Caterpillars are the larvae of butterflies and moths and are easy to recognize thanks to their soft, worm-like bodies. They can come in different sizes and colors, but they all have a tendency to completely destroy plants and trees. They are mainly present in autumn, but you can also find them during the other months when the weather is warm. If you are looking to get rid of them, you can try some natural methods; if these don't work, use potassium soft soap or other remedies. Finally, by learning about the exact species of insect you are dealing with, you can be able to get rid of it more easily.
Steps
Method 1 of 3: Natural Remedies
Step 1. Try Bacillus thuringiensis of the kurstaki (BTK) variety
It is a bacterium that develops naturally in dead or fallen organic material and represents a form of biological struggle useful for keeping caterpillars under control, as it attacks their digestive system. Additionally, it is considered safe because it is not harmful to animals or people, and dead caterpillars are not harmful to the animals that feed on it (such as birds).
- The bacterium should be applied at the right time to the leaves of affected plants or trees, as it needs to be eaten by caterpillars. Follow the instructions on the BTK package, but usually it needs to be applied twice: the first, about 10 days after the caterpillar eggs have hatched, and the second about two weeks later, when the insects are still small.
- This product is readily available commercially and you can look for it in gardening or home supply stores; usually, it is sold in the form of a powder, which must then be mixed with water and spread on the infested plants.
Step 2. Attract the birds to the area where the caterpillars are present
Birds are perhaps the best natural method of controlling infestation; therefore, it is a good idea to make the garden cozy for them; you can place a drinking trough, some feeders and even a house or two to entice them to nest on your property.
- If you have cats that frequent the garden, be sure to have them wear a collar with a bell to alert the birds when the animal is in the area.
- If you have enough space, you can keep chickens, which are other excellent predators for caterpillars; in fact, they feed on it and you no longer have to worry about managing the problem. In this case, however, you need to prepare the yard properly so that the chickens are safe, and it is therefore not a quick and easy way to solve the problem.
Step 3. Use jute to catch tree-dwelling caterpillars
If the infestation has hit the trees, you can wrap the trunk with this textile fiber. Caterpillars love to hide in the hot moments of the day and jute offers them an ideal shelter from the sun's rays; once they have gathered in large numbers on the fabric, you can get rid of several of them quickly.
This method is particularly effective for catching moth caterpillars, which tend to live in trees
Step 4. Drown them
If you are not afraid to touch them, this is another option to get rid of them without having to use chemicals or other harmful substances on the leaves.
- Fill a container halfway with water. The size depends on how many caterpillars you need to catch; if the infestation is relatively small, a cup is sufficient, but if you need to catch a lot, use a 20-liter bucket.
- Add the dish soap. If the container is relatively small, 60ml is enough, but add more if the bucket is large; this is not an exact science, so don't worry if the doses are not perfectly right.
- Grab the caterpillars with your hands and put them in the water, in which they die; wear gloves if you wish.
Step 5. Collect them and take them elsewhere
Remember that they eventually become butterflies and moths, playing an important role in flower pollination; you should therefore consider relocating them (for example to a nearby wooded area), where they can live without harming your plants.
If so, pick them up and put them in a bucket or vase; then take them to the area you have chosen and gently release them on a branch or on the leaves of a tree
Method 2 of 3: Soaps, Pesticides and other Remedies
Step 1. Try pyrethrin
It is a natural pesticide derived from plants, in particular from chrysanthemums, and which is toxic to many weeds, including caterpillars; it is usually safe for people and pets, but can be toxic if ingested in large quantities. This product is typically sold at gardening and home supply stores and usually needs to be sprayed on infested plants, where sunlight degrades it within a few days.
- When you go shopping for a pyrethrin-based pesticide, you probably come across products that contain "pyrethroids," which are basically the synthetic version of pyrethrum.
- To protect beneficial insects from the effects of this product, you should apply it to infested plants early in the morning and then cover them with an old sheet for 24 hours.
Step 2. Prepare a spray solution of potassium soft soap
This product must be sprayed directly on the caterpillars and works by destroying the skin of the insects. To prepare the mixture, simply combine two tablespoons of product with a liter of water in a spray bottle; shake the solution well and spread it on the body of the caterpillars you find.
Make sure the soap is biodegradable and based on plant derivatives, to avoid harming plants, animals and other insects that are not harmful to your plants
Step 3. Purchase a commercial pesticide
This should be considered a last resort, as it also harms beneficial insects and the environment; However, if the infestation has reached levels that require the use of chemicals, at least make sure you get one specifically indicated against caterpillars. You can find this information on the product packaging itself.
- Remember that if you have pets or small children, the use of pesticides can be dangerous because there is a risk of direct contact.
- It is also not recommended to use them in gardens where edible plants are grown.
Method 3 of 3: Controlling Caterpillars in the Garden
Step 1. Add some plants that attract beneficial insects to your garden
Some flowers, such as the star and yarrow or coriander, fennel or dill, recall some useful insects (which prey on other insects) which feed on caterpillars; be sure to choose plants that grow all season to entice these insects to come into your garden.
Growing this type of plants provides an alternative food source for beneficial insects, which can return even after capturing all the caterpillars
Step 2. Use an insect barrier
It is a type of fabric suitable specifically for this purpose and that covers the plants, preventing butterflies and moths from depositing their eggs on the leaves, from which the caterpillars are born.
This method is great for plants that produce autumn vegetables, for which pollination is not an important factor; covering the plants therefore does not affect the abundance of the crop
Step 3. Recognize the caterpillars
They can have different shapes and sizes; some are large while others are smaller, some species are hairy while others have a more worm-like appearance. If you haven't seen any caterpillars, but you notice that the plant leaves are full of holes, the garden is likely infested.
- It is possible to catch almost all of these insects by following one of the methods described so far, except the Malacosoma (galloned bombyx) which usually lives on trees forming cobwebs. You can control its population with the remedies described above, but you should also cut the branch where the nest is located to burn it.
- Although caterpillars are typically harmless to people and do not bite, there are some species that cause painful stings instead. There are several species of this type and the specimens are very different from each other; you can therefore assume that a hairy or hooked-spiked caterpillar can sting you if you touch it. It is never a fatal sting, but it can be very painful; you should therefore avoid touching the insect if you are not sure about the species.
Advice
- In the first phase of spring and summer yellow wasps use the caterpillars as a food source for their young.
- If there are only a few caterpillars in your garden and they are not doing much damage to the plants, you should leave them alone.
