Here in the Eastern US, there are multiple broods of 13 and 17 year Periodical Cicadas. Each brood contains 3 or 4 different species, which in many areas emerge in the same places. I have found some areas where one species is predominant, or the only one present. The next mass emergence for most of the Eastern states will be in 2021, brood X which has a 17 year cycle. Then in 2024 the massive broods XIX a 13 year event, and XIII a 17 year cycle will cover the states of Illinois, Indiana, Wisconsin and Iowa. Brood XIX will cover Illinois, southern Iowa, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Georgia, Tennessee, Kentucky, South and North Carolina and Virginia. There are many populations in areas that have yet to be documented, and there is still a huge amount of information we have not learned about these creatures. This year (2018) there is a small population of 17 year periodicals, brood VII, that make their appearance in Central New York. Here is a documentary I found on youtube. Sir David Attenborough covers it quite well in this short film.