Common voles (Microtus arvalis) are common small mammals in some European landscapes. They can be a major rodent pest in European agriculture and they are also a representative generic focal small herbivorous mammal species used in risk assessment for plant protection products. In this paper, common vole population dynamics, habitat and food preferences, pest potential and use of the common vole as a model small wild mammal species in the risk assessment process are reviewed. Common voles are a component of agroecosystems in many parts of Europe, inhabiting agricultural areas (secondary habitats) when the carrying capacity of primary grassland habitats is exceeded. Colonisation of secondary habitats occurs during multiannual outbreaks, when population sizes can exceed 1000 individuals ha(-1) . In such cases, in-crop common vole population control management has been practised to avoid significant crop damage. The species' status as a crop pest, high fecundity, resilience to disturbance and intermittent colonisation of crop habitats are important characteristics that should be reflected in risk assessment. Based on the information provided in the scientific literature, it seems justified to modify elements of the current risk assessment scheme for plant protection products, including the use of realistic food intake rates, reduced assessment factors or the use of alternativee focal rodent species in particular European regions. Some of these adjustments are already being applied in some EU member states. Therefore, it seems reasonable consistently to apply such pragmatic and realistic approaches in risk assessments for plant protection products across the EU.

Savi's pine vole (Microtus savii) is a rodent species of the Cricetidae family, inhabiting southern European agroecosystems. It is considered to be the main cause of rodent-attributed damage in Italy. To achieve an effective management, detailed knowledge of this species is needed. However, the available information about this species is fragmentary and incomplete. In this paper, the existing knowledge of Savi's pine vole taxonomy, reproduction, population dynamics, habitat and food preferences is reviewed in order to organise available information and identify priority areas of future research. Some of the changes in farming practices that have occurred in recent decades may have increased the impact of Savi's pine vole populations in crop fields. To manage this pest species effectively, an integrated strategy is recommended (involving habitat management, trapping and, when appropriate, the use of rodenticides). The apparent lack of cyclical population outbreaks and the relatively small litter size and long gestation and interpartum period of this species suggest that it could be more manageable than other vole species, while its strict herbivorous diet, stable population size in open habitats and wide distribution seem to indicate it as an ideal model species for risk assessment studies.

Identifying focal bird species appropriate to the situation in which a plant protection product is used is important for refined risk assessment (EFSA 2009). We analyzed the results of extensive field observations of newly drilled cereal fields in France in autumn over 2 seasons to determine real bird focal species. In 2011, birds were observed before and after drilling on wheat and barley fields drilled with imidacloprid‐treated seeds (i.e., “treatment” fields) or seeds treated with compounds other than imidacloprid (i.e., “alternative treatment” fields). Bird abundance, species richness, and diversity were significantly higher in wheat fields than barley fields; these findings led us to monitor only wheat fields in 2012. Statistical analyses did not show a significant effect of the drilling itself or between the treatment fields and the alternative treatment fields on the number and type of bird species. These results led to the pooling of 2011 data on all fields for focal species determination. Similarly, all bird monitoring data generated in 2012 before and after drilling were pooled and analyzed. Rules for determination of candidate focal species detailed in the EFSA (2009) guidance were followed. Carrion crow, wood pigeon, gray partridge, skylark, common starling, and pied wagtail were the bird species most frequently observed on wheat fields. This list of candidate species was processed to determine the most relevant focal species according to the method of Dietzen et al. (2014); this process resulted in the selection of skylark, gray partridge, wood pigeon, and pied wagtail as focal species to assess risks to birds for pesticides applied during drilling of winter cereals in France (September through November). Integr Environ Assess Manag 2019;00:000–000. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

