Combined effects of three insecticides with different modes of action on biochemical responses of the solitary bee Osmia bicornis.

Bees are simultaneously exposed to a variety of pesticides, which are often applied in mixtures and can cause lethal and sublethal effects. The combined effects of pesticides, however, are not measured in the current risk assessment schemes. Additionally, the sublethal effects of pesticides on a variety of physiological processes are poorly recognized in bees, especially in non-Apis solitary bees. In this study, we used a full-factorial design to examine the main and interactive effects of three insecticide formulations with different modes of action (Mospilan 20 SP, Sherpa 100 EC, and Dursban 480 EC) on bee biochemical processes. We measured acetylcholinesterase (AChE), glutathione S-transferase (GST) and esterase (EST) activities, as well as a nonenzymatic biomarker associated with energy metabolism, i.e., ATP level. All studied endpoints were affected by Sherpa 100 EC, and the activities of AChE and EST as well as ATP levels were affected by Dursban 480 EC. Moreover, complex interactions between all three insecticides affected ATP levels, showing outcomes that cannot be predicted when testing each insecticide separately. The results indicate that even if interactive effects are sometimes difficult to interpret, there is a need to study such interactions if laboratory-generated toxicity data are to be extrapolated to field conditions.

Mortality Pattern of Poecilus cupreus Beetles after Repeated Topical Exposure to Insecticide─Stochastic Death or Individual Tolerance?

The mortality of organisms exposed to toxicants has been attributed to either stochastic processes or individual tolerance (IT), leading to the stochastic death (SD) and IT models. While the IT model follows the principles of natural selection, the relevance of the SD model has been debated. To clarify why the idea of stochastic mortality has found its way into ecotoxicology, we investigated the mortality of Poecilus cupreus (Linnaeus, 1758) beetles from pesticide-treated oilseed rape (OSR) fields and unsprayed meadows, subjected to repeated insecticide treatments. We analyzed the mortality with the Kaplan-Meier estimator and general unified threshold model for survival (GUTS), which integrates SD and IT assumptions. The beetles were exposed three times, ca. monthly, to the same dose of Proteus 110 OD insecticide containing thiacloprid and deltamethrin, commonly used in the OSR fields. Kaplan-Meier analysis showed that the mortality of beetles from meadows was much higher after the first treatment than after the next two, indicating the IT model. Beetles from the OSR displayed approximately constant mortality after the first and second treatments, consistent with the SD model. GUTS analysis did not conclusively identify the better model, with the IT being marginally better for beetles from meadows and the SD better for beetles from OSR fields.

Hospital Admission Factors Independently Affecting the Risk of Mortality of COVID-19 Patients.

INTRODUCTION: COVID-19 is a disease characterized by high in-hospital mortality, which seems to be dependent on many predisposing factors. OBJECTIVES: The aim of this study was to analyze the clinical symptoms, abnormalities in the results of laboratory tests, and coexisting chronic diseases that independently affected the risk of in-hospital mortality in patients with COVID-19. PATIENTS AND METHODS: We analyzed the records of patients with COVID-19 who were hospitalized from 6 March 2020 to 30 November 2021. RESULTS: Out of the entire group of 2138 patients who were analyzed, 12.82% died during hospitalization. In-hospital mortality was independently associated with older age (OR 1.53, 95% CI 1.20-1.97); lower arterial blood oxygen saturation (OR 0.95, 95% CI 0.92-0.99); the presence of a neoplasm (OR 4.45, 95% CI 2.01-9.62), a stomach ulcer (OR 3.35, 95% CI 0.94-11.31), and dementia (OR 3.40, 95% CI 1.36-8.26); a higher score on the SOFA scale (OR 1.73, 95% CI 1.52-1.99); higher lactate dehydrogenase (LDH) (OR 1.08, 95% CI 1.05-1.12); higher N-terminal pro-brain natriuretic peptide (NT pro BNP) (OR 1.06, 95% CI 1.01-1.11); and lower total bilirubin in blood concentration (OR 0.94, 95% CI 0.90-0.99). CONCLUSIONS: We found that low oxygen saturation, old age, and the coexistence of cancer, gastric ulcers, and dementia syndrome were variables that independently increased mortality during hospitalization due to COVID-19. Moreover, we found that decreased platelet count and bilirubin concentration and increased levels of LDH and NT-proBNP were laboratory test results that independently indicated a higher risk of mortality. We also confirmed the usefulness of the SOFA scale in predicting treatment results. The ability to identify mortality risk factors on admission to hospital will facilitate both adjusting the intensity of treatment and the monitoring of patients infected with SARS-CoV-2.

