Evaluating the feasibility of using the red mason bee (Osmia bicornis L.) in different experimental setups

Background: Evaluating hazards of pesticides to beneficial insects has become very important for the assessment and registration of pesticides. Test methods for honeybees are well established in the laboratory, under semi-field and field conditions. However, experiences in using other pollinators as model species are limited. Here we present results of various experiments on the red mason bee (Osmia bicornis L.), a solitary, commercially used bee species. The aim was to compare methodologies, to assess test parameters, and to evaluate the feasibility of using O. bicornis in late season, when this bee species would have already finished its life cycle under natural conditions. Results: Hatching times and hatching rates varied depending on temperature and season. Provisioning and reproduction of O. bicornis were very variable, weather-dependent and not always reliably reproducible between seasons. They were higher in early than in late season in the field. In late season cardboard tubes showed greater cell production than wooden boards. Conclusion: O. bicornis is a good study system under semi-field and field conditions: cocoons are easy to handle, and to monitor. Since hatching rate and cell production decreased over time, experiments are most recommended in early to mid season. Cardboard tubes can be used as standardised, inexpensive nesting devices. However, they do not allow continuous observation and pollen sampling, and involve time-consuming handling in the laboratory. Our experiment on nest material was conducted in late season and may not mirror conditions in spring and early summer.Keywords: solitary bees, field experiments, semi-field experiments, reproduction, hatching, nestin

3.13 Tank mixtures of insecticides and fungicides, adjuvants, additives, fertilizers and their effects on honey bees after contact exposure in a spray chamber

In agriculture honey bees may be exposed to multiple pesticides. In contrast to single applications of plant protection products (PPP), the effects of tank mixtures of two or more PPP on honey bees are not routinely assessed in the risk assessment of plant protection products. However, tank mixes are often common practice by farmers. Mixtures of practically non-toxic substances can lead to synergistic increase of toxic effects on honey bees, observed for the first time in 19921 in combinations of pyrethroids and azole fungicides. 2004 Iwasa et al. already reported that ergosterol-biosynthesis-inhibiting (EBI) fungicides strongly increase the toxicity of neonicotinoids in laboratory for the contact exposure route. Furthermore, in agricultural practice additives, adjuvants and fertilizers may be added to the spray solution. For these additives usually no informations on potential side effects on bees are available when mixed with plant protection products. Therefore, it is considered necessary to investigate possible additive or synergistic impacts and evaluate potentially critical combinations to ensure protection of bees. Here, we investigated the effects on bees of combinations of insecticides, fungicides and fertilizers under controlled laboratory conditions. A spray chamber was used to evaluate effects following contact exposure by typical field application rates. Subsequently, mortality and behaviour of bees were monitored for at least 48 h following the OECD acute contact toxicity test 2143. Dependencies of synergistic effects and the time intervals between the applications of the mixing partners were evaluated.In agriculture honey bees may be exposed to multiple pesticides. In contrast to single applications of plant protection products (PPP), the effects of tank mixtures of two or more PPP on honey bees are not routinely assessed in the risk assessment of plant protection products. However, tank mixes are often common practice by farmers. Mixtures of practically non-toxic substances can lead to synergistic increase of toxic effects on honey bees, observed for the first time in 19921 in combinations of pyrethroids and azole fungicides. 2004 Iwasa et al. already reported that ergosterol-biosynthesis-inhibiting (EBI) fungicides strongly increase the toxicity of neonicotinoids in laboratory for the contact exposure route. Furthermore, in agricultural practice additives, adjuvants and fertilizers may be added to the spray solution. For these additives usually no informations on potential side effects on bees are available when mixed with plant protection products. Therefore, it is considered necessary to investigate possible additive or synergistic impacts and evaluate potentially critical combinations to ensure protection of bees. Here, we investigated the effects on bees of combinations of insecticides, fungicides and fertilizers under controlled laboratory conditions. A spray chamber was used to evaluate effects following contact exposure by typical field application rates. Subsequently, mortality and behaviour of bees were monitored for at least 48 h following the OECD acute contact toxicity test 2143. Dependencies of synergistic effects and the time intervals between the applications of the mixing partners were evaluated

Neonicotinoids and bees: A large scale field study investigating residues and effects on honeybees, bumblebees and solitary bees in oilseed rape grown from clothianidin-treated seed

