Terry L. Erwin (born 1940) is an entomologist with the Smithsonian Institution.Erwin is notable for his controversial estimate of 30 million as the total number of species.He found 1,200 species of beetles living in Luehea seemannii trees. Of those 1,200 species of beetles, he estimated that 163 are found only in the Luehea seemannii tree and not in other species of trees. There are about 50,000 species of trees in the tropics and beetles make up 40% of insects and related animals.