This monster tiger beetle is a native United States species but adult females are 38mm (males are smaller) which is far bigger than the maximum size of the largest listed Omus sp. at 20mm. The beetles run rapidly to chase down crickets and other insects, which are chopped up with the huge jaws. Adult crickets are taken. In captivity adults have lived three years at room temperature. There are 5 species in the genus found in the United States and 2 in Mexico.