Susceptibility of Phoenix roebelenii to Xylella fastidiosa

Following a request from the European Commission, the EFSA Plant Health Panel analysed a dossier submitted by Costa Rica Authorities to reach a conclusion on the host status of Phoenix roebelenii for Xylella fastidiosa. The Panel wishes first to stress the difficulties faced in providing compelling evidence for the non-susceptibility status of any particular plant species. The Panel acknowledges that the listing of P. roebelenii as a host of X. fastidiosa rests on a single report from California. Because isolation of X. fastidiosa from some hosts can be difficult, the Panel considers that the failure to isolate X. fastidiosa from P. roebelenii cannot be used to totally discard the detection of X. fastidiosa by ELISA and PCR. The Panel concludes that the detection of X. fastidiosa by two independent techniques provides sufficient evidence, although not totally conclusive, for the listing of P. roebelenii as a X. fastidiosa host plant. Concerning the survey data provided in the Costa Rican dossier, the Panel wishes to stress that such surveys cannot demonstrate the non-host status but can only provide a probability bound, upper estimate of the proportion of infected plants in the field. In the present case, and assuming all survey parameters to be optimal, the 95% confidence incidence threshold obtained is 0.2%, leaving the possibility that close to 25,000 P. roebelenii plants could be infected but undetected in the country. Accepting a scenario of local, non-systemic infection of P. roebelenii by X. fastidiosa would further increase uncertainties. In addition, the absence of data on the vector infection pressure further affects the ability to derive meaningful information on the P. roebelenii host status from the survey data. Appropriately conducted mechanical and/or vector-mediated inoculation experiments are critical to reach a more solid conclusion on the X. fastidiosa host status of P. roebelenii

Magmatism on rift flanks: insights from ambient noise phase velocity in Afar region

During the breakup of continents in magmatic settings, the extension of the rift valley is commonly assumed to initially occur by border faulting and progressively migrate in space and time toward the spreading axis. Magmatic processes near the rift flanks are commonly ignored. We present phase velocity maps of the crust and uppermost mantle of the conjugate margins of the southern Red Sea (Afar and Yemen) using ambient noise tomography to constrain crustal modification during breakup. Our images show that the low seismic velocities characterize not only the upper crust beneath the axial volcanic systems but also both upper and lower crust beneath the rift flanks where ongoing volcanism and hydrothermal activity occur at the surface. Magmatic modification of the crust beneath rift flanks likely occurs for a protracted period of time during the breakup process and may persist through to early seafloor spreading

Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate

Middle‐Atmosphere Dynamics Observed With a Portable Muon Detector

In the past years, large particle physics experiments have shown that muon rate variations detected in underground laboratories are sensitive to regional, middle‐atmosphere temperature variations. Potential applications include tracking short‐term atmosphere dynamics, such as Sudden Stratospheric Warmings. We report here that such sensitivity is not only limited to large surface detectors under highopacity conditions. We use a portable muon detector conceived for muon tomography for geophysical applications, and we study muon rate variations observed over 1 year of measurements at the Mont Terri Underground Rock Laboratory, Switzerland (opacity of ~700 meter water equivalent). We observe a direct correlation between middle‐atmosphere seasonal temperature variations and muon rate. Muon rate variations are also sensitive to the abnormal atmosphere heating in January–February 2017, associated to a Sudden Stratospheric Warming. Estimates of the effective temperature coefficient for our particular case agree with theoretical models and with those calculated from large neutrino experiments under comparable conditions. Thus, portable muon detectors may be useful to (1) study seasonal and short‐term middleatmosphere dynamics, especially in locations where data are lacking such as midlatitudes, and (2) improve the calibration of the effective temperature coefficient for different opacity conditions. Furthermore, we highlight the importance of assessing the impact of temperature on muon rate variations when considering geophysical applications. Depending on latitude and opacity conditions, this effect may be large enough to hide subsurface density variations due to changes in groundwater content and should therefore be removed from the time series.Facultad de Ciencias Astronómicas y Geofísica

Pest risk assessment of African Leucinodes species for the European Union

Following a request from the European Commission, the EFSA Panel on Plant Health performed a quantitative risk assessment for the EU of African Leucinodes species (Lepidoptera: Crambidae), which are fruit and shoot borers, especially of eggplant type fruit. The assessment focused on (i) potential pathways for entry, (ii) distribution of infested imports within EU, (iii) climatic conditions favouring establishment, (iv) spread and (v) impact. Options for risk reduction are discussed, but their effectiveness was not quantified. Leucinodes spp. are widely distributed across sub-Saharan Africa but are little studied and they could be much more widespread in Africa than reported. Much African literature erroneously reports them as Leucinodes orbonalis which is restricted to Asia. The import of eggplant type fruit from sub-Saharan Africa consists of special fruit types and caters mostly to niche markets in the EU. The main pathway for entry is fruit of Solanum aethiopicum and exotic varieties of eggplant (S. melongena). CLIMEX modelling was used with two possible thresholds of ecoclimatic index (EI) to assess establishment potential. Climates favouring establishment occur mostly in southern Europe, where, based on human population, 14% of the imported produce is distributed across NUTS2 regions where EI ≥ 30; or where 23% of the produce is distributed where EI ≥ 15. Over the next 5 years, an annual median estimate of ~ 8600 fruits, originating from Africa, and infested with African Leucinodes spp. are expected to enter EU NUTS2 regions where EI ≥ 15 (90% CR ~ 570–52,700); this drops to ~ 5200 (90% CR ~ 350–32,100) in NUTS2 regions where EI ≥ 30. Escape of adult moths occurs mostly from consumer waste; considering uncertainties in pathway transfer, such as adult emergence, mate finding and survival of progeny, the annual median probability of a mated female establishing a founder population in NUTS regions where EI ≥ 15 was estimated to be 0.0078 (90% CR 0.00023–0.12125). This equates to a median estimate of one founder population ~ every 128 years (90% CR approximately one every 8–4280 years). Using an EI ≥ 30, the median number of founder populations establishing in the EU annually is 0.0048 (90% CR 0.0001–0.0739), equating to a median estimate of one founder population approximately every 210 years (90% CR approximately one every 14–7020 years). Under climate change for the period 2040–2059, the percent of infested produce going to suitable areas would be increased to 33% for EI ≥ 15 and to 21% for EI ≥ 30. Accordingly, the waiting time until the next founder population would be reduced to median estimates of 89 years for EI ≥ 15 (90% CR ~ 6–2980 years) and 139 years for EI ≥ 30 (90% CR 9–4655 years). If a founder population were to establish, it is estimated to spread at a rate of 0.65–7.0 km per year after a lag phase of 5–92 years. Leucinodes spp. are estimated to reduce eggplant yield by a median value of 4.5% (90% CR 0.67%–13%) if growers take no specific action, or 0.54% (90% CR between 0.13% and 1.9%) if they do take targeted action, matching previous estimates made during a risk assessment of L. orbonalis from Asia