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.
Periodical Cicadas are so-named because they are not seen every summer. Instead, they are only seen periodically, every few years. Most periodical cicada species in Kentucky have a very predictable development cycle where the nymphs live underground for exactly 13 or 17 years, depending on the species.