readna.blogspot.com

Thursday, August 13, 2015

INSECTICIDES AND ITS EFFECTS ON THE ENVIRONMENT

Organized by chinedu j. INSECTICIDES AND ITS EFFECTS ON THE ENVIRONMENT WRITTEN BY OGWUEGBU CHIOMA 12/0272/ST NWANERI IJEOMA H. 12/0273/ST A SEMINAR RESEARCH SUBMITTED TO THE DEPARTMENT OF SCIENCE LABORATORY TECHNOLOGY, SCHOOL OF INDUSTRIAL AND APPLIED SCIENCE, FEDERAL POLYTECHNIC NEKEDE OWERRI SUPERVISED BY DR. ALI BILAR ALEX IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF NATIONAL DIPLOMA (ND) IN SCIENCE LABORATORY TECHNOLOGY. JANUARY 2015 CERTIFICATION This seminar has been read and approved for the department of Science Laboratory Technology, School of Industrial and Applied Science, Federal Polytechnic Nekede Owerri, Imo State. BY …………………………………… ……………………………. DR. ALI BILAR ALEX DATE (Supervisor) …………………………………… ……………………………. DR. ALI BILAR ALEX DATE (H.O.D.)   DEDICATION This seminar work is dedicated to God Almighty for His guidance and protection throughout these years of our academic predicament. This seminar work is also dedicated to the entire student of Science Technology Department (Chemistry).   ACKNOWLEDGEMENTS We wish to acknowledge our competent and humble supervisor Dr. Ali Bilar Alex for assisting us from all angles towards the successfulness of our seminar work. We also feel indebted to all our lecturers in Science Laboratory Technology and our able Head of Department Dr. Alex A.B. for their immense support both morally and academic towards our academic pursuit. We also appreciate the efforts of our friends, colleagues and the entire students of Science Laboratory Technology who contributed in one way or the other for this achievement. May Almighty God continue to guide them towards their future endeavour. We finally, express our extraordinary appreciations to our beloved parents/guardians Mr. & Mrs. Onyeanuna Ogwuegbu and Mr. & Mrs. Innocent Nwaneri for their numerous supports, financially and otherwise which constituted our major source of sustenance up to this level of academic achievement. TABLE OF CONTENTS Title Page - - - - - - - - i Dedication - - - - - - - - ii Acknowledgement - - - - - - - iii Table of Contents - - - - - - - iv CHAPTER ONE 1.0 Introduction - - - - - - - 1 1.1 Classification of Insecticides - - - - 3 1.2 Statement of problems - - - - - - 9 1.3 Aim - - - - - - - - - 11 1.4 Objectives - - - - - - - 11 CHAPTER TWO 2.0 Literature Review - - - - - - -13 CHAPTER THREE 3.0 Environmental effects of insecticides 3.1 Effects on non target species - - - - 22 3.1.1 Air - - - - - - - - - 22 3.1.2 Soil - - - - - - - - - 24 3.1.3 Water - - - - - - - - 22 3.1.4 Effect on plants - - - - - - 26 3.1.5 Effect on animals - - - - - - 27 3.1.6 Aquatic life - - - - - - - 28 3.1.7 Humans - - - - - - - - 29 CHAPTER FOUR 4.0 Conclusion and Recommendations 4.1 Conclusion - - - - - - - 32 4.2 Recommendations - - - - - - 33 References - - - - - - - 34   CHAPTER ONE 1.0 INTRODUCTION Insecticides are chemicals used to control insects by killing them or preventing them from engaging in behaviours deemed undesirable or destructive. Insecticide is also seen as any toxic substance that is used to kill insects. They include ovicides and Larvicides used against insect eggs and larvae respectively. Such substances are used primarily to control pests that infest cultivated plants or to eliminate disease – carrying insects in specific areas. Insecticides are commonly used in agriculture, public health and industrial applications, as well as household and commercial uses (e.g. control of roaches and termites). Insecticides are claimed to be a major factor behind the increase of agricultural 20th century’s productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans; some concentrate along the food chain. Insecticides can be classified in different ways: on the basis of their chemistry, their toxicological action or their mode of penetration (action). Many insecticides act upon the nervous system of the insect (e.g. cholinesterase (ChE) inhibition) while others act as growth regulators or endotoxins. Insecticides are applied in various formulations and delivery systems (e.g. sprays, baits, slow-release diffusion) that influence their transport and chemical transformation. Mobilization of insecticides can occur via run off (either dissolved or sorbed to soil particles), atmospheric deposition (primary spray drift) or sub-surface flow. Soil erosion from high intensity agriculture, facilitates the transport of insecticides into water bodies. Insecticides are designed to be lethal to insects, so they pose a particular risk to aquatic