The sight of a big, fat caterpillar munching on your cabbage is hard to stand, even when you know that the insect will eventually become a beautiful butterfly. If the caterpillars in your yard or garden have become hungry pests that strip your plants bare, then it’s probably time to get rid of them. You must act immediately or the caterpillars will multiply further and leave you with nothing. Here are tried and tested ways to get rid of caterpillars:
Caterpillar Control: Blast Them With BT Pesticide
Bacillus thuringiensis or BT is a type of bacteria that’s used to control the population of caterpillars. This natural pest control has been used by farmers and gardeners since the 1930s. Commercial preparations of the bacteria are still widely available today in feed stores and garden shops around the country.
How Does BT Work?
When a caterpillar bites a leaf that’s covered with BT, the bacteria multiply inside its body, damaging its digestive tract with sharp protein crystals. These substances are extremely toxic to the caterpillar, so it will stop feeding on your plants and die within 20 minutes after its first mouthful. Once the caterpillar dies, its body splits open, releasing more bacteria to protect your garden or lawn. The conditions that are required for BT to multiply are only found in the stomach of caterpillars, so butterflies, bees, earthworms, spiders, beetles, and humans are completely safe from poisoning.
How to Apply BT Pesticide
BT comes in liquid and powder form, both of which are easy to use. Some experts claim that a single application of BT permanently protects the garden from caterpillars. You may still reapply BT though, if you want to make sure that caterpillars will never feed on your plants again. Follow these instructions to correctly apply BT on your garden:
- For liquid BT: Mix one tablespoon of liquid BT per gallon of water. Apply the gallon of water over 1,000 square feet of your garden. Lightly spray the pesticide over the plants with caterpillars, making sure that the leaves are dripping with the formula. You may repeat this weekly during the season to guarantee the protection of your plants.
- For powder BT: Some experts advise against using the liquid form because it contains petroleum distillates that force BT into its spore stage, which delays its activity. To use powder BT, simply sprinkle it on the damp leaves of your plants, and let the moisture activate the bacteria. If your plants don’t have enough moisture, mix the powder BT into bottled water, and then spray it on your garden. Do not use tap water because its chlorine will destroy the bacteria.
While a single application of powder BT is enough to drastically reduce or eliminate caterpillars, you may reapply it every spring to ensure that they’ll never come back. Powder BT is available in one-pound canisters and three-pound bags at feed stores and garden shops. In addition, it’s best to apply BT in areas that don’t have agricultural antibiotics and fungicides, because these can harm the bacteria.
Other Ways to Get Rid of Caterpillars
There are many other ways to get rid of caterpillars aside from using the BT pesticide. The following caterpillar control methods have worked for other lawn and garden owners, they might work for you, too:
- Pick them up by hand: The most environmentally friendly way to get rid of caterpillars is to just pick them up by hand, and then crush them on the ground using your foot. This method is safest for your plants because you won’t be using any kind of chemical or organic pesticide. Remember though to wear rubber gloves when picking up caterpillars because their sting causes skin irritation. You may also use a stick to pull the caterpillars from the branches or stems of your plants, and then crush them on the ground.
- Destroy caterpillar nests and eggs: Caterpillar eggs and nests are very easy to spot during fall, as the leaves of plants have already dropped. Locate the eggs and nests, clip off the stems or leaves, then crush them on the ground. Always wear gloves when removing caterpillars no matter what method you use. If you don’t want to fill your garden with crushed caterpillars, you may drop their nests into a pail of soapy water. It’s best to do this early in the morning or late afternoon, so the caterpillars are in their nests.
- Put some predatory pests in your garden: Caterpillars are very rich in protein, so many animals make them a staple of their diets. Some birds, frogs, lizards, and wasps eat these insects regularly, naturally reducing their population. You can introduce more of these animals into your lawn or garden to keep the caterpillar population down. Be sure that these pest control animals are not pests themselves though, or you’ll just replace one problem with another.
- Make your own pesticide: Another way to get rid of caterpillars is to make your own pesticide. Just mix some garlic cloves and chili in water, and then spray the formula on the affected plants. This method should work if there are only a few caterpillars in your garden.
- Use insect glue: Insect glue is a non-drying adhesive that acts like a barrier to prevent insects from accessing the leaves or fruits of your trees. It’s best to use insect glue on trees because plants don’t have enough diameter for the glue to wrap around. To use the product, first, wrap a band of masking tape around the trunk of the tree. Apply a thin coat of insect glue on the masking tape, and leave it there for a month. Caterpillars should get trapped on the glue and die on its surface. When the glue begins to dry, simply remove the tape and replace it with a new one.
- Improve your gardening practices: In some cases, the problem is not really the caterpillars, but the garden owner’s gardening methods. If you have a major caterpillar problem, then maybe the plants or vegetables you’re growing are not really suitable for your environment. Do some research on the right conditions for your plants to see if they’re unnecessarily attracting too many caterpillars.
Another technique to prevent caterpillar infestation is to plant companion plants that cancel the scent of other plants; for instance, it’s a good idea to plant celery and tomatoes in your plot because they cancel out the scent of brassica, which deters cabbage white caterpillars. In order to do this, you will need to learn how to grow celery.
In addition, do not plant vegetables in rows, and rotate the crops every once in a while, so they don’t become easy targets for caterpillars. Also, enrich the soil with mulch and compost to make your plants stronger and more resistant to caterpillar infestation.
- Apply chemical pesticides: There are many chemical pesticides you can use to get rid of caterpillars. You can buy the following pesticides in feed stores and garden shops, and online on the Internet:
- Bifenthrin concentrate: Mix this pesticide with water and spray it on affected plants. This product is most effective when you’re treating large areas of your garden. Caterpillars die on contact with the pesticide, and the pesticide also acts as a repellent against migrating caterpillars.
- Permethrin dust: Sprinkle permethrin dust over fruits, vegetables, shrubs, or trees to repel and kill caterpillars. Permethrin dust is completely safe, and does not hurt your plants. You may apply it weekly on your plants to keep them protected from caterpillars, beetles, and whiteflies.
- Deltamethrin dust: Similar to permethrin dust, Deltamethrin dust is very easy to apply, and gets into tiny places where caterpillars hide. It holds moisture better than other dust pesticides and works quickly. It may last for several weeks if you live in a dry environment.
Be careful when using commercial chemical pesticides, because they may harm your plants if you apply too much of them. Read the instructions carefully or call the manufacturer if you have some questions on how to use the product.
You don’t have to get rid of caterpillars if they are not destroying all your plants. Many people just leave caterpillars alone, and wait for them to become butterflies. Don’t rush to kill caterpillars, because they may be the reason why your garden is still alive and thriving.
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