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Although theoretical work on optimal migration has been largely restricted to birds, relevant free-flight data are now becoming available for migratory insects. Here we report, for the first time in passion-vine butterflies, that Heliconius sara migrates directionally. To test optimal migration models for insects, we quantified the aerodynamic power curve for free-flying H. sara as they migrated across the Panama Canal. Using synchronized stereo-images from high-speed video cameras, we reconstructed three-dimensional flight kinematics of H. sara migrating naturally across the Panama Canal. We also reconstructed flight kinematics from a single-camera view of butterflies flying through a flight tunnel. We calculated the power requirements for flight for H. sara over a range of flight velocities. The relationship between aerodynamic power and velocity was "J"-shaped across the measured velocities with a minimum power velocity of 0.9 m/s and a maximum range velocity of 2.25 m/s. Migrating H. sara did not compensate for crosswind drift. Changes in airspeed with tailwind drift were consistent with the null hypothesis that H. sara did not compensate for tailwind drift, but they were also not significantly different from those predicted to maximize the migratory range of the insects.

Multimodal integration is a core neural process with a keen relevance during ecological tasks requiring learning and memory, such as foraging. The benefits of learning multimodal signals imply solving whether the components come from a single event. This challenge presumably depends on the timing and intensity of the stimuli. Here, we used simultaneous and alternate presentations of olfactory and visual stimuli, at low and high intensities, to understand how temporal and intensity variations affect the learning of a bimodal stimulus and its components. We relied on the conditioning of the proboscis extension response (PER) to train honey bees to an appetitive learning task with bimodal stimuli precisely controlled. We trained bees to stimuli with different synchronicity and intensity levels. We found that synchronicity, order of presentation, and intensity significantly impacted the probability of exhibiting conditioned PER responses and the latency of the conditioned responses. At low intensities, synchronous bimodal inputs produced maximal multisensory enhancement, while asynchronous temporal orders led to lower performances. At high intensities, the relative advantage of the synchronous stimulation diminished, and asynchronous stimuli produced similar performances. Memory retention was higher for the olfactory component and bimodal stimuli compared to the visual component, irrespective of the training's temporal configuration. Bees retained the asynchronous bimodal configuration to a lesser extent than the synchronous one, depending on the stimulus intensity. We conclude that time (synchrony), order of presentation, and intensity have interdependent effects on bee learning and memory performance. This suggests caution when assessing the independent effects of each factor. [ABSTRACT FROM AUTHOR]

