Increased Flight Duration Research Articles

Flying Drosophila show sex-specific attraction to fly-labelled food

Animals searching for food and sexual partners often use odourant mixtures combining food-derived molecules and pheromones. For orientation, the vinegar fly Drosophila melanogaster uses three types of chemical cues: (i) the male volatile pheromone 11-cis-vaccenyl acetate (cVA), (ii) sex-specific cuticular hydrocarbons (CHs; and CH-derived compounds), and (iii) food-derived molecules resulting from microbiota activity. To evaluate the effects of these chemicals on odour-tracking behaviour, we tested Drosophila individuals in a wind tunnel. Upwind flight and food preference were measured in individual control males and females presented with a choice of two food sources labelled by fly lines producing varying amounts of CHs and/or cVA. The flies originated from different species or strains, or their microbiota was manipulated. We found that (i) fly-labelled food could attract—but never repel—flies; (ii) the landing frequency on fly-labelled food was positively correlated with an increased flight duration; (iii) male—but not female or non-sex-specific—CHs tended to increase the landing frequency on fly-labelled food; (iv) cVA increased female—but not male—preference for cVA-rich food; and (v) microbiota-derived compounds only affected male upwind flight latency. Therefore, sex pheromones interact with food volatile chemicals to induce sex-specific flight responses in Drosophila.

Unmanned aerial system based spectroradiometer for monitoring harmful algal blooms: A new paradigm in water quality monitoring

Water quality issues continue to impact recreational and resource use of waterways in the Great Lakes and across smaller inland water bodies in their watersheds. With the advancements in small unmanned aerial systems (sUAS) and in small sensor production, sUAS offer flexibility to overcome several of the shortcomings of satellite and airborne systems, and complement their measurements in this environment. In this study, we deployed two different low-cost, boat launchable sUAS configurations instrumented with Ocean Optics STS hyperspectral Vis-NIR spectroradiometers capable of making measurements over an approximately 2.5 km2 area, below the cloud deck in the nearshore and open lake environment. Flights of these systems were conducted at ten locations over Lake Erie and the Maumee River. Measured spectra compared well with at-surface based Analytical Spectral Devices (ASD) Fieldspec measured spectra, and derived parameters were consistent with in-water FluoroProbe measured water quality parameters and field observations. Using flight data, we constructed transect maps of derived CI products which show the variability in algae abundance in open water. These systems provide high quality, low cost, very high spatial resolution (cm to m scale measurements) hyperspectral data in the nearshore environment, can be consistently flown at low altitude (minimizing atmospheric effects) below cloud cover and can be deployed on extremely short notice. With the continued advancement in sensor development, automated flight capabilities, and increased flight duration from vertical take off and landing (VTOL) platforms, water quality observation platforms such as these will soon be a common tool in resource manager's toolboxes.

A common neonicotinoid pesticide, thiamethoxam, impairs honey bee flight ability

Pesticides can pose environmental risks, and a common neonicotinoid pesticide, thiamethoxam, decreases homing success in honey bees. Neonicotinoids can alter bee navigation, but we present the first evidence that neonicotinoid exposure alone can impair the physical ability of bees to fly. We tested the effects of acute or chronic exposure to thiamethoxam on the flight ability of foragers in flight mills. Within 1 h of consuming a single sublethal dose (1.34 ng/bee), foragers showed excitation and significantly increased flight duration (+78%) and distance (+72%). Chronic exposure significantly decreased flight duration (−54%), distance (−56%), and average velocity (−7%) after either one or two days of continuous exposure that resulted in bees ingesting field-relevant thiamethoxam doses of 1.96–2.90 ng/bee/day. These results provide the first demonstration that acute or chronic exposure to a neonicotinoid alone can significantly alter bee flight. Such exposure may impair foraging and homing, which are vital to normal colony function and ecosystem services.

