An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 3: alternatives to systemic insecticides

Availability of Using Honeybees as Bioindicators of Pesticide Exposure in the Vicinity of Agricultural Environments in Taiwan

While pollinating, honeybees are subject to exposure to a variety of pesticides; with their characteristics of certain foraging distances, they could serve as bioindicators of pesticide exposure in a neighborhood. We conducted a study to assess availability by collecting and analyzing bee samples from 15 apiaries located in East Taiwan and dust samples from the adjacent environment, and by finding relations between both samples. Seventeen pesticides were selected for the analysis using gas or liquid chromatography coupled with mass spectrometry, and eight (three insecticides, two herbicides, and three fungicides) were more frequently detected from bee or dust samples; the levels of these pesticides were mostly under 1000 ng/g. Significant correlation results (r ≅ 0.8) between residue concentrations in bees and in dust suggest that honeybees could be a good bioindicator for exposure to herbicides and fungicides within certain ranges. The pesticide contents of sick/dead bees were much higher than those of healthy counterparts regarding any pesticide type, with the mean total concentrations of 635 ng/g and 176 ng/g, respectively. We conclude that honeybees could be used as bioindicators of pesticide exposure; sick/dead bees could serve as a warning sign of the severity of pesticide pollution.

Analytical Methods Based on Liquid Chromatography and Capillary Electrophoresis to Determine Neonicotinoid Residues in Complex Matrices. A Comprehensive Review

Neonicotinoids (NNIs) are neuro-active and systemic insecticides widely used to protect crops from pest attack. During the last decades, there has been an increase concern about their uses and toxic effects, especially to beneficial and non-target insects such as pollinators. To assess potential health hazards and the environmental impacts derived from NNIs uses, a great variety of analytical procedures for the determination of their residues and their metabolites at trace level in environmental, biological and food samples have been reported. Due to the complexity of the samples, efficient sample pretreatment methods have been developed, which include mostly clean-up and preconcentration steps. On the other hand, among the analytical techniques used for their determination, high-performance liquid chromatography (HPLC) coupled to ultraviolet (UV) or mass spectrometry (MS) detection is the most widely used, although capillary electrophoresis (CE) has also been employed in the last years, considering some improvements in sensitivity when coupling with new MS detectors. In this review, we present a critical overview of analytical methods based on HPLC and CE reported in the last decade, discussing relevant and innovative sample treatments for the analysis of environmental, food and biological samples.

A method for DNA extraction and molecular identification of Aphids

Aphid species (Insecta, Hemiptera) are economically important invasive pest throughout the world, though their identification is intricate due to tiny size and inconspicuous nature of morphology. Mitochondrial cytochrome c oxidase I (mtCOI) region has been proven to be a standard barcode to identify the diverse array of insect groups. Isolation of good quality DNA is a fundamental first step in insect DNA barcoding which is obtained by standardizing the DNA isolation method. In this study, we demonstrate a modified CTAB method for the isolation of DNA to maximize the quality and yield from small aphids. This method will help the researchers to efficiently isolate DNA from small aphid and the method can be utilized for other small insects as well. We evaluated the quality of the isolated DNA and the mtCOI gene region were subjected to PCR amplification. Further, the gene segment was sequenced and gene annotation was done by NCBI BLAST program through which the insect was found to be Aphis gossypii. This study provides a set of molecular tools that can be used for identification of insect at species level through DNA barcoding and biodiversity analysis.•Detailed method to maximize quality and quantity of genomic DNA isolated from aphids.•Molecular identification of aphids using mtCOI gene amplification and sequence validation.•First report on Aphis gossypii infecting Solanum trilobatum provides insights of pest identification and management.

Novel sustainable strategies to control Plasmopara viticola in grapevine unveil new insights on priming responses and arthropods ecology

BACKGROUND

Reduction of fungicide consumption in agriculture is globally recognized as a priority. Government authorities are fostering research to achieve a reduction of risks associated with conventional pesticides and promoting the development of sustainable alternatives. To address these issues, in the present study, alternative protocols for the control of downy mildew infection in grapevine were compared to the standard protocol. In the first protocol, only resistance inducers were used, comprising a single formulation with Acibenzolar S-methyl, laminarin and disodium-phosphonate. The second and third protocols followed the standard protocol but substituted phosphonates with phosphorus pentoxide and Ecklonia maxima extract.

