Search

Global declines of bumble bees and other pollinator populations are of concern because of their critical role for crop production and maintenance of wild plant biodiversity. Although the consensus among scientists is that the interaction of many factors, including habitat loss, forage scarcity, diseases, parasites, and pesticides, potentially plays a role in causing these declines, pesticides have received considerable attention and scrutiny. In response, regulatory agencies have introduced more stringent pollinator testing requirements for registration and reregistration of pesticides, to ensure that the risks to pollinators are minimized. In this context, guidelines for testing bumble bees (Bombus spp.) in regulatory studies are not yet available, and a pressing need exists to develop suitable protocols for routine higher-tier studies with these non-Apis sp., social bees. To meet this need, Bayer CropScience LP, Syngenta Crop Protection LLC US, and Valent USA. Corporation organized a workshop bringing together a group of global experts on bumble bee behavior, ecology, and ecotoxicology to discuss and develop draft protocols for both semi-field (Tier II) and field (Tier III) studies. The workshop was held May 8-9, 2014, at the Bayer Bee Care Center, North Carolina, USA. The participants represented academic, consulting, and industry scientists from Europe, Canada, the United States, and Brazil. The workshop identified a clear protection goal and generated proposals for basic experimental designs, relevant measurements, and endpoints for both semifield (tunnel) and field tests. These initial recommendations are intended to form the basis of discussions to help advance the development of appropriate protocol guidelines., (© 2015 The Authors. Integrated Environmental Assessment and Management Published by SETAC.)

The concept of source‐sink dynamics as a potentially important component of metapopulation dynamics was introduced in the 1980s. The objective of the present review was to review the considerable body of work that has been developed, to consider its theoretical implications as well as to understand how source‐sink dynamics may manifest under field conditions in the specific case of nontarget arthropods in the agricultural environment. Our review concludes that metapopulation dynamics based on field observations are often far more complex than existing theoretical source‐sink models would indicate, because they are dependent on numerous population processes and influencing factors. The difficulty in identifying and measuring these factors likely explains why empirical studies assessing source‐sink dynamics are scarce. Furthermore, we highlight the importance of considering the spatial and temporal heterogeneity of agricultural landscapes when assessing the population dynamics of nontarget arthropods in the context of the risk from the use of plant protection products. A need is identified to further develop and thoroughly validate predictive population models, which can incorporate all factors relevant to a specific system. Once reliable predictive models for a number of representative nontarget arthropod species are available, they could provide a meaningful tool for refined risk evaluations (higher tier level risk assessment), addressing specific concerns identified at the initial evaluation stages (lower tier level risk assessment). Environ Toxicol Chem 2021;40:2667–2679. © 2021 ERM, FMC, Syngenta, Bayer AG, BASF SE, Corteva agriscience. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether) is a broad-spectrum bactericide used throughout North America and Europe for a variety of antimicrobial functions. This paper addresses the risk to terrestrial organisms from several potential exposure pathways: Exposure experienced by earthworms, terrestrial plants, and soil microorganisms as the result of the use of sewage sludge containing triclosan as an agricultural soil amendment; secondary exposure by birds and mammals from consumption of earthworms that have been exposed to triclosan in soil; and secondary exposure by birds and mammals from consumption of fish exposed to triclosan as the result of wastewater treatment discharges. The assessment found satisfactory margins of safety for plants, earthworms, birds, fish, mammals, and soil microorganisms. The lowest margins of safety were for nontarget plants (100 for the typical scenario and 8 for the upper-bound scenario). However, these margins of safety are still above the European Union (EU) recommended fivefold assessment value for nontarget plants and are based on cucumber results from a vegetative vigor study conducted in quartz sand that is of limited relevance for risk assessment. In a pre-emergence study conducted in a more relevant soil (sandy loam), cucumbers showed no response to triclosan at the highest dose tested (1,000 μg/kg). A recent study provides limited field measurements of soil and earthworm concentrations. While that study finds higher soil and earthworm concentrations than were estimated in the present study, even these higher concentrations do not indicate significant risks. [ABSTRACT FROM AUTHOR]

As part of an industry-led initiative, the European Crop Protection Association (ECPA) have used available industry efficacy trial data to check the hypothesis of significant exposure via ‘weeds in the treated field’ exposure scenario, referred to in the EFSA bee Guidance Document, which suggests that if <10% of the area of use contains attractive flowering weeds then the exposure route is not relevant. Weed recordings from over 8500 industry herbicide efficacy trials from a range of arable (sunflower, maize, oilseed rape, cereals, sugar beet, potatoes, peas and beans) and permanent crops (orchards, citrus and grapes) were anlaysed to check the hypothesis of significant exposure route via weeds in the treated field. Information was extracted from efficacy trial control data to determine if the occurrence of attractive flowering weeds constitutes less than 10% of the area of use, thereby highlighting that attractive flowering weeds in treated agricultural fields are not applicable for many commercially grown crops. Here we present the analysis on the presence of weed species, growth stage of the weed species, attractiveness to bees of the weed species, the ground coverage of the weed species, the trial location and dates and the crop growth stage in the trials. The most pertinent questions being asked were ‘are attractive flowering weeds likely to be present in arable and permanent crop fields?’ and ‘what percentage of the area of the treated field might be occupied by attractive flowering weeds?. The project builds on the initial work from Maynard et al, 2014.As part of an industry-led initiative, the European Crop Protection Association (ECPA) have used available industry efficacy trial data to check the hypothesis of significant exposure via ‘weeds in the treated field’ exposure scenario, referred to in the EFSA bee Guidance Document, which suggests that if <10% of the area of use contains attractive flowering weeds then the exposure route is not relevant. Weed recordings from over 8500 industry herbicide efficacy trials from a range of arable (sunflower, maize, oilseed rape, cereals, sugar beet, potatoes, peas and beans) and permanent crops (orchards, citrus and grapes) were anlaysed to check the hypothesis of significant exposure route via weeds in the treated field. Information was extracted from efficacy trial control data to determine if the occurrence of attractive flowering weeds constitutes less than 10% of the area of use, thereby highlighting that attractive flowering weeds in treated agricultural fields are not applicable for many commercially grown crops. Here we present the analysis on the presence of weed species, growth stage of the weed species, attractiveness to bees of the weed species, the ground coverage of the weed species, the trial location and dates and the crop growth stage in the trials. The most pertinent questions being asked were ‘are attractive flowering weeds likely to be present in arable and permanent crop fields?’ and ‘what percentage of the area of the treated field might be occupied by attractive flowering weeds?. The project builds on the initial work from Maynard et al, 2014. [ABSTRACT FROM AUTHOR]