Genetic effects on flight capacity in the beet armyworm,Spodoptera exigua(Lep., Noctuidae)

AbstractThe beet armyworm,Spodoptera exigua, is an important migratory insect pest in tropical and subtropical regions worldwide. The current study investigated genetic variation in the flight capacity of both female and male moths, using a quantitative genetics approach. The offspring–parent regression showed that parents had a significant influence on the flight duration of offspring, and the heritability estimated as 0.302. The upward selection increased mean flight duration from 123.7 to 284.6 min in females and from 113.9 to 254.0 min in males during 8 h of flight test; by contrast, downward selection decreased it from 123.7 to 65.6 min in females and from 113.9 to 29.8 min in males, while it did not change significantly in either females or males of the control line over eight generations. The mean realized heritability was estimated as 0.432 based on upward selection but 0.130 on downward selection, suggesting the asymmetry of response to selection on flight capacity. Reciprocal crosses between the two selected lines confirmed the dominance of ‘long‐flying genes’ in the inheritance of flight capacity. A positive genetic correlation was found between increased flight duration and pupal weight. The presence of such additive genetic variance and covariance for flight capacity and the fitness trait, pupal weight, in the population ofS. exiguamay have underpinned the evolution of its migratory behaviour.

Altitudinal life‐history variation and thermal adaptation in the copper butterfly Lycaena tityrus

Understanding how organisms adapt to complex environments lies at the very heart of ecology and evolutionary biology. Clinal variation in traits related to fitness suggests a contribution of directional selection, and analyzing such variation has consequently become a key element in investigating adaptive evolution. In this study we examine climatic adaptation in the temperate‐zone butterfly Lycaena tityrus across replicated populations from low‐, (mid‐) and high‐altitudes, each reared at two different temperatures. In common garden experiments, high‐ compared to low‐altitude populations showed a longer development time accompanied by reduced larval growth rates, increased cold‐ but decreased heat‐stress resistance, and increased flight duration across a range of ambient temperatures. In contrast, differences in morphological traits such as pupal mass or wing size were negligible, suggesting that morphology is not necessarily indicative of flight performance. While patterns in stress resistance traits suggest adaptation to local temperatures, development times between populations were associated with differences in season length (enabling a second generation at lower altitudes, while high‐altitude populations are monovoltine) rather than with temperature per se. Mid‐altitude populations showed either intermediate patterns or patterns resembling low‐altitude populations. Plastic responses to different rearing temperatures resulted, as expected, in reduced larval and pupal development times at higher temperatures accompanied by higher growth rates and decreased pupal mass. Further, butterflies reared at a lower temperature showed reduced chill‐coma recovery times and decreased heat knock‐down resistance as compared to those reared at a higher temperature. In summary, this study demonstrates local adaptations to regional climates, and that environmentally‐induced plasticity can be as important as genetic factors in mediating adaptive responses.

Exobiological investigations on Russian spacecrafts.

To investigate the possibility of prebiotic synthesis of organic molecules in open space, conditions involved irradiating nucleosides and inorganic phosphate during five Earth-orbiting Russian space missions that included Salut-7 (13- and 16-month missions), Mir, Bion-11, and Cosmos-2044. Dry films of samples were exposed from 2 weeks up to 16 months to the entire set of factors encountered in open space during Earth-orbiting missions. After each mission, products synthesized during flight and any compounds that remained undegraded were analyzed. The analyses demonstrated that increased flight duration led to the decay of both synthesized nucleotides and initial nucleosides. Corresponding laboratory experiments indicated that infrared radiation caused the greatest amount of decay to products of prebiotic reactions. Experiments revealed that 5'-mononucleotides were the main chemical products of the major derivatives synthesized of certain nucleosides. Exposure to ultraviolet (UV) C(145) was more effective than UVC(254) in producing a comparatively higher yield of mononucleotides, while the energy flux of the latter was one order of magnitude less (10(-7) as compared with 10(-6) for UVC(145)). In the course of the laboratory simulation experiments the heating of solid samples yielded the greatest production amount (6.34% for adenosine derivatives).

A realistic view of the future of scientific ballooning

The events of the past twenty years have brought about significant increases in the reliability of scientific balloon vehicles and operations. Scientists have enjoyed an unprecedented flight success ratio in recent years. Significant discoveries in the atmospheric science and space science disciplines have recently been made using balloon-borne instruments. Unfortunately, the number of balloon flights is decreasing each year and the number of new scientists using balloons is decreasing. In order for scientific ballooning to survive well into the twenty-first century, significant improvements must be made in the way technological advances are planned and coordinated. These improvements must be based on the needs of our customer scientists. This paper summarizes the technological advances made in recent years that will meet the ever growing needs of the science community. The advances in balloon technology include increased flight duration ability, heavy load capability using new launch techniques, and very high altitude capability using thin films. The advances have been driven largely by the development work in NASA's ULDB program. Other advances have improved the possibilities of building a successful stratospheric airship and also of building balloons for exploration of other planets.

