Economic Aspects of Pest Control1)

The activities of economists associated with the IBP project entitled « The Principles, Strategies, and Tactics of Pest Population Regulation and Control in Major Crop Ecosystems » and their interaction with entomologists in the design and implementation of integrated control strategies are described. Profit maximization criteria and a method of considering farmers behaviour with respect to risk are developed. The term «economic threshold » is further clarified; and a simpler concept, « the damage threshold », is introduced. Regional institutions such as pest management co-operatives and districts and the factors which affect their introduction and successful operation are considered.     

EPIPRE: a Disease and Pest Management System for Winter Wheat,taking Account of Micrometeorological Factors1

EPIPRE (EPIdemic PREvention) is a cooperative project for supervised control of diseases and pests in wheat. It operates on a field by field basis. From every wheat field, basic data and field observations are stored in a data bank. Farmers send their field observations to the central team, which enters them in the data bank. Field data are updated daily by means of simplified simulation models. Expected damage and loss are calculated and used in a decision system, that leads to one of three major decisions: «treat», «don't treat», or «make another field observation». Exchange of information between farmers and central team is by mail. In 1978 EPIPRE started with Puccinia striiformis. Since then the number of pests and diseases which are considered have increased, so that in 1981 advice was given for P. striiformis, P. recondita, Erysiphe graminis, Septoria spp. and the cereal aphids, Sitobion avenae, Metopolophium dirhodum and Rhopalosiphum padi. For each of these pests and diseases predictive methods have been developed using explanatory simulation models as a tool. These explanatory models are based on knowledge of many input relations and some external factors (e.g. temperature) which govern most of the processes of the pest and disease population dynamics. On the basis of a sensitivity analysis with these models simplified decision rulés have been developed which are used in the advice system in which updating of the forcing variables is no longer needed.     

高效低风险是农药发展的必由之路

农药是与人类生存活动紧密相关的一类重要的农用化学品,随着人们对环境安全和自身健康日益关注,对农药认识和理解趋于全面和理性.笔者认为,目前对农药发展的要求已由“高效、低毒、低残留”发展和延伸到高效低风险的阶段.农药产业也应调整思路,积极更新产品.高效低风险农药已成为当前农药发展的必由之路.     

Similarities between the discovery and regulation of pharmaceuticals and pesticides: in support of a better understanding of the risks and benefits of each

An argument is presented by which the role of pharmaceuticals and pesticides can both be viewed in terms of contributing to human health. Comparisons are made in terms of discovery and development, regulatory policies and environmental and human impacts. Both technologies target particular biological functions, and in many cases they target similar molecular sites of action. Pharmaceuticals and pesticides undergo a similar registration process; however, both can enter the environment where they can have adverse effects on non-target organisms and, if misused, will have detrimental effects on human health or the environment. It is suggested that the risks associated with the two technologies are similar. The rejection of pesticides by the general public is based primarily on personal value systems and the uncertainty of risk management. It is concluded that plant and animal health are vital to maintaining human health, and that pesticides used in food production are, as with pharmaceuticals, a vital tool used to maintain human health.     

Researches on the evaluation of pesticide safety in humans using a pharmacokinetic approach

Similar to the pharmaceutical compounds, pesticides require human safety assessment for their registration and distribution; however, it is absolutely impossible to assess human safety by dosing humans with pesticides. Thus, how to appropriately evaluate the safety of pesticides in humans remains a great subject of debate. In this article, we present some examples of pesticide toxicity studies that identify species differences in toxicity and evaluate human safety by applying combinations of novel in vivo, in vitro, and in silico techniques to separately assess the key toxicodynamic (i.e., sensitivity) and/or toxicokinetic (i.e., exposure) factors. Because it is scientifically sound, the safety assessment strategy illustrated for three compounds in this article is expected to play an important role in the human safety assessment of agricultural compounds.     

