Matching commercial thrips predating phytoseids with the highly diversified climatic conditions of different strawberry production systems

Flower inhabiting thrips (Order: Thysanoptera) are a major threat to fruit quality in strawberry production around the world. As chemical control is often inefficient, alternative control measures are of broad and current interest. Their fast reproduction makes predatory mites highly suitable for thrips control in a crop with a relatively short cropping season like strawberry. However, climatic conditions of strawberry production can differ strongly depending on the production system (glasshouse, plastic tunnel, open field, etc.) and the time span of cultivation (depending mostly on planting date and the type of cultivar: summer-or everbearing). As predatory mites typically display a temperature-dependent life history and the current commercially available thrips predating phytoseids vary in geographic origin, one can assume that under certain climatic conditions some species will be more applicable than others. The goal of this study is to determine which species are suitable for which climatic conditions. Therefore all (Belgian) production systems and time spans are categorized into three climate types, simulated in the laboratory. The population build-up of seven predatory mite species (A. degenerans, A. montdorensis, A. andersoni, A. limonicus, A. swirskii, N. cucumeris and E. gallicus) were assessed for each of these climatic conditions. Under the coldest condition (A), the in West-Europe indigenous E. gallicus was the only species with a significant population build up. When moderate conditions (B) were simulated E. gallicus, N. cucumeris and A. limonicus were most successful. The warmest regime (C) was most adequate for E. gallicus and A. swirskii

SYNTHESYS+ Virtual Access - Report on the Ideas Call (October to November 2019)

The SYNTHESYS consortium has been operational since 2004, and has facilitated physical access by individual researchers to European natural history collections through its Transnational Access programme (TA). For the first time, SYNTHESYS+ will be offering virtual access to collections through digitisation, with two calls for the programme, the first in 2020 and the second in 2021. The Virtual Access (VA) programme is not a direct digital parallel of Transnational Access - proposals for collections digitisation will be prioritised and carried out based on community demand, and data must be made openly available immediately. A key feature of Virtual Access is that, unlike TA, it does not select the researchers to whom access is provided. Because Virtual Access in this way is new to the community and to the collections-holding institutions, the SYNTHESYS+ consortium invited ideas through an Ideas Call, that opened on 7th October 2019 and closed on 22nd November 2019, in order to assess interest and to trial procedures. This report is intended to provide feedback to those who participated in the Ideas Call and to help all applicants to the first SYNTHESYS+Virtual Access Call that will be launched on 20th of February 2020.This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published pdf

Evidence of tetragonal distortion as the origin of the ferromagnetic ground state in γ-Fe nanoparticles

γ-Fe and related alloys are model systems of the coupling between structure and magnetism in solids. Since different electronic states (with different volumes and magnetic ordering states) are closely spaced in energy, small perturbations can alter which one is the actual ground state. Here, we demonstrate that the ferromagnetic state of γ-Fe nanoparticles is associated with a tetragonal distortion of the fcc structure. Combining a wide range of complementary experimental techniques, including low-temperature Mössbauer spectroscopy, advanced transmission electron microscopy, and synchrotron radiation techniques, we unambiguously identify the tetragonally distorted ferromagnetic ground state, with lattice parameters a=3.76(2)Å and c=3.50(2)Å, and a magnetic moment of 2.45(5) μB per Fe atom. Our findings indicate that the ferromagnetic order in nanostructured γ-Fe is generally associated with a tetragonal distortion. This observation motivates a theoretical reassessment of the electronic structure of γ-Fe taking tetragonal distortion into account.The authors thank the Fund for Scientific ResearchFlanders, the Concerted Research Action of the KU Leuven (GOA/14/007), the KU Leuven BOF (STRT/14/002), the Hercules Foundation, the Portuguese Foundation for Science and Technology (CERN/FIS-NUC/0004/2015), and the European Union Seventh Framework through ENSAR2 (European Nuclear Science and Applications Research, Project No. 654002), and SPIRIT (Support of Public and Industrial Research Using Ion Beam Technology, Contract No. 227012). We acknowledge the European Synchrotron Radiation Facility (ESRF) for providing beam time (experiments 26-01-1018, 26-01-1057, 20-02-728, HC-1850, HC-2208), as well as C. Baehtz, N. Boudet, and N. Blancand for support during the experiments. We acknowledge the ISOLDE-CERN facility for providing beam time (experiment IS580) and technical assistance. The authors (L.M.C.P., F.K.) acknowledge the facilities and the scientific and technical assistance of the Australian Microscopy & Microanalysis Research Facility at the Centre for Advanced Microscopy, Australian National University. We also acknowledge the contribution of Prof. Mark Ridgway (Australian National University), who passed away before the work was completed

Prey colonization in freshwater landscapes can be stimulated or inhibited by the proximity of remote predators

1. Recent findings suggest that the colonization of habitat patches may be affected by the quality of surrounding patches. For instance, patches that lack predators may be avoided when located near others with predators, a pattern known as risk contagion. Alternatively, predator avoidance might also redirect dispersal towards nearby predator‐free patches resulting in so‐called habitat compression. However, it is largely unknown how predators continue to influence these habitat selection behaviours at increasing distances from outside of their own habitat patch. In addition, current information is derived from artificial mesocosm experiments, while support from natural ecosystems is lacking. 2. This study used bromeliad landscapes as a natural model system to study how oviposition habitat selection of Diptera responds to the cues of a distant predator, the carnivorous elephant mosquito larva. 3. We established landscapes containing predator‐free bromeliad habitat patches placed at increasing distances from a predator‐containing patch, along with replicate control landscapes. These patches were then left to be colonized by ovipositing bromeliad insects. 4. We found that distance to predators modulates habitat selection decisions. Moreover, different dipteran families had different responses suggesting different habitat selection strategies. In some families, predator‐free patches at certain distances from the predator patch were avoided, confirming risk contagion. In other families, these patches received higher numbers of colonists providing evidence of predator‐induced habitat compression. 5. We confirm that effects of predators in a natural ecosystem can extend beyond the patch in which the predator is present and that the presence or absence of remote predator effects on habitat selection depends on the distance to predators. The notion that perceived habitat quality can depend on conditions in neighbouring patches forces habitat selection studies to adopt a landscape perspective and account for the effects of both present and remote predators when explaining community assembly in metacommunities.</p

Nonlocal effect and dimensions of Cooper pairs measured by low-energy muons and polarized neutrons in type-I superconductors

The Pippard coherence length \u3be0 (the size of a Cooper pair) in two extreme type-I superconductors (In and Sn) was determined directly through high-resolution measurement of the nonlocal electrodynamic effect combining low-energy muon spin rotation spectroscopy and polarized neutron reflectometry. The renormalization factor Z=mcp*/2m (mcp* and m are the mass of the Cooper pair and the electron, respectively) resulting from the electron-phonon interaction, and the temperature-dependent London penetration depth \u3bbL(T) were determined as well. An expression linking \u3be0, Z, and \u3bbL(0) is introduced and experimentally verified. This expression allows one to determine experimentally the Pippard coherence length in any superconductor, independent of whether the superconductor is local or nonlocal, conventional or unconventional. \ua9 2013 American Physical Society.Peer reviewed: YesNRC publication: Ye