Cicadas are divided into two main categories:
- Annual cicadas, whose lifecycle takes two to five years, appear every year.
- Periodical cicadas have lifecycles of 13 or 17 years.
Periodical Cicadas
Periodical cicadas belong to the genus Magicicada. All periodical cicadas of the same lifecycle length that emerge in the same year are considered part of the same brood. Broods are given Roman numerals to identify them.
There are seven species of periodical cicadas, four with a 17-year cycle and three with a 13-year cycle. The species in each life-cycle group are distinctive in size, color, and song. The 17-year cicadas are generally northern, and the 13-year cicadas southern with considerable overlap in their distribution. In fact, both life-cycle types may occur in the same forest.
Magicicada adults have black bodies and striking red eyes and orange wing veins, with a black "W" near the tips of the forewings. Most emerge in May and June.
Annual Cicadas
Annual cicadas require 2-5 years to complete a life cycle and rarely are abundant enough to attract attention, but because many broods overlap, adults can be heard every year. Some of the annual cicada species are sometimes mistaken for the periodical cicadas, especially those in the genera Diceroprocta and Okanagana; these other species emerge somewhat later in the year but may overlap with Magicicada.
