Assessing the Distribution of Exotic Egg Parasitoids of Halyomorpha halys in Europe with a Large-Scale Monitoring Program.

The brown marmorated stink bug Halyomorpha halys is an invasive agricultural pest with a worldwide distribution. Classical biological control has been identified as the most promising method to reduce the populations of H. halys. Adventive populations of two candidates for releases, Trissolcus japonicus and Trissolcus mitsukurii, have recently been detected in Europe. To assess their distribution and abundance, a large-scale survey was performed. From May to September 2019, a wide area covering northern Italy and parts of Switzerland was surveyed, highlighting the expanding distribution of both Tr. japonicus and Tr. mitsukurii. Within four years after their first detection in Europe, both species have rapidly spread into all types of habitats where H. halys is present, showing a wide distribution and continuous expansion. Both exotic Trissolcus showed high levels of parasitism rate towards H. halys, while parasitization of non-target species was a rare event. The generalist Anastatus bifasciatus was the predominant native parasitoid of H. halys, while the emergence of native scelionids from H. halys eggs was rarely observed. The presence of the hyperparasitoid Acroclisoides sinicus was also recorded. This study provided fundamental data that supported the development of the first inoculative release program of Tr. japonicus in Europe.

Influence of nitrogen-based fertilization on nitrates occurrence in groundwater of hilly vineyards.

Nitrogen losses from intensive agricultural production may end up as high nitrate (NO3-) concentrations in groundwater, with a long-term impact on groundwater quality. The main objective of this study was to evaluate the impact of fertilization practices used for grape cultivation on groundwater quality of Tidone Valley, northwest of Italy, following an integrated socio-hydrogeological approach that consists on (i) the involvement of 175 farmers in the description of agricultural and fertilization practices, using a survey of ad hoc questionnaires, (ii) the evaluation of NO3- occurrence in groundwater and (iii) the identification of NO3- sources through isotopic and hydrochemical analysis. In this area, as for certain particular Apennines shallow aquifers, groundwater is of reduced interest due to its limited storage capacity and there are insufficient wells currently monitored by the local Environmental Agency (ARPAE) to evaluate the impact of agricultural fertilization on existing local aquifers. Farmers' questionnaires results highlighted an extensive use of inorganic nitrogen fertilization and a tendency of farmers to follow their own experience for fertilization. Chemical analyses revealed high variability of major and trace elements concentrations isotope data. NO3- concentrations were significantly higher in deeper wells with respects to shallow wells. Isotopic results indicated that groundwater NO3- origin is inorganic, in agreement with the land use and the declared viticultural practices. Comparing groundwater NO3- occurrence from the studied area with values of entire Emilia-Romagna Region, only 7.7% of groundwater samples showed values above the EQS. (50 mg NO3-/L) between Nov 2017 and Sept 2018, while in the entire region 11.5% of groundwater samples showed values above the EQS in the same period. Considering that the vineyards surface in the studied area represents almost 75% of the entire regional vineyard surface, the obtained results suggest a low to moderate impact of viticulture on NO3-concentration of regional groundwater.

Multi-actor approach and engagement strategy to promote the adoption of best management practices and a sustainable use of pesticides for groundwater quality improvement in hilly vineyards.

The adoption of pesticide mitigation measures and innovation at farm level, are seen as a drivers to reach the sustainable water policy objectives. With the aim to prevent the pesticide pressure of hilly vineyards on groundwater contamination, a stepwise approach in Tidone Valley was applied using different consultation mechanisms and involvement strategies throughout the overall process. Face to face meetings, direct surveys, participatory monitoring and planning of several activities aiming to inform, educate, improve skills, change of individual behaviour or raise awareness, or even initiatives to build institutional trust or support for new investment in innovation are some examples. These activities allowed us to involve key actors of water use and governance (such as farmers, advisors, representatives of drinking water management, farmer's associations, Winemaking cooperatives, local Health Authority), and to have a deeper knowledge of the context agricultural practices, of farmer's knowledge and skills concerning factors influencing water contamination and also to promote the most suitable Best Management Practices aimed at limiting the pesticide occurrence in groundwater. Indeed, the surveys results highlighted that the majority of the farms are small (64% of vineyards <10 ha), that most of the farmers (62%) are not aware of the current legislation on water, even if 64% of them declare to participate regularly to training courses for the prevention of water contamination and that there is a low to moderate level of adoption of Best Practices able to prevent contamination by pesticides. At the end of the overall process, it can be stated that the multi-actor approach and engagement strategy adopted were successful in improving attitudes to more sustainable practices. This is supported also by the monitoring data that show in 2019 a decrease by 44% of pesticides occurrences and a fall by 68% of values above EQSgw if compared with the period 2017-2018.