insects, but they also affect other aquatic invertebrates and fish.   1.1 CLASSIFICATION OF INSECTICIDES Insecticides can be classified in different ways: • Systemic insecticides are incorporated by treated plants. Insects ingest the insecticide while feeding on the plants. • Contact insecticides are toxic to insects when brought into direct contact. Efficacy is often related to the quality of pesticide application, with small droplets often improving performance. • Natural insecticides such as nicotine, pyrethrum and neem extracts are made by plants as defenses against insects. • Plant-incorporated protectants (PIPs) are systemic insecticides produced by transgenic plants. For instance, a gene that codes for a specific Baccilus thuringinsis biocidal protein was introduced into corn and other species. The plant manufactures the protein which kills the insect when consumed. • In organic insecticides are contact insecticides that is manufactured with metals and include arsenates, copper, and fluorine compounds, which are now seldom used, and sulfur, which is commonly used. • Organic insecticides are contact insecticides that comprise the largest numbers of insecticides available for use today. Insecticides are also classified based on their mode of action. Insecticide type and their modes of action Insecticide type Mode of Action 1 Organochlorine Most act on neurons by causing a sodium/potassium imbalance preventing normal transmission of nerve impulses while some act on the GABA (y-aminobutyric acid) receptor preventing chloride ions from entering the neutrons causing a hyperexcitable state characterized by tremors and convulsions; usually broad-spectrum insecticides that have been taken out of use.   Insecticide type Mode of Action 2 Organophosphate Cause acetylcholinesterase (AChE) inhibition and accumulation of acetylcholine at neuromuscular junctions causing rapid twitching of voluntary muscles and eventually paralysis; broad-range insecticides, generally the most toxic of all pesticides to vertebrates. 3 Organosulphur Exhibit ovicidal activity (i.e. they kill the egg stage); used only against mites with very low toxicity to other organisms.   Insecticide type Mode of Action 4 Carbamates Cause acetylcholinesterase (AchE) inhibition causing central nervous system effects (i.e. rapid twitching of voluntary muscles and eventually paralysis), very broad spectrum toxicity and highly toxic to fish. 5 Formamidines Inibit the enzyme monoamine oxidase that degrades neurotransmitters causing an accumulation of these compounds; affected insects become quiescent and die, used in the control of OP and carbamate resistant pests.   Insecticide type Mode of Action 6 Pyrethroids Acts by keeping open the sodium channels in euronal membranes affecting both the peripheral and central nervous system causing a hyper-excitable state causing such symptoms as tremors, incordination, hyperactivity and paralysis; effective against most agricultural insect pests; extremecy toxic to fish. 7 Nicotinoids Act on the central nervous system causing irreversible blockage of the postsynaptic nicotinergic acetylcholine receptors; used in the control of sucking insects, soil insects, whiteflues termites, turf insects and the Colorado potato beetle; have generally low toxicity to mammals, birds and fish.   Insecticide type Mode of Action 8 Organotins Inhibit phosphorylation at the site of dinitrophenol uncoupling, preventing the formation of ATP, used extensively against mites on fruit trees, formerly used as an antifouling agent and molluscacide; very toxic to aquatic life. 9 Antibiotics Act by blocking the neurotransmitter GABA at the neuromuscular junction, feeding and egg laying stop shortly after exposure while death may take several days; most promising use of these materials is the control of spider mites, leafminers and other difficult to control greenhouse pests. 10 Spinosyns Acts by disrupting bindiong of acetylcholine in nicotinic acetylcholine receptors at the postsynaptic cell, effective against caterpillars, lepidopteran larvae, leaf miners, thrips and termites, regarded for its high level of specificity 1.2 STATEMENT OF PROBLEMS Insecticides can be found almost in all natural habitats, having severe negative effects on natural flora and fauna, biodiversity, water resources and ecosystems, including the equilibrium of agroecosystems. Dependence on insecticides is driven by global agribusiness, which promotes a chemical based solution for food production and pest management in an urban, non agricultural setting, in which powerful corporations are able