We get many questions from worried readers who have seen caterpillars on trees or plants. For the most part, these creatures aren’t causing any real harm and can be left alone. However, some species can be quite destructive and should be removed for the health of the plant.
Frequent readers know that our advice is typically to remove the critter’s food source. Without food, they’ll leave on their own accord. However, this becomes difficult when the critter’s food is also your food. Examples include hornworm caterpillars, apple maggots, army worms, and plum curculios.
In these cases, our advice is to inspect your plants and remove any offending critters. Then, you can move them to an area where they will cause less concern. To do this, look over each of your plants, checking on the tops and bottoms of leaves. When you find one, pluck it off and place it in a bucket. Then empty the bucket elsewhere.
There are some circumstances when you won’t want to remove the caterpillar. Sometimes, nature is working in your favor. The hornworm caterpillar in the picture above is infested by parasitic wasps. They look like little tufts of cotton on its body. The worm will die from this in time, but while it is still alive it will help to infect other hornworms in your garden.
Depending on where you live, you may need to notify authorities if you find specific species. This is because those species cause a lot of damage and are very difficult to control. If you live in a location that depends heavily on an agricultural product, such as apples or tobacco, it’s a good idea to check with your local nursery to find out if there are any pests you should be keeping an eye out for.
We realize that inspecting every leaf of every tree in your yard is quite time consuming. For small growers, bagging specific fruit or individual trees is can be a solution. Tree covers can also be useful when protecting apple trees.
We know that fighting wildlife for your food can be frustrating. Some people will want to use chemical pesticides. In some cases, this may be required by law. However, these problems can often be controlled with some time and creativity. If you can avoid using harsh chemicals that may damage other animals in the area, we recommend doing so.