Because there are so many species, they are grouped according to how they feed. Foliage caterpillars feed on leaves while others will eat flowers and fruits.
There are as many species of caterpillars as there are butterflies and moths. This is because they are the larvae form of these many and varied members of the Order Lepidoptera.
The most common, and well known, of these is the green caterpillar aka the Tomato Hornworm. It’s the larvae form of the Five Spotted Hawkmoth. It has green skin, horizontal lines, and a horn on its backend. The color and lines help it blend into leaves which are its favorite food.
What kind of leaves do they eat? The foliage of just about every plant on the planet, including trees and shrubs, but most of them only go after one kind of plant.
When they are just hatched, they will munch on the surface layers of tissue on leaves and when they get a bit older, they will devour the entire leaf to the stem.
These little buggers love the leaves of fruit trees as well as ornamentals like magnolia trees. They use silk to fold leaves together and then, they use these shelters to feed in relative safety.
Leafrollers are host-specific, meaning, they only go after the leaves of one kind of plant or tree. Leaf roller caterpillars can cause so much stress to the fruit tree it will either drop its fruit early or the fruit will have deformities.
The Mimosa Webworm is the one most people see on mimosa trees.
These little guys are sneaky. They hide either underneath the soil of their host plant or in its dense crown during the day. Then, at night, it comes out to feed on foliage, seedlings, and to bore into veggies.
Cutworms are very dangerous to young plants as they will literally eat them all while with mature vegetables, they bore holes in the ends of their stems. These can lead to the vegetable dying from not getting nutrients from the main plant.
They prefer garden veggies, but they have been known to go over ornamentals as well. One example of this is the Imported Cabbageworm.
Borer caterpillars are a menace to trees of all kinds, doesn’t matter if they’re a nut, fruit, flowering, or ornamental kind of tree.
The eggs are laid on the damaged areas of bark and when they hatch, the little ones bore into the tree where they will feed out of sight.
Some species tunnel around just beneath the bark while others will go straight for the heartwood. There they will stay for two years before pupating and then crawling out as adults of whatever insect they are.
Peachtree borers are included in this group.
Caterpillars Eat What?
Besides everything? Below is a general list of what caterpillars prefer, in your garden, and out of it.
- Flowers – it doesn’t matter what kind of flowers these are or what the main plant is, they will target the buds, seeds, and blooms.
- Vegetables – vegetables in the Nightshade (especially pepper and tomato plants) and Cruciferae families are their favorites, but they will chew on vining plants as well as root vegetables.
- Fruits – apples, peach, plum, peppers, and many others. The tomato fruitworm caterpillar feeds on the tomato fruit.
- Grasses – grass includes all cereal crops like rye and oat as well as beans such as soybean. Cutworms do the most damage to these crops.
- Bark and Twigs – includes all manner of tree and shrub.
Other Things That They Feast On
This category includes honeycomb — Wax Moth Caterpillars can kill an entire hive.
Moss/lichen and hair (animal fibers, people hair, and feathers), as well as large blue butterfly caterpillars that look like red ant larvae.
Animal waste such as the skin of dead mice and birds, as well as owl pellets and feces in birds’ nests.
They also prey on each other. Dun-bar caterpillar is a leaf-eater but it will consume other caterpillars if it finds one, even another of its kind.
Types of Damage
How do you know you have caterpillars in your garden? You will see the damage before you ever see the caterpillars.
- Leaves will have gaping holes, edges missing or, the plant will be missing entire leaves including the stems.
- Fruits and vegetables will have holes bored into them or, they will have big sections eaten out of them. Small fruits might be missing entirely.
- Trees will have webbing on their leaves or have “tents” made of silk in the crooks of their branches.
- You may also notice frass aka “poop” beneath the host plants.
How To Stop Caterpillars From Eating My Plants?
Now that you know you don’t want to have them in your garden, what do you do? Below are some ways to not only get rid of any you might already have but prevent them from showing up.
Handpicking – the most natural and eco-friendly of all, this method requires a pair of gloves and a pail of soapy water.
Go out early in the morning and pluck them off your plants and drop them into the pail. You can also knock them on the ground and squish them.
Gloves are recommended because some caterpillars have hair that can cause skin irritation. This is the best way to get rid of green caterpillars, once you can find them.
Diatomaceous Earth (DE) – another natural remedy. Placed around the base of your plants, this will cut up the underside of any caterpillar that walks on it, taking out their legs as well. You can also make a spray out of it.
Controlling Garden Debris – the eggs of many butterflies and moths winter under leaf litter and other garden debris so it’s best to clean this all up right after harvest. Destroying weeds also helps.
For more information on how to get rid of them, and what eats caterpillars, see the article: 11 Natural Ways to Get Rid of Caterpillars on Plants.
While the green caterpillar is a pest, for all its cuteness, other caterpillars, such as the wooly bear caterpillar and the caterpillar of the Monarch Butterfly are beneficial.
Unfortunately, the bad ones outnumber the good ones so knowing how to spot them will go a long way to saving your garden.