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Appendix D: Pesticide Information
Pages 226-248

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From page 226...
... Nevertheless, the committee believes that the EPA should give added emphasis in benefit analysis to alternative pest control technologies under development. The methodology for such evaluation, however, is not well developed at present.
From page 227...
... Clearly, a systematic methodology needs to be developed for assessing the innovation process at its various stages and integrating such assessments into the benefit analysis. If the EPA were to emphasize the prospects for new pest control technologies in its benefit analyses, such a shift to a wider range of alternatives would decrease the long-run benefits of the pesticide under consideration, but not necessarily the more immediate impacts of its withdrawal.
From page 228...
... Although cultivation is still practiced for the control of weeds, and crop rotation provides some weed control, synthetic organic herbicides have become the predominant technology. Led by the discovery of the herbicidal properties of the phenoxy alkanoic acids in the early 1940s, chemistry soon followed that provided different mechanisms of action, a wider range of herbicidal activity on weeds, and differing selectivities to crops.
From page 229...
... PESTICIDE INNOVATION 229 TABLE D-1 Herbicidal Active Ingredients Used on Corn and Soybeans During 1982 Active Ingredient (million lbs.) Herbicide Corn Soybeans Single applications Acifluorfen 0.9 Alachlor 19.7 10.3 Atrazine 22.4 Bentazon 6.7 Butylate 22.4 Chloramben 2.7 Cyanazine 4.9 2,4-D 3.3 Dicamba 0.9 Fluchloralin 2.6 Glyphosate 2.2 Linuron 1.3 Metolachlor 3.2 6.9 Metribuzin 2.2 Trifluralin 20.4 Other 9.5 5.5 Total 86.3 61.7 Tank mixes Acifluorfen + bentazon 0.3 + 0.7 Alachlor + metribuzin 6.9 + 1.7 Alachlor + linuron 8.1 + 3.2 Alachlor + naptalam + dinoseb 1.5 + 1.3 + 0.6 Atrazine + alachlor 16.4 + 21.2 Atrazine + butylate 8.7 + 23.7 Atrazine + cyanazine 2.7 + 3.6 Atrazine + metolachlor 8.7 + 10.7 Atrazine + simazine 1.3 + 1.2 Bentazon + 2,4-D 0.4 + *
From page 230...
... In fact, carryover potential for the new classes of soybean herbicides is a matter of growing concern for weed scientists. BIOLOGICAL CONTROL Weed control by insects has been studied by a few scientists for a long time, and successful control has been accomplished for numerous weeds occurring in noncrop areas.
From page 231...
... Moreover, for sustained success, farmers must be weaned away from the synthetic organic herbicides that ensure effective weed control. In a similar vein, increased emphasis has recently been given to natural phytotoxins from pathogens that might be formulated and applied to weeds.
From page 232...
... That route engenders the same problems that now beset organic herbicides synthesized de nova. As with phytotoxins, natural products may be no less hazardous to humans and the environment than ones first synthesized by man.
From page 233...
... Although alternative weed control technologies hold some promise and may become more important, synthetic organic herbicides seem certain to be the preferred technology until the end of the century. Development of alternative technologies will require not only time and research, but also practical demonstrations to convince farmers that the alternatives will be as economical and dependable as synthetic organic herbicides.
From page 234...
... INSECT CONTROL T ROY FUKUTO INTRODUCTION Because they are effective, economical, and fast-acting, insecticides and acaricides are unique tools for relegating damaging insect and mite populations to subeconomic levels.
From page 235...
... To date, biologically active, natural products have been looked to by the agrochemical industry as leads for the chemical synthesis of structurally related compounds with improved biological and physical properties that are amenable to large-scale chemical synthesis. This latter requirement may ultimately become less important with advances in genetic engineering, since even complex molecules can be produced on a large scale, using fermentation processes with genetically .
From page 236...
... Octopamine, a biogenic amine that serves as neurotransmitter and neuromodulator, is found primarily in invertebrates and, therefore, compounds mimicking its action are expected to be selectively toxic to insects and acarines. Avermectins and Milbemycines The avermectins and milbemycins are natural products obtained by fermentation of the soil fungus species Streptomyces, which have demonstrated potent anthelmintic, acaricidal, and insecticidal activities.34 For example, the avermectins are highly effective against common veterinary ectoparasites, phytophagus mites, nematodes, and various insect species of Lepidoptera, Coleoptera, and Homoptera.
From page 237...
... and BAY SIR 8514. As indicated earlier, diflubenzuron inhibits chitin synthesis and is widely regarded as an insect growth regulator.~° Because of chitin-inhibiting action, diflubenzuron and related analogs should affect insects in all cuticle-forming stages.
From page 238...
... Other types of plants being sought as control agents are insect growth and behavior regulators, morphogenetic agents, insect juvenile hormones and phytochemical analogs, antijuvenile hormones, sex and alarm pheromones, and antifeedants.'4 The examination of plant products for antifeedant compounds has recently attracted much attention.'6 A number of plants are recognized for their elaborate chemical defense systems against phytophagous insects, and various naturally occurring compounds are being discovered that permanently impede feeding by specific insects. In general, natural products occurring in plants, animals, and microorganisms provide a rich source for new types of insect control agents.
From page 239...
... israelensis, which is an effective control agent for mosquito larvae and will very likely expand the spectrum of crop pests that can be controlled by bacterial insecticides. RESISTANCE Resistance is a preadaptive phenomenon, and since insects and bacteria have been together in nature for ages, it is conceivable that low levels of resistance to the bacterial toxins already exist.
From page 240...
... thuringiensis produces several toxins) , because the greater the number of targets in the insect the less likely it is that mutations will lead to increased resistance; · Simultaneous use of chemical and microbial agents for the same reason more than one target is involved; and · Use of an agent—microbiological or chemical with a rapid toxic action, to avoid a lasting selection pressure for resistance since the number of mutants produced will be proportional to exposure time.
From page 241...
... From this viewpoint, it has been postulated that bacterial insect pathogens are ideal systems for basic work on genetic engineering. However, mediator organisms must be selected with care and a watch kept to avoid undesirable contaminants entering the systems.
From page 242...
... This material is sold in many developing countries to control vegetable crop pests that can no longer be controlled by conventional insecticides. Phillip Grau of Abbott Laboratories estimates worldwide sales of Abbott's B
From page 243...
... Resistance might have been acquired by the local insects to the local virus or the observation might reflect differing levels of virulence among virus isolates. STABILITY, SENSITIVITY, AND PERSISTENCE Natural sunlight-ultraviolet radiation (> 290 nm)
From page 244...
... zea and Lymantria dispar exhibited no harm to mammals, fish, birds, or beneficial insects (including parasitic insects) , had no relationship to arboviruses, and had no effect on aquatic invertebrates.24 Extensive safety testing of Neodiprion lecontei NPV and N
From page 245...
... In addition, production costs are high. TOXICITY In numerous safety tests, no infections have been induced in mammals with the common microbiological control fungi.
From page 246...
... . These factors are sobering reminders that fungi and their products as pest control agents do not have an unlimited potential.
From page 247...
... thuringiensis toxin-producing genes can or will be transferred through the plant plasmids to weeds, thereby having an adverse affect on the beneficial insects that suppress the proliferation of weeds. SUMMARY The potential of microbiological insecticides has barely been tapped.
From page 248...
... Pp. 229-244 in Recent Advances in the Chemistry of Insect Control.


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