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How to Get Rid of Caterpillars

Caterpillars are one of the most common garden pests. Caterpillar infestation is the one of the biggest problems that farmers and gardeners face. If left alone, they can decimate entire crops and vegetable gardens. Different types of caterpillars will attack different types of plants, but there seems to be a caterpillar for every plant there is.   

They don’t just attack crops and vegetables, they are a nuisance to ornamental gardening as well. Leaf miners, Leafrollers, Cabbage Loopers, Tomato hornworms, Tent Caterpillars are all types of caterpillars. Although they are all so diverse, but they have one thing in common: They can destroy the plant they’re feeding on in a short amount of time or damage it beyond its usefulness. 

Different Ways to DETER Caterpillars 

Most of the time , people will not even think about caterpillars until they start seeing holes in their beautiful tomato plants or other vegetables or shrubs. The best thing to do is to try and deter them. Here are few things to do BEFORE the caterpillars start showing up.  

People will swear by these methods and although they CAN work, I don’t think there is ever a full proof way because like they say “Nature will find a way”. 

Companion Planting 

Planting flowers and herbs in your garden with strong scents can help to mask the scent of your vegetables and possibly prevent the butterfly or moth of even finding your plants in the first place. 

Peppermint Lavender, Sage, and Mugwort are examples of these companion plants. They all smell great and are relatively easy to maintain. 

Soap and Water  

Mix a small amount of liquid detergent in water to spray on the leaves of your plants. This does not directly kill the caterpillars like everyone thinks. It creates a slippery surface that they cannot feed on easily. It also creates a film over the leaves so adult insects are unable to attach eggs to the plant. 

This isn’t always effective because it has to be applied constantly, is easily washed off or just plain dries up in the heat when caterpillars are causing the most problems. 

Create a Bird Sanctuary 

Creating an environment to attract birds is THE best way to help deter many garden pests. Most birds entire diet consists of insects. For perspective, a swallow can eat over 60 insects an hour. A hummingbird will eat as many as 2000 small insects in a day in addition to its nectar intake. 

Studies have shown that Birds consume over 550 million tons of insects per year worldwide. Don’t ask me how they figured that out but that’s a lot of bugs. 

Hang feeders around the yard to attract birds to the area. Providing a source for water is a very important thing to consider. 

Attracting Pollinators  

Planting strong scented and colorful flowers throughout your yard will also attract pollinators.  

Most people don’t consider Wasps as pollinators but they are. Their slick bodies are not as efficient as a fuzzy honeybee or bumble bee at collecting pollen and distributing it from flower to flower. They have a high energy need and will fly from flower to flower collecting nectar and pollen. 

A big player in the control of caterpillars is a Wasp. Most people do not like to see wasps around their garden, but they are a beneficial insect in a few ways.  

Not all wasps have stingers. Some wasps do not have a stinger at all or their ovipositor is only used to lay eggs. Some will only attack insects unless provoked strongly. 

There are parasitic wasps who’s sole method for reproducing is to lay their eggs on large caterpillars. The eggs then hatch and consume the caterpillar for food from the inside out. 

Killing Caterpillars with Pesticides 

There is a constant debate over Organic and Synthetic pesticides and their effectiveness on insects and the harm done to the environment.  

Organic Pesticides 

If you choose to go the organic route there are a few different products to try. 

Neem Oil 

Neem oil is a natural oil extracted from the Neem tree. It affects the insects digestion and hormones that control their growth rate and ability to lay eggs. 

Vinegar Solutions 

Hold up, wait a minute! Something ain’t right!  The pest and weed solution that you will see all over the place on the internet touting as being organic may not be what you think.  

White Vinegar is made from Ethanol. And guess who makes all the corn used to create this ethanol? 

I’ll just leave that out there. 

Naturally Occurring Bacteria 

Both of the products I am familiar with are naturally occurring bacteria added to a product. When using both of these products be aware that they will die very quickly in sunlight so it’s best to apply in the late evening when most caterpillar are active anyway. 

Spinosad will affect honeybees as well so do not apply it during the day when honeybees are active in the area. 


The most commonly mentioned way to control caterpillars is BT or Bacillus Thuringeinsis. It is a naturally occurring soil-borne bacteria that is harmless to humans and other mammals and birds. All caterpillars are affected by this. Long story short, this bacterium affects their digestive system by blocking the protective system that saves the caterpillars stomach from its on digestive juices. The caterpillars die from their own digestive juices and the spores from the bacteria. This can take a few days to happen. 

One of the commercial names for the product containing BT is Thuricide. There are a few more on the market but this is the one I am familiar with and have had much success. 


Spinosad is what I am currently using in my garden. BT just wasn’t cutting it and just does not last as long or as fast apparently. Spinosad is a very similar product as it is also a naturally occurring bacteria. It is also harmless to humans. 

It can be ingested and also a contact poison. Upon contact, it affects the insect’s nervous system causing them to be paralyzed, effectively killing them in one or two days. 

Spinosad has a longer residual effect than BT. I am having really good results using it as an insecticide. It also has the advantage of affecting other insects like mosquitoes and flies. 

Spinosad will affect bees as well so make sure to not apply early in the morning or throughout the day while bees are working. 

Chemical Solutions 

If you need to rely on chemical solutions for your caterpillar problem, there are many products on the market. Most are created by using a synthetic solution of pyrethroids, which naturally occur in chrysanthemums.  

Bifenthrin, cyfluthrin, malathion and permethrin are among the active ingredients. 

The advantages of these products is their long-lasting residual effects and effectiveness. They are not choosy and will kill both pests and beneficial insects of all kinds. 

When using chemical pesticides, be sure to read the instructions for mixing and handling. When handled improperly, these products can pose a risk to humans, animals, and the environment. 

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