The use of sewage sludge as a soil improver has been promoted in agroecosystems. However, sludges can contain toxic trace elements because of suboptimal wastewater treatment. Nonetheless, field studies investigating the negative effects of these practices on pollinators are lacking. We collected honeybees from an area where sewage sludge use is widespread, and one where it is precluded. Trace elements in soils and bees were quantified. Cadmium, chromium, lead, mercury, and nickel were investigated because they were the least correlated elements to each other and are known to be toxic. Their levels were related to oxidative stress and energy biomarkers, midgut epithelial health, body size and wing asymmetry of honeybees. We found increased carbohydrate content in sites with higher cadmium levels, increased histological damage to the midgut epithelium in the sewage sludge area, and the presence of dark spherites in the epithelium of bees collected from the sites with the highest lead levels. Finally, we found that honeybees with the highest lead content were smaller, and that wing fluctuating asymmetry increased in sites with increasing levels of mercury. To the best of our knowledge, this is the first comprehensive study of the concentration and effects on honeybees of trace elements potentially deriving from soil amendment practices.

Urbanisation is associated with air and soil pollution, particularly from heavy metals. One of the tissues most exposed to such pollutants is the midgut epithelium as insects may ingest these pollutants with food. Bees are one of the most important urban insects, providing important ecosystem services such as pollination. However, to the best of our knowledge, no studies have investigated the possible histological alterations to the midgut epithelium of bees caused by urbanisation. We sampled workers of the ground-nesting, primitively eusocial bee Halictus scabiosae in a large metropolis (Milan), with the aim to test if individuals from areas characterised by higher urbanisation and consequently higher pollution levels-defined here by a greater proportion of roads-exhibit greater histological tissue and cellular alterations in the midgut epithelium. We obtained semi-thin sections of the midgut through histological techniques, and then adopted a semi-quantitative approach to assess morphological damage. The midgut presented a range of histological alterations including epithelium disorganisation, vacuolisation, and nucleus karyorrhexis (one of the stages of cellular death). We found higher histological damage score (calculated taking into account all found alterations) and frequency of karyorrhectic nuclei in sites with a higher proportion of roads (i.e. more urbanised). The observed alterations may underline a potential impairment of the digestive function in highly urbanised areas.

In fact, less than 1% of applied pesticides reach their target pests, while the remainder pollute the neighboring environment and adversely impact human health as well as non-target organisms in agricultural ecosystem. Pesticides can contribute to the loss of agrobiodiversity, which are essential to maintaining the agro-ecosystem's structure and functioning in order to produce and secure enough food. This review article examines the negative effects of pesticides on non-target invertebrates including earthworms, honeybees, predators, and parasitoids. It also highlights areas where further research is needed to address unresolved issues related to pesticide exposure, aiming to improve conservation efforts for these crucial species. These organisms play crucial roles in ecosystem functioning, such as soil health, pollination, and pest control. Both lethal and sub-lethal effects of pesticides on the selected non-target invertebrates were discussed. Pesticides affect DNA integrity, enzyme activity, growth, behavior, and reproduction of earthworms even at low concentrations. Pesticides could also induce a reduction in individual survival, disruption in learning performance and memory, as well as a change in the foraging behavior of honeybees. Additionally, pesticides adversely affect population growth indices, reproduction, development, longevity, and consumption of predators and parasitoids. As a result, pesticides must pass adequate ecotoxicological risk assessment to be enlisted by regulatory authorities. Therefore, it is important to adopt integrated pest management (IPM) strategies that minimize pesticide use and promote the conservation of beneficial organisms in order to maintain agrobiodiversity and sustainable agricultural systems. Furthermore, adopting precision agriculture and organic farming lessen these negative effects as well.less than

Soil supports life by serving as a living, breathing fabric that connects the atmosphere to the Earth's crust. The study of soil science and pedology, or the study of soil in the natural environment, spans scales, disciplines, and societies worldwide. Soil science continues to grow and evolve as a field given advancements in analytical tools, capabilities, and a growing emphasis on integrating research across disciplines. A pressing need exists to more strongly incorporate the study of soil, and soil scientists, into research networks, initiatives, and collaborations. This review presents three research areas focused on questions of central interest to scientists, students, and government agencies alike: 1) How do the properties of soil influence the selection of habitat and survival by organisms, especially threatened and endangered species struggling in the face of climate change and habitat loss during the Anthropocene? 2) How do we disentangle the heterogeneity of abiotic and biotic processes that transform minerals and release life-supporting nutrients to soil, especially at the nano-to microscale where mineral-water-microbe interactions occur? and 3) How can soil science advance the search for life and habitable environments on Mars and beyond-from distinguishing biosignatures to better utilizing terrestrial analogs on Earth for planetary exploration? This review also highlights the tools, resources, and expertise that soil scientists bring to interdisciplinary teams focused on questions centered belowground, whether the research areas involve conservation organizations, industry, the classroom, or government agencies working to resolve global chal-lenges and sustain a future for all.