to control how food is produced and influence policies at a local, national and international level There are economically viable alternatives to insecticides, and pesticide based food systems are not necessarily needed to feed the world’s population. Most insecticides will have an effect on some beneficial insects: predators and parasitoids (parasites that kill their hosts) of insect pests and pollinators. Insecticides may affect higher levels of the food chain since insects are a major food source for many vertebrate species such as birds and reptiles. Any insect in the upper crop canopy at the time of spraying will be exposed to a potentially lethal dose of insecticide at the time of application, depending on insect species and insecticide. Insects such as foraging honey bees entering treated canola fields at flower can be harmed if re-entry occurs shortly after application (El Hasani et al, 2008). The mortality of beneficial insects is an important consideration when spraying complex ecosystems such as forests or perennial agricultural crops that are established over a period of years. Insecticide applications made to agricultural monocultures once within a growing season may not result in long term suppression of beneficial insect populations. Repopulation can occur from untreated fields, roadsides, forage fields and other unsprayed areas. Most insects are not injurious, and, ideally, an insecticide that affects only the target species should be employed. The abundance and diversity of beneficial arthropods is very high in most ecosystems. The abundance of arthropod predators in Uganda and Democratic Republic of Congo listed by Munyuli (2006) includes, Coccinellidae, Staphylinidae, Syrphidae, Anthocoridae, Mantidae, Dermaptera, ground beetle, predatory mite, lygaeid bugs, Anthocoridae, dragonflies and spiders. In a study of alfalfa insects in southern Alberta, Harper (1988) reported that only 15 % of about 400 arthropod species (including mites, spiders and insects were considered to be crop pests; the rest had a beneficial impact to the crop and to the farmer. 1.3 AIM The aim of this study is to study insecticides and its effects to the environment. 1.4 OBJECTIVES (1) The long-term objective of this seminar work is to develop an improved understanding of what insecticides are. (2) To know the classification of insecticide on various basis. (3) To update the available scientific knowledge on the effects and mitigation of insecticides on non-target species and the environment.   CHAPTER TWO 2.0 LITERATURE REVIEW The mode of action of pesticides is a highly complex subject covering many fields, such as biology and chemistry and has many practical implications. Since the Second World War, many synthetic pesticides, such as DDT, have been introduced. At that time, the knowledge of the biochemical and physiological processes in organisms was not sufficiently clear to make it possible for us to understand properly either the mode of action of the insecticides at the target site or their uptake, distribution or degradation in the environment (Stenersen, 2004). Nowadays, we have better knowledge of how nerve impulses are transmitted, how plants synthesize amino acids, and how fungi invade plant tissue: however, in spite of all this knowledge, textbooks “do not tell us where and why pesticides interfere with the normal processes” (Stenersen, 2004). Concerns over the environmental and human health impacts of chemical control of locusts and grasshoppers have led to considerable interest in developing “mycoinsecticides based on entomopathogenic fungi” (Arthur et al., 2002). Although, these products provide effective control of the pests, they also affect host feeding, fecundity and mobility and potential recycling of the fungus to new generations of insects through horizontal transmission. It is generally recognized that natural enemies play an important role in regulating pest populations. The most severe constraint to realizing the potential of natural enemies in field crops is disruption through the widespread use of insecticides with broad toxicity to both pest and their natural enemies. (Naranjo et al, 2002) Traditionally, measuring the acute toxicity of pesticides to beneficial insects has relied largely on the determination of an acute median lethal dose or concentration (Desneux et al, 2007); however, this approach does not take into account indirect effects induced by pesticides. There are other con sequences, such as sublethal effects on the physiology and behavior of beneficial and natural enemies that must be taken into