Letter 58 — On Being (§2)

“There is an insect, called by the Greeks oestrus, which drives cattle wild and scatters them all over their pasturing grounds; it used to be called asilus in our language, as you may believe on the authority of Vergil:— Near Silarus groves, and eke Alburnus’ shades Of green-clad oak-trees flits an insect, named Asilus by the Romans; in the Greek The word is rendered oestrus. With a rough And strident sound it buzzes and drives wild The terror-stricken herds throughout the woods.”