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.
How many species are there? There are about 3,000 known species of cicada worldwide, according to the Smithsonian Natural Museum of History. There are annual cicadas, which appear every year, and periodical cicadas, such as the ones emerging in the northeast U.S., which appear in 13- and 17-year life cycles.