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International Society of Chemical Ecology 28th Annual Meeting July 22–26 2012 Vilnius, Lithuania The meeting hosted by Vilnius University Lithuanian Academy of Sciences Nature Research Centre Dear Colleagues, It is my great pleasure to welcome you at the 28th Annual Meeting of International Society of Chemical Ecology in Vilnius, the beautiful capital of Lithuania, one of the new EU member states with a 1 000 year history. Lithuania is famous for its amber where ancient insects are often embedded. Each year a different country welcomes researchers who gather aiming to pre­ sent and discuss the most recent results in the area of chemical ecology. I believe that this meeting will stimulate further collaboration and warm relationship bet­ ween biologists, entomologists, ethologists, chemists and researchers of many oth­ er disciplines related to interdisciplinary science of chemical ecology. Topics of the scientific programme cover nearly the whole very broad field of chemical ecology from animal­animal and plant­animal interactions by means of chemicals to evolutionary and molecular biology, chemistry of natural prod­ ucts, chemical ecology of various groups of organisms, applied aspects of chemical ecolo gy. Let me wish you a lot of useful bring­back­home ideas in promoting advance in your research and best impressions of staying together in Vilnius, the capital of Lithuania. Chair of the host team of the meeting Professor Vincas Būda ISCE Silver and Silverstein-Simeone Medal Lectures Silverstein­Simeone Medal Lecture 93 Moderator: Wendell Roelofs EVERYTHING’S IN FLUX: A NEUROETHOLOGICAL JOURNEY T. C. Baker Center for Chemical Ecology, Department of Entomology, Penn State University, University Park, Pennsylvania, USA E-mail: [email protected] I have been presented with many fascinating opportunities to learn about insect olfaction related to behavior over the several decades I have been allowed to be one of the fortunate, paid explorers in the field of Chemical Ecology. One of the earliest opportunities I had was to puzzle over the relationship between the time­courses and amplitudes of electroantenno­ gram responses to puffs of pheromone component odorants and the resulting upwind flight responses of moths. Trying to figure out how the timing of male moths’ contacts with indi­ vidual strands of pheromone altered their in­flight maneuverings through the air was another challenge. More recently, an opportunity to try to explain one of the most puzzling and per­ plexing issues in moth pheromone olfaction presented itself: why, in nearly every species, are the majority of olfactory receptor neurons (ORNs) tuned to the most abundant pheromone component in a species’ sex pheromone blend? A related question concerned ORNs that are co­compartmentalized in the same sensillum: why does the ORN tuned to the most abundant pheromone component in the blend have a larger diameter dendrite than the ORN tuned to the minor component and produce a larger amplitude action potential than the minor component ORN? It had seemingly been counterintuitive that the accepted explanation tout­ ing increased sensitivity should be valid, because in that case the greatest number of ORNs should be tuned to the least abundant pheromone components, not the most, because these trace components should be the most difficult to detect. It turns out that it is no accident that time kept emerging as a factor that we paid attention to over several decades of studies. In­ deed, timing is everything; the resulting hypothesis we have come up with involves molecular abundance­related flux, not concentration. This idea applies nicely not only to the evolution of peripheral sex pheromone olfactory systems, but also to the peripheral olfactory systems that detect general odorants involved in host­finding. 94 Silver Medal Lecture Moderator: Ring Carde WAR IN THE PLANKTON: SUBLETHAL AND RECIPROCAL IMPACTS OF RED TIDE ALGAE ON COMPETING PHYTOPLANKTON J. Kubanek1, 2, K. L. Poulson-Ellestad1, E. K. Prince1, R. D. Sieg1, T. L. Myers1, C. H. Redshaw1, J. Roy1, J. Byrne3, M. Viant3, C. Jones2, F. M. Fernandez2, J. Naar4, B. Nunn5 1 School of Biology and 2 School of Chemistry & Biochemistry, Aquatic Chemical Ecology Center, Georgia Institute of Technology, Atlanta, GA, USA 3 School of Biosciences, University of Birmingham, Birmingham, UK 4 Center for Marine Science, University of North Carolina at Wilmington, Wilmington, NC, USA 5 Department of Medicinal Chemistry and School of Oceanography, University of Washington, Seattle, WA, USA E-mail: [email protected] How individual species come to be dominant members of marine planktonic communities is not deeply understood; however, it is thought that chemistry plays a substantial role. For example, some red