Five new Erpetogomphus Hagen in Selys larvae from Mexico, with a key to the known species (Anisoptera: Gomphidae)

The final instars of Erpetogomphus bothrops Garrison, E. elaps Selys, E. eutainia Calvert, E. liopeltis Garrison, and E. viperinus Selys are described and illustrated. Most of these are similar in many features, except E. eutainia which is notoriously different. A key for the separation of all known Erpetogomphus larvae is included.