Action of dithiocarbimates salts on the honey bee and its pathogen Nosema ceranae.

Apis mellifera, crucial pollinators for both native and cultivated plants, also yield various products such as honey, wax, royal jelly, and propolis, extensively utilized in the food, pharmaceuticals, and cosmetics industries. Nosema ceranae, a prevalent microsporidian worldwide, stands as a significant pathogen for A. mellifera, showing resistance to conventional antibiotics. Consequently, the exploration of novel compounds for N. ceranae control becomes imperative. Dithiocarbimate derivatives emerge as promising antifungal candidates under evaluation for combating various pathogens, particularly those affecting plants. This study assessed the toxicity profile of six dithiocarbimate derivatives on A. mellifera worker survival and N. ceranae pathogen. Among these, four compounds exhibited minimal bee mortality and proceeded to further evaluation against N. ceranae. In vitro assays demonstrated their inhibitory effects on spore germination. Remarkably, the most potent compound suppressed N. ceranae spores by 62% at a concentration of 20 µmol L-1in vivo. Thus, these dithiocarbimate derivatives represent promising new antifungal agents for combatting nosemosis in honey bee populations.

Insights about levels and source appointment of petroleum hydrocarbons in Brazilian semi-arid coastal: baseline status assessment for ocean decade targets.

The Ocean decade (2021-2030) for sustainable development proclaimed in 2017 by the UN, seeks to promote and conserve the sustainable use of oceans, seas, and marine resources. For this, the distribution of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and biomarkers, in sediments from the Fortaleza coastal zone (Mucuripe harbor (MH) and Inner Continental shelf (ICS)) were used to assess the impacts of anthropogenic activities in the area. The concentrations of total n-alkanes (Σ16 n-alkanes) in MH and ICS sediments varied from 35.9 to 94.9 and 17.9 to 197.3 µg g-1, respectively, while the isoprenoids phytane and pristane in MH and ICS sediments ranged from 0.1 to 1.69 ug g-1 and from 0.14 and 1.20 µg g-1, respectively. Most of the sediment samples presented carbon preference index (CPI) values close to unity, indicating that the area is submitted to petroleum-related sources. The concentrations of Σ16 PAHs in MH and ICS sediments varied from 87.0 to 562.0 and 98 to 288.0 ng g-1. This work presents the first investigation of the petroleum biomarkers hopanes and steranes in the Fortaleza coastal zone, in which ΣBiomarkers varied from 0.10 to 1.79 and 0.02 to 0.24 ug g-1 in MH and ICS sediments, respectively. The presence at stations of biomarkers also indicates petrogenic input. The diagnosis of the distribution of pollutants in the investigated zones of the Fortaleza coast suggests contamination from urban areas and oil spills and vessel traffic.

Water vulnerability to pesticide contamination in a Brazilian semiarid watershed.

This study aimed to prepare an inventory of the main active ingredients of pesticides and estimate the risk of pollution of groundwater and surface water resources in a Brazilian semiarid basin. The inventory was prepared using data from government agency databases. The contamination risk estimate was obtained using the GOSS index, Groundwater Ubiquity Score (GUS), Groundwater Screening Index (GSI), Leachability Index (LIX), US Environmental Protection Agency (USEPA) criteria, Leaching Index (LEACH), and Relative Leaching Potential Index (RLPI). The inventory identified 57 active ingredients commercialized under a well-defined chemical class. Most of these (51.5%) belong to the very dangerous class, while 43.6% belong to the moderately toxic class. The GOSS model showed that 23.7% of the active ingredients have a low potential, 50.85% have a moderate potential, and 13.56% have a high potential for surface water contamination, with its transport being associated with the sediment. The GUS index indicates a low potential for groundwater contamination. However, the GSI points to a high potential for water contamination, the USEPA criteria for a possible contamination of groundwater, and, according to the LIX, most of the pollutants do so by leaching. The information provided contributes to the management of xenobiotic compounds in arid and semiarid basins, adding to the water security effort by providing tools for the assessment of potential pesticide pollution. Integr Environ Assess Manag 2023;19:804-816. © 2022 SETAC.

Zinc-dithiocarbimates for the control of Hemileia vastatrix: a versatile alternative.

BACKGROUND: The purpose of this work was to investigate the potential use of zinc-dithiocarbimate salts to control Hemileia vastatrix, the causal agent of the coffee leaf rust disease, and to evaluate their toxicity towards Apis mellifera, one of the most important coffee plant pollinators. RESULTS: Zinc-dithiocarbimate salts were prepared and fully characterized by infrared, proton (1 H) and carbon-13 (13 C) nuclear magnetic resonance and elemental analyses of carbon (C), hydrogen (H), nitrogen (N) and zinc (Zn). X-ray diffraction technique studies confirmed the proposed structures. The salts inhibited the germination of H. vastatrix spores in vitro, with a 50% inhibitory concentration (IC50 ) from 12 to 18 µmol.L-1 and a 90% inhibitory concentration (IC90 ) from 23 to 26 µmol.L-1 . Zinc-dithiocarbimate salts with the best in vitro results were selected for in vivo experiments with Coffea arabica var Caturra and with the pollinator A. mellifera. The results were similar to those of Mancozeb, a broad-spectrum contact fungicide, with a good control of the disease and low toxicity to the honeybee. CONCLUSION: The zinc-dithiocarbimate complex salts have potential to control coffee leaf rust, with low toxicity to the pollinator insect. © 2022 Society of Chemical Industry.