RESULTS

The results showed that at veraison downy mildew incidence and severity in all tested protocols were significantly reduced compared to nontreated controls on both canopy and bunches. Expression analysis of key genes involved in plant stress response, indicated that the two protocols for phosphites substitution induced a remodulation of salicylic acid (SA) and jasmonic acid (JA), with positive impact on yields. Analysis of the first protocol revealed that the primed state induced a short delay in bunch ripening, with a shift of carbohydrate metabolism to boost the plant defences, involving an upregulation of defence related-gene, SAR response and a decreased ROS detoxification. Additionally, analysis on the arthropods populations, in parallel with the positive results achieved using alternatives to conventional fungicides, were enriched by those showing the potential of naturally occurring predators of spider mites.

CONCLUSION

This study provides practical solutions to reduce the environmental impact of treatments for the control downy mildew in viticulture. © 2022 Society of Chemical Industry.

Risk Assessment and Area-Wide Crop Rotation to Keep Western Corn Rootworm Below Damage Thresholds and Avoid Insecticide Use in European Maize Production

Simple Summary

Diabrotica virgifera virgifera LeConte, the Western corn rootworm (WCR), is a maize-specific pest that has been a serious threat in Europe since the mid-1990s. To properly implement integrated pest management, it is necessary to identify the key factors associated with risks of crop damage from WCR and to evaluate the effectiveness of area-wide strategies based on agronomic measures, such as crop rotation, in reducing those risks. In Italy and Croatia, a survey of agronomic and cultural factors in fields damaged by WCR allowed us to determine that the beetle population size accounts for most of the risk of maize damage from WCR. Crop rotation (without insecticide use), both structural and flexible, was the most effective strategy for keeping WCR populations below the damage threshold. This indicates that WCR management can be carried out in accordance with European Union regulations to limit or avoid insecticide treatments and reduce environmental impacts.

Abstract

The Western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, has been a serious quarantine pest to maize in Europe since the mid-1990s. The integrated pest management of WCR requires an accurate knowledge of the factors that contribute most to risks of crop damage, as well as knowledge of effective area-wide strategies based on agronomic measures, such as crop rotation. In Italy and Croatia, agronomic and cultural factors in fields damaged by WCR were evaluated through a long-term survey. Based on the survey results, high-WCR densities contribute most to risks of damage to maize. Extensive field research in north-eastern Italy compared large areas of continuous maize production with areas under different crop rotation systems (i.e., a structural one with one-time maize planting in a three-year rotation and a flexible one with continuous maize planting interrupted when beetle populations exceed the threshold). The objective was to evaluate the effectiveness of different rotation regimes as possible best practices for WCR management. Captures of beetles in yellow sticky traps, root damage, larval densities, and damage to maize plants (e.g., lodging) were assessed at the center of each area. The results demonstrated the both structural and flexible crop rotation systems were effective strategies for maintaining WCR below damage threshold densities without the need for insecticides.

Integrated approach for the analysis of neonicotinoids in fruits and food matrices

We searched for five neonicotenoids (namely acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam) in 67 samples of fruits, leaves, pollen and honey via HPLC-MS by employing QueChERs for extraction and purification. Clothianidin was never detected, while imidacloprid was identified in apple (9.2 µg/kg) and pollen (18-28 µg/Kg), thiacloprid in peaches (21-35 µg/kg) and acetamiprid was identified in the hazel leaves (1266 µg/kg), honey (13-26 µg /Kg) and pollen (11-24 µg/kg). Since the levels found of acetamiprid in hazel, honey and pollen were concerning, we accomplished a study to identify and characterize the possible transformation products via a laboratory simulation. The methodology exploited the analysis by HPLC-HRMS and its application in all matrices. We identify twelve transformation products, whose formation involved dimerization, hydroxylation, oxidation, demethylation and cleavage of the molecule. Three of them were also detected in hazel leaves.