The external respiration and gas exchange in space missions

Literature data and results of our own studies into an effect of micro- and macro-gravity on an external respiration function of man are presented. It is found that in cosmonauts following the 7–366 day space missions there is an enhanced tendency associated with an increased flight duration toward a decrease in the lung volume and breathing mechanics parameters: forced vital capacity of the lungs (FVC) by 5–25 percent, peak inspiratory and expiratory (air) flows (PIF, PEF) by 5–40 percent. A decrease in FVC appears to be explained by a new balance of elastic forces of the lungs, chest and abdomen occuring in microgravity as well as by an increased blood filling and pulmonary hydration. A decline of PIF and PEF is probalbly resulted from antigravitational deconditioning of the respiratory muscles with which a postflight decreased physical performance can in part be associated. The ventilation/perfusion ratios during orthostasis and +G Z and +G X accelerations are estimated. The biophysical nature of developing the absorption atelectases on a combined exposure to accelerations and 100% oxygen breathing is confirmed. A hypothesis that hypervolemia and pulmonary congestion can increase the tendency toward the development of atelectases in space in particular during pure oxygen breathing is suggested. Respiratory physiology problem area which is of interest for space medicine is defined. It is well known that due to present-day technologic progress and accomplishments in applied physiology including applied respiration physiology there currently exist sophisticated technical facilities in operation maintaining the life and professional working capacity of a man in various natural environments: on Earth, under water and in space. By the way, the biomedical involvement in developing and constructing such facilities has enabled an accumulation of a great body of information from experimental studies and full-scale trails to examine the effects of the changed environments both and its individual systems including an external respiration function. In this case, it should be remembered that the external respiration system has some physiological and morphological properties due to which the body systems are particularly subjected to environmental effects. Thus, according to figurative comparison by Evald Veible a contact area of the lungs with an external environment i.e. an alveolar surface is large and equaled approximately to tennis-court size, as the alveolocapillary membrane thickness is negligible and amounts to one fiftieth of a writing-paper sheet [1]. From this it follows that such a fine and highly organized structure must be extremely dependent upon any external exposures including gravitational ones since from the physical viewpoint of physics the lungs represent a quasiconical three-dimensional elastic body suspended in the thoracic cavity and in which there occur the gravity-induced internal tensions incrementing in a base-to-apices direction. As a result of these tensions, in the lungs various physical gradients: hydrostatic, pleural and transpulmonary pressures, pulmonary time constant, vertical gradient of the volume and structure of alveoli, etc. are developed.

Desiccation, Flight, Glycogen, and Postponed Senescence in Drosophila melanogaster

Drosophila melanogaster selected for postponed aging have increased resistance to desiccation and increased flight duration. These and other populations were tested for longevity, flight duration, glycogen content, and stress resistance under a variety of conditions. It was found that desiccation resistance was positively associated with flight duration and glycogen content, while glycogen was exhausted in the course of desiccation, as it is in flight Flies with postponed aging also have lower water-loss rates (WLRs) when dead, suggesting that factors other than glycogen content are partly responsible for their increased desiccation resistance. However, total epicuticular hydrocarbon does not appear to determine desiccation resistance. Starvation resistance does not vary in a manner that corresponds with desiccation resistance, under either selection or manipulation, but does vary in association with lipid level This suggests at least two physiological mechanisms by which aging has been postponed in these flies: increased lipid content and increased glycogen content. These mechanisms are at least somewhat independent, evolutionarily, genetically, and physiologically.

Influence of Environmental-Conditions on Flight Duration of Epiphyas-Postvittana (Walker) (Lepidoptera, Tortricidae)

Flight responses of the light brown apple moth, Epiphyas postvittana (Walker), to changes in air temperature, atmospheric humidity, feeding and mating activities were studied under controlled conditions. Flights occurred within the air temperature range from 10 to 30-degrees-C, with the longest flight duration at 20-degrees-C for both sexes. A change of atmospheric humidity significantly influenced flight duration of females, but not of males, at 20-degrees-C. The longest flight duration of the female moths occurred at a relative humidity of 60%. Provision of honey solution or water improved flight duration of the moths aged three days or older. Mating increased flight duration of females from the age of three days onwards, presumably as a result of reduced body weight associated with oviposition.