{"id":780,"date":"2024-05-08T09:23:18","date_gmt":"2024-05-08T13:23:18","guid":{"rendered":"https:\/\/site.extension.uga.edu\/fultonag\/?p=780"},"modified":"2024-05-08T14:29:51","modified_gmt":"2024-05-08T18:29:51","slug":"whats-the-buzz-about-periodical-cicadas","status":"publish","type":"post","link":"https:\/\/site.extension.uga.edu\/fultonag\/2024\/05\/whats-the-buzz-about-periodical-cicadas\/","title":{"rendered":"What\u2019s the Buzz About Periodical Cicadas?"},"content":{"rendered":"\n

Have you heard about the impending cicada-pocalypse? In May, periodical cicadas, which only emerge once every 13 years, will be crawling out of the ground across the southeastern U.S.<\/p>\n\n\n\n

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After emerging, adult cicadas form large groups on trees and shrubs; image by the author in Troup County, 2024<\/figcaption><\/figure>\n\n\n\n
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Adult periodical cicada; image by the author in Troup County, 2024<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

So What?<\/h2>\n\n\n\n

Perhaps you\u2019re thinking, \u201cI see cicadas every year. What\u2019s the big deal?\u201d Those cicadas you see every summer and fall are annual, or dog-day, cicadas, which emerge on an annual basis.<\/p>\n\n\n\n

Periodical cicadas are more special. They are unique to eastern North America and found nowhere else in the world. They only emerge from the ground every 13 or 17 years, depending on their brood. Broods are separate populations of cicadas that emerge on the same cycle.<\/p>\n\n\n\n

Brood XIX (\u201cnineteen\u201d), also called the \u201cGreat Southern Brood,\u201d are 13-year cicadas set to emerge across the Southeast this year. Small areas throughout central Illinois will see a dual emergence of Brood XIX and Brood XIII (\u201cthirteen\u201d). The last time these two broods\u2019 emergence matched up was in 1803, when Thomas Jefferson was president!<\/p>\n\n\n\n

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Map of periodical cicada broods in the United States. Brood XIX (light blue) will be emerging in Georgia this year; Source: US Forest Service<\/figcaption><\/figure>\n\n\n\n

In Georgia, we will see a solo emergence from Brood XIX, but it\u2019s still pretty cool. Just because periodical cicadas only appear aboveground every 13 or 17 years doesn\u2019t mean they don\u2019t exist in the interim. In fact, they\u2019re alive that whole time, tunneling underground in their nymph (juvenile) stage and feeding on roots of hardwood trees.<\/p>\n\n\n\n

Cicada Life Cycle<\/h2>\n\n\n\n

On May nights, the cicada nymphs use their claw-like front legs to tunnel up to the soil surface. The nymphs immediately find the closest tree or shrub (or other vertical surface) and start climbing up, up, up. Most will stop within the first ten feet, latch onto the bark and begin to molt. First, they split their exoskeleton down the back, then lean backwards and squeeze their new, adult body through the fissure. They hang belly up for a while and use gravity to help their wings unfurl. Over several hours, the cicada pumps hemolymph (insect \u201cblood\u201d) into its expanding wings until they are full size. Meanwhile, the exoskeleton cures, hardens and develops its bright colors.<\/p>\n\n\n\n

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Adult cicada squeezing through the back of its exoskeleton; image by the author in Troup County, 2024<\/figcaption><\/figure>\n\n\n\n
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The “shell” of the cicada nymph, called an exuvia, is left behind after the adult emerges; image by the author in Troup County, 2024<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Millions of individual cicadas will emerge like this over the next several weeks, and scientists still don\u2019t know how they accomplish this amazing synchronicity.<\/p>\n\n\n\n

After the wings harden, the cicada can fly up into the tree canopy and begin its ultimate objective: mating! The buzzing you hear is a mating call made by males as they try to lure in females. These deafening calls can reach up to 90 decibels, or as loud as a lawnmower. Once a pair deem each other suitable, they mate.<\/p>\n\n\n\n

The female uses a serrated structure called an ovipositor to saw small slits along the tips of branches, where she lays her eggs. The adults die soon after and will all be gone by June. The eggs remain inside the protected crevices for six to ten weeks until the new nymphs hatch. They drop down to the ground and tunnel into the soil to begin their 13-year-long development. Thus, the cycle continues.<\/p>\n\n\n\n

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Female cicada using her ovipositor to lay eggs in a twig; Image by Laura Jesse, ISU Plant & Insect Diagnostic Clinic<\/figcaption><\/figure>\n\n\n\n
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Oviposition “scars” left behind on a twig after female cicada laid her eggs; Image by Joe Boggs, OSU Extension<\/figcaption><\/figure>\n\n\n\n
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Cicada eggs laid inside a twig; Image by Joe Boggs, OSU Extension<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Because of this huge chunk of time they spend underground as nymphs, periodical cicadas actually have the longest development time of any insect species in North America. Talk about late bloomers!<\/p>\n\n\n\n

Are Cicadas Good?<\/h2>\n\n\n\n

Cicadas are great for our ecosystems. Their tunneling aerates our native soils, and the decaying bodies of the deceased adults act as a natural fertilizer.<\/p>\n\n\n\n

Not to mention the food source they provide. All these insects emerging at once is a bumper crop for predators. Nymphs and adults are tasty morsels for birds, fish, deer and other wildlife. Even dogs will eat them and may vomit if they binge too many (\u201ctoo much roughage at one time,\u201d says University of Georgia entomologist Nancy Hinkle). Still, there are more cicadas than our predators can consume, so some survive to sustain the population.<\/p>\n\n\n\n

It\u2019s worth noting that cicadas are not a threat to us or our pets. They are not poisonous, don\u2019t bite, don\u2019t transmit diseases and won\u2019t feed on crops. Egg laying by the females may cause aesthetic damage to branch tips, but this is not likely to harm your trees.<\/p>\n\n\n\n

Where to Find Them<\/h2>\n\n\n\n

Finding periodical cicadas can be a guessing game. In the Atlanta area, the US Forest Service says we may see Brood XIX in Fulton and Cherokee Counties. Surveys done by UGA entomologists during the 2011 emergence reported them in Fayette and Coweta counties.<\/p>\n\n\n\n

Regardless, you will only find them in hardwood forests that have not been disturbed in at least 13 years and likely longer. Look for mature forests with minimal soil disturbance that are relatively close to a stream or creek. The app iNaturalist is a great way to check if others in your area have reported seeing any.<\/p>\n\n\n\n

If you do see a cicada, how do you know if it\u2019s the periodical type? Periodical cicadas are mostly black with red eyes and orange-tinted wings, while annual cicadas are green with black eyes. Dr. Hinkle makes it even simpler: \u201cAny cicada you see before June is a periodical cicada; any cicada you see after June is an annual cicada.\u201d<\/p>\n\n\n\n

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Periodical cicadas are mostly back with red eyes and orange-tinted wings and emerge before June; Image by Pat Milliken<\/figcaption><\/figure>\n\n\n\n

If you happen to see one, note the date and location, and take a photo! Report your observations on iNaturalist, and send your photos to your local Extension agent for good measure. If you live in Fulton County, I am anxiously awaiting your email\u2026<\/p>\n\n\n\n

Contact Your Extension Agent<\/h2>\n\n\n\n

Gabrielle LaTora<\/strong>
Agriculture and Natural Resources Agent
UGA Extension Fulton County
gabrielle.latora@uga.edu
404-613-7670<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

Have you heard about the impending cicada-pocalypse? In May, periodical cicadas, which only emerge once every 13 years, will be crawling out of the ground across the southeastern U.S. So What? Perhaps you\u2019re thinking, \u201cI see cicadas every year. What\u2019s the big deal?\u201d Those cicadas you see every summer and fall are annual, or dog-day, […]<\/p>\n","protected":false},"author":458,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28,6,16,8,29],"tags":[],"class_list":["post-780","post","type-post","status-publish","format-standard","hentry","category-conservation","category-entomology","category-native-plants","category-soil","category-urban-forestry"],"_links":{"self":[{"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/posts\/780","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/users\/458"}],"replies":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/comments?post=780"}],"version-history":[{"count":3,"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/posts\/780\/revisions"}],"predecessor-version":[{"id":801,"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/posts\/780\/revisions\/801"}],"wp:attachment":[{"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/media?parent=780"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/categories?post=780"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/fultonag\/wp-json\/wp\/v2\/tags?post=780"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}