Crop pests

Genetic Control. Some Insect pests have been successfully controlled by releasing sterile Insect males in sufficient quantity so that the pest population cannot reproduce. This has proven particularly effective in the control of the screwworm fly, a major pest of cattle (33). Genetic engineers may be able to provide other genetic techniques that will enhance the control of crop pests (34). 

Selective toxicity is also important in relation to the development of resistance or tolerance to pollutants from two distinct points of view. On the one hand, there is interest among scientists concerned with crop protection and disease control in mechanisms by which crop pests, vectors of disease, plant pathogens, and weeds develop resistance to pesticides. Understanding the mechanism should point to ways of overcoming resistance, for example, other compounds not affected by resistance mechanisms or synergists to inhibit enzymes that provide a resistance mechanism. On the other hand, the development of resistance can be a useful indication of the environmental impact of pollutants. 

HCH, sometimes misleadingly termed benzene hexachloride (BHC), exists in a number of different isomeric forms of which the gamma isomer has valuable insecticidal properties. These were discovered during the 1940s, and HCH came to be widely used as an insecticide to control crop pests and certain ectoparasites of farm animals after the Second World War. Crude technical BHC, a mixture of isomers, was the first form of HCH to be marketed. In time, it was largely replaced by a refined product called lindane, containing 99% or more of the insecticidal gamma isomer. 

The JPPA has its own research institute in Ibaraki prefecture and two experimental stations in Kochi and Miyazaki for conducting many types of research services to evaluate the performance of agrochemicals. The research institute and experimental stations have test fields, greenhouses and research laboratories with the capability for chemical analyses. The research institute also provides several services such as identification of virus diseases or other crop pests on plants. 

Deviation from the 860.1500 test location guideline should be discussed with EPA prior to starting a specialized marketing plan if significant delays are to be avoided during the review process. OPPTS 860.1500 outlines how the number of tests in a study can be modified relative to SEN labels. The use of an SEN may be a particularly useful way to manage unique crop pests found in limited easily definable and reasonably confined production regions. 

Crop Pest Period Average Annual Loss Dollars... 

Crop Pest insect species (common name) Disruptant (mixing ratio) Country Applied field (ha) ... 

Evans V J and Jenkyn J F (2000), Fungicides for control of ergot in cereal crops , Pest and Diseases, Proceedings of an international conference held at the Brighton Hilton Metropole Hotel, UK, 13-16 November 2000, 511-514. 

Trap crops Pest control Deguine et al. (2009) Kalinova (2009) Runyon et al. (2009) Torres et al. (2009)... 

Stapleton JJ (1991) Physical effects of soil solarization-thermal inactivation of crop pests and pathogens and other soil changes caused by solarization. In DeVay JE, Stapleton JJ, Elmore... 

Hussaini SS. (2001) Scope of entomopathogenic nematodes against crop pests. In Rabindra RJ, Kennedy JS, Sathiah N, Rajasekaran B, Srinivasan MR (eds) Microbial control of crop pests. CAB International, Wallingford, UK, pp. 180-221. 

In addition to plaguing humans directly, flies spread pathogens that infect a significant number of plants and animals. Veterinary medicine must deal with horse flies and black flies, as well as pests with such curious names as warble flies and bot flies. There are ubiquitous stable flies that look like everyday house flies but deliver a painful bite, and a multitude of less familiar species that prey on sheep, rodents, and rabbits. Flies that are crop pests typically feed on their plant hosts as larvae. Seedcorn maggots, for... 

Insect Control. Grasshoppers were chosen as an assay organism because they are a major crop pest in the grain producing plains and plateau states, they are readily available year round from the Agricultural Experiment Station at Montana State, and they are relatively easy to maintain in the laboratory. Two species, Melanoplus bivitattus and Melanoplus sanguinipes. have been used in these assays. 

The tubingensins A (379) and B (380) showed activity against the widespread crop pest Heliothis zea, and display in vitro anti-viral activity against herpes simplex virus type 1 with IC50 values of 8 and 9 pg/mL, respectively (346) (see Scheme 2.100). Some bis-basic ethers of carbazoles are anti-viral. When tested against Encephala myocarditis viral infection, several N-ethyl substituted bis-basic carbazoles of the general formula 490 were shown to be active (448) (Scheme 4.9). 

Verkerk, R.H.)., Leather, S.R., Wright, D.J. 1998. The potential for manipulating crop-pest-nat-ural enemy interactions for improved insect pest management. Bulletin of Entomological Research 88 493-501. 

There are additional miscellaneous factors which impinge on the worker reentry process, the most important being crop, pest management practices, work practices, and labor relations. 

Insects have evolved resistance to Bt toxins in the laboratory, yet only one crop pest, the diamondback moth (Plutella xylostella), has evolved resistance to Bt toxins under open field conditions (Tabashnik et al. 2003). But this resistance was not caused by Bt crops, rather it occurred in response to repeated foliar sprays of Bt toxins to control this pest on conventional (non-GE) vegetable crops (Tabashnik 1994). Based partly on the experience with diamondback moth and because Bt crops cause season-long exposure of target insects to Bt toxins, some scientists predicted that pest resistance to Bt crops would occur in a few years. 

Miles, J.R.W. (1976) Fates of insecticides applied to lands and crops. Pest. Monit. J. 10, 87-91. 

As discussed earlier, OC pesticides have played an important part in the management of crop pests. The following pages discuss, in brief, the use and toxicity of selected OC pesticides. 

Cyclodienes are an important group of chlorinated pesticides. The group hep-tachlor includes insecticides such as chlordane, aldrin, dieldrin, endosulfan, and heptachlor and its epoxide. These are used for the control of a variety of plant pests in agriculture and household environments. The entry of cyclodienes to the global market has created easy management for the control of crop pests. They appeared after World War II as tools to protect food crops and control diseases from pests. In fact, humans were protected from malaria, typhus, and loss of food crops by pesticides. 

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