Insects and Spiders - Threatened And Endangered Insect Species In The United States, Threatened And Endangered Foreign Species Of Insects

Insects are members of the Animalia kingdom and belong to the phylum Arthropoda, along with crustaceans. There are many classes of arthropods, including the insects and arachnids. Both are invertebrates, but insects have six legs, while arachnids have eight legs. The arachnids include spiders, mites, ticks, scorpions, and harvestmen.

Insects are the most diverse group in the animal kingdom. Scientists are not certain of the total number of insect species; estimates range as high as thirty million species. Nearly one million of the species have been described. Insects have not been nearly as thoroughly studied as the vertebrate groups, and so there are likely to be many endangered insects whose desperate state is unknown.

Insects and arachnids, like numerous other species, suffer from diminished habitat as a result of encroaching development, industrialization, changing land use patterns, and invasive species.