Negative Disease Forecasting Prediction of the Disease-free Period of Irrigated Potatoes1

Although correlations can be established between the microclimate of an irrigated field and the macroclimate, their use is limited because the timing and duration of irrigation is not known beforehand, and it is practically impossible in consequence to predict crop microclimate in an irrigated crop. Nevertheless, a strong link can be found between some elements of the macroclimate and the disease-free period, for example for Phytophthora Infestons on irrigated potatoes. Temperatures of 10–12°C, or 18–20°C, early in the season are associated with long disease-free periods of 60–70 days. At intermediate temperatures, the disease-free period is shorter but cannot be predicted exactly. Such empirical relations can be used to provide « negative » forecasts, i.e. the expected duration of the disease-free period, and so avoiding unnecessary spraying.     

Fonctionnement d'un réseau d'avertissements contre les tavelures sur répondeurs téléphoniques dans la vallée de la Garonne1

Les tavelures du pommier et du poirier constituent L'un des principaux soucis des arboriculteurs de la vallée de la Garonne. A la demande des exploitants et en association avec eux, le Service de la protection des végétaux a créé un réseau d'avertissements tavelures. Grâce à une quinzaine de thermohumectographes répartis sur L'ensemble de la région, chaque contamination est décelée et située dans le temps. Deux fois par jour, matin et soir, L'analyse des éléments bioclimatologiques, recueillis par les thermohumectographes, est réalisée pour mettre à jour les messages diffuseés par les répondeurs. Ce réseau a permis à ses adhérents de passer des traitements préventifs d'assurance au système des traitements « stop » ou d'arrêt, qui présente un intérèt économique non négligeable. Dans un proche avenir, il pourra être utilise pour tirer un profit maximal du système des traitements curatifs. Il constitue L'ébauche d'une action de lutte intégrée, limitée d'abord au problème phytosanitaire principal de la région: les tavelures, auxquelles sera associé le raisonnement des interventions contre L'oïdium et le carpocapse. Apple and pear scab are among the most important diseases for growers in the Garonne valley, because of the mild wet spring conditions characterizing the Atlantic climate. The Plant Protection Service has set up a warning network to recommend scab treatment dates, at the request of growers and with their cooperation. Fifteen temperature and leaf-wetness recording units are permanently in place and cover the whole region. They allow foci to be defined in space and in time. Growers use a telephone system to be informed of the infection risks and of the recommendations for treatment in their own orchards. The data from the recording units are analyzed twice a day (morning and evening) to update the messages on the telephone service. This system has allowed growers to move from preventive « insurance » treatment to a system of treatment by intervention, with important economic consequences. It should also allow maximum benefit from the increasingly used system of available treatment. This system is a first step towards integrated control of scab, and in due course, mildew and codling moth.     

Problems and Prospects in Plant Virus Identification1

Reliable identification is a prerequisite to the study and control of plant viruses and virus diseases. Viruses are now increasingly studied for their intrinsic properties, in addition to their variable biological properties. This has caused some degree of order to emerge from the intricacy of plant viruses. Ten « commandments » are listed which permit reasonably reliable diagnosis of plant virus diseases in the scientific laboratory. New viruses are still often discovered. Routine tests for virus infection, carried out by plant protection, quarantine and especially certification services, never guarantee absolute freedom from viruses. A simple, but the least reliable of indexing methods, is that of visual observation. Infectivity tests are meant to trace the infectious agents with indicator plants. Using serology, one can detect certain viruses more directly and specifically. Electron microscopy allows the observation of the virus particles themselves. The choice of test is always a compromise between efficiency and reliability. Through scientific research both are constantly being improved. With the increasing amount of information on plant viruses, diagnosis is tending to shift from mere visual observation to the more reliable study of aetiology.     

Are Pesticides Suitable Model Substances for the Evaluation of Industrial Chemicals in the Environment?