Change in the Clinical Picture of Hospitalized Patients with COVID-19 between the Early and Late Period of Dominance of the Omicron SARS-CoV-2 Variant.

This study aimed to compare the clinical picture of COVID-19 in the initial and later period of Omicron dominance and to identify populations still at risk. A retrospective comparison of the clinical data of 965 patients hospitalized during the early period of Omicron's dominance (EO, January-June 2022) with 897 patients from a later period (LO, July 2022-April 2023) from the SARSTer database was performed. Patients hospitalized during LO, compared to EO, were older, had a better clinical condition on admission, had a lower need for oxygen and mechanical ventilation, had less frequent lung involvement in imaging, and showed much faster clinical improvement. Moreover, the overall mortality during EO was 14%, higher than that in LO-9%. Despite the milder course of the disease, mortality exceeding 15% was similar in both groups among patients with lung involvement. The accumulation of risk factors such as an age of 60+, comorbidities, lung involvement, and oxygen saturation <90% resulted in a constant need for oxygen in 98% of patients, an 8% risk of mechanical ventilation, and a 30% mortality rate in the LO period. Multiple logistic regression revealed lower odds of death during the LO phase. Despite the milder course of infections caused by the currently dominant subvariants, COVID-19 prophylaxis is necessary in people over 60 years of age, especially those with comorbidities, and in the case of pneumonia and respiratory failure.

Effects of agricultural landscape structure and canola coverage on biochemical and physiological traits of the ground beetle Poecilus cupreus.

The intensifications in the agricultural landscape and the application of pesticides can cause adverse effects on the fitness of organisms in that landscape. Here, we investigated whether habitats with different agricultural pressures influenced acetylcholinesterase (AChE) activity - a biomarker for exposure to pesticides, respiration rate, and resistance to starvation in the ground beetle Poecilus cupreus. Two differently structured landscapes were selected for the study, one dominated by small (S) and another by large (L) fields. Within each landscape three habitat types were selected: in the S landscape, these were habitats with medium (M), small (S) and no canola (meadow, 0) coverage (i.e., SM, SS, S0), and in the L landscape habitats with large (L), medium (M) and no canola (meadow, 0) coverage (i.e., LL, LM, L0), representing different levels of agricultural pressure. The activity of AChE was the highest in beetles from canola-free habitats (S0 and L0), being significantly higher than in beetles from the SM and SS habitats. The mean respiration rate corrected for body mass was also the highest in S0 and L0 beetles, with significant differences between populations from L0 vs. SS and from S0 vs. SS. Only beetles from S0, SS, L0, and LM were numerous enough to assess the resistance to starvation. Individuals from the LM habitat showed better survival compared to the canola-free habitat in the same landscape (L0), whereas in S landscape the SS beetles survived worse than those from S0, suggesting that characteristics of L landscape may lead to developing mechanisms of starvation resistance of P. cupreus in response to agricultural pressure.

Floral resources,energetic value and pesticide residues in provisions collected by Osmia bicornis along a gradient of oilseed rape coverage.

Pollinators in agricultural landscapes are facing global decline and the main pressures include food scarcity and pesticide usage. Intensive agricultural landscapes may provide important food resources for wild pollinators via mass flowering crops. However, these are monofloral, short-term, and may contain pesticide residues. We explored how the landscape composition with a different proportion of oilseed rape (6-65%) around Osmia bicornis nests affects floral diversity, contamination with pesticides, and energetic value of provisions collected by this species of wild bees as food for their offspring. Altogether, the bees collected pollen from 28 plant taxa (6-15 per nest) and provisions were dominated by Brassica napus (6.0-54.2%, median 44.4%, 12 nests), Quercus sp. (1.2-19.4%, median 5.2%, 12 nests), Ranunculus sp. (0.4-42.7%, median 4.7%, 12 nests), Poaceae (1.2-59.9%, median 5.8%, 11 nests) and Acer sp. (0.6-42%, median 18.0%, 8 nests). Residues of 12 pesticides were found in provisions, with acetamiprid, azoxystrobin, boscalid, and dimethoate being the most frequently detected at concentrations up to 1.2, 198.4, 16.9 and 17.8 ng/g (median 0.3, 10.6, 11.3, 4.4 ng/g), respectively. Floral diversity and energetic value of provisions, but not the Pesticide Risk Index depended on landscape structure. Moreover, pollen diversity decreased, and energetic value increased with landscape diversity. Thus, even a structurally simple landscape may provide diverse food for O. bicornis if the nest is located close to a single but resource-diverse patch. Both B. napus and non-crop pollen were correlated with pesticide concentrations.

