Summary This paper examines the entomological investigations carried out by the French naturalist Henri-Louis Duhamel du Monceau during a series of insect epidemics that ravaged France in the second half of the eighteenth century.1 This article began as a paper for Pamela H. Smith's ?Knowledge in Transit? graduate seminar. I would like to thank the participants of that seminar for comments and feedback. I would also like to thank Pamela Smith, Carl Wennerlind, Anya Zilberstein, Christopher L. Brown, Charly Coleman, Matthew (...) Jones, Peter Walker and Melissa Morris for their suggestions and comments on this paper. Finally, thanks to Vanessa Copeland for invaluable assistance in the archives in Paris. The author acknowledges support from the Social Sciences and Humanities Research Council of Canada and the Graduate School of Arts and Sciences, Columbia University. It shows how a particularly fierce invasion of caterpillars in the Angoumois region in the 1760s sparked theoretical debates about the nature of animal generation between academic naturalists, farmers, provincial officials and amateur naturalists. As part of a wider effort to reform agricultural production in France, Duhamel du Monceau sought to eliminate vernacular understandings of insect generation and to reform local pest control techniques. In his attempt to develop a body of pest-control knowledge grounded in the systematic observation of insect generation, however, Duhamel du Monceau relied heavily on the efforts of amateur naturalists. The paper shows how he mobilized a nation-wide network of entomological observers, and collected specimens and observational reports from farmers, improving landlords and local officials throughout France. Some informants did not only act as ?mere? observers, but formulated their own causal claims about insect generation that sometimes contradicted those of their metropolitan counterpart. Finally, it demonstrates that a ?patriotic? discourse that joined agricultural improvement and civic virtue provided a powerful impetus for the formation of collaborative relationships between academic naturalists, state officials and enlightened agricultural improvers. (shrink)

Despite the application of 2.5 million tons ofpesticides worldwide, more than 40% of all potentialfood production is lost to insect, weed, and plantpathogen pests prior to harvest. After harvest, anadditional 20% of food is lost to another group ofpests. The use of pesticides for pest control resultsin an estimated 26 million human poisonings, with220,000 fatalities, annually worldwide. In the UnitedStates, the environmental and public health costs forthe recommended use of pesticides total approximately$9 billion/yr. Thus, there is a need (...) for alternativenon-chemical pest controls, and genetic engineering(biotechnology) might help with this need. Diseaseand insect pest resistance to various pests has beenslowly bred into crops for the past 12,000 years;current techniques in biotechnology now offeropportunities to further and more rapidly improve thenon-chemical control of disease and insect pests ofcrops. However, relying on a single factor, like theBacillus thuringiensis toxin that has beeninserted into corn and a few other crops for insectcontrol, leads to various environmental problems,including insect resistance and, in some cases, athreat to beneficial biological control insects andendangered insect species. A major environmental andeconomic cost associated with genetic engineeringapplications in agriculture relates to the use ofherbicide resistant crops (HRC). In general, HRCtechnology results in increased herbicide use but noincrease in crop yields. The heavy use of herbicidesin HRC technology pollutes the environment and canlead to weed control costs for farmers that may be2-fold greater than standard weed control costs. Therefore, pest control with both pesticides andbiotechnology can be improved for effective, safe,economical pest control. (shrink)

Multiplicity and continual change characterize the Peruvian agricultural knowledge and information system (AKIS), reflecting changes in the agricultural sector as a whole. The evolution of these changes can be traced back to the pre-Columbian era when a relatively stable and well-organized system based on indigenous knowledge prevailed. During colonial (1532–1821) and early Republican times (beginning 1821) several changes affecting the agricultural sector contributed to a weakening of indigenous knowledge systems. During the 20th century extension services provided by the government and (...) a variety of private organizations began to play an important role in the dissemination of information, albeit in an erratic way. Since the 1970s the system increased in complexity with the emergence of non-governmental institutions. Today government participation is limited and there is a more important participation by a number of NGOs and private organizations. This diversity of actors using different approaches has generated disarray in the information system owing to the lack of coherent policies to guide the interaction among actors. This paper uses the case of potato pest control-related information to illustrate changes in local knowledge systems. It differentiates pest control based on indigenous knowledge, chemical control, and integrated pest management (IPM) and explains how changes in the system have influenced the use of these three types of information in AKIS. Currently, the coexistence of different types of potato pest control information promoted and used by diverse and usually unconnected sets of organizations and individuals presents a challenge and requires inter-institutional action guided by clear policies to promote sustainable agriculture. (shrink)

Farmers are experts on their natural environment and are innate experimenters. However they do not know everything. Filling in gaps of missing farmer knowledge can help them improve their experiments. The authors designed and taught a course to Honduran farmers that effectively covered a number of key points on insect ecology and biology that farmers had not understood. After receiving the course many farmers did experiments to solve pest problems without synthetic pesticides.

