Beneficial insects resistance

Explanatory knowledge is information that explains why things are so or why certain effects will happen. Here is where it is possible to determine the direction of the solution. Examples the way Bt proteins affect specific pest and beneficial insects what are the main reasons for unwelcome erosion effects mechanisms of vertical gene flow mechanisms of resistance development. 

Once resistant pests attack a monoculture, all plants either survive or perish. Unfortunately, immediate economic interests push the former to see nothing else than the crop of interest. This turns against the conservation of natural product diversity even side zones, as the field margins and roadsides, are no more left as a refugee for beneficial insects (Crawley 1999). 

Schuster, M. F. and Calderon, M. (1986). Interactions of host plant resistant genotypes and beneficial insects in cotton ecosystems. In Interactions of Plant Resistance and Parasitoids and Predators of Insects, eds. D. J. Boethel and R. D. Eikenbary, pp. 84-97. New York John Wiley Sons. 

It should be clear to us that the development of resistance is always to be expected to any insecticide we may choose to apply, but it is not inevitable. DDT stayed effective against the European corn borer for at least 15 years (Table VIII) and there are several other examples, including diazinon and the western corn rootworm in Nebraska. Some of the species of beneficial insects which formerly suffered from insecticide damage, such as braconid parasites, lady beetles, mayfly nymphs and honeybees, have now developed certain tolerances, while several of the Phytoseiid mites which feed on the plant-feeding spider mites are becoming as resistant as their prey to OP s and carbamates. 

Cotton is one of the crops most heavily reliant upon insecticide use. Although Bt cotton has been introduced in some areas, insecticide sprays remain as important components of cotton pest management programs. In some areas of the cotton belt, the majority of applications are made by aircraft. Issues which have been of regulatory concern in recent years include pest resistance associated with the frequent sprays, beneficial insect effects, worker exposure, and spray drift impacts on surfrice water quality. Products currently in use include organophosphates such as azinphos-methyl, methyl parathion, acephate, and disulfoton, pyrethroids such as lambda-cyhalodirin and carbamates such as methomyl. 

It does not harm most beneficial insects, has a low toxicity to mammals and birds, does not bioaccumulate, breaks down quickly in sunlight, adsorbs to and does not leach from soils, but still has a broad spectrum of activity against Lepidoptera. Strains of B. thuringiensis that control Coleoptera (beetles) have also been found. Bacillus sphaer-icus works better on mosquitoes because it resists ultravio-... 

A solution to the sampling problem, and to the apparent lack of resistance genes of interest in the target beneficial species, might be to use molecular cloning techniques to insert pesticide resistance genes from one species into different beneficial insect or mite species (7 ). ... 

With increasing awareness of the side effects of pesticides and the increasing number of cases of pesticide resistance, integrated pest management (IPM) is an important method of pest control. IPM involves using cultural methods of control combined with the use of pesticides. Pesticide use is minimised in an attempt to protect and enhance the activities of beneficial insects (natural enemies and polhnating insects) and extend the life of the pesticides that are available. 

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