Hyginus Fabulae, 52 Aegina.
When Jupiter desired to sleep with Aegina, the daughter of Asopus, but feared Juno, he took Aegina to the island of Delos and impregnated her. Aeacus was born of this pregnancy. When Juno came to know of this, she put into the water a snake that poisoned it, such that whoever drank of the water would pay his debt to nature [i.e. perish]. However, since Aeacus had lost all his friends and, on account of the small number of men alive, could not linger, he took note of the ants and asked Jupiter to give him these as men to protect him. Then Jupiter turned the ants into men, who were called the Myrmidons — because in Greek ants are called μύρμηκες. And the island took on Aegina's name.
— translation RTMacfarlane
52. Aegina
Iuppiter cum Aeginam Asopi filiam uellet comprimere et Iunonem uereretur, detulit eam in insulam Delon et grauidam fecit, unde natus est Aeacus. (2) hoc Iuno cum rescisset, serpentem in aquam misit quae eam uenenauit, ex qua qui biberet, debitum naturae soluebat.(3) quod cum amissis sociis Aeacus prae paucitate hominum morari non posset, formicas intuens petiit ab Ioue ut homines in praesidio sibi daret. tunc Iuppiter formicas in homines transfigurauit, qui Myrmidones sunt appellati quod Graece formicae μύρμηκες dicuntur. insula autem Aeginae nomen possedit.