In this paper we propose and analyze a prey-predator type dynamical system for pest control where prey population is treated as the pest. We consider two classes for the pest namely susceptible pest and infected pest and the predator population is the natural enemy of the pest. We also consider average delay for both the predation rate i.e. predation to the susceptible pest and infected pest. Considering a subsystem of original system (...) in the absence of infection, we analyze the existence of all possible non-negative equilibria and their stability criteria for both the subsystem as well as the original system. We present the conditions for transcritical bifurcation and Hopf bifurcation in the disease free system. The theoretical evaluations are demonstrated through numerical simulations. (shrink)

Of the four types of biological control, (1) natural, (2) conservation, (3) augmentation, and (4) importation), ethical concerns have been raised almost exclusively about only one type: importation. These concerns rest largely on fears of extinction of animal species. Importation biological control is a cost-effective alternative to chemical control for basic food crops of resource-poor farmers. Regarding the other types of biological control, natural biological control is not consciously manipulated by humans. Augmentation has some technical (...) concerns, but is generally an environmentally-sound, viable alternative to chemicals and offers local employment. Conservation can help empower farmers to preserve native species, while saving labor and money and reducing chemical insecticides. (shrink)

Adoption of integrated pest management(IPM) practices in the Guatemalan highlands has beenlimited by the failure of researchers andextensionists to promote genuine farmer participationin their efforts. Some attempts have been made toredress this failure in the diffusion-adoptionprocess, but farmers are still largely excluded fromthe research process. Understanding farmers'agricultural knowledge must be an early step toward amore participatory research process. With this inmind, we conducted a semi-structured survey of 75Cakchiquel Maya farmers in Patzún, Guatemala, tobegin documenting their pest control (...) practices. Theirresponses revealed that their understanding ofbiological and curative pest control is limited.However, their broad knowledge of cultural preventivepest control practices could explain why they hadfaced few pest problems in their traditionalmilpa (intercrop of corn, beans, and other edibleplants). The majority of these preventive practicesare probably efficient and environmentallyinnocuous. (shrink)

Pest control operations andexperimentation on sentient animals such as thebrushtail possum can cause unnecessary andavoidable suffering in the animal subjects.Minimizing animal suffering is an animalwelfare goal and can be used as a guide in thedesign and execution of animal experimentationand pest control operations.The public has little sympathy for the possum,which can cause widespread environmentaldamage, but does believe that control should beas painless as possible. Trapping and poisoningprovide only short-term solutions to the possumproblem and often involve (...) methods that causesuffering. Intrusive experiments connected withthese methods of control and published in thelast 6 years are reviewed. Many of theexperiments do not attain the welfare standardsrequired by members of the public. (shrink)

Integrated pest management (IPM) has been widely promoted in the developing world, but in many regions its adoption rates have been variable. Experience has shown that to ensure IPM adoption, the complexities of local agro-production systems and context-specific folk knowledge need to be appreciated. Our research explored the linkages between farmer knowledge, pest management decision making, and ecological attributes of subsistence maize agriculture. We report a case study from four rural communities in the highlands of southeast Honduras. Communities (...) were typified by their agro-environments, IPM training history, and levels of infestation by a key maize pest, the fall armyworm (Spodoptera frugiperda Smith). Although variable, infestation levels generally did not justify pest management intervention. Consequently, crop losses from this pest were considered of low importance and most farmers proceeded in a rational fashion by refraining from action in their fields. Farmers attributed the low degree of pest infestation predominantly to abiotic causal factors (rainfall, temperature). The role of natural enemies in controlling this pest (i.e., biological control) was deemed of low importance by farmers; nevertheless, a broad array of such organisms was mentioned by farmers as operating in their maize crop. Farmers’ knowledge of natural enemies only partially matched scientific knowledge and was associated with the ecological features of their respective field settings. Local knowledge about natural enemies was mainly restricted to abundant and easily observable predatory species. Farmers who were knowledgeable about biological control were also familiar with a larger variety of pest management alternatives than uninformed farmers. Management options covered a wide range of curative techniques, including conservation biological control. Farmers who relied on insecticides to manage pest outbreaks knew less about biological control and pesticide alternatives. In contrast, farmers who received IPM training mentioned more types of natural enemies and were familiar with a broader range of alternative pest management tactics. Our research suggests that IPM training modifies local knowledge to better fit its environmental context. This paper provides insights in the environmental context of local agro-ecological knowledge and its linkage with pest management decision making. It also constitutes a basis for modifying IPM extension programs to deliver locality-specific technologies while strengthening the local knowledge base. (shrink)

The potential negative impacts of biological pest control on non-target species have become the focus of a contentious debate. In this article, we use examples from both classical and augmentative biological control of fruit fly pests in Hawaii to address several important factors in assessing non-target risks of fruit fly parasitoids. Several fruit fly parasitoids have been introduced to Hawaii and contribute substantially to the reduction of pest populations in the state's farms and forests. However, an (...) historical lack of host-specificity testing of these parasitoids with non-target species has raised concerns about their impact on non-pest fruit flies, including some flies deliberately introduced for biological control of weeds and others that are endemic Hawaiian species. When developing protocols to assess risks of introduced fruit fly parasitoids, we need first to define an appropriate range of species against which host specificity should be tested. For assessing susceptibility of a non-target species to parasitoids, behavioral tests are as important as suitability tests. Experimental factors, such as host-exposure substrate, absence or presence of preferred hosts, and laboratory vs. natural conditions, are shown to affect the results of host-specificity tests and risk analysis. Still, assessing long-term, indirect ecological impacts of parasitoids and weighing potential risks and benefits in multiple dimensions (besides dollar values) remains a challenge to environmentalists, conservationists, applied ecologists, and biocontrol practitioners. (shrink)