Neonicotinoid insecticide metabolites in seminal plasma: Associations with semen quality

Animal studies have revealed that exposure to neonicotinoid insecticides (NNIs) could compromise male reproductive function; however, related data on the occurrence of NNIs and their specific metabolites in human seminal plasma are scarce. To explore the potential effects of NNI exposure on male semen quality, we determined the concentrations of NNIs and some of their metabolites (collectively defined as mNNIs) in seminal plasma samples collected from men (n = 191) who visited a fertility clinic in Shijiazhuang, North China from 2018 to 2019. Associations between the mNNI concentrations and semen quality parameters were assessed using linear regression models, adjusting for important covariates. In the seminal plasma samples, desmethyl-acetamiprid (DM-ACE, detection frequency: 98.4%), imidacloprid-olefin (IMI-olefin, detection frequency: 86.5%), and desmethyl-clothianidin (DM-CLO, detection frequency: 70.8%) were frequently detected at median concentrations of 0.052, 0.003, and 0.007 ng/mL, respectively; meanwhile other compounds were detected at less than the method detection limits. In the single-mNNI models, the IMI-olefin concentration was associated with decreased progressive motility [IMI-olefin concentration: percent change (%Δ) = -17.0; 95% confidence interval (CI) = -30.3, -0.92; the highest tertile compared with the lowest tertile: %Δ = -21.1; 95% CI = -37.5, -0.23]. Similar results were found in the multiple-mNNIs models. No other inverse associations were found between the other mNNI concentrations and semen quality parameters. This is the first study to identify the occurrence of mNNIs in the seminal plasma and the potential associations of their concentrations with human semen quality parameters. These findings imply an inverse association between the IMI-olefin concentration and semen quality.

Pollinator conservation requires a stronger and broader application of the precautionary principle

The accumulating scientific evidence on global insect and pollinator decline is fuelling calls for pollinator conservation policies. A broad range of regulating and incentivising policies is undoubtedly needed to address the diverse threats to pollinator abundance and diversity, but implementing policies and regulations is beset by socio-political challenges. Lessons could be learned from the past and current applications of concepts central to biodiversity conservation. Given the uncertainties and data gaps, the concept of the Precautionary Principle (PP) is particularly important. The PP means that when it is scientifically plausible that human activities may lead to morally unacceptable harm, actions shall be taken to avoid or diminish that harm: uncertainty should not be an excuse to delay action. This paper reviews the role of the PP in pollinator conservation. The current research front is fragmented: the PP is briefly mentioned as relevant in literature on biodiversity conservation because of the scientific uncertainties regarding insect decline and their diverse drivers. A separate strand of literature contains studies on specific cases where the PP has played a role in the regulation of specific threats to pollinators: systemic insecticides and global trade in bees. Although limited to two significant threats to pollinator abundance and diversity, these studies provide important lessons on the challenges of implementing precautionary pollinator conservation policies and underline socio-political aspects of the 'human-dimensions' of pollinator conservation. Specifically, they highlight that ambiguity is a greater challenge than scientific uncertainty, which may be heightened when policies are intended to regulate specific economic sectors. We suggest that more attention should be paid to the discrepancy between the PP as formally included in policies or regulations and its inadequate implementation (too little too late) in a context of scientific uncertainty and societal conflict.

Evaluating the Endophytic Activities of Beauveria bassiana on the Physiology, Growth, and Antioxidant Activities of Extracts of Lettuce (Lactuca sativa L.)

Endophytic entomopathogens have growth promoting, nutrient fortifying, and anti-insect properties that could improve the yield and quality of lettuce (Lactuca sativa L.). Lactuca sativa is a vegetable crop with high demand; however, it is susceptible to aphid infestations. This study's objectives were to assess the pathogenicity of Beauveria bassiana (strain: SM3) (Bals.) Vuil. (Hypocreales) against Myzus persicae Sulzer, tissue colonization of lettuce by conidia of B. bassiana, as well as the effects of fungal inoculation on growth, tissue nutrient content, and proximate composition of the lettuce plants. Furthermore, the involvement of tissue nutrients in mediating the influence of endophytic fungus on the plant traits was examined. Insects and plants were exposed to four fungal conidial concentrations: 0, 1 × 10⁶, 1 × 10⁷ and 1 × 10⁸ conidia mL^-1 in an anti-insect bioassay and a greenhouse experiment, respectively. The B. bassiana strain was pathogenic against M. persicae, inducing mean insect mortality of 78% at the highest concentration (1 × 10⁸ conidia mL^-1). The B. bassiana endophytically colonized up to 76% of plants exposed to 1 × 10⁸ conidia mL^-1. Crown size and plant height varied significantly among treatments. However, the plant fresh and dry weights and nutrient elements N, P, K, Ca, and Mg did not vary significantly among treatments. Among the plant macronutrients assessed, only tissue carbon content was significantly (p < 0.01) affected by conidial treatments. The tissue C and Cu contents significantly correlated with the antioxidant capacity of the lettuce plants. Most of the micronutrients, viz. Mn, Fe, Cu, and B were remarkably higher (p < 0.05) in the fungus-treated plants than in the control plants. The antioxidant capacity (FRAP and TEAC) of plant extracts varied significantly (p < 0.001) among treatments, with the highest conidial treatment yielding the most increased antioxidant activity. In conclusion, the B. bassiana strain was endophytic to lettuce, pathogenic against M. persicae, and induced increased micro-nutrient tissue contents and antioxidant activities. This study demonstrated that B. bassiana could be potentially used in the biofortification of nutritive and medicinal qualities of plants.

