When considering pests, we need to take a broader perspective. In this case, I noticed aphids on my catnip plant, then spotted the aphids and ants. What’s going on when aphids, ants, and ladybugs are on the same plant?

What Do Aphids Do?

Aphids are sap sucking insects that are very common on vegetables and flowers, and while catnip repels some pests, they are vulnerable to aphids. Aphids were thick on this particular plant, and it affected its growth, as evidenced by the curled and stressed tops.

What is the Role of Ants?

The ants, on the other hand, do not harm the plant at all. They are there for the aphids. Ants stroke the aphids with their antennae to encourage them to produce a sweet substance called honeydew, which ants love to eat.

Farmer Ants and Their Aphid Herds

The crazy thing is that the ants actually farm the aphids, sometimes leading them to more desirable parts of the plant where the aphids find better food sources. There are also instances where the ants clip the wings of aphids to prevent them from flying to a new source. We don’t often consider this complex relationship with insect species.

Ants also defend aphids from their primary predator, ladybugs. When possible, they’ll herd them away from ladybugs, but when push comes to shove, they’ll aggressively confront the ladybug head-on.

Can Ladybugs Be That Bad?

It makes sense for the ants to try to keep the ladybugs away from the aphids because ladybugs will consume up to 50 aphids per day. On the insect level, that is a lot of sugary little treats.
The reality is that ladybugs are enemies of the aphids from pretty much day one. The larvae, which resemble mini alligators, are voracious aphid eaters, devouring 100 everyday.

How to Handle the Situation

It’s a good thing to have the ladybugs on the scene, but the challenge is to eliminate, or at least reduce, the number of ants without killing the ladybugs.

Many of the go-to remedies for discouraging ants, such as vinegar or diatomaceous earth, can also be problematic for ladybugs. The best approach is to bait the ants specifically. In this case, you need to coax them with sugar.

Borax, the kind we use in laundry, disrupts the ants’ digestive system and ultimately kills them. Mix 2 tablespoons of borax with 2 cups of white sugar and 1 cup of water. Pour this mixture into shallow saucers or wax paper placed on the ground near the affected plant to attract the ants away from the aphids. There is no guarantee this sweet temptation might be enough to dissuade them from tending to the aphids, but it’s worth a shot.

By reducing the ant numbers, it can allow the ladybugs to do what they do best: eat aphids.

Getting Rid of Aphids

If you want to eliminate all of the aphids, the good news is that they are easy to kill. The first step is to take a hose and blast them with water, using your fingers to rub away the aphids as you go.

Eliminating Mealy Cabbage Aphids

For a more severe infestation, grabbing a bottle of insecticidal soap is also a good course of action, or using Neem oil on the plants.

Aphids are a nuisance, but it’s best if you can let nature take its course in its fascinating balance.