Late diagnosis of HIV infection in Warsaw: Estimating the scale of the problem and demographic trends.

BACKGROUND: Late diagnosis of a significant number of people with HIV remains a problem. This study analysed 1711 patients from the Hospital for Infectious Diseases in Warsaw who were diagnosed with HIV infection in 2008-2010 and 2016-2018. METHODS: Patients with late diagnosis and advanced disease were distinguished on the basis of the consensus definition. In statistical analysis, non-parametric tests were used to compare the groups: the χ2 test for categorized data and the Mann-Whitney U test for the comparison of continuous variables. RESULTS: There were no statistically significant differences in the percentage of patients with early diagnosis, late diagnosis, advanced disease and patients with an indicator disease between the two analysed periods in the Warsaw centre. A much higher percentage of men than women was found. The dominant route of acquisition among newly diagnosed patients and among late presenters in both periods were men who have sex with men (MSM). The highest percentage of patients with late diagnosis was among heterosexual men and the lowest was among MSM in both periods. CONCLUSIONS: The results of the analysis of patients from the Warsaw centre confirmed that late diagnosis of HIV infection continues to be a problem, with no improvement seen over the analysed periods, although the scale of the problem is smaller than in national and European statistics. MSM and heterosexual men appear to be key groups in need of intensified testing.

Is the definition of late diagnosis correct?

BACKGROUND: The study analysed 1711 patients of the Hospital for Infectious Diseases in Warsaw diagnosed with HIV infection in 2008-2010 and 2016-2018. Research was conducted examining the changes in CD4 cell counts before starting antiretroviral (ARV) treatment in order to find people who were misclassified as late-diagnosed. METHODS: Patients with late diagnosis were distinguished on the basis of the consensus definition. The Mann-Whitney U-test was used to analyse the change in CD4 cell counts before starting ARV treatment. RESULTS: In the years 2008-2010, the CD4 count was remeasured before starting ARV treatment in 90 late-diagnosed patients. The median change in the CD4 count was 22 cells/µL. In 49 of these, the number of CD4 cells spontaneously increased before the start of treatment. We can suspect that these patients were misclassified as late-diagnosed. CONCLUSIONS: The consensus definition of late diagnosis often leads to overestimation of the number of late-diagnosed patients. The crucial problem is a transient decline in the CD4 lymphocyte count in the acute phase of HIV infection. A potential solution is to introduce serum HIV viral load measurement into the definition.

The effectiveness of erysipelas prophylaxis depends on the cumulative dose of benzathine penicillin G.

Erysipelas is an acute infection due to S. pyogenes and is characterized by a high risk of relapses. The number of patients suffering from one or more recurrences varied depending on the study and accounted for between 16% and 47% of the total number of those affected. Antibiotic prophylaxis with the use of penicillin can reduce the risk of recurrence by 47%. A number of 873 patients with erysipelas treated at the Hospital for Infectious Diseases in Warsaw from 2010 to 2018 was enrolled in the study. Benzathine-penicillin G was given intramuscularly at a dose of 1.2 MU or 2.4 MU or 3.6 MU. The earliest moment that prophylactic treatment was administered was the first episode of erysipelas recurrence. The decision to administer the antibiotic and the dose to use was discretionally made by the examining physician. Altogether 104 (11.9%) persons experienced at least one episode of erysipelas recurrence during the study period. A total of 2976 doses of benzathine- penicillin G (BP) were administered. The most common dose was that of 2.4 MU (2380, 80%). The dose of 1.2 MU was given 567 times (19%). The highest dose, i.e. 3.6 MU, was administered to only 5 patients (8 applications, 0.2%). No effect was shown by either the number of benzathine- penicillin G administered doses (p=0.07) or the median dose (p=0.65), whereas patients without relapse received a statistically higher cumulative dose of the antibiotic (p=0.047). Age was a risk factor of recurrence only in the group of diabetic patients (p=0.03). Benzathine penicillin G given in an appropriate cumulative dose is effective in preventing erysipelas recurrence.

