Estimates of the number of insect species in the world range from about 750,000 to one million. However, some experts believe there are really twice this number. About 7,000 new insect species are described each year. At the same time, however, unknown numbers are lost when their habitats, mainly tropical rain forests, are destroyed.
Sources: The Encyclopedia of Insects, pp. 1,12; Parker, Sybil P. Synopsis and Classification of Living Organ-isms, vol. 2, p. 327.