It has a much wider distribution than its sister species, Apis andreniformis.

It is considered most similar to its sister species E. bimaculatus.

In cases where they represents species, sister species is sometimes used.

Subsequent molecular analyses have suggested that its sister species may instead by P. femoristriga.

A superspecies consisting of two sister species is called a species pair.

This environmental gradient ultimately results in genetically distinct sister species.

Large and Braggins (2004) note that the two may represent sister species.

The two sister species diverged at around 1.9-3.0 million years ago.

An older sister species with more primitive features was found in amber that is 90 to 100 million years old.

And indeed, the rate of evolution was 51% faster in the tropical than their temperate sister species.