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. Erwin estimated that there are about twice as many species of insects and related animals in tropical trees as there are on the ground of the forest.
Erwin served as secretary of the Society of Systematic Biologists from 1973 to 1975, and is currently the editor in chief of ZooKeys. He has described over 20 genera and more than 400 species of insect, and is commemorated in the names of 47 species, two genera, one subfamily and one subspecies.
- SI NMNH Entomology Staff: Terry Erwin
- Hambler, Clive (2004). Conservation. Cambridge University Press. p. 14. ISBN 0-521-80190-7.
- Rice, Marlin E. (27 April 2015). "Terry L. Erwin: She Had a Black Eye and in Her Arm She Held a Skunk". ZooKeys. 500: 9–24. doi:10.3897/zookeys.500.9772. (Reprinted from American Entomologist 61(1)
- SSB - Past Presidents and other Officers
- "Celebrating with the 'beetle' man: Terry Erwin's 75th birthday". ZooKeys. 541: 1–40. 2015. doi:10.3897/zookeys.541.7316.