This is every gardener's nightmare: you walk out of the house one morning and see that yesterday's thriving plant has now been cut in half, crushed by a cutworm. These nocturnal caterpillars are the larvae of several species of moths. When feeding, the caterpillars will cut young plants and can even damage the entire garden. The good news is that stem borer caterpillars can be controlled with a few simple tactics that don't involve the use of toxic chemicals. See Step 1 below to find out how.
Step
Method 1 of 3: Monitoring and Protecting Plants
Step 1. Know the signs of a plant that has been attacked by stem borer caterpillars
You won't see caterpillars during the day because they forage at night. Most planters don't know they have a problem with the caterpillar borer until they see the evidence in the morning, after the caterpillars have gnawed at the crops the night before. At that time, you can't tell how many caterpillars there are in the garden. Suppressing the population before it explodes will help save your garden. Here are the signs to watch out for:
- The plant is cut off near the base of the stem.
- Plants are wilted or damaged.
- There is caterpillar droppings.
- There are stem borer caterpillars that you can find as you dig and turn the soil around the damage site. Caterpillar colors can vary, including gray, brown, pink, black, etc. Some of them are speckled, others are striped, some are even plain.
Step 2. Remove weevils from plants at night
Go out at night with a flashlight and remove the caterpillars from the plants one by one. Put it in a bucket of soapy water to submerge it, then throw it away. Repeat this method for several days until the population decreases. Keep checking throughout caterpillar season to kill more.
Step 3. Create the "collar" of the plant
Borer caterpillars like to eat plants by attacking the stems, essentially decapitating the precious vegetables in your garden. If you put a barrier around the stems, the caterpillars will have a harder time eating them. Cut cardboard, plastic, or other hard material 10 cm wide into a tube to attach as a collar for the plant. You can also use a cardboard tube or drink can with a hole in the end.
The disadvantage of this method is that each stem of the plant must have its own collar to prevent the caterpillars from damaging it. If you have a large garden with hundreds of plants, combine this method with other ways so you don't spend the entire season dressing the tiny plants with collars
Step 4. Attach the collar around the stem of the plant
Press 2cm deep into the ground so that the collar stands up to 8cm high. Caterpillars will not be able to climb cardboard and metal surfaces nor get under the collar. If you're cutting a collar out of cardboard or plastic, make sure the joints are tapered tightly so there's no gaps for the caterpillars to slip through.
Step 5. Wrap the stems of the plant
To further protect the plant, you can wrap the stems to prevent caterpillars from eating them. Cut plastic straws to the length you need. After that, split the straw on the long side and tuck it into the stem of the plant to wrap it around. Insert the lower end of the straw into the soil.
Alternatively, you can wrap each rod in a piece of cardboard, cardboard, or aluminum foil and pierce the bottom end into the soil
Method 2 of 3: Using Natural Antidotes and Pesticides
Step 1. Spread Bacillus thuringiensis into the garden
These are bacteria that are known to kill stem borer caterpillars and are widely available in plant stores. This natural way to get rid of caterpillars will not harm plants or animals. Sprinkle Bacillus thuringiensis on the caterpillar infested area.
- These bacteria will also kill moths and other types of butterflies. So, if you don't want to hurt other insects, don't use this method.
- Spray pesticides in the afternoon to get the maximum out of stem borer caterpillars. Since the caterpillars feed after dark, pesticides must be applied in fresh condition when they emerge for dinner. Reapply the pesticide after it rains until the plant is large enough to survive caterpillar attacks.
Step 2. Try diatomaceous earth
It is a natural powder made from ground fossils and can be sprinkled around the caterpillar infested area. Diatomaceous earth is harmless to humans, plants, or animals, but it can kill insects that walk on it by piercing the body and causing the insect to dehydrate. Do not sprinkle diatomaceous earth on an area whose insect population you want to keep healthy.
- Apply diatomaceous earth around the base of the plant where borer activity is suspected. Diatomaceous earth can be applied with a bulb applicator (a kind of large pipette) so it doesn't get into the eyes or accidentally inhaled because it can cause irritation.
- Try using ground egg shells or ground coffee as an alternative.
Step 3. Use cornstarch
Stem borer caterpillars like to eat cornstarch, but this food will hurt the digestive system. They will overeat to the point of killing themselves. Sprinkle cornstarch on the caterpillar infested area. Do not be too much because it can invite other pests.
Step 4. Make the syrup (molasses)
The syrup mixed with sawdust and bran will produce a thick paste that you can spread in a circle around the plant where the caterpillars usually gather. As the caterpillars crawl over them, the sticky paste will stick to their bodies and this will prevent the caterpillars from damaging the plants.
Method 3 of 3: Changing the Garden Environment
Step 1. If possible, delay planting for two weeks
After a caterpillar attack at the start of the season, the number of moth larvae and the degree of damage after this will generally decrease.
- Consider planting parenial flowers in the garden. Plant around the outside of the vegetable garden as a form of prevention for weedworms. Unlike weeds and tall grass, the flowers die in the fall as the adult moths find a place to lay their eggs.
- Hoe the soil before the growing season to expose and kill any larvae that nest beneath the surface.
Step 2. Keep the garden tidy
Remove weeds from the garden and from the surrounding area to reduce moth spawning grounds. This will also reduce some of the food that the borer caterpillar can sustain. Cut the grass short around the garden.
Step 3. Clean up the post-harvest garden
Remove any plant debris from the post-harvest garden to prevent moths from laying eggs there. Hoe the soil again after the harvest season to expose the larvae and reduce their population.
If you can, let the chickens forage in the garden after the soil has been hoeed. Chickens will eat all the caterpillars on the ground
Step 4. Make the garden caterpillar-friendly
Making the garden animal-friendly is a great way to control weevils because birds and other animals like to eat them. Invite the following animals to enjoy caterpillars in your garden:
- Frog
- Mole
- Fireflies
- Bird
- Other poultry, such as chicken
Tips
- Place bird feeders and water containers to invite birds to visit your garden. Birds such as blue jays, blackbirds, wrens and sparrows love to eat caterpillars. Nematodes (roundworms) also feed on borer caterpillars and are usually sold in some plant shops. Meanwhile, the caterpillar predators that are the easiest to find around us are chickens. Chickens will scavenge the ground and eat caterpillars.
- Sometimes a mixture of non-bleaching dish soap and water is also effective at keeping the weeds away from plants.
- Since most of the plants that caterpillars attack are food crops, it is best to use organic pesticides instead of chemicals.
