The 17-year Cicadas are here! Get the nets and fire up the grill?


Posted by justtracy | Posted in Gardening, Insects | Posted on 09-05-2013

17 year cicadas

Photo: 17-year cicada on my Rhododendron “Northern Hi-Lights” (Northern Hi-Lights Azalea). Getting his bearings I believe before the mating season heats up, baby.

The 17-year cicadas will emerge in areas of Virginia this year and specifically, in Spotsylvania County where I live.  I have seen a significant amount of holes as evidence and I have already seen at least three winged adults and several more nymphs freshly out of those holes stumbling around. Stomp!

I have done a lot of reading on these insects to prepare myself for their arrival and take necessary precautions. They leave their underground homes and make their way up to daylight when the soil is precisely 64 degrees.  I have not heard their mating call yet however.

Their peak mating season/noise will be mid May to mid June.  It is about 5 days after you hear the males only ‘sing’ to attract females that the females will begin to lay egss. This is where the situation gets unpleasant for a woody ornamental and tree lover like myself with lots of new young plants in my yard.

The females have a sawlike apparatus to slice open twigs of trees and woody ornamentals to lay their eggs in. This is where the damage occurs. This usually leads to flagging where the end or the entire twig will die. They are particularly drawn to a sturdy, woody twig that is 1/4″ minimum to a 1/2″ maximum size.  They usually seek out Maples, Oaks, Hickories, and Fruit trees including ornamental trees. They also will use berry producing trees and shrubs like Dogwoods and Serviceberries.

Older trees are usually not significantly affected by these insects and can tolerate some damage without stress. One or two cicadas aren’t going to affect a young or ornamental tree or shrub. But a heavier volume can cause significant damage. The best advice is to be aware and assess the situation before you take action.  When you hear the cicadas, and you have trees or shrubs that are of concern to you, check them every couple of days for cicadas or flagging (noticeable dying of a twig due to the split created by the female to lay eggs). If you suspect or know that you will have a heavy presence, the most recommended method for control is a net with 1/4″ or smaller openings to cover the tree or shrub.  These nets are commonly sold at lawn and garden centers as bird netting. I have also seen the use of cheesecloth used as a cover as well.

There are also some pesticides that can help as well, especially those with active ingredients Permethrin. Only use if you have significant infestation and damage and read and follow the label. And there has been some research on the active ingredient Imidacloprid used as a systemic that shows it may decrease the amount damage caused by females. For more information on control methods, see Resource links below.

They are out and about a relatively short time so that by the end of June or early July, they will all but be a memory. Where did they go? The adults die and the eggs in the twigs hatch and fall to the ground where they burrow into the soil where they will live for 17 years. And repeat.

Why do we not get so worked up about the annual cicadas? Birds typically can handle them on their own. They love  them. But the periodic cycadas usually provide such a feast that they overwhelm our feathered friends ability to consume. And fishermen? Get your cicada flies ready. Fish also love to pounce on them as well on low branches over streams. And they 17 year cicadas are known for being loud. Really really loud.

And a side note: In my research I did read a blog from a wedding website that has actually advised all brides-to-be to avoid getting married outside in June if you are in an area affected by the 17-year cicadas. If you are attending one of those outside wedding, you may want to take your own veil.

Oh, and apparently they are pretty tasty. Gag. See link at bottom of resources for recipes.

A few facts.

They are not Locusts or even related. Locusts are swarming species of short-horned  grasshoppers in the family Arcididae in the order Orthoptera. (see

17-year cicadas are Magicicada, a genus of the 13-year and 17-year periodical cicadas of eastern North America in their only family Cicadidae and order Hemiptera. (see

Some form of cicadas do occur every year and are known as annual cicadas. Most are familiar with the species called ‘dog-days cicadas’ that come out mid summer. My mom always used to say when you heard those cicadas, it meant summer was half over. :-(

They do not eat that much. Nymphs in the ground feed on tree roots but damage is minimal and the adults feed very little during their short time mating. So damage to other perennials, annuals, vegetables or crops is not a consideration.

They do not sting or bite or swarm people or animals. They are looking for each other to mate in a short amount of time, so their activity and numbers can be creepy.

Resources for further information
(Note: Check with your state extension website for the facts on Cicadas in your area)

Virginia Cooperative Extension Fact Sheet: Periodical Cicada

Virginia Tech New: Cicadas Invasion bugs some, excites others

University of Illinois Extension: Cicadas

Are you a fan of Cicadas?  Check out this site for everything you ever wanted to know about them:

The Gardner’s Network: Control of the 17-year cicada

Shrub Nets for Cicadas: TGN Pumpkin Nook

Permethrin: National Pesticide Information Center: Permethrin

From the Department of Entomology, University of Maryland: Comparison of Exclusion and Imidacloprid for Reduction of Oviposition Damage to Young Trees by Periodical Cicadas (Hemiptera: Cicadidae).

If you can’t beat ’em, eat em!  See: