They’re noisy and they’re disgusting looking. The buzzing sound from the trees is a springtime staple in North Alabama. They dive bomb unsuspecting pedestrians. Their carcasses litter the sidewalk.
Meet the cicadas.
Matt Candeias, environmental protection specialist in the Garrison’s Directorate of Public Works environmental division, answered our questions about these nuisance insects.
“Thanks for giving these wonderful bugs some attention,” he said.
What’s making all the buzzing noise in front of Garrison headquarters building 4488 and along the Redstone running trails?
Answer: All that buzzing you are hearing around Garrison headquarters and, indeed, throughout the entire region are the calls of the Brood XIX cicadas. There are three different species currently calling right now and each can be distinguished by the sound it makes.
Why are the cicadas noisier than ever this spring?
Answer: This year is a special year for these cicadas. Brood XIX are periodical cicadas, which means they don’t appear every year like annual cicada species do. Instead, these three periodical cicada species spent 13 years underground drinking sap from plant roots. Every 13 years, these species emerge to mate and lay eggs. Research suggests this mass emergence provides the cicadas safety in numbers. While many get eaten, far more live long enough to reproduce. The reason they are so noisy is because there are literally millions of cicadas calling from trees and shrubs.
How prevalent are they in the U.S. and in the southern U.S.?
Answer: Cicadas as a whole are widespread, with species occurring all over the world. The species that make up Brood XIX are unique to the USA. They only occur in the Southeast and parts of the Midwest. We just don’t see them because they spend most of their lives underground and only emerge to mate every 13 years.
Are cicadas more common during certain times of the year? Why is that?
Answer: Brood XIX cicadas will only ever emerge in the spring. However, Alabama is home to many other cicada species that tend to emerge at various times throughout mid- to late-summer. The reason is because adults only live a couple weeks and need to find a mate during that very short window of time. By emerging together, each species is able to maximize their chances of being able to find mates.
What nuisance do they pose, other than the noise? Sometimes we see their carcasses on the sidewalk.
Answer: Other than noise, cicadas pose no threat to anything, including humans. Females can damage small twigs when they lay their eggs, but this generally doesn’t affect the trees and shrubs in any serious way. In fact, cicadas are an important part of the ecosystem, especially those of Brood XIX. All but the strictest herbivores have cicadas on the menu this year. Millions of cicadas mean most wildlife are not having any trouble finding food this spring and are better able to raise their own young as a result. Birds, turtles, fish and more can be found gorging themselves on cicadas. In fact, these animals are going to have a boom year of their own thanks to all the nutrients they get from eating cicadas. Turkeys are especially benefiting from the Brood XIX emergence. As they emerged from the ground, the juvenile cicadas left behind burrows that help aerate compacted soils and allow water to infiltrate and recharge aquifers. The adult cicadas that aren’t eaten will eventually die and fall to the ground, and their bodies will provide a lot of much-needed fertilizer for trees and other plants. Researchers have found that trees like oaks often produce bumper seed crops in the years following a mass cicada emergence. Altogether, this is a very important event for our local ecosystem.
How long do cicadas live? What are their mating habits? Why do we notice them more in the springtime?
Answer: Cicadas live many years, but most of that time is spent in their immature phase underground where we can’t see them. They grow slowly because sap is low in nutrients, and they need to build up a lot of energy to emerge as adults and mate. We only start to notice them when they emerge and mature into their adult form. Males gather on the branches of trees and vibrate special muscles that create the buzzing sound we can hear. All that buzzing attracts the females, which only make subtle clicking sounds that let males find them. After mating, the males will soon die followed by the females once they have laid their eggs in the tips of branches. The whole adulthood of a cicada only lasts a couple weeks.
Do they carry diseases or germs? Do they sting or bite?
Answer: Cicadas do not carry any diseases or germs that can affect humans or other animals. They do not sting, and their mouths are adapted for sucking sap from stems and twigs. Therefore, they cannot bite and are completely safe. Think of them as the gentle giants of the bug world.
Anything else you can tell us about those noisy little creatures?
Answer: Cicadas are very important for our ecosystem. They bolster life around them and their beneficial impacts on the environment will be felt for years to come. Brood XIX is also very special. It will be another 13 years before their offspring will emerge again and we are very lucky to experience such an amazing natural event. Insects like cicadas are great indicators of how well we take care of the environment. If they were to disappear, we would really have to start worrying about our own future.
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