Homogeneity of agriculture landscape promotes insecticide resistance in the ground beetle Poecilus cupreus.

The intensification of agriculture leads to increased pesticide use and significant transformation from small fields towards large-scale monocultures. This may significantly affect populations of non-target arthropods (NTA). We aimed to assess whether the multigenerational exposure to plant protection products has resulted in the evolution of resistance to insecticides in the ground beetle Poecilus cupreus originating from different agricultural landscapes. Two contrasting landscapes were selected for the study, one dominated by small and another by large fields. Within each landscape the beetles were collected at nine sites representing range of canola coverage and a variety of habitat types. Part of the collected beetles, after acclimation to laboratory conditions, were tested for sensitivity to Proteus 110 OD-the most commonly used insecticide in the studied landscapes. The rest were bred in the laboratory for two consecutive generations, and part of the beetles from each generation were also tested for sensitivity to selected insecticide. We showed that the beetles inhabiting areas with medium and large share of canola located in the landscape dominated by large fields were less sensitive to the studied insecticide. The persistence of reduced sensitivity to Proteus 110 OD for two consecutive generations indicates that either the beetles have developed resistance to the insecticide or the chronic exposure to pesticides has led to the selection of more resistant individuals naturally present in the studied populations. No increased resistance was found in the beetles from more heterogeneous landscape dominated by small fields, in which spatio-temporal diversity of crops and abundance of small, linear off-crop landscape elements may provide shelter that allows NTAs to survive without developing any, presumably costly, resistance mechanisms.

[The use of ultrasound in suspected giant cell arteritis - a case report]. / Wykorzystanie ultrasonografii w podejrzeniu olbrzymiokomórkowego zapalenia tetnic ­ opis przypadku.

Giant cell arteritis (GCA) is a type of large and middle arteries vasculitis that occurs in patients aged over 50 years. The typical symptoms include pain and tenderness in the temporal region, sudden vision impairment or loss and jaw claudication. If left untreated the disease may lead to permanent blindness. The diagnosis is based on the ACR criteria and the treatment of choice are glicocorticosteroids. The ultrasonography with color Doppler is characterized by high sensitivity and specificity which makes it a valuable diagnostic tool, especially in questionable cases. A CASE REPORT: 86-year-old woman, with a history of sudden left eye vision loss that occurred one month ago, reported to the hospital due to right eye vision impairment progression. The symptoms and characteristic of patient's complaints suggested GCA, however patient didn't meet the diagnostic criteria. The ultrasonography examination was used, which revealed features typical for GCA ("halo" sign and non-compressible arteries - compression sign), which contributed to the decision of the immediate treatment initiation with corticosteroids which stopped the progression of the disease and led to the slight right eye vision improvement. CONCLUSIONS: The ultrasonography examination is a useful and valuable diagnostic tool for patients with suspected GCA and its use is especially significant in the questionable cases diagnosis.

Toxicokinetics of three insecticides in the female adult solitary bee Osmia bicornis.

The worldwide decline of pollinators is of growing concern and has been related to the use of insecticides. Solitary bees are potentially exposed to many insecticides through contaminated pollen and/or nectar. The kinetics of these compounds in solitary bees is, however, unknown, limiting the use of these important pollinators in pesticide regulations. Here, the toxicokinetics (TK) of chlorpyrifos (as Dursban 480 EC), cypermethrin (Sherpa 100 EC), and acetamiprid (Mospilan 20 SP) was studied for the first time in Osmia bicornis females at sublethal concentrations (near LC20s). The TK of the insecticides was analysed in bees continuously exposed to insecticide-contaminated food in the uptake phase followed by feeding with clean food in the decontamination phase. The TK models differed substantially between the insecticides. Acetamiprid followed the classic one-compartment model with gradual accumulation during the uptake phase followed by depuration during the decontamination phase. Cypermethrin accumulated rapidly in the first two days and then its concentration decreased slowly. Chlorpyrifos accumulated similarly rapidly but no substantial depuration was found until the end of the experiment. Our study demonstrates that some insecticides can harm solitary bees when exposed continuously even at trace concentrations in food because of their constant accumulation leading to time-reinforced toxicity.

