Search

Since widespread monitoring began in 1976 in the UK, habitat‐specialist butterfly populations have declined dramatically. The main driver is habitat degradation, caused primarily by land‐use change, perhaps interacting with changes in vegetation phenology.Here, we focus on two declining species: Boloria selene (Dennis & Schiffermüller) and Boloria euphrosyne L., Lepidoptera: Nymphalidae. We hypothesise that these species differ in their preferred breeding habitat, and this is driven by differences in their temperature preferences, mediated by vegetation cover.We use mark‐release‐recapture techniques and oviposition observations to characterise and compare adult distribution, habitat use and oviposition site preferences of the two species.Egg‐laying females of both species are shown to occur in areas with relatively high abundance of the larval food plants, Viola spp. (violets), principally V. riviniana, and they oviposit where Viola spp. abundance is locally high. However, in contrast to B. selene, ovipositing B. euphrosyne tends to occur in areas with relatively short and sparse cover of vegetation.B. euphrosyne oviposit in sites with a relatively high plant surface temperature irrespective of ambient temperatures, in contrast with B. selene in which the temperature of oviposition sites increases as ambient temperature increases. These differential temperature strategies likely underlie differences in breeding habitat preference.Microclimatic cooling caused by increased vegetation growth in spring may be one reason B. euphrosyne is declining in the UK, while both B. euphrosyne and B. selene may be affected by declining Viola spp. availability. Our data provide further evidence that drivers of butterfly declines can be multi‐factorial, and paradoxically, that thermophilic species do not necessarily benefit from climate warming if responses of other species result in cooling of their habitats. [ABSTRACT FROM AUTHOR]

Summary: Many strains of Pseudomonas colonise plant surfaces, including the cherry canker pathogens, Pseudomonas syringae pathovars syringae and morsprunorum. We have examined the genomic diversity of P. syringae in the cherry phyllosphere and focused on the role of prophages in transfer of genes encoding Type 3 secreted effector (T3SE) proteins contributing to the evolution of virulence.Phylogenomic analysis was carried out on epiphytic pseudomonads in the UK orchards. Significant differences in epiphytic populations occurred between regions. Nonpathogenic strains were found to contain reservoirs of T3SE genes. Members of P. syringae phylogroups 4 and 10 were identified for the first time from Prunus.Using bioinformatics, we explored the presence of the gene encoding T3SE HopAR1 within related prophage sequences in diverse P. syringae strains including cherry epiphytes and pathogens. Results indicated that horizontal gene transfer (HGT) of this effector between phylogroups may have involved phage. Prophages containing hopAR1 were demonstrated to excise, circularise and transfer the gene on the leaf surface.The phyllosphere provides a dynamic environment for prophage‐mediated gene exchange and the potential for the emergence of new more virulent pathotypes. Our results suggest that genome‐based epidemiological surveillance of environmental populations will allow the timely application of control measures to prevent damaging diseases. [ABSTRACT FROM AUTHOR]

Hot surfaces that can ignite explosible dust clouds can occur in various process situations in industry, e.g. inside furnaces, burners and dryers of various kinds. Hot surfaces can also be generated accidentally e.g. by frictional overheating of bearings and other mechanical parts, and electrically. To avoid accidental ignition of dust clouds by hot surfaces, it is essential to know the minimum temperature of any hot surface, at which a given explosible dust cloud that makes contact with that surface, will ignite. Currently the Godbert-Greenwald (G-G) furnace is the most commonly used apparatus for experimental laboratory-scale assessment of this minimum temperature for various dusts. The G-G furnace was developed by Godbert and Greenwald in 1935. Two pioneering "forerunners" of this apparatus were described by M. J. Taffanel and A. Durr (1911) in France, and by R.V. Wheeler (1913) in UK. However, neither the two "forerunners" nor the G-G furnace itself were originally intended for assessing maximum permissible temperatures of hot surfaces in industrial plant for preventing accidental hot-surface ignition of dust clouds there. This new use of the G-G furnace was not introduced in UK and the USA until in the 1940ies. The G-G furnace still appears to be the most widely used apparatus for assessing minimum hot-surface temperatures (MITs) for ignition of explosible dust clouds in air in industrial plant. However, not least in view of the history of the furnace, it is clear that the MITs that it produces do not apply to all possible hot-surface ignition scenarios that can be foreseen in industry. In most countries this problem is overcome by introducing a rather generous safety margin between the measured MIT for a given dust and the maximum permissible hot-surface temperature in industrial plants that produce and/or handle this dust. [ABSTRACT FROM AUTHOR]