Definitions are given for the terms «environmental chemical>> and «undue persistence>>. A suggested model for the general evaluation of environmental chemicals is a balanced combination of the evaluations of environmental radioactivity and of pesticides. The classification of environmental chemicals should be based on chemical structures only, independent of use patterns. For the evaluation of any chemical, the knowledge of its total production and of the quantitative use pattern is indispensable.     

Framework for defining pesticide maximum residue levels in feed: applications to cattle and sheep

BACKGROUND

Pesticide residues in animal feed can endanger animal health and compromise the safety of livestock products for human consumption. Even though policymakers such as the European Union and the World Health Organization have established maximum residue levels (MRLs) for pesticides in both human food and animal feed, there is no systematic management of pesticides in animal feed that considers the entire supply chain. In response, we propose a framework for defining consistent MRLs for pesticides in animal feed that assesses the impact of defined MRLs on upstream (e.g., MRLs in feed crops) and downstream (e.g., MRLs in livestock products) sectors of the livestock-product supply chain.

RESULTS

The MRLs determined for the selected pesticides in the feed of cattle and sheep as case study animals indicate that lipophilic pesticides tend to have lower MRLs than hydrophilic pesticides, primarily due to the relatively high toxicity and biotransfer factors of lipophilic pesticides. In addition, we observe that, primarily for lipophilic pesticides, upstream and downstream regulations are not aligned in terms of defining MRLs in feed using current MRLs in crops with relevance to feed and foods of animal origin.

CONCLUSION

Some of the current pesticide regulations in the livestock-product supply chain need to be re-evaluated to ensure that MRLs in the upstream sector (i.e., crops) do not result in unacceptable residues in the downstream sector (i.e., MRLs in livestock products affecting animal and human health). Finally, we provide recommendations for optimizing the derivation of MRLs in feed, including the evaluation of residue fate during feed and food manufacturing processes. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Biopesticide based sustainable pest management for safer production of vegetable legumes and brassicas in Asia and Africa

Vegetables are one of the important crops which could alleviate poverty and malnutrition among the smallholder farmers in tropical Asia and Africa. However, a plethora of pests limit the productivity of these crops, leading to economic losses. Vegetable producers overwhelmingly rely on chemical pesticides in order to reduce pest‐caused economic losses. However, over‐reliance on chemical pesticides poses serious threats to human and environmental health. Hence, biopesticides offer a viable alternative to chemical pesticides in sustainable pest management programs. Baculoviruses such as nucleopolyhedrovirus (NPV) and granulovirus (GV) have been exploited as successful biological pesticides in agriculture, horticulture and forestry. Maruca vitrata multiple nucleocapsid NPV (MaviMNPV) was found to be a unique baculovirus specifically infecting pod borer on food legumes, and it has been successfully developed as a biopesticide in Asia and Africa. Entomopathogenic fungi also offer sustainable pest management options. Several strains of Metarhizium anisopliae and Beauveria bassiana have been tested and developed as biopesticides in Asia and Africa. This review specifically focuses on the discovery and development of entomopathogenic virus and fungi‐based biopesticides against major pests of vegetable legumes and brassicas in Asia and Africa. © 2019 Society of Chemical Industry     

Shifting focus from the population to the individual as a way forward in understanding,predicting and managing the complexities of evolution of resistance to pesticides

The evolution of resistance to pesticides is often conceptualised and modelled at a population level, but population‐based approaches ignore important aspects of variability between individuals within populations that may be essential drivers of resistance. Here it is argued that individual‐based modelling has the potential to generate new insights and perspectives, thus deepening our understanding of the complexities of the evolutionary dynamics of resistance to pesticides. Copyright © 2012 Society of Chemical Industry     

Implication of human drug transporters to toxicokinetics and toxicity of pesticides