Effects of agricultural landscape structure, insecticide residues, and pollen diversity on the life-history traits of the red mason bee Osmia bicornis.

Agricultural landscapes have changed substantially in recent decades, shifting from the dominance of small fields (S) with diverse cropping systems toward large-scale monoculture (L), where landscape heterogeneity disappears. In this study, artificial nests of the red mason bee, Osmia bicornis, were placed in S and L landscape types on the perimeter of oilseed rape fields representing different oilseed rape coverages (ORC, % land cover). The local landscape structure around each nest was characterised within a 100, 200, 500, and 1000 m radius using ORC and 14 landscape characteristics, which were then reduced by non-metric multidimensional scaling (nMDS) to two axes: nMDS1 characterised the dataset primarily according to land fragmentation and the main crop, whereas nMDS2 captured the prevalence of more natural areas in the landscape. Pollen diversity and insecticide risk levels in the pollen provisions collected by the bees were analysed, and their dependence on the landscape structure was tested. Thereafter, the effects of pollen diversity, insecticide risk, and landscape structure on the life-history traits of bees and their sensitivity to topically applied Dursban 480 EC were determined. Pollen taxa richness in a single nest ranged from 3 to 12, and 34 pesticides were detected in the pollen at concentrations of up to 320 ng/g for desmedipham. The O. bicornis foraging range was relatively large, indicating that the landscape structure within a radius of ~1000 m around the nest is important for this species. Pollen diversity in the studied areas was of minor importance for bee performance, but the ORC or landscape structure significantly affected the life-history traits of the bees. Contamination of pollen with insecticides affected the bees by decreasing the mass of newly emerged adults but their sensitivity to Dursban 480 EC was not related to environmental variables.

Physiological and biochemical response of the solitary bee Osmia bicornis exposed to three insecticide-based agrochemicals.

The physiological and biochemical stress induced by pesticides need to be addressed in economically and ecologically important non-Apis solitary bees, particularly at lower than field-applied concentrations. Thus, the aim of the present study was to analyse the physiological and biochemical changes in female adult Osmia bicornis bees upon continuous oral exposure to three insecticide-based agrochemicals - i.e. Dursban 480 EC (active ingredient - a.i. chlorpyrifos), Sherpa 100 EC (a.i. cypermethrin), and Mospilan 20 SP (a.i. acetamiprid), in a toxicokinetic manner (feeding with either insecticide-contaminated food or uncontaminated food (controls) for 8 d in the contamination phase followed by 8 d of decontamination (i.e. feeding with uncontaminated food)). All three tested agrochemicals altered the energetic budget of bees by the deprivation of energy derived from lipids and carbohydrates (but not proteins) and/or a decrease in respiration based metabolic rate (energy consumption) compared to the controls. The activities of acetylcholinesterase and glutathione-S-transferase enzymes were not altered by insecticides at tested concentrations. These results show that chronic exposure to at least some pesticides even at relatively low concentrations may cause severe physiological disruptions that could potentially be damaging for the solitary bees.

Risk factors for complicated course and recurrence of Clostridioides Difficile infections during COVID-19 pandemic.