Evaluation of groundwater contamination sources by plant protection products in hilly vineyards of Northern Italy.

In Europe, 25% of groundwater has poor chemical status. One of the main stressors is agriculture, with nitrates and plant protection products (PPPs) causing failure in 18% and 6.5%, respectively, of groundwater bodies (by area). EU legislation for the placement of the PPPs on the market is one of the most stringent in the world. However, recent monitoring studies in hilly vineyards of Tidone Valley, north-west of Italy, show presence of PPPs used for grapevine cultivation in 15 out of 26 groundwater wells monitored, at values above the Environment Quality Standard (EQS) for groundwater (0.1 µg/L). However, no information about the contamination sources are available. Therefore, the objective of the present work is to evaluate the groundwater contamination sources by PPPs, in a small catchment with intensive viticulture, by collecting and integrating monitoring data, sub-surface water movement data and territorial characteristics. The results show that in wells used for PPP's mixture preparation and sprayer washing located at the top of hilly vineyards, with low slope and no water movement in the surrounding soil, the contamination is most likely from point sources. On the contrary, for wells located in a fenced area at the bottom of the hill, far away from vineyards and being used for drinking water production, the contamination is most likely from diffuse sources. Our results were used to raise awareness on groundwater contamination from PPPs among farmers in the study area; moreover a waterproof platform for sprayers washing, equipped with wastewater recovery and disposal system, able to avoid point-source contamination, was implemented in a local demonstration farm. Several demonstration activities were then organised with the farmers of the entire Valley in order to show its functionality and promote its diffuse use.

First evaluation of pesticides occurrence in groundwater of Tidone Valley, an area with intensive viticulture.

Agricultural practice often involves an intensive and incorrect use of pesticides and fertilizers. These chemicals can leach through the soil profile and contaminate groundwater, including drinking water. For this reason, an effective groundwater monitoring is strongly advisable. The aim of this study was to investigate the groundwater contamination by plant protection products (PPPs) on a hilly area situated in the Tidone Valley, North-West of Italy, a region characterized by an intensive viticulture production. This area is not included in the national groundwater monitoring plan and therefore scarce information is available regarding the quality of groundwater, even though the local Environmental Agency previously revealed the occurrence of PPPs at values higher than the Environmental Quality Standard downstream this area. Hence, a monitoring wells network was developed following an upstream-downstream criterion, a list of pesticides to be monitored, based on a multi-actor approach, and an analytical method for PPPs detection and quantification. The analytical approach involved solid phase extraction followed by High-Performance Liquid Chromatography tandem mass spectrometry. The results of three monitoring campaigns revealed the occurrence of seven PPPs at a level higher than EQS for groundwater (0.1 µg/L) in 30% of the wells. The main pesticides detected were Chlorantraniliprole, Dimethomorph, Fluopicolide, Metalaxyl-M, Penconazole, and Tetraconazole, all commonly used in viticulture, together with S-metolachlor, authorized for cereal cropping. Statistical analysis revealed a significant influence of the sampling time, slope of the soil surrounding the wells, wells depth and wells location on the concentration of five PPPs. Therefore, the results obtained show that the improper use of PPPs for grapevine cultivation may cause groundwater contamination and suggest the need for a deeper analysis of territorial reality, including hydrology studies and farmer behavior and for an urgent introduction of best management practices and mitigation measures to promote a sustainable use of PPPs in viticulture.