Human membrane drug transporters are recognized as major actors of pharmacokinetics. Pesticides also interact with human drug transporters, which may have consequences for pesticide toxicokinetics and toxicity. The present review summarizes key findings about this topic. In vitro assays have demonstrated that some pesticides, belonging to various chemical classes, modulate drug transporter activity, regulate transporter expression and/or are substrates, thus bringing the proof of concept for pesticide‐transporter relationships. The expected low human concentration of pesticides in response to environmental exposure constitutes a key‐parameter to be kept in mind for judging the in vivo relevance of such pesticide‐transporter interactions and their consequences for human health. Existing data about interactions of pesticides with drug transporters remain, however, rather sparse; more extensive and systematic characterization of pesticide‐transporter relationships, through the use of high throughput in vitro assays and/or in silico methods, is, therefore, required. In addition, consideration of transporter polymorphisms, pesticide mixture effects and physiological and pathological factors governing drug transporter expression may help to better define the in vivo relevance of pesticide‐transporter interactions in terms of toxicokinetics and toxicity for humans. © 2019 Society of Chemical Industry     

Britain's Pest Monitoring Network for Aphids and Moths1

There is a need for continuous monitoring of insect populations to provide, in the short term, early warning of the presence of pests and, in the long term, to record and analyse faunal changes resulting from changes in agricultural practice and urbanisation, and the rate of spread of pests and resistance to pesticides. The Rothamsted Insect Survey examines aerial populations of two major insect groups throughout the year. Two hundred and sixty species of aphids are sampled daily at a height of 12 m by a grid of 21 suction traps. Early warning of the migration of 32 aphid species of economic importance is provided in weekly bulletins issued to farmers and advisers. This aerial sampling is generally cheaper, quicker and provides earlier warning of the presence of aphids than crop sampling. Six hundred species of moths are sampled by 195 light traps and the data are being used to assess the magnitude and reasons for seasonal, annual and long-term changes in the insect fauna, especially of pest species. The information on both insect groups is stored on magnetic tape and computerized maps are produced to illustrate the distribution in time and space of given species and as a research tool in studies on their population dynamics. The prospects and value of extending this system to continental Europe, and the help and expertise that Rothamsted could give in the eventuality, are outlined. Les populations dinsectes doivent dtre soumises à un recensement continu afin dassurer, à court terme, un avertissement précoce de la presence des ravageurs, et, à long terme, la possibilite d'enregistrer et d'analyser les changements qui interviennent dans la faune à la suite de I'evolution des pratiques agricoles et de I'urbanisation, et de déterminer la vitesse de dissémination des ravageurs ainsi que leur résitance aux pesticides. Le «Rothamsted Insect Survey » observe les populations de deux groupes d'insectes durant toute L'année. Deux cents soixante espèces de pucerons sont échantillonnées quotidiennement dans 21 localites differentes à L'aide de pièges à succion disposes a 12 m au-dessus du sol. Les exploitants et les conseillers sont avertis, par des bulletins hebdomadaires, des migrations de 32 espèces de pucerons d'importance économique. L'échantillonnage aérien semble être meilleur marché et plus rapide qu'un échantillonnage réalisé au niveau de la culture;de plus, il assure un avertissement plus précoce. Six cents espèces de lépidoptéres sont recensées au moyen de 195 piéges lumineux dans le dessein danalyser la magnitude et les causes des variations saisonnieres, annuelles, et à long terme surtout en ce qui concerne les ravageurs. Les données ainsi recueillies sont enregistrées sur bandes magnétiques et servent à L'etablissement de cartes à L'aide d'ordinateurs; ces cartes indiquent la distribution temporelle et spatiale de chaque espèce et constituent un élement important dans l'étude de la dynamique des populations. L'extension de ce réseau à L'Europe continentale présente deL'intérêt et la façon dont la Station de Rothamsted peut y apporter son soutien est exposée dans la présente communication.     

Isoboles,a graphic representation of synergism in pesticides

It is possible to give a graphic representation of the effect of two pesticides applied jointly or of the effect of pesticides to which substances have been added. Each of the components is expressed in a coordinate. In the graph a quantitatively defined effect, e.g. a mortality of 50%, is inserted. These values are obtained by interpolation. The line which connects the points is called an isobole afterLoewe & Muischnek (1926) who used it for drugs. With an isobole the effect of different proportions of the components can be evaluated. The various types of isoboles are described and illustrated for some experiments with insecticides, herbicides and fungicides.     