The Cuban government has undertaken the task of transforming insect pest and weed management from conventional to organic and more sustainable approaches on a nationwide basis. This paper addresses past programs and current major areas of research and implementation as well as provides examples of programs in insect and weed management. Topics covered include the newly constructed network of Centers for the Reproduction of Entomophages and Entomopathogens (CREEs), which provide the infrastructure for the implementation of biological control on (...) state, cooperative, and private farm operations. CREE programs include the mass rearing and release of Trichogramma spp. to manage insect pests of cassava, tobacco, sugarcane, and improved pasture. The entomopathogens, Bacillus thuringiensis, Beauveria bassiana, Metarhizium anisopliae, and Verticillium lecanii, are being mass produced in the CREEs and applied to control a number of key insect pests. A traditional method employed by peasant farmers of using the predatory ant Pheidole megacephala (Fabricius) in the biological control of sweetpotato and banana insect pests has been further developed and implemented. Efforts are underway to rear nematode species that attack insect pests and identify plant extracts with insecticidal qualities as potential management tools. Weed management has moved away from dependence on herbicides and toward alternative techniques that include weed suppression based on rotation schemes, limited use of selective herbicides, and new tillage equipment and practices. (shrink)

Pest control operations andexperimentation on sentient animals such as thebrushtail possum can cause unnecessary andavoidable suffering in the animal subjects.Minimizing animal suffering is an animalwelfare goal and can be used as a guide in thedesign and execution of animal experimentationand pest control operations.The public has little sympathy for the possum,which can cause widespread environmentaldamage, but does believe that control should beas painless as possible. Trapping and poisoningprovide only short-term solutions to the possumproblem and often involve (...) methods that causesuffering. Intrusive experiments connected withthese methods of control and published in thelast 6 years are reviewed. Many of theexperiments do not attain the welfare standardsrequired by members of the public.Possums also act as vectors for bovinetuberculosis. While this is not as important inthe minds of the public as environmentaldegradation, as long as people wish to continueraising cattle, this disease needs to becontrolled.Immunocontraception is a humane means ofcontrolling possums with wide publicacceptance. The use of vaccines for cows and/orpossums would also cause far less sufferingthan present eradication operations. Researchinto these methods does require some intrusiveexperimentation. This can be reduced if liveanimals are not used for secondary antibodyharvesting, if adequate analgesia is provided,and if potential vaccines or contraceptives aretested under conditions that would beexperienced in the field. (shrink)

Less than 0.1% of pesticides applied for pest control reach their target pests. Thus, more than 99.9% of pesticides used move into the environment where they adversely affect public health and beneficial biota, and contaminate soil, water, and the atmosphere of the ecosystem. Improved pesticide application technologies can improve pesticide use efficiency and protect public health and the environment.

Our study in China of two Integrated Pest Management (IPM) training programs for farmers shows that one is more effective than the other in reducing pesticide applications as well as in imparting to farmers an understanding of the rice ecosystem. The two training programs are based upon two different paradigms of IPM. This article uses a triangulated method of measuring concept attainment among farmer trainees in China as one measure of the effectiveness of training. Concepts of insect ecology brought (...) about by training, as well as persistence of concepts one year after training, are measured. This information is compared to farmer data on pesticide applications and yields in order to determine the comparative effectiveness of two models of IPM farmer training in Sichuan Province. Results indicate that the Farmer Field School (FFS) model of training, based upon a new Ecology-Based IPM paradigm, is more effective than the 3 Pests 3 Diseases (3P3D) model based upon an older Economic Threshold IPM paradigm. Crop yield results and pesticide applications by farmers after training are also used to indicate which of these paradigms of insect pest control is more effective, hence scientifically accurate. (shrink)

The 1989 collapse of trade relations with the former socialist bloc plunged Cuba into an economic and food crisis. Cuban farmers, scientists, and planners have responded with alternative agricultural technology to make up for imported food and Green Revolution inputs that are no longer available. A review of Cuban experience to date with biological pest control practices shows that, on the one hand, significant progress has been made that may serve as a model for other countries, while, on (...) the other hand, there still remains a long way to go if Cuba is to create a truly sustainable agriculture. It is essential that we understand the Cuban case if we are to be concerned about ethical issues in biological control. The apparent ability of Cuba to overcome a food crisis without significant use of pesticides stretches our concept of the possible. It thus helps refute the most common argument – that we couldn't “feed the hungry” without pesticides – against taking the “ethical” position in real-world pest management policy debates. (shrink)

No presente artigo analisamos como a ocorrência de epidemias de doenças contagiosas levaram o poder político e o conhecimento médico ao uso de diferentes técnicas e mecanismos para as enfrentar, como a instalação de quarentenas. Veremos como as epidemias de lepra e de peste e a atual pandemia de Covid-19 colocam em uso diferentes dispositivos e técnicas de controle e vigilância sobre os contaminados. A descoberta de que a restrição de movimento e o isolamento dos infectados diminui a disseminação de (...) doenças contagiosas foi, e ainda é, uma das primeiras recomendações médicas na situação de epidemias. Nesse sentido, veremos como, das quarentenas antigas à quarentena atual, intensificamos ainda mais a vigilância sobre os corpos ao passarmos de um controle sobre a pele para um controle sob a pele. (shrink)

