Were you around when the cicadas were all over the east coast? Learn some cool facts about cicadas so you know more next time you see them! #STEMvee
[Video Description: Alicia, an Asian woman wearing a dark green short sleeve top, is sitting in the foreground. The background has light brown wood paneling. On left side is a plant and lamp. The right side has a ladder and a black shelf of several plants.
1:36 – a photo (top right) of a cicada in three stages, left is a cicada nymph, the exoskeleton of a cicada, and an adult cicada
2:00 – a photo (top right) of a white cicada underground molting from a brown exoskeleton shell
5:50 – a full screen image: This video is sponsored by RIT/NTID Regional STEM Center. Below is a logo of RIT on the left with National Technical Institute for the Deaf on the right]
Transcript: Do you live on the east coast? Were you surrounded by thousands of flying insects back in May? Have you heard about the brood X of cicadas that come out every 17 years? Were you like me and said you’ll stay inside until they’re gone but eventually they grew on you? We may be a little late, but here are some cool facts for the next time you see a cicada. This year, 2021, marked the emergence of billions of cicadas from the ground at the end of their 17-year life cycle. On the east coast, this 17-year emergence is from Brood X. However, this is not the only brood and there are 12 other 17-year broods, each emerging in different areas every 17 years. There are also 13-year cicadas as well and even annual cicadas. The life cycle of these periodical cicadas starts with adult cicadas depositing eggs on tree branches, which we experienced this past May. These eggs will hatch to reveal nymphs that will fall to the ground and burrow into the soil. From there they spend years feeding on the fluids sucked from the roots of plants and trees. During this time, they shed their exoskeleton, a process called molting, five times over the years. Eventually, they rise up from the dirt following the light to repeat the life cycle. The time they spent in the soil is crucial for trees because they aerate the soil and provide nutrients for these trees. Cicadas emerging out of the ground together is part of their survival strategy. By emerging together, billions of cicadas overwhelm their predators and these predators cannot eat them all, which means some of these cicadas will be able to mate and reproduce unbothered. Why do cicadas emerge periodically? Some hypothesize that by having a long life cycle, cicadas can prevent predators from matching their reproductive timing. For example, a 12-year cicada species could be wiped out by any predator species with a 2-, 3-, 4-, or 6-year life cycle because each cicada emergence would be met with a boom in the predator population. So for the 13- or 17-year cicadas, no predator life cycle matches theirs, thus allowing these cicadas to survive. But how do 17-year cicadas, for example, know when to come out? When they feed on the liquid in the roots, cicadas can detect when there is an increase of fluid flowing through the roots. This happens during the spring growing season for plants. After 17 cycles of this, they wait for the soil to reach 64 degrees and then they begin digging towards the ground. However, climate change may contribute to some stragglers — periodical cicadas that emerge earlier than expected. Some scientists believe that longer growing seasons and warming weather could be confusing to cicadas, causing them to emerge earlier. More time and data are needed to know if there is an effect. In addition to periodical cicadas, there are cicadas that emerge every 2 to 5 years. Among more than 3,400 species of cicadas, only 7 species make up the 13- or 17-year cicada broods, and they are found only in the US. The rest emerge every 2-5 years with the same goal. Wild! Over the next few years, see if you can catch an annual cicada and keep an eye out for the next brood swarm!
