Semiochemical-based alternatives to synthetic toxicant insecticides for pollen beetle management

There is an urgent need to develop sustainable pest management systems to protect arable crops in order to replace the current over-reliance on synthetic insecticides. Semiochemicals are insect- or plant-derived chemicals that are used by organisms as information signals. Integrated pest management tools are currently in development that utilise semiochemicals to manipulate the behaviour of pest insects and their natural enemies to provide effective control of pests within the crop. These innovative tools usually require fewer inputs and can involve multiple elements therefore reducing the likelihood of resistance developing compared with use of synthetic toxicants. We review here the life cycle of the pollen beetle Brassicogethes aeneus (previously known as Meligethes aeneus) which is a pest insect of oilseed rape (Brassica napus) and describe the current knowledge of any behaviour mediated by semiochemicals in this species. We discuss the behavioural processes where semiochemical-based control approaches may be appropriate and consider how these approaches could be integrated into an integrated pest management strategy for this important arable crop

In vitro irradiation station for broad beam radiobiological experiments

The study of the interaction of charged particles with living matter is of prime importance to the fields of radiotherapy, radioprotection and space radiobiology. Particle accelerators and their associated equipment are proven to be helpful tools in performing basic science in all these fields. Indeed, they can accelerate virtually any ions to a given energy and flux and let them interact with living matter either in vivo or in vitro. In this context, the University of Namur has developed a broad beam in vitro irradiation station for use in radiobiological experiments. Cells are handled in GLP conditions and can be irradiated at various fluxes with ions ranging from hydrogen to carbon. The station is mounted on a 2 MV tandem accelerator, and the energy range can be set up in the linear energy transfer (LET) ranges that are useful for radiobiological experiments. This paper describes the current status of the hardware that has been developed, and presents results related to its performance in term of dose-rate, energy range and beam uniformity for protons, alpha particles and carbon ions. The results of clonogenic assays of A549 lung adenocarcinoma cells irradiated with protons and alpha particles are also presented and compared with literature. © 2011 Elsevier B.V. All rights reserved

Advances in the Mechanistic Understanding of Iron Oxide Nanoparticles’ Radiosensitizing Properties

peer reviewe

North Sea Wrecks - An interdisciplinary approach towards understanding the risks posed by wrecks containing munitions in the North Sea

Shipwrecks and dumped munitions continue to be a major hazard in the North Sea. Research within the EU Interreg project North Sea Wrecks (NSW), in cooperation with DLR, is generating new insights into the status of wrecks, the potential leakage of pollutants from munitions loads and the effects of contamination on exposed marine organisms in the North Sea environment. Further, historical documents are compared to models and visual inspections of the wreck. Samples of water, sediment and organisms are being analysed. Combining the results of these different fields of research allows for a better understanding of the environmental risks deriving from these wrecks. The extended article will detail the wreck of the SMS Mainz as a case study

Root-emitted volatile organic compounds: can they mediate belowground plant-plant interactions?

peer reviewedBackground Aboveground, plants release volatile organic compounds (VOCs) that act as chemical signals between neighbouring plants. It is now well documented that VOCs emitted by the roots in the plant rhizosphere also play important ecological roles in the soil ecosystem, notably in plant defence because they are involved in interactions between plants, phytophagous pests and organisms of the third trophic level. The roles played by root-emitted VOCs in between- and within-plant signalling, however, are still poorly documented in the scientific literature. Scope Given that (1) plants release volatile cues mediating plant-plant interactions aboveground, (2) roots can detect the chemical signals originating from their neighbours, and (3) roots release VOCs involved in biotic interactions belowground, the aim of this paper is to discuss the roles of VOCs in between- and within-plant signalling belowground. We also highlight the technical challenges associated with the analysis of root-emitted VOCs and the design of experiments targeting volatile-mediated root-root interactions. Conclusions We conclude that root-root interactions mediated by volatile cues deserve more research attention and that both the analytical tools and methods developed to study the ecological roles played by VOCs in interplant signalling aboveground can be adapted to focus on the roles played by root-emitted VOCs in between- and within-plant signalling

Differentiation in putative male sex pheromone components across and within populations of the African butterfly Bicyclus anynana as a potential driver of reproductive isolation

Sexual traits are often the most divergent characters among closely related species, suggesting an important role of sexual traits in speciation. However, to prove this, we need to show that sexual trait differences accumulate before or during the speciation process, rather than being a consequence of it. Here, we contrast patterns of divergence among putative male sex pheromone (pMSP) composition and the genetic structure inferred from variation in the mitochondrial cytochrome oxidase 1 and nuclear CAD loci in the African butterfly Bicyclus anynana (Butler, 1879) to determine whether the evolution of “pheromonal dialects” occurs before or after the differentiation process. We observed differences in abundance of some shared pMSP components as well as differences in the composition of the pMSP among B. anynana populations. In addition, B. anynana individuals from Kenya displayed differences in the pMSP composition within a single population that appeared not associated with genetic differences. These differences in pMSP composition both between and within B. anynana populations were as large as those found between different Bicyclus species. Our results suggest that “pheromonal dialects” evolved within and among populations of B. anynana and may therefore act as precursors of an ongoing speciation process

Characterization of volatile organic compounds emitted by Barley (Hordeum vulgare L.) roots and their attractiveness to wireworms

Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here for the first time on the identification of VOCs emitted by barley roots (Hordeum vulgare L.). Twenty nine VOCs were identified from isolated 21-d-old roots. The detection of root volatiles was dependent on the medium used for root cultivation. From 7-d-old roots cultivated on sterile Hoagland gelified medium, 24 VOCs were identified, on sterile vermiculite 33 VOCs, and on non-sterile vermiculite 34 VOCs. The major VOCs identified were fatty acid derived compounds, including hexanal, methyl hexanoate, (E)-hex-2-enal, 2-pentylfuran, pentan-1-ol, (Z)-2-(pentenyl)-furan, (Z)-pent-2-en-1-ol, hexan-1-ol, (Z)-hex-3-en-1-ol, (E)-hex-2-en-1-ol, oct-1-en-3-ol, 2-ethylhexan-1-ol (likely a contaminant), (E)-non-2-enal, octan-1-ol, (2E,6Z)-nona-2,6-dienal), methyl (E)-non-2-enoate, nonan-1-ol, (Z)-non-3-en-1-ol, (E)-non-2-en-1-ol, nona-3,6-dien-1-ol and nona-2,6-dien-1-ol. In an olfactometer assay, wireworms (larvae of Agriotes sordidus Illiger, Coleoptera: Elateridae) were attracted to chemical cues emanating from barley seedlings. We discuss the role of individual root volatiles or a blend of the root volatiles detected here and their interaction with CO2for wireworm attraction