Drawing from a four-year study of US science institutions that support biological control of arthropods, this article examines the decline in biological control institutional capacity in California within the context of both declining public interest science and declining agricultural research activism. After explaining how debates over the public interest character of biological control science have shaped institutions in California, we use scientometric methods to assess the present status and trends in biological control programs within both the (...) University of California Land Grant System and the California Department of Food and Agriculture. We present available data on the number of scientific positions and the types of positions to discuss the impact on the amount of public interest research on biological control in California. We use sociograms to depict how biological control science networks have been reconfigured over time. Our quantitative and qualitative analyses indicate that the following factors contributed to the decline of biological control science in California over the 45-year period analyzed: (1) the institutional reconfiguration of university research priorities; (2) the fraying networks within and increasing specialization of biological control science; (3) the transformation of the social organization of the life science work, including privatization; and (4) the abandonment of this thematic area by civil society activist groups. This broad array of forces suggests that biological control, as a public interest science, will require a deliberate intervention, based on advocacy of clear public interest criteria. (shrink)

Mutations in the methyl‐CpG‐binding protein 2 (MeCP2) cause Rett syndrome, a severe neurodevelopmental disease associated with ataxia and other post‐natal symptoms similar to autism. Much research interest has focussed on the implications of MeCP2 in disease and neuron physiology. However, little or no attention has been paid to how MeCP2 turnover is regulated. The post‐translational control of MeCP2 is of critical importance, especially as subtle increases or decreases in MeCP2 amounts can affect neuron morphology and function. The latter point (...) is of particular importance for gene therapeutic approaches in which exogenous wild‐type MeCP2 is being introduced into diseased neurons. Further to this, we propose two hypotheses. The first hypothesis discusses the poly‐ubiquitin‐mediated post‐translational regulation of MeCP2 through its two PEST domains. The second hypothesis explores the use of histone deacetylase inhibitors to modulate the amounts of MeCP2 expressed in conjunction with the aforementioned therapeutic approaches. (shrink)

Foreign knowledge being tested: European physicians fighting the Moscow plague of 1771. – The transfer of Western medicine to Russia increased significantly in the Eighteenth century. Foreign doctors were employed, their writings translated, their education standards copied. But who regarded that knowledge as superior and why? Taking the Moscow Plague of 1771 as a case study, this article examines the crucial role foreign and Russian medical practitioners played during the epidemic. It argues that especially those ideas and practices that were (...) useful for social control filtered into politics and public discourse, but failed to convince the majority of the population. (shrink)

Conservation policy in New Zealand is centred around an objective to totally eradicate three invasive species; the ship rat, the brushtail possum and the stoat, by 2050. The preferred control method to achieve this is large scale poisoning operations with 1080 and similar toxins. This project is backed up by governmental and non-governmental agencies and surrounded with discourse of ‘war’ and ‘invasion’. The ‘Big Three’ predators are endowed with sinister motives as a means of mobilising support. This self-described ‘war’ (...) is evaluated in terms of ‘just war’ theory and found wanting. In particular there are issues with the recruitment of children for killing, humiliation of combatants, questionable economic motives for the ‘war’, deception by government agencies, lack of consultation, a lack of consideration of alternatives, the use of excessive suffering, and unrealistic expectations. An alternative paradigm of ‘compassionate conservation’ is proposed for New Zealand. Instead of trying to get back to a stable pre-colonial state of nature, I propose a holistic approach that respects both ecosystems and their members and takes into account new understandings of ecosystems as dynamic processes. (shrink)

Based on the Lotka–Volterra system, a pest-natural enemy model with nonlinear feedback control as well as nonlinear action threshold is introduced. The model characterizes the implementation of comprehensive prevention and control measures when the pest density reaches the nonlinear action threshold level depending on the pest density and its change rate. The mortality rate of the pest is a saturation function that strictly depends on their density while the release of natural enemies is also (...) a nonlinear pulse term depending on the density of real-time natural enemies. The exact impulsive and phase sets are given. The definition and properties of the Poincaré map corresponding to the pulse points on the phase set are provided. We investigate the existence and stability of boundary and interior order-1 periodic solution. The theoretical analysis developed in the present paper combined with nonlinear controlling measures as well as nonlinear action threshold methods and techniques laid the foundation for the establishment and analysis of other state-dependent feedback control models. (shrink)

Toxic plants have been used for years in agriculture to control major crop pests. However, the continuous exposure of targeted pests to toxins dramatically increases the rate of resistance evolution (Gassman et al. in Annu Rev Entomol 54:147–163, 2009a ; Tabashnik et al. Nat Biotechnol 26:199–202, 2008 ). To prevent or delay resistance, non toxic host plants can be used as refuges. Our study considers spatial and temporal refuges that are respectively implemented concurrently or alternatively a toxic crop. A (...) conceptual model based on impulsive differential equations is proposed to describe the dynamics of the susceptible and resistant pest populations over time. The mathematical study enlightens threshold values of the proportion of the spatial refuge and key parameters that should help to understand evolution of pest resistance to toxic crop. (shrink)

