Cicadas

Cicadas, probably both Magicicada septendecim and Magicicada cassinii have arrived in southwestern Virginia. In Virginia there are eleven primary broods of the 17-year cicada and two primary broods of the 13-year cicada. Every year they will emerge somewhere in the state, but Brood X due in 2021 is one of the largest and impacts our area in Northern Virginia including Prince William, Loudoun, Fairfax, and Fauquier counties.

It is not until next spring that we will hear the “song” which is the mating call of the males. For most people, the droning song of the cicada is nothing more than a slight annoyance, which only appears ocassionally. To me the “song” sounds like wind on a cell phone connection, but you can listen to the actual chorus on the u-Tube video. Male cicadas sing quite loudly by vibrating membranes on the sides of their abdominal segment. Male songs and choruses are a courtship ritual to attract females for mating. If you hear the cicadas chorus in the spring report the finding to Magicicada.org. Most people are more familiar with the dogday cicada that is prevalent annually in mid summer. Their song is later in the summer and not as persistant.

The annual dogday cicada is a mottled, dark green color. The 17 year or 13 year periodical cicada is black, with red eyes and orange legs. “Adults have clear wings with distinctive orange veins. When viewed from the front the wings form an inverted "V" and meet at the top like a roof.”

Both the 17-and 13-year cicadas damage many ornamental and hardwood trees. Oaks are commonly attacked but the most seriously damaged are newly planted fruit and ornamental trees such as apple, dogwood, peach, hickory, cherry, and pear. Pines and other conifers are not commonly attacked. This fall will not be a good time to plant any of these trees in our region as they may be damaged next spring when Brood X emerges. 

Brood X due next in 2021

Cicadas do not pose a danger to these plants through feeding, but instead through their egg-laying habits. Cicada females select pencil-width branches or vines, then implant their eggs into them using a sharp egg laying tube called an ovipositor. The nymphs then hatch from the eggs and drop down to burrow into the soil where they begin harmlessly feeding on the plants’ roots. The egg implantation causes the branch or vine to split and wither, a phenomenon known as “flagging” where a group of leaves on an otherwise healthy part of the plant turn brown and die. For a small tree or young vine, too many flagging sections can stunt their growth or even kill them outright.

Damage from Cicidas 

Cicidas  Image from VA Tech