The 17 year Periodical Cicada (Magicicada septendecim) spends five juvenile stages underground only to surface in large numbers every 17 sears. At this time the nymph molts and emerges from its exoskeleton as an adult. There are a number of populations of Periodical cicadas throughout the US with either 13 or 17 year nymph stages. Different populations will emerge during different years, but the adult stage occurs during the same year for all members of the same population. This one is from the population in Hamden, Connecticut.