This process is called sublimation. The opposite (deposition) is where a gas turns directly into a solid. Sublimation occurs if the pressure and temperature are right for the specific substance, so that the solid phase in a phase diagram borders the gas phase.
Most cicadas go through a life cycle that lasts from two to five years. Some species have much longer life cycles, such as the North American genus, Magicicada, which has a number of distinct broods that go through either a 17-year or, in some parts of the world, a 13-year life cycle.
Adult cicadas only have a lifespan of two to four weeks, according to a fact sheet (PDF) published by the university. Only the females, which unlike their male counterparts are silent, likely will remain after mating, Shetlar said in a Thursday phone interview.