Should you worry that Cicadas are bad news for your garden? This article explores everything you should know about these insects and their destructive capabilities.
After spending 17 years underground, here they come again. A new brood of periodical cicadas has officially made its appearance in people’s backyards.
Known as Brood X, these insects have been feeding on sap from the roots of underground plants for the past 17 years. Now, as they are emerging to the surface, they will be spending a couple of weeks here courting, mating, flying, and making gardeners worry about their outdoor spaces.
Yet, the truth is that Cicadas are mostly harmless to gardens. Experts offer mixed opinions on the subject of whether or not these insects pose a real threat to our gardens. But, generally, it is believed that the worst they can do is cause some minor damage.
Before we dig deeper into how cicadas can affect your plants and what you can do about it, let’s first learn more about these insects. Keep reading our article to find out more!
What Do We Know About Cicadas?
Cicadas are oval-shaped, flying insects that produce a buzzing and a clucking song heard in nature throughout summer. While most cicada species emerge every year, some have a very interesting life cycle, only appearing every decade or so.
Here are some interesting fun facts to know about cicadas, that will help you to better understand these insects:
- Cicadas have been around on earth since the age of dinosaurs.
- Cicadas’ appearance can vary depending on the species. Some can be black, brown, or green, and they feature either red, white, or blue eyes.
- The cicadas’ species that emerge above ground only every decade or so live primarily in the eastern and central US.
- Only the cicada males create the buzzing sound, and they do so to call for female cicadas to mate.
- Some cicada mating calls can be heard up to 1 mile (1.5 km) away. Each species of cicadas has a unique song.
- Some songs of cicadas can reach 90 decibels which is roughly the same level as a lawnmower.
- These insects are herbivores, meaning they only eat vegetation. While young cicadas feed on the sap of plant roots, moulting cicadas eat twigs, and adult cicadas don’t feed at all.
- Cicadas do not sting or bite. These insects don’t have the mouthparts to do that. They only feature a long, straw-like tube that they use to suck liquids from trees and other plants.
- Cicadas can be cooked and consumed by people. They aren’t toxic for pets and humans, as it is believed. In fact, they make a great snack and a good source of protein.
Why Do Cicadas Emerge?
For over a decade, cicadas that are part of certain species lie dormant in the underground. But why do they emerge after such a long time?
The emergence of cicadas is not a strange phenomenon but a natural one that has been happening for tens of thousands of years. Annually, as the weather gets warmer in the US, people start hearing the familiar buzzing and clicking of cicadas. But, once in a decade or so, the number of cicadas that emerge at the surface grows to millions of winged insects that come out at once. They fly around, courting and mating for about a month, and then they die. This year, too, a group of cicadas called Brood X is emerging to the surface in several states for the first time since 2004. The Brood X is among the largest broods of these insects that have a 17-year life cycle.
There are 3,000 species of cicadas globally. Yet, only seven of them share a synchronized life cycle that makes them emerge from the underground every 13 or 17 years. While above ground for several weeks during the summer, cicadas will fill outdoor spaces across the US, which might be driving gardeners like you crazy for not knowing whether their gardens are safe or not.
Do Cicadas Affect Your Plants?
Short answer: not that much! Surely not like locusts do.
As a gardener, you might be really scared that the masses of cicadas that emerge from the underground can harm your plants. The truth is that crop destruction is more of a reputation that suits locusts rather than cicadas.
Although very loud and numerous, cicadas don’t really have the ability to do much damage to plants and crops. That’s because the only reason for their emergence is to mate. Eating plants is likely one of the last things on their to-do list after digging their way out of the soil.
In fact, cicadas might actually help your plants. When they die, after flying around, mating, and laying eggs, their decomposing bodies might make an excellent fertilizer for your garden. More precisely, their bodies have a lot of nitrogen in them, which, after they die, can act as a nitrogen-rich fertilizer.
Cicadas do eat plant roots, but the damage brought to the roots, which is very often not too serious, is done during the years previous to their emergence. However, adult cicadas can do some damage to certain plants as they look for places to lay their eggs while ignoring others. More precisely:
Bushes and young trees can be most affected
If there are some plants that can be more prone to damage caused by cicadas, that can be bushes and young trees.
Cicadas drink sap from plants that feature woody stems and branches, which are the same places where they lay their eggs during the four weeks spent above the ground. The issue is that they don’t look for a particular species of young wood plants to lay their eggs. They can attack all types of plants, from sapling trees to ornamental shrubs, blueberries, grapevines, or bramble fruits.
For healthy adult trees, cicadas’ attack doesn’t represent major damage that may kill them. Yet, for young bushes and trees, which are more vulnerable to damage, the attack of cicadas might be life-threatening.
Besides sucking the sap from these plants, cicadas also cut slits in tree branches, a phenomenon that is known as flagging, to lay their clutches of eggs, where female cicadas can deposit up to 600 eggs in clutches of 25 at a time.
Lawns are protected
Cicadas that will end up in your garden are going to leave your precious lawn alone. They do not feed on liquids from grass, and they also do not lay their eggs there.
The only “damage” they can bring to your lawn is that you’ll find some cicada emergence holes, about half-inch wide, on the ground. And, although these holes can be annoying and mess with your lawn’s appearance a little bit, they do not do represent permanent damage.
How To Protect Your Garden From Cicadas?
Although there isn’t much to protect in your garden from cicadas, some plants that are more vulnerable even to the minor damage caused by these insects might appreciate a little bit of help from you.
As with all potential problems that plants may face, prevention is the best way to avoid damage from cicadas. So, if you live in an area where masses of cicadas are expected to emerge any time soon, you should better delay planting young trees until the moment they finish their work above the ground and die.
Protect plants with physical barriers
If you already grow bushes and young trees in your garden, your best bet is to protect them from cicadas with physical barriers. For example, you can use netting to protect your young trees and shrubbery by keeping the adult cicadas away from laying eggs in their branches. You can use fine mesh insect netting to cover all your vulnerable plants or barrier plant bags for individual trees and shrubs.
Don’t use insecticides
As it is with any other pest, you may be thinking that the best way to keep cicadas away is to use chemical insecticides. Keep in mind that this doesn’t really work when it comes to cicadas. First of all, these insecticides are simply not even as effective as netting is. Besides that, all the chemicals will only damage your young trees and bushes more.
What’s more, to keep cicadas away from your plants with chemical insecticides, you’d have to apply them every two or three days for the entire period when cicadas are around. That will not only cost you a lot but will also affect other beneficial insects and pollinators.
Take extra care of damaged plants
If you can’t stop cicadas from causing a little damage to your plants, at least make sure that you take extra care of your damaged plants to help revive them. Affected trees and woody plants need extra mulch and water to recover.
Bottom line, cicadas aren’t actually bad news for your outdoor space and the plants you grow. Although they can cause some harm to your young plants as they lay their eggs, it’s typically not a major concern for healthy plants and trees. So, instead of worrying about these insects, you can relax and observe their fascinating life-cycle.