Aqueous and Ethanolic Plant Extracts as Bio-Insecticides-Establishing a Bridge between Raw Scientific Data and Practical Reality

Global demand for food production is causing pressure to produce faster and bigger crop yields, leading to a rampant use of synthetical pesticides. To combat the nefarious consequences of its uses, a search for effective alternatives began in the last decades and is currently ongoing. Nature is seen as the main source of answers to crop protection problems, supported by several examples of plants/extracts used for this purpose in traditional agriculture. The literature reviewed allowed the identification of 95 plants whose extracts exhibit insecticide activity and can be used as bio-pesticides contributing to sustainable agriculture. The option for ethanol and/or water extracts is more environmentally friendly and resorts to easily accessible solvents, which can be reproduced by farmers themselves. This enables a bridge to be established between raw scientific data and a more practical reality. Azadirachta indica, Capsicum annuum, Nicotiana tabacum and Tagetes erecta are the most researched plants and have the potential to be viable options in the pest management approach. Azadirachta indica showed the most promising results and Brevicoryne brassicae was the most targeted pest species, being tested against the aqueous and/or ethanolic extracts of 23 different plants. Maceration using dried material (usually leaves) is the extraction method preferred by the majority of authors.

Prototyping a Knowledge-Based System to Identify Botanical Extracts for Plant Health in Sub-Saharan Africa

Replacing synthetic pesticides and antimicrobials with plant-based extracts is a current alternative adopted by traditional and family farmers and many organic farming pioneers. A range of natural extracts are already being marketed for agricultural use, but many other plants are prepared and used empirically. A further range of plant species that could be effective in protecting different crops against pests and diseases in Africa could be culled from the large volume of knowledge available in the scientific literature. To meet this challenge, data on plant uses have been compiled in a knowledge base and a software prototype was developed to navigate this trove of information. The present paper introduces this so-called Knomana Knowledge-Based System, while providing outputs related to Spodoptera frugiperda and Tuta absoluta, two invasive insect species in Africa. In early October 2020, the knowledge base hosted data obtained from 342 documents. From these articles, 11,816 uses—experimental or applied by farmers—were identified in the plant health field. In total, 384 crop pest species are currently reported in the knowledge base, in addition to 1547 botanical species used for crop protection. Future prospects for applying this interdisciplinary output to applications under the One Health approach are presented.

Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) in Europe: Current Status and Sustainable Pest Management

Simple Summary

Diabrotica virgifera virgifera, also known as western corn rootworm (WCR), is a maize-specific pest that has been a serious threat in Europe since the mid-1990s. Between 1995 and 2010, European countries were involved in international projects to plan pest control strategies. However, since 2011, collaborative efforts have declined and the overview of knowledge on WCR is in great need of updating. Therefore, a review of scientific papers published between 2008 and 2020, in addition to direct interviews with experts responsible for WCR management in several European countries, was conducted to (1) summarize the research conducted over the last 12 years and (2) describe the current WCR distribution and population in the EU, and the management strategies implemented. A considerable amount of new knowledge has been gained over the last 12 years, which has contributed to the development of pest management strategies applicable in EU agricultural systems. There is no EU country reporting economic damage on a large scale. In many countries, solutions based on crop rotation are regularly implemented, avoiding insecticide use. Therefore, WCR has not become as serious a pest as was expected when it was discovered in much of Europe.

