Importance of olfactory and visuel cues of Echium for host-plant finding of the oligolectic bee Osmia adunca (Megachilidae)

Solitary bees are important pollinators of flowers. Besides nectar they collect pollen at flowers mainly to provide their larvae with food. Many bee species collect pollen only on a few closely related plant species (oligolecty) (Müller & al. 1997). Little is known about the visual and olfactorial signals they use for host-plant finding (Wcislo & Cane 1996). However, bees can olfactorily distinguish between different pollen species (von Frisch 1923), and a species-specific chemistry of pollen odour is known for some plant species (Bergström & al. 1995, Dobson & al. 1999). Further, it was shown that naïve oligolectic bees recognize their host-plant on the basis pollen volatiles (Dobson & Bergström 2000) and that flower-experienced bees could use pollen odours to assess pollen availability (Dobson & al. 1999). Besides scent, also visual cues are of relevance for host-plant finding, and bees orientate especially spectral contrasts. Biotests with dummy flowers revealed that colour contrast and not intensity and dominant wavelengths are influencing innate behavioural responses (Lunau 1990). Further it was shown that naïve bumblebees were most motivated to land on a flower when visual stimuli from the antheres are combined with olfactorial stimuli from the pollen (1992). We choose Osmia adunca P., which is highly specialized on Echium L., as a model to investigate the importance of floral cues for an oligolectic bee. Because bees learn to associate odours with reward more rapidly than visual cues (Menzel 1985), we hypothesize that scent plays a major role in attraction flower-experienced O. adunca females. We used gas chromatography to compare the scent of three Echium species with the scent of a closely related Anchusa species, and a spectrometer to compare the colour of the three Echium species. Additionally we conducted a biotest to determine the importance of visual and olfactorial signals of Echium for host-plant finding of experienced O. adunca females.Bienen besuchen Blüten, um u. a. Pollen zu sammeln, der hauptsächlich der Versorgung der Larven dient. Einige Bienenarten sammeln Pollen von nur einer oder wenigen Pflanzengattungen und werden als Oligolekten bezeichnet. Der Anlockung von Bienen dienen olfaktorische und visuelle Blütensignale. Wir postulierten, dass die eng auf Echium (Boraginaceae) spezialisierte Mauerbiene Osmia adunca (Hymenoptera: Megachilidae) gattungsspezifische visuelle und olfaktorische Blütensignale benutzt, um ihre Wirtspflanzen zu finden erkennen. Mittels chemischer Analysen (GC) konnten wir einen Echium-spezifischen Duft nachweisen, der sich deutlich von einer nah verwandten Anchusa Art unterscheidet. Biotests in einem Flugkäfig mit blütenerfahrenen, nestbauenden Weibchen ergaben weiterhin, dass Echium-Blütenduft bei der Erkennung der Pflanzen im Nahbereich eine große Rolle spielt, während visuelle Signale wahrscheinlich bei der Fernanlockung von Bedeutung sind. Die einem Reflexionsspektrometer analysierten visuellen Signale dreier Echium Arten ähnelten sehr und könnten daher vermutlich eine Funktion zur Anlockung von O. adunca haben. Weitere Tests müssen nun zeigen, welche Blütensignale naive Tiere für die Wirtspflanzenerkennung nutzen

Stream-based perception for cognitive agents in mobile ecosystems

Cognitive agent abstractions can help to engineer intelligent systems across mobile devices. On smartphones, the data obtained from onboard sensors can give valuable insights into the user's current situation. Unfortunately, today's cognitive agent frameworks cannot cope well with the challenging characteristics of sensor data. Sensor data is located on a low abstraction level and the individual data elements are not meaningful when observed in isolation. In contrast, cognitive agents operate on high-level percepts and lack the means to effectively detect complex spatio-temporal patterns in sequences of multiple percepts. In this paper, we present a stream-based perception approach that enables the agents to perceive meaningful situations in low-level sensor data streams. We present a crowdshipping case study where autonomous, self-interested agents collaborate to deliver parcels to their destinations. We show how situations derived from smartphone sensor data can trigger and guide auctions, which the agents use to reach agreements. Experiments with real smartphone data demonstrate the benefits of stream-based agent perception

Interpopulation variation in pollinators and floral scent of the lady's-slipper orchid Cypripedium calceolus L.

