Plant protection products (PPPs) are intended to protect plants against pests. However, they are also known to contribute unequivocally to the decline of biodiversity due to their negative impact on biological groups such as terrestrial invertebrates, birds, and amphibians. At the intersection of ecotoxicology, social sciences, and law, numerous studies address the discrepancy between the regulatory framework's objectives to protect biodiversity and the actually observed impacts of legally used PPPs. The main reasons put forward are the normalization constraints of ecotoxicity tests andthe inability to anticipate effects in the current substance-by-substance risk assessment process given the complexity of multifactorial interactions in the ecosystems and the real conditions of PPP use. Therefore, the greater the consideration given to the systemic complexity of indirect effects, the less possible it is to quantify the contribution of a given cause, in our case, a PPP. This is a core issue in legal disputes regarding the liability of those who develop PPPs, those who use them, as well as decision-makers who approve them. This article explores legal possibilities to better address the missing link between substance-by-substance assessment and authorization processes, and biodiversity protection instruments. The aim is to question the division of roles between scientific expertise, legal disputes, and public policy.

Rumen microorganisms are primarily essential for feed decomposition and nutrition of the host animal, playing a key role in the health and well-being of cattle as well as the efficiency of milk or meat production. However, they also generate pollutant emissions such as methane. Analysing this microbiota under different farming conditions is therefore essential for optimizing production while minimizing its environmental impact. In this study, with metataxonomic sequencing and qPCR, we analysed the composition of the cow rumen microbiota sampled through the cannula and via esophageal tubing before morning feeding under two contrasting diets, low- and high-starch contents. Buccal swabs were also collected at the same sampling times to assess their potential as a proxy for the rumen microbiota. The two rumen sampling methods resulted in similar taxonomic compositions of bacteria, Archaea, fungi and protozoa and showed similar changes after the diet shift, indicating that the use of esophageal tubing is a reliable method for capturing the microbiota structure and its potential shifts following dietary changes. In contrast, the buccal swabs did not accurately reflect the rumen microbiota under the low- and high-starch diets, even after specific stringent filtering of the buccal sequences. Furthermore, we identified microbial markers of acidogenic challenge, with Dialister spp. also detected in buccal swab samples as potential indicators.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-18063-1.

Recent zoonotic disease emergences emphasize the importance of studying wildlife parasite communities. As wild hosts frequently harbour diverse parasite species, understanding the drivers of multiple infection patterns in free-ranging hosts is critical for elucidating the ecological and epidemiological dynamics of parasite communities. In this study, we analysed co-infection patterns in European roe deer (Capreolus capreolus) inhabiting a fragmented rural landscape in southwestern France. Using data from 130 samples of GPS-tracked deer, we examined the influence of proximity to livestock, host activity levels, age, sex and between-parasite interactions on the presence of 11 parasitic taxa. Hierarchical modelling of species communities (HMSC) revealed that proximity to livestock significantly increased the likelihood of infection with orofecally transmitted parasites (Toxoplasma gondii, gastrointestinal parasites). Sex and age were other key predictors, with males and juveniles exhibiting a higher frequency of parasite presence, likely influenced by hormonal and immune system differences. Activity levels showed distinct age-related effects, with higher activity levels being positively associated with increased parasite prevalence in yearlings, but not in adults. In contrast, parasite association patterns within individual hosts were weak, suggesting minimal interactions between parasite species. Our findings highlight the interplay between exposure and susceptibility in shaping co-infection patterns and underscore the value of hierarchical modelling approaches in multi-parasite systems.

We necropsied a red fox (Vulpes vulpes) with gross and histologic lesions suggestive of leptospirosis, with intralesional argyrophilic bacteria. Real-time PCR detected Leptospira spp. in multiple organs. We identified Leptospira interrogans related to the Australis serogroup by typing the 16S rRNA and Lfb1 genes and by multilocus sequence typing.