Pollution produced by exposure to pesticides is a major concern for food security because the negative impacts on pollinators. Fipronil, an insecticide broadly used around the globe has been associated with the ongoing decline of bees. With a characteristic neuroactive toxicodynamic, fipronil leads to cognitive and motor impairments at sublethal dosages. Despite of regional bans, multilevel strategies are necessary for the protection of pollinators. Recent evidence suggests that specific nutrients in the diets of bees may induce protection against insecticides. Here, we evaluated whether the administration of three phytochemicals, namely rutin, kaempferol and p-coumaric acid provide protection to the Africanized honey bee Apis mellifera against oral administration of realistic dosages of fipronil. We tested the potential impairment produced by fipronil and the protection induced by the phytochemicals in learning, 24h memory, sucrose sensitivity and motor control. We found that the administration of fipronil induced a concentration-dependent impairment in learning and motor control, but not 24h memory or sucrose sensitivity across a 24h window. We also found that the administration of rutin, p-coumaric acid, kaempferol and the mixture was innocuous and generally offered protection against the impairments induced by fipronil. Overall, our results indicate that bees can be prophylactically protected against insecticides via nutrition, providing an alternative to the ongoing conflict between the use of insecticides and the decline of pollinators. As the studied phytochemicals are broadly present in nectar and pollen, our results suggest that the nutritional composition, and not only its production, should be considered when implementing strategies of conservation via gardens and co-cropping. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2005.04.013 Byline: Robert B. Srygley, Robert Dudley, Evandro G. Oliveira, Andre J. Riveros Abstract: We tested whether migrating Aphrissa statira butterflies orient with a magnetic compass. We captured migrants flying over Lake Gatun, Panama, and exposed experimental butterflies to a strong magnetic field. These and unmanipulated control butterflies were released back over the lake. Experimental butterflies had a more dispersed pattern of orientation than control butterflies. The average direction adopted was northeast, 160[degrees] anticlockwise to the natural migratory direction. Unmanipulated control butterflies adopted two diametrically opposed orientations: one shifted 33[degrees] clockwise, and another 147[degrees] anticlockwise, to the migratory direction. Control and experimental butterflies differed in that some controls oriented towards the migratory direction. These differences in orientation support the hypothesis of a sense for magnetic orientation cues. Unmanipulated butterflies released over the lake when the sky was completely overcast were significantly oriented towards their direction before capture (187[degrees] and 203[degrees], respectively), further supporting the magnetic compass hypothesis. In a third experiment, we obstructed sun compass cues and reversed the horizontal component of the local geomagnetic field to position magnetic north towards the geographical south pole within a flight arena into which we released individual butterflies. Experimental butterflies experiencing the reversed magnetic field oriented on average 180[degrees] opposite to their natural migratory direction. Control butterflies, for which the position of magnetic north was unaltered, were oriented both towards and 180[degrees] opposite to the natural migratory direction. This difference between orientations of control and experimental butterflies also supports the hypothesis of a sense for magnetic orientation cues. Author Affiliation: (a) Smithsonian Tropical Research Institute, Republic of Panama (a ) Department of Zoology, University of Oxford, U.K. (a ) Department of Integrative Biology, University of California-Berkeley, U.S.A. (As.) Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Brazil (aa) Departamento de Biologia, Universidad Nacional de Colombia, Colombia Article History: Received 30 January 2004; Revised 5 April 2004; Accepted 12 April 2005 Article Note: (miscellaneous) MS. number: 7987R

Flavonoids are among the secondary plant metabolites most intensely studied over the last decades. The reason for this surge in interest come from the evidence supporting multiple effects on human and animal health, particularly based on antioxidant functions. Importantly, among flavonoids, Quercetin, a naturally occurring molecule originally derived from the tree Quercus has been at the core of research. Quercetin has functions ranging from antioxidant to antiapoptotic, cell growth regulator, antidiabetics and anti-inflammatory. Following these findings, synthetic and naturally occurring Quercetin derivatives have received increasing attention. Focusing on derivatives enables an understanding of the pathways that underlie the activity of each molecule as each variant may target specific points along the pathway. In turn, understanding the structural and functional relationships among molecules will enable better targeting in biomedicine. Thus, we aimed to analyze the chemical structural similarity profiles among Quercetin and its derivatives, further identifying the biological functions and suggesting targets for research based on a literature review. As a result of these approaches, we built a similarity tree based on molecular structure and 2,326 traits extracted from NCBI through ChemmineR package for R. Following the review, we identified major biological activities and the main physiological systems and organs targeted by each derivative of Quercetin. Biological activities for each molecule were selected following a bibliographic search using the databases Web of Science, Scopus and PubMed. The complete records and cited references of the 38,185 identified manuscripts were imported into VOSviewer for the bibliometric analysis. We found that R-O-R' and R-O-S functional groups played a major role in the determination of the similarity profiles. Moreover, we found a large variation in the number of studies that focus on all molecules. The most studied systems were the nervous, liver, cardiac and immune, whereas the most studied functions were antioxidant, antibacterian, anti-inflammatory, antiviral, antineoplasic, and the inhibition of tyrosine kinase, MAO and TNF alpha. Based on these results we point at least 11 gaps of functions based on similarity and further discuss new targets. [ABSTRACT FROM AUTHOR]