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Floral scent evolution in the genus jaborosa (Solanaceae): Influence of ecological and environmental factors

Floral scent is a key communication channel between plants and pollinators. However,the contributions of environment and phylogeny to floral scent composition remain poorly understood. In this study, we characterized interspecific variation of floral scent composition in the genus Jaborosa Juss. (Solanaceae) and, using an ecological niche modelling approach (ENM), we assessed the environmental variables that exerted the strongest influence on floral scent variation, taking into account pollination mode and phylogenetic relationships. Our results indicate that two major evolutionary themes have emerged: (i) a ?warm Lowland Subtropical nectar-rewarding clade? with large white hawkmoth pollinated flowers that emit fragrances dominated by oxygenated aromatic or sesquiterpenoid volatiles, and (ii) a ?cool-temperate brood-deceptive clade? of largely fly-pollinated species found at high altitudes (Andes) or latitudes (Patagonian Steppe) that emit foul odors including cresol, indole and sulfuric volatiles. The joint consideration of floral scent profiles, pollination mode, and geoclimatic context helped us to disentangle the factors that shaped floral scent evolution across ?pollinator climates? (geographic differences in pollinator abundance or preference). Our findings suggest that the ability of plants in the genus Jaborosa to colonize newly formed habitats during Andean orogeny was associated with striking transitions in flower scent composition that trigger specific odor-driven behaviors in nocturnal hawkmoths and saprophilous fly pollinators.Fil: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Ibañez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Dötterl, Stefan. Paris-lodron-university Of Salzburg; AustriaFil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Raguso, Robert A.. Cornell University, Dept. Of Neurobiology And Behavior; Estados Unido

A Novel Class of Defensive Compounds in Harvestmen: Hydroxy-γ-Lactones from the Phalangiid Egaenus convexus

When threatened, the harvestman Egaenus convexus (Opiliones: Phalangiidae) ejects a secretion against offenders. The secretion originates from large prosomal scent glands and is mainly composed of two isomers of 4-hydroxy-5-octyl-4,5-dihydro-3H-furan-2-one (1), a β-hydroxy-γ-lactone. The compounds were characterized by GC-MS of their microreaction derivatives, HRMS, and NMR. After the synthesis of all four possible stereoisomers of 1, followed by their separation by chiral-phase GC, the absolute configurations of the lactones in the Egaenus secretion was found to be (4S,5R)-1 (90%) and (4S,5S)-1 (10%). Hydroxy-γ-lactones represent a new class of exocrine defense compounds in harvestmen

Nocturnal bee pollinators are attracted to guarana flowers by their scents.

Floral scent is an important component of the trait repertoire of flowering plants, which is used to attract and manipulate pollinators. Despite advances during the last decades about the chemicals released by flowers, there is still a large gap in our understanding of chemical communication between flowering plants and their pollinators. We analyzed floral scents of guarana (Paullinia cupana, Sapindaceae), an economically important plant of the Amazon, using chemical analytical approaches, and determined the attractiveness of the scent to its nocturnal bee pollinators using behavioral assays in the field. Pollen loads of attracted bees were also analyzed. Inflorescences of guarana emit strong scents, both during day and at night, with some semi-quantitative differences between day- and night-time scents

New Phytologist / The betrayed thief the extraordinary strategy of Aristolochia rotunda to deceive its pollinators

Pollination of several angiosperms is based on deceit. In such systems, the flowers advertise a reward that ultimately is not provided. We report on a previously unknown pollination/mimicry system discovered in deceptive Aristolochia rotunda (Aristolochiaceae). Pollinators were collected in the natural habitat and identified. Flower scent and the volatiles of insects (models) potentially mimicked were analyzed by chemical analytical techniques. Electrophysiological and behavioral tests on the pollinators identified the components that mediate the plantpollinator interaction and revealed the model of the mimicry system. The main pollinators of A. rotunda were female Chloropidae. They are food thieves that feed on secretions of true bugs (Miridae) while these are eaten by arthropod predators. Freshly killed mirids and Aristolochia flowers released the same scent components that chloropids use to find their food sources. Aristolochia exploits these components to deceive their chloropid pollinators. Aristolochia and other trap flowers were believed to lure saprophilous flies and mimic brood sites of pollinators. We demonstrate for A. rotunda, and hypothesize for other deceptive angiosperms, the evolution of a different, kleptomyiophilous pollination strategy. It involves scent mimicry and the exploitation of kleptoparasitic flies as pollinators. Our findings suggest a reconsideration of plants assumed to show sapromyiophilous pollination.(VLID)221519