http://threepercenternation.com/2018/08/with-the-17-year-anniversary-of-911-approaching-here-are-20-haunting-photos-never-before-seen/
Cicadas are back!
Some people love them, others are revolted. Cicadas, those big, loud, harmless bugs are emerging across the Mid-Atlantic. Cicadas have been reported in recent days in Fairfax, Va., Potomac, Md., and Annapolis, Md. A cicada brood emerges once every 17 years, but since there are different broods, you'll see them more than once every 17 years.
2017 - https://www.9news.com/article/news/cicadas-underground-for-17-years-start-to-emerge/439950785
Parts of the Northeast will hear the distinct buzzing sound of 17-year cicadas this spring.
Periodical cicadas are classified into different broods and can arrive from underground in 13 or 17-year cycles, according to the National Pest Management Association (NPMA). The broods are identified by roman numerals and are named based upon the geographic regions as well as the timing of their emergence.
https://www.accuweather.com/en/weather-news/17year-cicadas-to-emerge-eastern-us-this-spring-2016/56066745