Caterpillar Control in Fruit Trees

Caterpillars are the larva of moths and butterflies. They are classified under the order of Lepidoptera. Lepidoptera come in all types and sizes, many of which can cause serious damage to fruit trees and their fruit. This article will help you understand how to control caterpillar damage on your fruit trees in an organic, yet effective way. 

The first step to controlling any pest infestation is to identify the type of caterpillar that is infesting your tree. Being able to identify the species of caterpillar that you are dealing with will allow you to do further research on the pest. This is an important step because understanding a pest's life cycle and feeding habits will allow you to determine how and when to apply the correct treatment. For example, you will treat a leaf mining caterpillar different then you will a leaf eating caterpillar. Also, one caterpillar may be more common in the spring when another species will be more common in the summer.

Once you have identified the caterpillar species, you can determine the best treatment. Larger caterpillars like the tent caterpillar are big enough to be remove by hand and soaked in soapy water or given the "sole treatment" (squished under the sole of your shoe). Many caterpillars are so small or their numbers are so large that removing them by hand would be a very tedious task for a busy gardener.

Removing Small Caterpillars by Hand is A Tedious Task

The safest organic way to control most caterpillars on fruit trees is the use of Bacillus thuringiensis also known as Bt. Bacillus thuringiensis is a strain of bacteria that, when ingested, will infect the gut of all insects in the order of Lepidoptera. For this to work effectively it must be ingested by the caterpillar so leaf mining caterpillars or caterpillars that have entered the core of an apple, for example, are protected from Bt treatments because the outer plant tissues act as a shield.

Like all insect control, effective treatments are targeted and timed correctly. It is important to know the types of Lepidoptera common in your area and a little about their life cycle. For example Bt treatment that occurs right after caterpillar eggs hatch will be more effective and will prevent any damage to your fruit or your fruit trees because their first feeding will infect them with the bacteria strain before their appetite grows when they mature.

Large Caterpillars Have Large Appetites

Like all pest control (even the organic ones) there will be casualties. If you use large amounts of Bt you will be killing off your butterfly population including the beneficial ones like Monarchs. This is why it is important to understand what you are treating for and when and where to treat. Monarchs feed primarily on milk weed, so if you are treating caterpillars on your fruit trees, make sure your spray is staying on your fruit tree. Avoid spraying in the wind or being careless and over spraying your trees.