Subject: Brood X Cicadas emerging 4 years early
Location: Silver spring, MD
May 17, 2017 12:28 pm
Our cicadas aren’t supposed to emerge till 2021, but we are being flooded right now. I’ve never understood why some broods have 13 year cycles, other broods have 17 year cycles. Is it possible that our population of Brood X cicada, which last emerged in 2004, is converting from a 17-year cycle to a 13 year cycle? Is there a precedence for this?
Thank you for sending in your marvelous images and for posing such an interesting theoretical question. First thing is that not all Periodical Cicadas are the same species. According to BugGuide, there are at least seven species in North America, with three of them being on a 17 year cycle and four on a 13 year cycle. More northern species have a 17 year cycle while southern species are on a 13 year cycle. According to Cicada Mania, 2017 will see the emergence of Brood VI, but there is a note that reads: “If you’re in VA, MD, DC, DE, IN, TN, & OH head over to our Brood X straggler page.” There is a further note that reads: “Brood X stragglers are emerging in Tennessee (around Knoxville), Washington D.C., Virginia (counties around D.C.), Maryland (counties around D.C.), Ohio (around Cincinnati), Delaware, Indiana, & Kentucky! These stragglers are emerging 4 years ahead of time. HOT weather this week will cause even more to emerge, and they may begin to chorus (synchronized singing) as well. Note: because of the significant number of cicadas emerging ahead of time, this might be an acceleration event. Periodical cicada accelerations occur when a significant group of an established brood emerge in years ahead of the main brood, and sometimes the accelerated group are able to reproduce and create what is essentially a new brood. Brood VI was likely part of Brood X at one point of time1. We’ll have to see if the Brood X stragglers are able to survive predation, and reproduce in significant numbers to sustain future populations.” We would not discount global warming as a contributing factor in the acceleration. We are featuring your submission on our home page banner.