Theoretical and experimental studies on prey–predator systems where predator is supplied with alternate sources of food have received significant attention over the years due to their relevance in achieving biological conservation and biological control. Some of the outcomes of these studies suggest that with appropriate quality and quantity of additional food, the system can be steered towards any desired state eventually with time. One of the limitations of previous studies is that the desired state is reached asymptotically, which makes (...) the outcomes not easily applicable in practical scenarios. To overcome this limitation, in this work, we formulate and study optimal control problems to achieve the desired outcomes in minimum (finite) time. We consider two different models of additional food provided prey–predator systems involving Holling type IV functional response (with inhibitory effect of prey). In the first scenario, additional food is incorporated implicitly into the predator’s functional response with a possibility of achieving biological conservation through co-existence of species and biological control by maintaining prey at a level that is least harmful to the system. In the second, the effect of additional food is incorporated explicitly into the predator’s compartment with the goal of pest management by maintaining prey density at a very minimal damaging level. For both cases, appropriate optimal control strategies are derived and the theoretical findings are illustrated by numerical simulations. We also discuss the ecological significance of the theoretical findings for both models. (shrink)

Microorganisms belong to the main regulators of insect populations under natural conditions. They perform this function in several ways. In the first place, bacterial metabolites exist which are as potent as chemical insecticides. In the second, entomopathogenic fungi and viruses spread deadly infections among insect populations. The use of advanced techniques in molecular biology, genetic engineering and biotechnology is increasingly expanding the potential of microorganisms as agents of insect pest control.

Conservation policy in New Zealand is centred around an objective to totally eradicate three invasive species; the ship rat, the brushtail possum and the stoat, by 2050. The preferred control method to achieve this is large scale poisoning operations with 1080 and similar toxins. This project is backed up by governmental and non-governmental agencies and surrounded with discourse of ‘war’ and ‘invasion’. The ‘Big Three’ predators are endowed with sinister motives as a means of mobilising support. This self-described ‘war’ (...) is evaluated in terms of ‘just war’ theory and found wanting. In particular there are issues with the recruitment of children for killing, humiliation of combatants, questionable economic motives for the ‘war’, deception by government agencies, lack of consultation, a lack of consideration of alternatives, the use of excessive suffering, and unrealistic expectations. An alternative paradigm of ‘compassionate conservation’ is proposed for New Zealand. Instead of trying to get back to a stable pre-colonial state of nature, I propose a holistic approach that respects both ecosystems and their members and takes into account new understandings of ecosystems as dynamic processes. (shrink)

Conservation policy in New Zealand is centred around an objective to totally eradicate three invasive species; the ship rat, the brushtail possum and the stoat, by 2050. The preferred control method to achieve this is large scale poisoning operations with 1080 and similar toxins. This project is backed up by governmental and non-governmental agencies and surrounded with discourse of ‘war’ and ‘invasion’. The ‘Big Three’ predators are endowed with sinister motives as a means of mobilising support. This self-described ‘war’ (...) is evaluated in terms of ‘just war’ theory and found wanting. In particular there are issues with the recruitment of children for killing, humiliation of combatants, questionable economic motives for the ‘war’, deception by government agencies, lack of consultation, a lack of consideration of alternatives, the use of excessive suffering, and unrealistic expectations. An alternative paradigm of ‘compassionate conservation’ is proposed for New Zealand. Instead of trying to get back to a stable pre-colonial state of nature, I propose a holistic approach that respects both ecosystems and their members and takes into account new understandings of ecosystems as dynamic processes. (shrink)

Radopholus Similis or burrowing nematode, is one of the most damaging and widespread nematodes attacking bananas, causing toppling or blackhead disease. A mathematical model for the population dynamics of R. Similis is considered, with the aim of investigating the impact of climatic factors on the growth of R. Similis. In this paper, based on the life cycle of R. Similis, we first propose a mathematical model to study and control the population dynamics of this banana pest. We show (...) also how control terms based on biological and chemical controls can be integrated to reduce the population of R. Similis within banana-plantain roots. Sensitivity analysis was performed to show the most important parameters of the model. We present the theoretical analysis of the model. More precisely, we derive a threshold parameter N0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{N}}_0$$\end{document}, called the basic offspring number and show that the trivial equilibrium is globally asymptotically stable whenever N0≤1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{N}}_0\le 1$$\end{document}, while when N0>1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{N}}_0> 1$$\end{document}, the non trivial equilibrium is globally asymptotically stable. After, we extend the proposed model by taking account climatic factors that influence the growth of this pest. Biological and chemical controls are now introduced through impulsive equations. Threshold and equilibria are obtained and global stabilities have been studied. The theoretical results are supported by numerical simulations. Numerical results of model with biological and chemical controls reveal that biological methods are more effective than chemical methods. We also found that the month February is the best time to apply these controls. (shrink)

In recent years the notion of biological specificity has attracted significant philosophical attention. This paper focuses on host specificity, a kind of biological specificity that has not yet been discussed by philosophers, and which concerns the extent to which a species is selective in the range of other species it exploits for feeding and/or reproduction. Host specificity is an important notion in ecology, where it plays a variety of theoretical roles. Here I focus on the role of host specificity in (...) biological control, a field of applied ecology that deals with the suppression of pests through the use of living organisms. Examining host specificity and its role in biological control yields several valuable contributions to our understanding of biological specificity. In particular, I argue that host specificity cannot be fully understood in terms of Woodward’s well-known account of causal specificity. To adequately account for host specificity, we need a notion of causal specificity that takes into consideration the extent to which a variable’s effects are similar to one another – a dimension not captured in Woodward’s account. In addition, the literature on host specificity in biological control highlights certain aspects in which causally specific relationships can be practically valuable that have not yet been addressed in philosophical discussions of specificity. That literature also reveals that in certain contexts specificity can hinder rather than foster effective control, thus leading to a nuanced assessment of the practical value of specific causes. (shrink)