Abstract

Western corn rootworm (WCR), or Diabrotica virgifera virgifera LeConte, became a very serious quarantine maize pest in Europe in the mid-1990s. Between 1995 and 2010, European countries were involved in international projects to share information and plan common research for integrated pest management (IPM) implementation. Since 2011, however, common efforts have declined, and an overview of WCR population spread, density, and research is in serious need of update. Therefore, we retained that it was necessary to (1) summarize the research activities carried out in the last 12 years in various countries and the research topics addressed, and analyze how these activities have contributed to IPM for WCR and (2) present the current distribution of WCR in the EU and analyze the current population levels in different European countries, focusing on different management strategies. A review of scientific papers published from 2008 to 2020, in addition to direct interviews with experts in charge of WCR management in a range of European countries, was conducted. Over the past 12 years, scientists in Europe have continued their research activities to investigate various aspects of WCR management by implementing several approaches to WCR control. A considerable amount of new knowledge has been produced, contributing to the development of pest management strategies applicable in EU farming systems. Among the 10 EU countries analyzed, there is no country reporting economic damage on a large scale. Thanks to intensive research leading to specific agricultural practices and the EU Common Agricultural Policy, there are crop-rotation-based solutions that can adequately control this pest avoiding insecticide use.

An update of the Worldwide Integrated Assessment (WIA) on systemic pesticides. Part 4: Alternatives in major cropping systems

We present a synthetic review and expert consultation that assesses the actual risks posed by arthropod pests in four major crops, identifies targets for integrated pest management (IPM) in terms of cultivated land needing pest control and gauges the implementation "readiness" of non-chemical alternatives. Our assessment focuses on the world's primary target pests for neonicotinoid-based management: western corn rootworm (WCR, Diabrotica virgifera virgifera) in maize; wireworms (Agriotes spp.) in maize and winter wheat; bird cherry-oat aphid (Rhopalosiphum padi) in winter wheat; brown planthopper (BPH, Nilaparvata lugens) in rice; cotton aphid (Aphis gossypii) and silver-leaf whitefly (SLW, Bemisia tabaci) in cotton. First, we queried scientific literature databases and consulted experts from different countries in Europe, North America, and Asia about available IPM tools for each crop-pest system. Next, using an online survey, we quantitatively assessed the economic relevance of target pests by compiling country-level records of crop damage, yield impacts, extent of insecticide usage, and "readiness" status of various pest management alternatives (i.e., research, plot-scale validation, grower-uptake). Biological control received considerable scientific attention, while agronomic strategies (e.g., crop rotation), insurance schemes, decision support systems (DSS), and innovative pesticide application modes were listed as key alternatives. Our study identifies opportunities to advance applied research, IPM technology validation, and grower education to halt or drastically reduce our over-reliance on systemic insecticides globally.

Improving the compatibility of pesticides and predatory mites: recent findings on physiological and ecological selectivity

Integrated pest management relies upon the application of selective pesticides that do not hinder biological control. Phytoseiid mites represent an interesting case-study: they are amongst the most frequently used biological control agents and often are less affected by pesticides than their prey by natural tolerance or by developing resistance. The selectivity of a pesticide is determined by physiological processes that include metabolism, transport, and the affinity to the target-site. Genomic and transcriptomic studies start to elucidate the genetic and molecular mechanisms of differential toxicity in some phytoseiid species, such as a mutation in the sodium channel conferring pyrethroid resistance. Ecological selectivity is achieved by smart applications of pesticides and management practices that influence the persistence of phytoseiid mites on plants. Although modern pesticides often show lower acute toxicity, there is a need for robust assays and procedures that quantify lethal and sublethal effects, through different routes and times of exposure.

Appearance of Thiacloprid in the Guttation Liquid of Coated Maize Seeds

Thiacloprid (TCL) uptake by maize plants that emerge from coated seeds has been investigated and characterized via measurements of the compound in the guttation liquid. TCL levels were determined in the guttation liquid: (a) under field and semi-field conditions, (b) for different maize varieties, (c) applying different dosages, and (d) as affected by cross-contamination between maize seeds via soil. Cross-contamination was described by uptake interactions between seeds coated with TCL and neighboring seeds not coated or coated with other neonicotinoids, e.g., either thiamethoxam (TMX) or clothianidin (CLO). TCL levels remained under 100 µg/mL in the guttation liquid under field conditions, and were quantifiable even on the 39th day after planting of coated seeds. Higher levels up to 188.6 µg/mL were detected in plants grown under semi-field conditions in pots. Levels in the guttation liquid were also found to be influenced by the applied dosages. The uptake of TCL was found to vary for different maize varieties. Appearance of TCL as a cross-contaminant in the guttation liquid of neighboring plants emerging from non-coated maize seeds indicates translocation of the compound via soil. Peak levels of TCL cross-contamination were found to be lower (43.6 µg/mL) than the corresponding levels in the parent maize plants emerging from coated seeds (107.5 µg/mL), but values converge to each other. Similar trends were observed with neighboring seeds coated with other neonicotinoids (TMX or CLO). The translocation rate of TCL and its uptake by other plants seem to be lower than that of TMX or CLO.

