Periodical cicada (Magicicada septendecim) in Hamden, Connecticut, in June 2013. Periodical cicadas exist exclusively in the eastern United States. The species of periodical cicada that will emerge in Connecticut ? Magicicada septendecim ? spends 17 years developing underground as a nymph, feeding on sap from tree roots. For a brief period in the late spring of the 17th year, the nymphs of the entire brood emerge around sunset, climb up tree trunks, and transform into winged adults that have black bodies with orange trim, ruby-like eyes, and stiff glossy wings.