An emergent contradiction in the contemporary development of biological control is that of the prevalence of the substitution of periodic releases of natural enemies for chemical insecticides and the dominance of biotechnologically developed transgenic crops. Input substitution leaves in place the monoculture nature of agroecosystems, which in itself is a key factor in encouraging pest problems. Biotechnology, now under corporate control, creates more dependency and can potentially lead to Bt resistance, thus excluding from the market a key (...) biopesticide. Approaches for putting back biological control into the hands of farmers (from artesanal biotechnology for grassroots biopesticide production Cuban style to farmer-to-farmer IPM networks, etc.) have been developed as a way to create a farmer centered approach to biological control. (shrink)

At the end of the 1920s, Tanganyika Territory experienced several serious rodent outbreaks that threatened cotton and other grain production. At the same time, regular reports of pneumonic and bubonic plague occurred in the northern areas of Tanganyika. These events led the British colonial administration to dispatch several studies into rodent taxonomy and ecology in 1931 to determine the causes of rodent outbreaks and plague disease, and to control future outbreaks. The application of ecological frameworks to the control (...) of rodent outbreaks and plague disease transmission in colonial Tanganyika Territory gradually moved from a view that prioritised 'ecological interrelations' among rodents, fleas and people to one where those interrelations required studies into population dynamics, endemicity and social organisation in order to mitigate pests and pestilence. This shift in Tanganyika anticipated later population ecology approaches on the African continent. Drawing on sources from the Tanzania National Archives, this article offers an important case study of the application of ecological frameworks in a colonial setting that anticipated later global scientific interest in studies of rodent populations and rodent-borne disease ecologies. (shrink)

This paper presents research conducted during two coffee farming seasons in Costa Rica. The study examined coffee farmers’ weed management practices and is presented in the form of a case study of small-scale farmers’ use of labor and herbicides in weed management practices. Over 200 structured interviews were conducted with coffee farmers concerning their use of hired labor and family labor, weed management activities, support services, and expectations about the future of their coffee production. ANOVA and regression analyses describe the (...) relationships between farm size, labor, and herbicide use, and three farm types (i.e., conventional, semi-conventional, and organic). Based on findings regarding the amount of labor used to manually control weeds on different types of farms (large farms, small conventional, semi-conventional, and organic farms) I am able to challenge small conventional farmers’ perceived need for herbicide use. Semi-structured interviews of coffee farmers and extension workers further revealed a dominant role played by agro-chemical companies in assisting farmers with production problems, and documented a high transaction cost for information provided from elsewhere. Chemical companies hire extension workers to visit farmers at their farms, free of charge, to offer recommendations on how to treat different pest problems, while government and cooperative extension agents charge for the service. There is a need to increase the amount of resources available to the National Coffee Institute to fund one-on-one farmer support services in order to balance the influence of agro-chemical company representatives and allow farmers to make better decisions regarding weed management. (shrink)

The ArgumentThe vine lousePhylloxera vastatrixbecame a “pest” as it was transferred from North America and from France to Germany during the 1870s. Embodying the “invading alien,” it assumed a cultural position that increasingly gained importance in Imperial Germany. In this process, the minute insect, living invisibly underground, was made visible and became constitutive of the scientific-technological object, “pest,” pertaining to a scientific discipline, modern economic entomology. The “pest” phylloxera emerged by being made visible in a way that (...) enabled control measures against it. Thus, visibility functioned as a prerequisite for control measures. I differentiate between social visibility and physical visibility, as well as between social control and physical control of the “introduced pest.” The object phylloxera emerged at the intersection of techniques of social control such as surveillance, techniques of physical control such as disinfection, and representational practices of the sciences such as mathematics and graphics. The space of its visibility was not the vineyard as property of a vintner but the vineyard as national territory, where German (viti-) culture was defended against foreign infiltration and destruction. Many vintners had alternate visions of the grapevine disease, they resented the invasion and destruction of their vineyards by government officers, and thus they did not participate in the social and epistemic constitution of the “pest.” By 1914, the “introduced pest” had not yet become an effective “machinery.” However, the “pest” as an object of scientific knowledge emerged together with economic entomology. The field became organized as a discipline in Germany in 1913, forty years after the phylloxera had first aroused the minds of some worried Wilhelmians, and, together with its nationalistic images, the field of “pest” control became organized towards a redefinition of German society and its perceived dangers. (shrink)

According to resource limitation, a more realistic pest management is that the impulsive control actions should be adjusted according to the densities of both pest and natural enemy in the field, which result in nonlinear impulsive control. Therefore, we have proposed a Beddington–DeAngelis interference predator-prey model concerning integrated pest management with both density-dependent pest and natural enemy population. We find that the pest-eradication periodic solution is globally stable if the impulsive period is less (...) than the critical value by Floquet theorem. The condition of permanent is established, and a stable positive periodic solution appears via a supercritical bifurcation by bifurcation theorem. Finally, in order to investigate the effects of those nonlinear control strategies on the successful pest control, the bifurcation diagrams showed that the model exists with very complex dynamics. Consequently, the resource limitation may result in pest outbreak in complex ways, which means that the pest control strategies should be carefully designed. (shrink)