consideration. Floate et al., (1989), conducted a study of insects found in wheat in Saskatchewan and round that insecticides differed significantly n their contact and residual toxicity on carabid beetle predators of the wheat midge, when applied at maximum recommended field rates. Deltamethrin, the least toxic insecticide, caused approximately 30% mortality in the carabid predators, however its residual toxicity on the soil remained constant for one week Carbofuran and chlorpyrifos, the most toxic contact sprays, caused 83 to 100% mortality. The residual toxicity of carbofuran after one week declined significantly, whereas chiorpyrifos remained high. A spatio-temporal model to study effects of contamination and biological impact of pesticides on non target invertebrates was developed by Jepson (1989). The chronological sequence starts with exposure and uptake. This can have direct and indirect components such as the direct exposure to and uptake of droplets of pesticides at the time of spraying and subsequent indirect exposure via contact with surface residues or ingestion of contaminated pray. Next, the effects of the pesticide may be direct, via lethal or sublethal toxic action, or indirect, through depletion of food resources. The last phase corresponds to a recovery stage, where the population returns to its original densities within the treated area. The non target impact of deltamethrin, a broad spectrum pyrethroid insecticide on insects of maize, was studied by Badji et al., (2006). By spraying insecticide on the canopy of the crop to control fall armyworm, the main pest of maize in the tropics, the chemical inevitably reaches the soil affecting epigeic arthropods. These arthropods have important roles in structuring tropical agro-ecosystems, since they have an important role in the soil accumulation of organic matter, the action of decomposer microorganisms, soil structure and nutrient cycling, incidence of soil nernatodes and fungal plant diseases, as well as encouraging plant root development. A similar study conducted by Wiktelius et al., in 1999 to assess the effects of the organochiorine insecticide lindane on non target organisms in African maize agroecosystems. They concluded that lindane reduced the number of Coliembola in over 80%, ants were reduced by 64% and spiders were reduced by 53%. Another finding was that lindane significantly reduced organic matter breakdown in over 45% of the trials. Another study on the predatory fauna in cornfields and response to neonicotinoid seed treatment was conducted by Aibajes et al., (2003). Application of the insecticide imidacloprid as a seed dressing is a common practice to prevent the damage by certain species of rootworms. Imidacloprid is a nitromethylene derivate with a mode of action-similar to that of nicotine, acting on the postsynaptic membranes of insects. It has a systemic action in plants and contact toxicity. After studying the effects of this insecticide for a period of five years, the authors reported little or no difference in yield between treated and untreated crops. They concluded that a combination of removal of predators and herbivores in the treated plots and control of herbivores by predators in the untreated plot explained their results. Therefore, the cost was not compensated by the benefits, adding only the negative effects on the environment and natural enemies. The study, also, reported the integrated effects of the chemical seed dressing on predators because these may be affected through different pathways: 1. Direct exposure of soil fauna to the insecticide, 2. Eating contaminated prey or sucking phloem from plant, 3. The consequence of depriving predators of their prey, 4. The seed dressing may affect the facultative predators through direct ingestion of the insecticide or metabolites from pollen or plant tissue. In temperate ecosystems in particular, carabid, staphylinid beetles and spiders are important for their biomass, diversity and their quality as predators of phytophagous organisms. Above ground applications of pesticides affects sensitive components of the soil ecosystem in arable areas (Everts et al., 1989). Dixon & McKiniay (1992), studied the effect of insecticide-treated arid untreated potatoes on the pitfall trap catches of aphids. They reported significant increases in trap catches of beetles (natural predators of aphids) in treated plots than in the controls; they speculated that insecticides cause a decrease in the aphid (prey) population, invoking an increase in hungry, active beetles more likely to fail into pitfall traps. Hungry