were marked with P-32 and taken to an apple grove for a flight behavior study. The method used to determine the flight range was to put out an array of tagged trees in a cross pattern with the colonies arranged in the center point of a 0.8 ha test area. The tagged trees were located 10 meters apart in the 4 rows of 50 meters each, arranged according to the North, South, East, and West directions. Bees were collected while visiting the tagged tree flowers twice a day, during a ten-day period. The number of honeybees marked decreased in relation to the distance from the hives. Analysis of variance showed that a linear regression was highly significant to describe the process. Geographic directions did not affect the activity of the bees.

The article presents a study which examined the age and sex differences in fuel load and biometrics of aquatic warblers acrocephalus paludicola at an autumn stopover site in the Loire Estuary in the northwest of France. Morphometric traits of 176 individuals captured at the site in relation to age and sex were observed. Significant sex differences in wing length, third primary feather length and body mass, with males being longer winged and heavier than males, were found.

The article focuses on a study which compared patterns in primary moult and body mass of Greenshanks Tringa nebularia caught at inland wetlands in Zimbabwe, and on the east and west coasts of South Africa. It concludes that Greenshanks caught at inland wetlands of Zimbabwe experience a shorter return migration distance and lower competition in comparison to coasts and get abundant food during the entire austral summer.

A system of differential equations of the variable-mass body spatial motion was solved on the basis of a modern technique for calculating aerodynamic coefficients and inertial-mass characteristics of aircraft. The best working parameters of a jet engine were chosen to increase the flight range on retention of the optimal jet engine dimensions. [ABSTRACT FROM AUTHOR]