Neonicotinoids: Spreading, Translocation and Aquatic Toxicity

Various environmental and ecotoxicological aspects related to applications of neonicotinoid insecticides are assessed. Dosages of neonicotinoids applied in seed coating materials were determined and are compared to other applications (spray and granule). Environmental levels in soils and affecting factors in translocation are discussed. Excretion of neonicotinoids via guttation from coated maize seeds up to two months upon emergence, as well as cross-contamination of plants emerged from non-coated seeds or weeds nearby have been demonstrated. Contamination of surface waters is discussed in scope of a worldwide review and the environmental fate of the neonicotinoid active ingredients and the formulating surfactant appeared to be mutually affected by each other. Toxicity of neonicotinoid active ingredients and formulations on Daphnia magna completed with some investigations of activity of the detoxifying glutathione S-transferase enzyme demonstrated the modified toxicity due to the formulating agents. Electrophysiological results on identified central neurons of the terrestrial snail Helixpomatia showed acetylcholine antagonist (inhibitory) effects of neonicotinoid insecticide products, but no agonist (ACh-like) effects were recorded. These data also suggested different molecular targets (nicotinergic acetylcholine receptors and acetylcholine esterase enzyme) of neonicotinoids in the snail central nervous system.

Time-Cumulative Toxicity of Neonicotinoids: Experimental Evidence and Implications for Environmental Risk Assessments

Our mechanistic understanding of the toxicity of chemicals that target biochemical and/or physiological pathways, such as pesticides and medical drugs is that they do so by binding to specific molecules. The nature of the latter molecules (e.g., enzymes, receptors, DNA, proteins, etc.) and the strength of the binding to such chemicals elicit a toxic effect in organisms, which magnitude depends on the doses exposed to within a given timeframe. While dose and time of exposure are critical factors determining the toxicity of pesticides, different types of chemicals behave differently. Experimental evidence demonstrates that the toxicity of neonicotinoids increases with exposure time as much as with the dose, and therefore it has been described as time-cumulative toxicity. Examples for aquatic and terrestrial organisms are shown here. This pattern of toxicity, also found among carcinogenic compounds and other toxicants, has been ignored in ecotoxicology and risk assessments for a long time. The implications of the time-cumulative toxicity of neonicotinoids on non-target organisms of aquatic and terrestrial environments are far reaching. Firstly, neonicotinoids are incompatible with integrated pest management (IPM) approaches and secondly regulatory assessments for this class of compounds cannot be based solely on exposure doses but need also to take into consideration the time factor.

Impacts of neonicotinoid seed treatments on soil-dwelling pest populations and agronomic parameters in corn and soybean in Quebec (Canada)

Agricultural soil pests, including wireworms (Coleoptera: Elateridae), are managed primarily with pesticides applied directly to seeds before sowing. Seeds coated with neonicotinoids have been used widely in Quebec (Canada) for several years. To assess the agronomic and economic value of neonicotinoid seed treatments in soybeans and corn in Quebec, trials were conducted from 2012 to 2016 in 84 fields across seven regions in Quebec. We evaluated the effect of neonicotinoid seed treatments on soil pest densities, crop damage and yield. The results showed that 92.6% of corn fields and 69.0% of soybean fields had less than 1 wireworm per bait trap. However, no significant differences in plant stand or yield were observed between treated and untreated corn or soybeans during the study. This study shows that neonicotinoid seed treatments in field crops in Quebec are useful in less than 5% of cases, given the very low level of pest-associated pressure and damage, and that they should not be used prophylactically. Integrated pest management (IPM) strategies need to be developed for soil insect pests to offer effective alternative solutions to producers.

