There are about 29 species of cicada in Colorado that range in size and color. They often have black bodies with varying shades and patterns of brown, white, green, or red. Some commonly observed cicadas in Colorado include Megatibicen spp., Platypedia putnami, Cacama valvata, and Okanaga bella. The Megatibicen spp. are relatively large at 2.5–4 cm (1-1 1/2 inches) long, while other species are only about 1.3 cm (1/2 inch) long. Adults have very short antennae and four transparent wings that extend beyond the abdomen and are folded over the back at rest. The immatures, called nymphs, are different shades of brown and live underground where they feed on plant fluids by piercing the roots of grasses, shrubs, and trees.
- Cicadas are large insects that do not bite or sting. They spend most of their lives underground as nymphs.
- Although cicadas can occasionally injure plants while laying eggs, it is not typically a cause for concern as mature healthy plants can tolerate the injury.
- Young susceptible plants can be protected with preventative netting. Aside from this, there are no management recommendations for cicadas since they do not cause significant injury to plants.
Adult of Platypedia putnami. Note the clear wings that extend beyond the tip of the abdomen. Image credit: William M. Ciesla, Forest Health Management International, Bugwood.org
Cicada eggs arranged in rows. Image credit: Lacy L. Hyche, Auburn University, Bugwood.org
Cicada nymph. Image credit: John Ghent, Bugwood.org
Adult cicada emerging from nymphal case. Note the white appearance and collapsed wings of the adult cicada. Image credit: Joseph OBrien, USDA Forest Service, Bugwood.org
Tree injured by oviposition behavior of cicadas. Image credit: USDA Forest Service – Forest Health Protection Intermountain Region – Ogden, UT , USDA Forest Service, Bugwood.org
Life history and habits
All cicadas have three life stages: egg, nymph, and adult. The mating calls of cicadas can only be heard during the day and are produced with a structure called a tymbal on the abdomen, or by rustling of the wings. Often, cicadas are more easily heard than seen as males produce a loud buzzing, shrill, rustling, or clicking noise to attract females. After mating, females use an ovipositor to cut an egg-laying site in small twigs and branches. Newly emerged nymphs tunnel into the soil in search of small roots to feed on. Cicadas overwinter underground as nymphs. Mature nymphs emerge from the ground and crawl upward on tree trunks, posts, fences, and the sides of buildings where they molt into adults, leaving behind exuviae (shed skins). The newly emerged adults remain inactive for several hours while blood is pumped to the wings and the exoskeleton hardens. Cicadas typically live four to six weeks after emerging from the soil, depending on the weather.
Cicadas are some of the most long-lived insects, and most of their development occurs underground. In Colorado, most species require three to five years to fully develop. Although not found in Colorado, the periodical 17-year and 13-year cicadas are very long lived. They occur east of the Mississippi river and emerge in large numbers every 17 or 13 years.
While cicadas do not usually cause significant injury to plants, oviposition behaviors produce puncture wounds that can cause twigs to break and die. One species, Platypedia putnami, can significantly injure plants when large numbers of females seek oviposition sites.
Deploying netting over young susceptible plants can help prevent oviposition injuries. Several natural enemies of cicadas occur in Colorado. The cicada killer wasps (Sphecius spp.) inhabit southeastern and southwestern parts of the state. These wasps paralyze adult cicadas and transport them back to nest cells to provide food for their young. One species of beetle, Sandalus niger (family: Rhipiceridae), is a parasite of cicada nymphs. Vertebrate predators such as birds and small mammals will also feed on cicadas.
Gaye, W. 2017. Cicada Fact Sheet. Maryland Department of Agriculture. Available https://mda.maryland.gov/plants-pests/Documents/Cicada-Facts-2017.pdf
Hahn, J. 2018. Cicadas. University of Minnesota – Extension. Available https://extension.umn.edu/yard-and-garden-insects/cicadas
UCIPM. (n.d.). Pests in Gardens and Landscapes. University of California Agriculture and Natural Resources. Available https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/INVERT/cicadas.html