INTRODUCTION: The primary symptom of Clostridioides difficile infection (CDI) is diarrhea of varying severity. Both malnutrition and clinical nutrition increase the risk for contracting Clostridioides difficile (C. difficile) infection and the likelihood of relapses. Moreover, the risk for recurrence is higher if there is infection with a hypervirulent strain (NAP1/BI/027). Hypoalbuminemia predisposes to a severe course of the disease and morbidity. MATERIAL AND METHODS: Analysis was carried out of the data regarding patients hospitalized at the Regional Hospital for Infectious Diseases in Warsaw from 01 January 2020 to 31 December 2021 who were diagnosed with C. difficile infection. A severe course of infection was diagnosed when a blood test showed a leukocyte count greater than or equal to 15,000/µl and/or a creatinine concentration >1.5 mg/dl (>132.6 mmol/l). RESULTS: Clostridioides difficile infection was the reason for 185 hospitalizations (involving 108 women and 77 men), of 167 patients aged from 22 to 93 years old. There were 68 (37%) cases of recurrent infection. Seventy-five (41%) infections met the study's criteria for severe CDI, and 12 (7%) patients died. Out of the total number of hospitalizations, 41 (22%) were due SARS-CoV-2 co-infection. PCR tests detecting binary toxin revealed 34 (18%) positive results. Infection with a hypervirulent strain was an independent risk factor for the recurrence of diarrhea which had C. difficile etiology. Overall, during an episode of diarrhea, one antibacterial drug was used in 139 cases (75%), two in 27 (15%), three in 14 (8%) situations, and four - twice (1%). Among these, drugs not recommended for the treatment of CDI were used in 21 (11%) cases. The number of antibacterial drugs administered during an episode of diarrhea was an independent risk factor for the death of the infected person. Clinical nutrition was applied during 19 hospitalizations (10%), out of which 12 (63%) cases showed a severe course of C. difficile infection, while four patients (21%) died. Using clinical nutrition methods was an independent risk factor for a severe course of the disease and patient death. CONCLUSIONS: Clinical nutrition and the number of antibiotics used during an episode of diarrhea are independent risk factors for the death of a patient with CDI. Infection with a hypervirulent strain increases the risk for relapse.

Analysis of the occurrence of hemophagocytic lymphohistiocytosis (HLH) features in patients with sepsis: a prospective study.

HLH syndrome may mimic sepsis but requires entirely different treatment. The aim of the study was to assess the occurrence of HLH features in patients with sepsis and the influence these exert on the patients' prognosis. The prospective study included 108 patients with suspected sepsis who were routinely evaluated according to HLH criteria. They were divided into group I (SOFA = 2, n = 57) and group II (SOFA ≥ 3, n = 51). Four patients were excluded from analysis: 1 with real HLH, 2 with Still's disease and 1 with lymphoma. The median (IQR) concentration of ferritin was 613.4 (850.3) ng/mL, however 6 patients revealed a remarkedly high ferritin concentration > 3000 ng/mL, including 2 with ferritin > 10,000 ng/mL. In total, 21 patients met ≥ 4/8 HLH criteria and were found to have sepsis with HLH-like syndrome (SHLS). Out of these, 19 responded to antimicrobials, 2 died due to infection. The sepsis patients presented with the following HLH criteria: fever (95.2%), hyperferritinemia (57.3%), splenomegaly (43.4%), reduced NK cell activity (35.2%), high sCD25 activity (27.4%) and rarely: hypertriglyceridemia (14.4%), duopenia (5.8%), hypofibrinogenemia (1.9%). Although group II patients had higher odds for SHLS presentation (OR 3.26, p = 0.026) and for death (OR 14.3, p = 0.013), SHLS occurrence had no impact on the risk of death (OR 0.77, p = 0.75). Sepsis patients can present with SHLS exclusively due to severe infection. Duopenia, hypertriglyceridemia, hypofibrinogenemia and high level of sCD25 are unusual in sepsis and might indicate real HLH syndrome. Hyperferritinemia, even as high as in real HLH syndrome, can occur in sepsis patients.

Different effects of Zn nanoparticles and ions on growth and cellular respiration in the earthworm Eisenia andrei after long-term exposure.