The Addition of a Pheromone to a Floral Lure Increases Catches of Females of the Click Beetle Agriotes ustulatus (Schaller) (Coleoptera: Elateridae)

Agriotes ustulatus is an economically important click beetle in Europe. A female-produced pheromone, (E,E)-farnesyl acetate, has been identified and is used for monitoring and detecting males. More recently, a floral lure targeting females with modest, but significant, activity has been described. Based on preliminary data, we hypothesized, that similar to the effects on the congeneric A. brevis, addition of the pheromone to the floral lure should improve female A. ustulatus catches. Also, as click beetles have been reported to respond to white light, we studied possible interactions between visual and chemical cues. In field trials, the addition of the synthetic pheromone to the floral lure resulted in a dramatic increase in the number of females trapped, whereas male catches remained unaffected and equal to those in traps baited with pheromone only. A white visual cue did not influence trap catches. Maximum catches of both sexes of A. ustulatus can be achieved using the pheromone and the floral lure inside the same trap. Furthermore, the compounds can be formulated in a single polyethylene bag dispenser, making handling of the trap easier. Due to a much larger proportion of females in the catch, this improved trap may be a promising tool for semiochemical-based, environmentally sound agricultural practice against this important pest.

An Analytical Survey of Trace Heavy Elements in Insecticides

There are many types of insecticides traded in the local and international markets, which vary depending on the type of target insect (e.g., whether crawling or flying). This paper aimed to assess the concentration of trace elements present in the various pesticide formulations (solid, liquid, and gaseous). This study was conducted in two groups: the first group was comprised of zinc, copper, iron, chromium, phosphorus, selenium, and cobalt; the second group included four heavy toxic elements (arsenic, thallium, lead, and mercury). These elements were analyzed by inductively coupled plasma/optical emission spectrometry (ICP-OES).

Local applications but global implications: Can pesticides drive microorganisms to develop antimicrobial resistance?

Pesticides are an important agricultural input, and the introduction of new active ingredients with increased efficiencies drives their higher production and consumption worldwide. Inappropriate application and storage of these chemicals often contaminate plant tissues, air, water, or soil environments. The presence of pesticides can lead to developing tolerance, resistance or persistence and even the capabilities to degrade them by the microbiomes of theses environments. The pesticide-degrading microorganisms gain and employ several mechanisms for attraction (chemotaxis), membrane transport systems, efflux pumps, enzymes and genetical make-up with plasmid and chromosome encoded catabolic genes for degradation. Even the evolution and the mechanisms of inheritance for pesticide-degradation as a functional trait in several microorganisms are beginning to be understood. Because of the commonalities in the microbial responses of sensing and uptake, and adaptation due to the selection pressures of pesticides and antimicrobial substances including antibiotics, the pesticide-degraders have higher chances of possessing antimicrobial resistance as a surplus functional trait. This review critically examines the probabilities of pesticide contamination of soil and foliage, the knowledge gaps in the regulation and storage of pesticide chemicals, and the human implications of pesticide-degrading microorganisms with antimicrobial resistance in the global strategy of 'One Health'.

Contamination of the guttation liquid of two common weeds with neonicotinoids from coated maize seeds planted in close proximity

Neonicotinoid uptake by maize plants emerged from coated seeds and by two common weeds grown in close proximity to coated seeds has been studied. Uptake of thiamethoxam (TMX) and clothianidin (CLO) have been characterized via guttation liquid measurements. The creeping thistle (Cirsium arvense), a well-known maize weed, as well as red poppy or Flanders poppy (Papaver rhoeas) were chosen as model species. The results confirmed that cross-contamination may occur by uptake of the neonicotinoid AIs through soil from neighbouring plants that emerged from coated seeds. Although the levels of these neonicotinoids were substantially lower in the guttation liquid of the weeds than in that of maize plants emerged from coated seeds, the compounds were detected up to 36th day after planting of the maize seeds. The highest peak concentrations of TMX were around 150 and 21 mg L^-1, while similar data for CLO were around 70 and 21 mg L^-1 for maize and creeping thistle, respectively. Mostly due to its higher guttation intensity significantly lower values were determined for red poppy (0.740 mg L^-1).

