Economic Entomology

Insects are regarded by some as the main competitors of humans for dominance on the earth. Humans depend on insects for pollination of many crops, for production of honey and silk, for the decomposition of organic matter and the recycling of carbon, and for many other vital ecological roles. But it is the negative impact of insect pests that has been of greatest concern to humans. There are no reliable estimates of aggregate losses caused by insects as vectors of pathogens and parasites of humans and domestic animals, as agents causing direct damage to dwellings and other human-made structures, and as pests of crop plants and farm animals, but the amounts run to probably hundreds of billions of dollars annually. Losses caused by insects and vertebrate pests worldwide in the production of only eight principal food and cash crops (barley, coffee, cotton, maize, potato, rice, soybean, and wheat) between 1988 and 1990 have been estimated at $90.5 billion.

In the late 1800s and early 1900s, entomology became established in many academic and research institutions as a discipline equal in rank with botany and zoology. The diversity of insects and their economic importance was the justification for ranking the study of a class of animals (Insecta) as being equivalent to the study of two kingdoms of organisms (plants and animals other than insects). Through the first half of the twentieth century, there was a schism between basic and applied (or economic) entomology. Since then, common use of the expression "economic entomology" has declined, being replaced by designations of its principal branches, such as agricultural entomology, forest entomology, urban entomology, and medical and veterinary entomology. A detailed historical account is beyond the scope of this article, but Table I provides a chronology of some landmarks in the development of agricultural entomology through the ages.

The realm of agricultural entomology includes all basic studies of beneficial and pest insects associated with agricultural crops and farm animals. This article deals mainly with crops, but the general principles and concepts are equally applicable to farm animals. The starting point of such studies is a correct identification of the insect species, in accordance with the science known as biosystematics.

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