tide­forming dinoflagellates produce toxic secondary metabolites that are hypothesized to enhance dinoflagellate fitness by acting as grazer deterrents, allelopathic agents, or antimicrobial defenses. In field and lab experiments we have shown that the red tide dinoflagellateKarenia brevis is allelopathic, inhibiting the growth of several co­occurring phytoplankton species, but that K. brevis natural products other than well­known brevetoxins are responsible for suppressing most of these species. At least one phytoplankton competitor, Skeletonema costatum, retaliates against K. brevis, reducing its allelopathic effects and degrad­ ing waterborne brevetoxins. Several other phytoplankton species also metabolize brevetoxins, removing these toxins from the water column and mitigating the negative effects on inverte­ brates. Death is a rare outcome of K. brevis allelopathy, with more subtle responses predomi­ nating, such as reduced photosynthetic output and increased cell permeability. These changes in cellular metabolism and physiology may be more readily characterized and measured by a systems biology approach than by growth or cell lysis assays. NMR metabolomics has pro­ vided preliminary evidence for sub­lethal impacts of exposure to K. brevis allelopathy on the metabolism of neighboring phytoplankton. Future work will expand upon these initial results with mass spectrometry­based metabolomics and proteomics methods, as well as experi­ ments with other vulnerable competing phytoplankton species, with the goal of identifying cellular targets and understanding the molecular mechanisms of red tide allelopathy. Our re­ sults indicate that chemically­mediated interactions are reciprocal, and that ecosystem­level consequences of red tides (such as fish kills caused by waterborne toxins) may depend upon which other phytoplankton species are present. Plenary report 95 THE PHEROMONE PHENOMENON W. Francke Institute of Organic Chemistry, University of Hamburg, Germany E-mail: [email protected] Molecular recognition is prerequisite to the beginning of life, and thus “chemical signalling” is the oldest means for the transmission of information. Principles of chemical signalling may have evolved several times and for different reasons, typical elements being made up of a broad spectrum of secondary metabolites originating from the ubiquituous pathways of classical catabolism or metabolism (1). As for their biogenetic origin, most of the relevant compounds are acetogenins, poly­ ketides, and terpenoids, the biosynthesis of which is not restricted to animals, but is also valid in plants and microorganisms, in terrestrial as well as in aquatic ecosystems. The role of (endo)symbionts in the production and transformation of animal associated chemical signals as well as in evolutionary processes (e. g. insect plant­relationships) needs to be investigated. • Acetogenins show straight carbon skeletons, frequently forming rows of bis­homologues. • Polyketides involving propanoate units will typically show (n,n+2x)-dimethyl- branching. • Terpenes show isoprene-units as substructures, diversified by derivatization. Due to past co­evolutionary processes, structures of semiochemicals from plants, insects, and microorganisms can be identical, a phenomenon based on de novo­synthesis as well as on sequestration. The same compound may be used as a chemical messenger by quite dif­ ferent organisms and in an entirely different ecological context. The information linked to a specific chemical structure is not necessarily constant and may change during evolution. This becomes particularly evident in compounds causing a high status of alertness in the receiver, i. e. signals that cause attraction, aggression, defense or stampede. Compounds evolved in the context of defense, may even change into attractants. This scenario may not only indicate similar biogenetic pathways but also common roots including aspects of coevolution. It points to general concepts in the establishment of “chemi­ cal languages” and the principle development of appropriate receptor systems. Consequently, questions concerning an “etymology” of semiochemicals may be raised. Any chemical signal needs a receptor at the receiver site – and it may be asked whether semiochemicals may also be recognized by proteins that are not primarily involved in chemi­ cal communication. As a result, would it make sense to generally screen semiochemicals for biological activities other than their presently known function? Methyl p­hydroxybenzoate, a component of the honey bee queen pheromone, exhibits strong antibiotic properties – and there are quite some more examples proving the physiological versatility of semiochemicals. Consequently, it may also be asked whether two organisms reacting

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