Apis mellifera (Insecta: Hymenoptera) in the target of neonicotinoids: A one-way ticket? Bioinsecticides can be an alternative

The recent decline of Apis mellifera populations around the world has been subject of intense research due to ecological and economic damages resulting from the loss of pollination services. The intensive use of insecticides from the neonicotinoids group is among the possible causal factors of this decline, including also sub-lethal effects. However, the use of synthetic insecticides has been increased on a global scale in the recent decades. In order to evaluate an alternative to the use of neonicotinoids, this work investigated the effects of a bioinsecticide and its major compound on A. mellifera (Apidae: Hymenoptera), one of the main pollinators of crop plants. For this, bees were exposed, by contact and ingestion, to the essential oil of Cymbopogon martinii (Poaceae: Poales), to geraniol (major compound) and the insecticide imidacloprid to evaluate the toxicity and behavioral effects as well as the locomotion changes and immune responses of bees treated with these compounds. In general, toxicity was greater through ingestion and the insecticide imidacloprid was more toxic to A. mellifera compared to the essential oil and its major compound. The individual and collective behaviors (i.e. trophallaxis, grooming, avoidance) as well as the immune responses of bees were not significantly affected by bioinsecticides. However, the locomotion response and flight orientation of the bees were significantly altered by insecticide when administered by ingestion. Our results highlight the potential of C. martinii essential oil and its major compound as a possible alternative to mitigate the harmful effects of neonicotinoids on bees.

Widespread detections of neonicotinoid contaminants in central Wisconsin groundwater

Neonicotinoids are a popular and widely-used class of insecticides whose heavy usage rates and purported negative impacts on bees and other beneficial insects has led to questions about their mobility and accumulation in the environment. Neonicotinoid compounds are currently registered for over 140 different crop uses in the United States, with commercial growers continuing to rely heavily on neonicotinoid insecticides for the control of key insect pests through a combination of in-ground and foliar applications. In 2008, the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) began testing for neonicotinoids in groundwater test wells in the state, reporting detections of one or more neonicotinoids in dozens of shallow groundwater test wells. In 2011, similar detection levels were confirmed in several high-capacity overhead center-pivot irrigation systems in central Wisconsin. The current study was initiated to investigate the spatial extent and magnitude of neonicotinoid contamination in groundwater in and around areas of irrigated commercial agriculture in central Wisconsin. From 2013-2015 a total of 317 samples were collected from 91 unique high-capacity irrigation wells and tested for the presence of thiamethoxam (TMX), a neonicotinoid, using enzyme-linked immunosorbent assays. 67% of all samples were positive for TMX at a concentration above the analytical limit of quantification (0.05 μg/L) and 78% of all wells tested positive at least once. Mean detection was 0.28 μg/L, with a maximum detection of 1.67 μg/L. Five wells had at least one detection exceeding 1.00 μg/L. Furthermore, an analysis of the spatial structure of these well detects suggests that contamination profiles vary across the landscape, with differences in mean detection levels observed from landscape (25 km), to farm (5 km), to individual well (500 m) scales. We also provide an update of DATCP's neonicotinoid monitoring in Wisconsin's shallow groundwater test wells and private potable wells for the years 2011-2017.

Widespread detections of neonicotinoid contaminants in central Wisconsin groundwater

Neonicotinoids are a popular and widely-used class of insecticides whose heavy usage rates and purported negative impacts on bees and other beneficial insects has led to questions about their mobility and accumulation in the environment. Neonicotinoid compounds are currently registered for over 140 different crop uses in the United States, with commercial growers continuing to rely heavily on neonicotinoid insecticides for the control of key insect pests through a combination of in-ground and foliar applications. In 2008, the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) began testing for neonicotinoids in groundwater test wells in the state, reporting detections of one or more neonicotinoids in dozens of shallow groundwater test wells. In 2011, similar detection levels were confirmed in several high-capacity overhead center-pivot irrigation systems in central Wisconsin. The current study was initiated to investigate the spatial extent and magnitude of neonicotinoid contamination in groundwater in and around areas of irrigated commercial agriculture in central Wisconsin. From 2013–2015 a total of 317 samples were collected from 91 unique high-capacity irrigation wells and tested for the presence of thiamethoxam (TMX), a neonicotinoid, using enzyme-linked immunosorbent assays. 67% of all samples were positive for TMX at a concentration above the analytical limit of quantification (0.05 μg/L) and 78% of all wells tested positive at least once. Mean detection was 0.28 μg/L, with a maximum detection of 1.67 μg/L. Five wells had at least one detection exceeding 1.00 μg/L. Furthermore, an analysis of the spatial structure of these well detects suggests that contamination profiles vary across the landscape, with differences in mean detection levels observed from landscape (25 km), to farm (5 km), to individual well (500 m) scales. We also provide an update of DATCP’s neonicotinoid monitoring in Wisconsin’s shallow groundwater test wells and private potable wells for the years 2011–2017.