It means big head. Bighead. It is the Spanishization of the term Megacephala. In Entomology it is a Latin epithet that means big head, bighead. The epithet is usually a complement to the genus to form a scientific name and is explanatory to some characteristic of the species. For example : the scientific name of the lioness ant is Pheidole megacephala, meaning that it is a bighead ant (big head).