In this study, the effects of zinc nanoparticles (ZnO-NPs) and ions (ZnCl2) on the mortality, growth, maturation, and cellular respiration of the earthworm Eisenia andrei were assessed. Earthworms were individually exposed for 98 days, starting from the juvenile stage, to soils contaminated with either ZnO-NPs or ZnCl2 (125, 250, 500 and 1000 mg Zn kg-1 dry weight (dw)). Exposure to the highest-concentration ionic treatments (500 and 1000 mg kg-1) caused 100% mortality, while for other treatments, mortality did not exceed 15% at the end of exposure. Compared to the control treatment, both 125-1000 mg kg-1 ZnO-NPs and 125 or 250 mg kg-1 ZnCl2 stimulated earthworm growth, which might be due to a hormetic effect. ZnO-NPs and ZnCl2 caused different responses at medium Zn concentrations (250 and 500 mg kg-1): earthworms exposed to ionic treatment at 250 mg kg-1 were characterized by a significantly lower growth constant, lower cellular respiration rate, later inflection point, and higher final body weight than those exposed to ZnO-NPs treatments at the same (250 mg kg-1) or twice as high (500 mg kg-1) nominal Zn concentrations. However, differences were not observed in all examined parameters between the studied forms when the highest-concentration ZnO-NPs treatment was compared with the lowest-concentration ionic treatment, which was likely due to the same levels of available Zn concentrations in those treatments. Overall, different growth and maturation strategies accompanied by pronounced differences in cellular respiration were adopted by earthworms exposed to low and medium levels of either ZnO-NPs or ZnCl2.

Supporting non-target arthropods in agroecosystems: Modelling effects of insecticides and landscape structure on carabids in agricultural landscapes.

Intensification of agricultural practices is one of the most important drivers of the dramatic decline of arthropod species. We do not know, however, the relative contribution to decline of different anthropogenic stressors that are part of this process. We used high-resolution dynamic landscape models and advanced spatially-explicit population modelling to estimate the relative importance of insecticide use and landscape structure for population dynamics of a widespread carabid beetle Bembidion lampros. The effects of in-crop mitigation measures through the application of insecticides with reduced lethality, and off-crop mitigation measures by increasing abundance of grassy field margins, were evaluated for the beetle along the gradient of landscape heterogeneity. Reducing the insecticide-driven lethality (from 90 to 10%) had larger positive impacts on beetle density and occupancy than increasing the abundance of field margins in a landscape. The effects of increasing field margins depended on their width and overall abundance in the landscape, but only field margins 4 m wide, applied to at least 40% of fields, resulted in an increase in beetle population density comparable to the scenario with the smallest reduction of insecticide-driven lethality we considered. Our findings suggest the importance of field margins rather as a supporting not stand-alone mitigation measure, as they generally improved effects of reduction of insecticide-driven lethality. Therefore, adding sufficiently broad off-field habitats should help to maintain viable beetle populations in agricultural landscapes even with moderate use of insecticides. In general, the less persistent the insecticides are in the environment, the larger positive impacts of applied mitigation measures on beetle populations were found. We also showed that the effectiveness of applied mitigation measures strongly depends on landscape and farmland heterogeneity. Thus, to achieve the same management or mitigation target in different landscapes might require different strategies.

The development of the solitary bee Osmia bicornis is affected by some insecticide agrochemicals at environmentally relevant concentrations.

Solitary bees provide essential pollination services for many arable crops, but are prone to global decline. Agricultural intensification, which is connected with pesticide usage, is among major threats to bees and, thus, to the food security and ecosystem stability. As it may not be possible to cease pesticide usage currently because of the growing demand for food, it is crucial to understand the pesticide toxicities to bees for better protection of pollinator populations. The majority of studies have focused on social bees, and those on solitary bees studied effects of adult exposure, whereas these bees are also likely to be exposed as larvae via the consumption of contaminated pollen. Here, the effects of three commonly used insecticide-based plant protection products on the development of the solitary bee, Osmia bicornis (red mason bee), were studied by exposing larvae to insecticide-contaminated multifloral pollen. The tested insecticides were: Dursban480EC, containing the organophosphate chlorpyrifos (CHP), Sherpa100EC, containing the pyrethroid cypermethrin (CYP), and Mospilan20SP with the neonicotinoid acetamiprid (ACT). When compared to the control larvae fed with uncontaminated-pollen, both CHP and CYP significantly reduced the O. bicornis larval survival and their body mass at all tested concentrations. In contrast, ACT did not affect either larval survival or body mass, but the length of larval stage to cocoon formation was significantly shortened compared to controls. None of studied insecticides affected the mass of cocooned individuals. However, at least 80% of individuals exposed to any of the tested insecticides died before reaching the adult stage, whereas 43% of the controls emerged successfully after overwintering. Although no clear monotonic dose-response relationships were found, our study showed that at least some insecticide formulations affect the development of O. bicornis even at concentrations actually found in pollen in the field, indicating an urgent need for revising current pesticide usage recommendations.