carabid beetles, they concluded, are more active than satiated ones. Grant (1989) monitored the insecticide side effects of tsetse fly spraying in Africa. Some of his findings were that many terrestrial and aquatic insects suffer from sublethal effects. Insects dislodged to the ground or carried downstream can not be characterized as mortality. Similarly, tens of thousands of disoriented aquatic larvae and nymphs enter the drift for a few hours after spraying but only some of them will re-attach themselves, recover and reach maturity. Many insects will be lost to predation and drowning during recovery from the toxic chemical. The complete picture of insecticide impact on non target populations must take into account individual recovery, not least because ecosystem recovery is partly dependent upon it. Migratory locusts invade crops of Madagascar and require applications of insecticides over several thousands of square kilometers where non target arthropods can be affected. One of the insecticides used by Peveling et al., (1999) was the organophosphate fenitrothion, which caused medium to long term population declines of more than 75% of epigeal non target insect taxa, such as springtails and ants. The insecticide also impacted non target grasshoppers, reducing them by 50 to 60%. The authors proposed an integrated control approach adapted to the particular conservation priorities of the area, keeping in mind that the least toxic or hazardous product is not always the most environmentally safe. The concept that pest control should be based on economic as well as ecological considerations is a pervasive force in integrated pest management (Naranjo et al., 2002). The literature provides plenty of evidence of insecticide effects on non target species. Since there is more than direct mortality induced by pesticides on beneficial insects, Desneux et al., (2007) listed the sublethal effects of pesticides on community ecology. CHAPTER THREE 3.0 ENVIRONMENTAL EFFECTS OF INSECTICIDES 3.1 EFFECTS ON NON TARGET SPECIES Some insecticides kill or harm other creatures in addition to those they are intended to kill. For example, birds may be poisoned when they eat food that was recently sprayed with insecticides or when they mistake an insecticide granule on the ground for food and eat it. Sprayed insecticide may drift from the area to which it is applied and into wildlife areas, especially when it is sprayed aerially. 3.1.1 AIR Insecticides can contribute to air pollution. Insecticide drift occurs when insecticides suspended in the air as particles are carried by wind to other areas, potentially contaminating them. Insecticides that are applied to crops can volatilize and may be blown by winds into nearby areas, potentially posing a threat to wildlife. Weather conditions at the time of application as well as temperature and relative humidity change the spread of the insecticide in the air. As wind velocity increases so does the spray drift and exposure. Low relative humidity and high temperature result in more spray evaporating. The amount of inhalable insecticides in the outdoor environment is there for often dependent on the season. Also, droplets of sprayed insecticides or particles from insecticides applied as dusts may travel on the wind to other areas, or pesticides may adhere to particles that blow in the wind, such as dust particles. Ground spraying produces less insecticide drift than aerial spraying does. Insecticides that are sprayed on to fields and used to fumigate soil can give off chemicals called volatile organic compounds, which can react with other chemicals and form a pollutant called tropospheric ozone. Insecticide use accounts for 6 percent of total tropospheric ozone levels. 3.1.2 SOIL Many of the chemicals used in insecticides are persistent soil contaminants, whose impact may endure for decade and adversely affect soil conservation. The use of pesticides decreases the general biodiversity in the soil. Not using the chemicals results in higher soil quality, with the additional effect that more organic matter in the soil allows for higher water retention. This helps increase yields for farms in drought years, when organic farms have had yields 20 – 40% higher than their conventional counterparts. A smaller content of organic matter in the soil increases the amount of insecticide that will leave the area of application, because organic matter binds to and helps break down insecticides. Degradation and sorption are both factors which influence the persistence of insecticides in soil. Depending on the chemical nature of the