Even though there are over 1,300 species of insects called cicadas, the ones that we know the most about are the annual or Dog-Day cicada and the 17-year periodical cicada.
Annual cicadas, which are the ones we hear at dusk during mid-July and August, have a life cycle that lasts for 2 to 5 years, but adults will emerge every year. Cicadas emerge at different times throughout the summer and they rarely emerge in large numbers at one time.
The other cicada is the periodical cicadas that resurface every 13 to 17 years. They are loosely categorized into Broods as they emerge within specific areas during different years across most of the US.
Both of these cicadas inflict the same type of damage to trees and large shrubs. They damage the plants both above and below ground. The female lays her eggs into slits she makes using her ovipositor into the tips of tender young branches.
The periodical cicada causes more damage than the annual cicada, so it is fortunate that these cicadas come out on such an infrequent basis. When the female makes the slit, she deposits 20 to 30 eggs. She will continue making these slits and depositing eggs into the same branch or on other branches. She will continue laying eggs for two to four weeks and can deposit up to 600 eggs. All this feeding can result in a condition known as flagging, where the tips of the branches die from the damage of the egg laying process. This does not kill the tree, but can make it look unsightly.
Six to ten weeks later, the nymphs, or larvae, hatch and drop to the ground. They burrow 6 to 18 inches into the soil, attach themselves to a tree root and slowly begin to feed on plant roots, by feeding on the sap of the roots. They will move within the soil profile and can reach depths of 8 feet. Depending on the species, this feeding will last for up to 17 years before they emerge and start the whole process again.
Controlling cicadas is usually not recommended for the average homeowner. The annual cicadas usually do not inflict enough damage to be a concern to the overall health of the trees in a home landscape.
Brood V is expected to emerge this year in the areas designated by this map. If you live in this area and have smaller trees, you may want to cover them with nylon netting or cheese cloth. The netting should have a mesh no larger than ¼ inch. Cover the tree when the first song from the male is heard and leave it on the tree for 4 weeks or until the last of the singing stops.
Chemical control is available, but, due to the large populations and the mobility of the cicadas, it is often difficult to actually make an impact. If you choose this route, many of the commercially available insect control products that are labelled to spray on trees and shrubs will work on cicadas.
Be sure to read the label first before purchasing or using the product and do not spray any blooming trees or shrubs to protect pollinators, such as honeybees.
Having lived through 3 generations of periodical cicadas, the damage that was actually seen was minor. When they do emerge, a feeding frenzy ensues and just about every animal joins in the “feast”. Dogs, cats, raccoon’s, opossums, skunks and other animals will gorge themselves on cicadas. They make an incredible amount of sound during the day. Often times, the chirping of the males can be heard inside a car even with the windows closed and the A/C on. They can be bothersome, but the experience is quick and it can be a story you can tell to future generations.