In 2013, the European Food Safety Authority (EFSA) has highlighted several data gaps regarding the exposure and risk of pesticides to honeybees, bumblebees and solitary bees, including the risks from exposure to contaminated nectar and pollen. This study aims to contribute data, results and conclusions to obtain more information on exposure and risks of flowering oilseed rape seed treated with the neonicotinoid clothianidin, to pollinators. Semi-field and field trials were conducted at five different locations across Germany, using the Western honeybee (Apis mellifera L.), the buff-tailed bumblebee (Bombus terrestris L.) and the red mason bee (Osmia bicornis L.) as study organisms.Highest amounts of clothianidin residues were measured in single samples of mud cell walls (7.2 μg kg-1) and pollen (5.9 μg kg-1) from solitary bee nests. Residues in nectar from honey sacs, honeybee combs and bumblebee nests (2.2, 2.9, and 3.0 μg kg-1 respectively) showed no clear differences in the amount of residues, neither did residues in pollen (1.5, 1.8, and 1.3 μg kg-1 respectively). These results suggest differences in the risk profiles of those three bee species. Keywords: clothianidin, residues, honeybees, bumblebees, solitary bees, field, semi-fiel

Two-year field data on neonicotinoid concentrations in guttation drops of seed treated maize (Zea mays)

We present neonicotinoid concentrations in guttation drops of commonly used maize (Zea mays) cultivars, germinated from seeds coated with active substances (a.s.): i) imidacloprid (IMD), ii) clothianidin (CTN) and iii) thiamethoxam (THM) over two growing seasons. In one variant clothianidin was applied as seed granule. The trial took place at the experimental fields of the Julius Kühn-Institut in Berlin in 2010 and 2011. Data from 2010 are related to a presentation of “Pesticides in guttation droplets following seed treatment – field studies” (Schenke et al., 2011) [1] presented at the SETAC North America conference and only some figures were used in the “Scientific opinion on the science behind the development of a risk assessement of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees)” (EFSA, 2012) [2]. Only parts of the data from 2011 was presented in relation to the “Exposure of Coccinellidae to guttation droplets on maize seedlings with seed or granule treatment of neonicotinoids” (Schenke and Heimbach, 2014) [3].The article describes the study sites, the variants of treated maize seeds, sample collection and the analytical methods used to quantify the neonicotinoids and relevant metabolites of IMD (5-OH-IMD and IMD-olefine) and of THM (CTN) in guttation drop samples. The complete field data set is publicly available at the OpenAgrar repository under https://doi.org/10.5073/20180907-142020 (Schenke et al., 2018) [4]

Mapping Motor Neuroplasticity after Successful Surgical Brachial Plexus Reconstruction Using Navigated Transcranial Magnetic Stimulation (nTMS)

Brachial plexus reconstruction (BPR) consists of the complex surgical restoration of nerve structures. To further understand the underlying motor cortex changes and evaluate neuroplasticity after a successful surgery, we performed a navigated transcranial magnetic stimulation (nTMS) study mapping the postoperative motor representation of the formerly plegic arm. We conducted a prospective nTMS study mapping the musculocutaneous nerve as a representative, prominent target of BPR including a patient (n = 8) and a control group (n = 10). Measurements like resting motor threshold (RMT), cortical motor area location, and size were taken. Mathematical analysis was performed using MATLAB 2022, statistical analysis was performed using SPSS 26, and nTMS mapping was performed using the Nexstim NBS 5.1 system. Mapping was feasible in seven out of eight patients. Median RMT on the affected hemisphere was 41% compared to 50% on the unaffected hemisphere and they were 37% and 36% on the left and right hemispheres of the control group. The motor area location showed a relocation of bicep brachii representation at the middle precentral gyrus of the corresponding contralateral hemisphere. Motor area size was increased compared to the control group and the patient’s unaffected, ipsilateral hemisphere. Understanding cortical reorganization is important for potential future treatments like therapeutic nTMS. The issue of motor neuroplasticity in patients with brachial plexus lesions is worth exploring in further studies

Intestinal Dysbiosis Amplifies Acetaminophen-Induced Acute Liver Injury.

To test this hypothesis, we assessed the association of proton pump inhibitor (PPI) or long-term antibiotics (ABx) intake, which have both been linked to intestinal dysbiosis, and occurrence of ALF in the 500,000 participants of the UK BioBank population-based cohort. For functional studies, male Nlrp6-/- mice were used as a dysbiotic mouse model and injected with a sublethal dose of acetaminophen (APAP) or lipopolysaccharide (LPS) to induce ALF