A Study On Harmful Effects Of Invertebrate And Vertebrate Pests And Their Biological Control In Indian Agriculture.

Biological control is a method of restricting effects of harmful animals, pathogens and plants using other useful organisms, e.g. microorganisms, insects and plants that inhibit the harmful organisms. The method takes advantage of basic ecological interactions between organisms, such as predation, parasitism, pathogenicity and competition. Today, biological control is used primarily for controlling pests in crop cultivation. Advantages of biological control are that no artificial substances are added, and that pathogens / animals that develop resistance against biological control agents are rare. Biological control is an important component of integrated pest management. Biological control is the beneficial action of parasites, pathogens, and predators in managing pests and their damage. Biocontrol provided by these living organisms, collectively called “natural enemies,” is especially important for reducing the numbers of pest insects and mites. Use of natural enemies for biological control of rangeland and wild land weeds (e.g., Klamath weed, St. Johnswort) is also effective. Plant pathogens, nematodes, and vertebrates also have many natural enemies, but this biological control is often harder to recognize, less well understood, and/or more difficult to manage. Conservation, augmentation, and classical biological control are tactics for harnessing natural enemies’ benefits. Biocontrol (for vertebrates in particular, the manipulation of habitat conditions) should not be employed a priori , because, if done improperly, the treatment can create more problems than it cures. In fact, it can cause more problems than the use of poisons. With repeated poisoning of vertebrate pests there is concern about the possibility of subtle and undesirable physiological and behavioral responses, or of carcinogenic and mutagenic effects on both the target species and on non target populations. However, when a habitat is modified, there is little doubt but what it will produce more pronounced interactions with other species of animals than would usually result from population reductions caused by either chemosterilents or toxicants. Observations indicate that natural biomes have a well-established , stable, animal-soil-vegetation complex which usually is not delicately balanced. A natural change (e.g., by disease) or man-caused change (e.g., by shooting), in the density of a native species of browsing, grazing, seed-eating, or predatory mammal does not precipitate a dramatic "balance-of-nature" type chain reaction of responses by other components of the biological community.. There are two broad approaches to reducing the density of troublesome populations of rodents, birds, predators, and other vertebrates. They are biological control and "conventional " methods of control. Control of vertebrates biologically implies the use of a biological process. This can be accomplished in several ways. One is by use of a biological agent such as a chemosterilant which disrupts successful breeding of the pest species; in another method a predator or disease may be used to increase the mortality rate