Background, aim and scopeSeed treatments are widely used on cereals and other annual crops throughout Europe. Most of the formulated pesticide is found on the outside of the seed, the husk. Risk assessments of seed treatments are especially needed for granivorous mice living in the agricultural landscape e.g. for registration using the guidance for risk assessment for birds and mammals (EFSA 2009). The dehusking of seeds before consumption is a known behaviour of these mammals, but so far, no quantitative data on the reduction of exposure of seed treatments by dehusking were published. Therefore, we aimed at providing a first quantitative estimate of this behaviour-related exposure reduction for the wood mouse (Apodemus sylvaticus) with different seed types.Materials and methodsWe evaluated the efficiency of dehusking behaviour of 20 wood mice captured in the wild for four different seeds (wheat, barley, maize and sunflower). One experimental setup used a fungicide seed treatment where the remaining seed husks of consumed seeds were analysed with a HPLC-MS/MS technique. In the second setup, we measured generic pigment present in a blank seed treatment formulation and determined the leftover pigment in the husks with a photometric technique.ResultsThe exposure reduction was similar for the fungicide and the pigment design where the same seed types were studied. We could demonstrate exposure reductions ranging from around 60% for cereals to almost 100% for sunflower seeds as a result of the dehusking behaviour.DiscussionSince exposure reduction was similar in both approaches, working with pigments would be a generic way to estimate the impact of dehusking behaviour on seed treatment exposure. This behaviour can result in a substantial exposure reduction and should, therefore, be considered in a seed-type specific way in the risk assessment of pesticide seed treatments.ConclusionsIt is proposed to include a seed-specific dehusking factor in the calculations of estimated theoretical exposure of seed treatments for granivorous mice. The approach of accounting for a dehusking-related exposure reduction by field relevant wild mammal species seems a more promising way to advance the risk assessment instead of using generic species and neglecting behavioural traits. The pigment approach could be used to gather data for exposure reduction for other species and seed types. Its advantage is that it is harmless to the test species and comparatively cheap since no chemical analysis is involved.Recommendations and perspectivesSeed treatments are used for most of the cereal crops grown in Europe today. Their advantages usually include a lower application rate and the reduction of drift compared to a conventional spraying regime. However, there is a potential risk especially for granivorous mice, and its assessment is challenging in case of a high residue concentration on the dressed seeds. The concept of a dehusking factor in the risk assessment scheme for seed treatments for granivorous mice is a valid approach to account for t...

The Savi's pine vole, Microtus savii is an Italian species living in grasslands, both natural and anthropogenic (i.e. agroecosystems) where it is generally considered a pest because it may damage crops and orchards. As for most rodent pests, the extent of the damage might depend on population density and temporal food availability (e.g. Brown et al. 2007, Jacob & Tkadlek 2010. However, data on demographic parameters are not available, making ecologically-based management strategies difficult to plan. Therefore, we conducted a study on Savi's pine vole demography for one year in two study areas in central Italy using capture-mark-recapture method. Density values ranged from 3 to 32 ind./ha, the highest population densities occurred in October, while the lowest occurred in February-April in both study areas. Turnover rates of both populations were very high, with time of residency usually no longer than two months. Juveniles´ survival was constant in both study areas, but it differed between the two populations regarding adults. The two populations showed similar demographic trends along the year with relatively small intra-annual fluctuations. The breeding season covered the whole year in both areas. The results here presented contribute to add meaningful information about this poorly known species, and could be useful to plan population control strategies for this rodent in agroecosystems. population density, survival rate, turnover, time of residency in the population and sex ratio. The aim of our study was to improve for the first time knowledge on demography of this endemic species in agricultural landscape. Our data should be useful for planning and developing efficient control strategies for this species known as a pest (e.g. Jacob 2013, Ranchelli et al. 2016). Materials and methods Study areaThis study was carried out in two peach orchards of 2 ha each. These plots are located in two regions of central Italy, Emilia-Romagna and Tuscany, where climatic conditions are similar.The study area in Emilia Romagna is located near the town of Imola (44°21′ N, 11°42′ E), in a highlyfragmented, predominantly rural area, with average annual rainfalls of 750 mm and mean annual temperatures ranging between +2.6°C and +23.7°C. The landscape of two study areas is similar, characterized by plain topography and formed by agricultural plots separated by ditches and secondary roads. Savi's pine voles here coexist with common voles (Microtus arvalis), with the latter attaining very low densities. The study area in Tuscany, about 125 km away from the previous one, is located near the town of Foiano della Chiana (43°15′ N, 11°48′ E), hereafter Foiano, an area relatively far away from urban settlements, with average annual rainfalls of 700 mm and mean annual temperatures between +5.8°C and +23.0°C. The only vole species to be found in this area is the Savi's pine vole. Both areas consist of peach orchards, similarly managed, with trees ageing from 5 to 15 years, with a between-trees distance ranging from 1.5 to 3 meters (depending...