Whether you manage outdoor plants or you are an indoor houseplant enthusiast, there's a good chance you've come across aphids before. If you're new to managing plants, you may be wondering what aphids actually are. Keep reading to learn if these pesky critters are insects or arachnids, how big they are, and what their feeding behavior is like.


What do aphids look like?

Before we go into more detail about what an aphid actually is, let's talk about what they look like. Below are the common characteristics of aphids that you can use to help recognize them:

  1. Aphids are usually about 1/16th of an inch to 1/8th of an inch in length
  2. They have soft, pear-shaped bodies
  3. They can vary in color and may be green, yellow, red, brown, or black. The color can depend on the specific species of aphid as well as on the t ypes of plants they eat.
  4. Sometimes they can have a furry, woolly appearance due to a secretion of a white, waxy substance that covers their bodies
  5. You can distinguish aphids from other insects by the tube-like structures that project at the ends of their abdomen, referred to as cornicles. All aphids will have these structures though they may be less obvious on some specie s.

On its own, an aphid doesn't seem like it would be too much of a nuisance, especially considering its small size. But the issue is t hat aphids typically group together. In fact, groups of aphids can repopulate so quickly that some will have to abandon the stems and leaves that the group originated on in order to travel to another suitable host plant. Aphids generally walk from one plant to another, and there are some species that will produce winged aphids which will fly to find a new host plant.

What are aphids?

Aphids are a type of insect that belong to the Aphidoidea superfamily. In the animal kingdom taxonomy, this superfamily is within the order Homoptera, which includes other sap-feeding insects. There are around 32,000 species of sap-feeding insects in this order including:

  1. Aphids
  2. Cicadas
  3. Scales
  4. Mealybugs

Aphids fall in the family Sternorrhyncha, while cicadas and froghoppers fall in the family Auchenorrhyncha. S cales and mealybugs (also part of the Sternorrhyncha family) are also fairly common plant pests that can be a nuisance and cause damage.

Now that you know what aphids look like and what kind o f animal they are, let's talk a little bit more about their behavior and specifically about what aphids eat.

What do aphids eat?

Aphids are destructive to plants because they feed on plant sap. Aphids use their sharp mouthparts to pierce the plant they're residing on, and then suck out plant sap. Plant sap includes sugars, water, and other nutrients of the plant. When plants ar e deprived of these nutrients, they may start to exhibit the telltale signs of aphid damage. Some of these s igns include discoloration and yellowing leaves, weakened stalks and stems, and plant withering. Sometimes this damage can cause stunted and dead shoots as well as overall poor plant growth.

Ap hids can be damaging to your plants as they feed on them. The good news is that they themselves can be eaten by other common insects such as ladybugs, which can help keep the problem under wraps. Unfo rtunately, aphids also attract other creatures to your garden that can be a little more pesky than your average ladybug. Other pests that feed on aphids or aphid honeydew include parasitic wasps and a nts. If you find yourself dealing with unwanted garden pests, the good news is you're not alone.