Pest of the Month: Aphids
Interested in learning more about the most common pests that you may come across on trees in North America? We are going to discuss one specifically every month to give you as much information as possible. This month’s pest is aphids.
We are going to talk about what aphids are if you don’t know, as well as what harm they can do to trees and plants, and how to get rid of them safely. Let’s first start with what these are.
What are Aphids?
Aphids are fairly small, growing up to about an eighth of an inch long, pear-shaped, soft bodied insects that vary in color. Depending on their food source and species, they can be black, brown, red, green or yellow.
Typically these bugs are wingless, but some are able to grow wings if the populations are high. They have two antennae at the tip of their head that are almost whip-like, and a pair of tube-like structures called cornicles projecting out of their back end.
When aphids feed, they secrete very large amounts of a sticky fluid that is known as honeydew. This overly sweet goo will drip onto plants and attract ants, as well as promote a dark sooty mold growth on leaves. If you have cars or outdoor furniture underneath infested trees they will also be covered with this sticky substance.
These insects are members of the superfamily Aphidoidea , and they are commonly known as the greenfly and blackfly even though their colors can vary widely. Their typical life cycle involves flightless females giving birth to female nymphs without male involvement. They then mature rapidly and breed and multiply quickly. In more temperate regions, there is a phase of sexual reproduction that occurs in the autumn season, with the insects overwintering often as eggs.
Because they can multiply so rapidly by asexual reproduction, they can become a big problem pretty quickly.
How Do Aphids Damage Your Trees?
So how do these pests damage your trees?
Typically, if you only have a few or even a moderate amount of leaf-feeding aphids on your trees or in your garden, you won’t have to deal with too many issues.
However, if you have a large group of aphids in your yard, they can cause your leaves to turn yellow and stunt shoots. On top of that, they can also produce quite a large quantity of sticky honeydew, which will turn black with the growth of a sooty mold fungus.
Not all, but some species of aphids can actually inject a toxin into plants, which causes the leaves to curl and will further distort its growth. A few other species can actually cause gall formations as well.
Aphids can also transmit viruses from plant to plant when it comes to specific vegetable and ornamental plants. Examples of these plants are melons, pumpkins, cucumbers, squash, beans, potatoes, chard, beets, lettuce, and bok choy. These viruses can yellow, mottle, or curl leaves and stunt the plant’s growth. These losses, especially with a large garden, can be huge, and they are also difficult to prevent because this can happen even with just a few aphids.
Some aphid species attack parts of plants other than the shoots or leaves as well. The lettuce root aphid is actually a soil dweller that attacks lettuce roots in the springtime and early summer, which causes the plants to wilt and sometimes even die. In the fall, this same species moves to poplar trees and overwinters in the egg stage and produces leaf galls on it in the spring.
The woolly apple species of aphids infest woody parts of apple limbs and roots, especially near their pruning wounds, and this can cause overall decline in the tree’s health if they’ve been infested for several years.
Having a heavy infestation of root and crown aphids on carrots can weaken their tops, which cause them to tear off when the carrots are harvested.
The list truly goes on and on, but these are the most common issues that come from certain kinds of aphids.
How Do You Get Rid of Aphids?
So now let’s talk about getting rid of these pests. There are many different solutions , so you have choices when it comes to removing them.
If your population isn’t too large, you can simply heavily prune and cut away the populated areas of your trees. This will only be convenient if you have a smaller population, but it is the most direct way of getting rid of these pests.
You can also use insects to get rid of aphids, believe it or not. Commercially available options include lacewing and ladybugs, as these bugs are fantastic natural predators. The best results will come about when you use these bugs with lower to medium pest levels. If populations are pretty high, use a least-toxic natural pesticide to establish control and then release the bugs to maintain it.
For large populations of aphids, you will need to break out some sort of insect killer to control the mass spreading of the bugs. Something like Diatomaceous Earth Powder does a great job of killing off the pests while not using any toxins that are harmful to kids or pets.
Our Final Thoughts on Aphids
We hope you found our guide to aphids helpful, and that you are able to contain them in your garden and landscaping. If you do find that you need additional help with getting rid of these bugs, don’t hesitate to contact us today for help!