Rabbits are a major vertebrate pest in New Zealand. An application has been made recently to import and release in New Zealand the biological control agent Rabbit Calicivirus Disease. In this paper we discuss the findings from a qualitative study and a national survey of New Zealanders' perceptions of rabbits, rabbit control, and RCD. New Zealanders' position on the introduction of RCD is complex, and includes concern for the rabbit as a sentient individual that deserves a humane (...) death if it is to be killed, appreciation of the environmental and agricultural damage it causes, and skepticism about the information on RCD currently being provided. Because perceptions of biological control include risk perceptions, we draw upon the literature on public perceptions of risk to interpret the results. We also discuss some ethical and practical issues arising from our study. We contend that the complexity of the issues, and the nature of their presentation, requires a public decision-making process involving two-way communication. (shrink)

This overview and synthesis of the papers presented in this Special Issue suggests that there is a remarkably rich set of ethical issues having direct relevance to the development and practice of biological control for the management of agricultural pests. The perception and resolution of ethical issues appear to emerge from a set of factors that includes one's ethical viewpoint (anthropocentric or biocentric), agricultural system (industrial or sustainable), economic context (rich or poor), and power structure (expert or public). From (...) this set of parameters at least five major ethical questions can be formulated: (1) How should we regulate and apply biological control in the face of persistent ecological uncertainty regarding environmental impacts? (2) How ought we to balance the established and expected benefits of biological control to human and ecosystem well-being against the known and anticipated risks? (3) Who should be empowered to develop policies and make decisions regarding the study and practice of biological control? (4) How can we assure a more just distribution of benefits and costs associated with biological control technologies (e.g., sharing the costs of nonmarketable goods and services that benefit the public, and compensating people from whom biological control agents are acquired), and (5) Can biological control be justified as a resource substitution for pesticides or is its ethical application only possible as part of a reconceptualization of agricultural production? These central questions and possible answers are presented in a varied set of provocative analyses by some of the leading thinkers and authorities in their fields. (shrink)

A participatory rural appraisal inthree West African countries examined thepossibility for replacing chemical pesticidesto control locusts and grasshoppers with abiological control method based on anindigenous fungal pathogen. The fungus iscurrently being tested at different sites inthe Sahel and in the humid tropics of WestAfrica. Structured group interviews, individualdiscussions, and field visits, were used toobtain farmers' perceptions of locust andgrasshoppers as crop pests, their quantitativeestimation of crop losses, and theirwillingness to pay for locust control. Farmersas well as plant (...) protection officers generallyperceived locusts and grasshoppers as importantpests that cause significant damage. Farmerswere aware of some of the risks of the use ofchemical pesticides, but not of the potentialalternatives. The use of the fungus in anoil-formulation and standard Ultra Low Volume(ULV) equipment was demonstrated, and theresults discussed with farmers. Theirimpressions of biological control werefavorable, and they expressed an interest inusing the technology. Farmers' expressedwillingness to pay for locust control is small,but not negligible. Locusts and grasshoppersare very visible pests and thus amenable topressure from farmers to local administrators,as well as by farmers' relatives in the city onthe national government. Therefore, politicalpressure for locust control is strong, althoughnational governments spend little on it,depending mostly on foreign donors. Donors areincreasingly worried about the environmentaleffect of the large amounts of chemicalpesticides used on locust control, and arepushing for more benign alternatives. Theresults of the present survey indicate thatthere may be a potential market for abiopesticide against grasshoppers and locustson cash crops in the humid areas. The potentialmarket in the Sahel depends on a reduction ofcosts or a subsidy of its price. This subsidycould be justified by the expected reduction inenvironmental and health costs when replacingchemical pesticides. Since donors are thecurrent purchasers of chemical pesticides forthe Sahel, they would also be expected to beinvolved in the purchase of the biologicalproduct. (shrink)

Philosophers, policymakers, and scientists have long asserted that ecological science – and especially notions of homeostasis, balance, or stability – help to determine environmental values and to supply imperatives for environmental ethics and policy. We argue that this assertion is questionable. There are no well developed general ecological theories having predictive power, and fundamental ecological concepts, such as 'community' and 'stability', are used in inconsistent and ambiguous ways. As a consequence, the contribution of ecology to environmental ethics and values lies (...) more in the realm of natural history and case studies than in the realm of general theory. Moreover, although general ecological theory is unable to contribute to environmental values in the way many philosophers and policymakers have hoped, environmental values can and do contribute to ecological hypotheses and methods. Using examples related to preservation versus development, hunting versus animal rights, and controversies over pest control, we show that, because ecology is conceptually and theoretically underdetermined, environmental values often influence the practice of ecological science. (shrink)

Social policies are used to regulate how members of a society interact and share resources. If we expand our sense of community to include the ecosystem of which we are a part, we begin to develop an ethical obligation to this broader community. This ethic recognizes that the environment has intrinsic value, and each of us, as members of society, are ethically bound to preserve its sustainability. In assessing the environmental risks of new agricultural methods and technologies, society should not (...) freely trade economic gains for ecological damage, but rather seek practices that are compatible with ecosystem health. This approach is used to evaluate the environmental risks associated with genetically engineered insect-resistant trees. The use of insect-resistant trees is a biologically based pest control strategy that has several advantages over pesticide use. However, the use of genetically engineered trees presents particular ecological concerns because the trees are long lived and often are not highly domesticated. The main environmental concerns reviewed include: (1) adaptation of pests to the trees, leading to a non-sustainable agricultural practice, (2) transgenic trees producing environmental toxins, (3) insect resistance enhancing the invasiveness of the tree, causing it to become weedy or invade wild habitats, and (4) transfer of the transgene to wild or feral relatives of the tree, possibly increasing the invasiveness of weeds or wild plants. Some methods are available to offset these risks; however, the environmental risks associated with this technology have been poorly researched and need to be more clearly identified so that when we evaluate the risks, it is based on the best information obtainable. To fulfil an ethical obligation to the environment, public policies and government regulations are needed to preserve the sustainability of both the environment and the future of our production systems. A better understanding of both the ecological issues and of genetic engineering in general are needed on the part of citizens and policy makers alike to ensure that sound environmental decisions are made. Otherwise, the environmental benefits of this technology, mainly decreasing the use of more toxic pesticides in tree crops and forests, will either be lost or traded for other environmental hazards. (shrink)

The Green Revolution in India which was heralded in the 1960‘s was a mixed blessing. Ambitious use of agro-chemicals boosted food production but also destroyed the agricultural ecosystem. Of late Indian farmers and agricultural scientists have realized this and are anxious to find alternatives – perhaps a non-chemical agriculture – and have even revived their age-old traditional techniques of natural farming. Scientists are working to find economically cheaper and ecologically safer alternatives to agro-chemicals. Blue-Green Algae Biofertilizers, Earthworm Vermicomposts, biological (...) class='Hi'>control of pests and herbal biopesticides are showing promise. Saline agriculture and sewage farming are also being promoted in India to augment food production in the face of water scarcity. There is a move to search for alternative foods, which are more nutritious, cheaper and have shorter harvest cycles. Farm and food policy in India has to change its outlook before there can be a second green revolution. (shrink)

Disease in wildlife raises a number of issues that have not been widely considered in the bioethical literature. However, wildlife disease has major implications for human welfare. The majority of emerging human infectious diseases are zoonotic: that is, they occur in humans by cross-species transmission from animal hosts. Managing these diseases often involves balancing concerns with human health against animal welfare and conservation concerns. Many infectious diseases of domestic animals are shared with wild animals, although it is often unclear whether (...) the infection spills over from wild animals to domestic animals or vice versa. Culling is the standard means of managing such diseases, bringing economic considerations, animal welfare and conservation into conflict. Infectious diseases are also major threatening processes in conservation biology and their appropriate management by culling, vaccination or treatment raises substantial animal ethics issues. One particular issue of great significance in Australia is an ongoing research program to develop genetically modified pathogens to control vertebrate pests including rabbits, foxes and house mice. Release of any self-replicating GMO vertebrate pathogen gives rise to a whole series of ethical questions. We briefly review current Australian legal responses to these problems. Finally, we present two unresolved problems of general importance that are exemplified by wildlife disease. First, to what extent can or should 'bioethics' be broadened beyond direct concerns with human welfare to animal welfare and environmental welfare? Second, how should the irreducible uncertainty of ecological systems be accounted for in ethical decision making? (shrink)

Transgenic crops currently available foruse potentially provide environmental benefits, suchas reduction in insecticide use and substitution ofless toxic for more toxic herbicides. These benefitsare contingent on a host of factors, such as thepotential for development of resistant pests,out-crossing to weedy relatives, and transgenic cropmanagement regimes. Three scenarios are used toexamine the potential sustainability of transgeniccrop technologies. These scenarios demonstrate thatexisting transgenic varieties, while potentiallyimproving the sustainability of agriculture relativeto existing chemical based production systems, fail inenabling a fully sustainable agriculture. Genetictraits (...) that have a higher potential for promoting asustainable agriculture have been precluded fromdevelopment for a number of reasons. These include thelack of EPA and USDA regulatory policies thatexplicitly promote sustainable traits; the structureof the agricultural biotechnology industry, which isdominated by agricultural chemical companies; andpatent law and industry policies that proscribe farmhouseholds from saving transgenic seed and tailoringtransgenic crops to their local environmentalconditions – ecological, social, and economic. (shrink)

Robots are widely expected—and pushed—to transform open-field agriculture, but these visions remain wedded to optimizing monocultural farming systems. Meanwhile there is little pull for automation from ecology-based, diversified farming realms. Noting this gap, we here explore the potential for robots to foster an agroecological approach to crop production. The research was situated in The Netherlands within the case of _pixel cropping_, a nascent farming method in which multiple food and service crops are planted together in diverse assemblages employing agroecological practices (...) such as intercropping and biological pest control. Around this case we engaged with a variety of specialists in discussion groups, workshops, and design challenges to explore the potential of field robots to meet the multifaceted demands of highly diverse agroecological cropping systems. This generated a spectrum of imaginations for how automated tools might—or might not—be appropriately used, ranging from fully automated visions, to collaborative scenarios, to fully analogue prototypes. We found that automating agroecological cropping systems requires finding ways to imbue the ethos of agroecology into designed tools, thereby seeking to overcome tensions between production aims and other forms of social and ecological care. We conclude that a rethinking of automation is necessary for agroecological contexts: not as a blueprint for replacing humans, but making room for analogue and hybrid forms of agricultural work. These findings highlight a need for design processes which include a diversity of actors, involve iterative design cycles, and incorporate feedback between designers, practitioners, tools, and cropping systems. (shrink)