insecticide, such processes control directly the transportation from soil to water, and in turn to air and our food. 3.1.3 WATER Insecticides are found to pollute stream and over 90% of wells samples in a study by the Geological survey. Insecticide residues have also been found in rain and groundwater studies showed that insecticide concentrations exceeded those allowable for drinking water in some samples of river water and ground water. Insecticide impacts on aquatic systems are often studied using a hydrology transport model to study movement and state of chemicals in rivers and streams. As early as the 1970s quantitative analysis of insecticide runoff was conducted in order to predict amounts of insecticide that would reach surface water. There are four major routes through which insecticides reach the water; it may drift outside of the intended area when it is sprayed, it may percolate or leach through the soil, it may be carried to the water as runoff, or it may be spilled. 3.1.4 EFFECT ON PLANTS Nitrogen fixation, which is required for the growth of higher plants, is hindered by insecticides in the soil. The insecticides DDT, methyl parathion and especially pentachlorophenol have been shown to interfere with legume-rhizobium chemical signaling. Reduction of these symbiotic chemical signaling results in reduced nitrogen fixation and thus reduced crop yields. Insecticides can kill bees and are strongly implicated in pollinator decline, the loss of species that pollinate plants including through the mechanism of colony collapse disorder (CCD), in which worker bees from a beehive or western honey bee colony abruptly disappear. Loss of pollinators means a reduction in crop yields. Sublethal doses of insecticides (i.e. imidacloprid and other neonicotinoids) affect bee foraging behaviour. On the other side, insecticides have some direct harmful effect on plant including poor root hair development, shoot yellowing and reduced plant growth. 3.1.5 EFFECT ON ANIMALS Many kinds of animals are harmed by pesticides, leading many countries to regulate insecticide usage through biodiversity Action Plans. Animals including humans may be poisoned by insecticide residues that remain on food, for example when animals enter sprayed fields or nearby areas shortly after spraying. Insecticides can eliminate some animals’ essential food sources, causing the animals to relocate, change their diet or starve. Residues can travel up the food chain, for example birds can be harmed when they eat insects and worms that have consumed insecticides., some insecticides can bioaccumulate, or build up to toxic levels in the bodies of organisms that consume them over time, a phenomenon that impacts species high on the food chain especially hard. 3.1.6 AQUATIC LIFE Fish and other aquatic biota may be harmed by insecticide contaminated water. Insecticides are typically more toxic to aquatic life. Insecticide surface runoff into rivers and streams can be highly lethal to aquatic life, sometimes killing all the fish in a particular stream. Application of insecticides to bodies of water can cause fish kills when the dead plants decay and consume the water’s oxygen, suffocating the fish. Repeated exposure to sublethal doses of some insecticides can cause physiological and behavioral changes that reduce fish populations, such as abandonment of nests and broods, decreased immunity to disease and decreased predator avoidance. Insecticides can accumulate in bodies of water to levels that kill off 200 plankton, the main source of food for young fish. Insecticides kill off insects on which some fish feed, causing the fish to travel farther in search of food and exposing them to greater risk from predators. The faster a given insecticide breaks down in the environment, the less threat it poses to aquatic life. 3.1.7 HUMANS Insecticides can enter the body through inhalation of aerosols, dust and vapour that contain insecticides, through oral exposure by consuming food/water, and through skin exposure by direct contact. Insecticides secrete into soils and gourd water which can end up in drinking water and insecticide spray can drift and pollute the air. The effects of insecticides on human health depend on the toxicity of the chemical and the lengthy and magnitude of exposure. Farm workers and their families experience the greatest exposure to agricultural pesticides through direct contact. Every human contains insecticides in their fat cells. Children are more susceptible and sensitive to insecticides, because they are still developing and have a weaker immune system than adults.’ Children may be more exposed due to their closer proximity to the ground and tendency to put unfamiliar objects in their mouth. Toxic residue in food may contribute to a child’s exposure. The chemical can bioaccumulate in the body over time. Exposure effects can range from mild skin irritation to birth defects, tumors, genetic changes, blood and nerve disorders, endocrine disruption, coma or death. Developmental effects have been associated with insect ides. Recent increases in childhood cancers in throughout North America such as leukemia, may be a result of somatic cell mutations. Insecticides targeted to disrupt insects can have harmful effect on mammalian nervous systems. Both chronic and acute alternations have been observed in exposes. DDT and its breakdown product DDE disturb estrogenic activity and possibly lead to breast cancer. Fetal DDT exposure reduces male penis size in animals and can produce undescended testicles. Insecticide can affect fetuses in early stages of development, in utero and even if a parent was exposed before conception. Reproductive disruption has the potential to occur by chemical reactivity and through structural changes.   CHAPTER FOUR 4.0 CONCLUSION AND RECOMMENDATIONS 4.1 CONCLUSION Because of the problems associated with the heavy use of some chemical insecticides, current insect-control practice combines their use with biological methods in an approach called INTEGRATED CONTROL. In this approach, a minimal use of insecticide may be combined with the use of pest-resistant crop varieties, the use of crop raising methods that inhibit pest proliferation, the release of organisms that are predators or parasites of the pest species, and the disruption of the pest’s reproduction by the release of sterilized pests and the setting of traps and baits. 4.2 RECOMMENDATIONS • Practicing integrated pest management can significantly reduce the amount of insecticides needed to control many insect problems. • Using a targeted insecticide minimizes the risk to beneficial or non-target insects or species. • Using more than one insecticide product in the same location can increase or decrease each one’s effectiveness. It may also result in a greater risk to health and the environment so it should be avoided. • Insecticidal baits can be used instead of spraying large areas, especially for social insects like ants. This can decrease the risk of exposure but do not place baits where children and pets would access.   REFERENCES Abo El-Ghar, G. and El-Sayed, A. (1992). Long-term effects of insecticides on Diaeretiella rapae (M’Intosh), a parasite of the cabbage aphid. Pesticide sciences 36:109-114. Arthurs, S., Matthew, B. and Juergen, L. (2002). Field observations of the effects of fenitrothion and Metharhizium anisopliae van acridium on non-target ground dwelling arthropods in the sathel. Biological Control 26, 333-340. Badji, C., Guedes, R., Silva, A., Correa, A., Queiroz, M. and Michereff-Filho, M. (2006). Non-target impact of deltamethrin on soil arthropods of maize fields under conventional and no-tillage cultivation. Journal of Applied Entomology 131(1), 50-58. Bostanian, N., Laroeque, N., chouinard, G. and Coderre, D. (2001). Baseline toxicity of several pesticides to Hvaliodes vitripermis (Say) (Hemiptera: Miridae). Pesticide Manager Science, 57, 1007-1010. Bourassa, S., Carcamo, H., Larney, F., and Spence, J.(2008) Carabid assemblages (Coleoptera: Carabidae) in a rotation of three different corps in southern Alberta, Canada A comparison of sustainable and conventional farming. Environmental entomology: 37(5), 1214-1223. Class, Thomas J., Kintrup, J. (1991). “Pyrethroids and Household insecticides: analysis, indoor exposure and persistence” Fresenius’ Journal of Analytical Chemistry 340 (340): 446. Colin, M.E., Bonmatin, J.M., Moineau, I, (2004). “A method to quantity and analyze the foraging activity of honey bees. Relevance to the sublethal effects induced by systemic insecticides”. Achieves of Environmental contamination and Toxicology 47(3) 387-395. Fishel, F.M., (2009). Pesticide Toxicity Profile. Neonicotinoid Pesticides IFAS publication # p1-80. Karl Grandin, ed (1948). “Paul Muller Biography”. Les. Prix Nobel. The Nobel foundation. Retrieved 2008-07-24. Oldroyd, B,P. (2007). “Wha’s killing American Honey Bees?”. PLoS Biology 5 (6): e168. Palmer, WE, Bromley, PT, and Brandenburg, RL. (2007)). Wildlife and Pesticides – Peanuts. North Carolina Corporative Extension Serive. Van Emden, H.F., Peakall, David B. (3o June 1996). Beyond Silent Spring. Springer. ISBN 978-0-014-72800-6.

No comments:

Post a Comment