有机氯类禁限用农药抗体的制备和应用研究进展

农药在防治病虫害、提高农产品产量和质量方面效果显著,但一些农药因高毒、致癌、致畸、致突变、代谢缓慢,对人类和环境产生不利影响而被我国禁止或限制使用。有机氯类禁限用农药作为其中产量最多、用量最大的一类,存在较高的健康或环境风险而备受关注。建立高效便捷的有机氯类禁限用农药残留的检测方法,对确保食品安全、助力绿色生态农业发展、打破食品进出口技术贸易壁垒具有重要意义。免疫分析法以其快速、简便、灵敏等优势被广泛应用于食品中农药残留的检测。本文综述了有机氯类禁限用农药免疫检测方法的研究进展,介绍了半抗原的合成和抗体的制备,总结了抗体在免疫检测中的应用,主要包括酶联免疫分析法、免疫层析试纸条法、化学发光法、荧光免疫分析法和免疫传感器,可对未来有机氯类禁限用农药免疫分析法的进一步研究开发提供参考。     

手性农药毒性机制的对映体选择性

综述了手性农药在急性毒性、慢性毒性、细胞毒性、藻类与植物毒性及生物体富集方面的对映体选择性差异。大量研究显示,手性农药的不同对映异构体对于非靶标作用体的毒性存在显著差异,这种选择性差异既取决于手性农药的对映异构体,同时又与作用的受体相关。探讨了手性农药毒理学研究的重点和发展方向——在对映体水平上对手性农药的毒理机制进行全面深入的研究,对于评价农药对健康的风险及生产绿色高效的单一或复合的对映体农药具有指导意义。     

Laboratory and glasshouse screening of pesticides for adverse effects on the parasite Encarsia formosa gahan

Glasshouse screening of ten pesticides and the effect of water damping showed that all of the pesticides, with the possible exceptions of quinomethionate and heptenophos, were suitable for use in integrated control programmes involving Encarsia formosa. About 50 pesticides were screened in the laboratory for residual effects on adult E. formosa. They were grouped according to whether their effects were harmful, moderate or negligible. Acaricides, except quinomethionate, had negligible effects; fungicides generally had negligible effects though a few had moderate effects. Insecticides were equally divided between those which were harmful or moderate in effect. Individual examples are discussed more fully in relation to previous work and their commercial use in integrated control programmes. The two screening methods produced similar results though the laboratory method had the advantage of being much more rapid. Attention is drawn to the need for a simple test to identify pesticides having sublethal effects on natural enemies and for the standardisation of test methods.     

The effects of pesticides on species of non-target Heteroptera inhabiting cereal fields in southern England

The effects of pesticides on beneficial predatory arthropods have been widely studied; this paper however deals with their effects on Heteroptera, an important beneficial insect group and food source for farmland birds. Field trials were used to evaluate pesticide effects under realistic conditions of application on a commercial arable farm and compared with previously published laboratory findings. Fungicides were found to produce very low levels of mortality, not significantly different from control treatments. Aphicides varied in their impact, producing non-significant to highly significant mortality levels. The likely ecological impact of pesticides on various heteropteran groups found within the field and field boundary is discussed. © 1997 SCI.     

Modelling pesticide run-off to surface waters. Part I: Model theory and development

A conceptual model is presented to estimate the concentrations of pesticides appearing in surface waters following their application as part of agricultural production. The model has been formulated particularly to deal with soils that are prone to bypass flow and require artificial sub-surface drainage. Pesticide concentrations and loads can be calculated at field drainage outlets or for whole headwater catchments. The data required to run the model are generally readily available from published sources (within the UK) and these data have been detailed. The assumptions made in the model are stated and the limitations with respect to the general applicability of the model are discussed. © 1998 Society of Chemical Industry