Don't try to figure out whether your avocado tree has a persea mite infestation by looking for the bug -- seeing this yellow insect requires a 10X magnifying glass. Instead, inspect the tree for telltale damage. This mite feeds on the underside of leaves, weaving white webs by the foliage's veins for protection as it sucks its chlorophyll. The result is an avocado tree with brown leaves which fall prematurely, exposing wood and fruit to sun that can burn them. Predatory mites are one way of eliminating persea mites.
Things You'll Need
Small paper bags
Order mites that prey on persea mites. Galendromus helveolus and Neoseiulus californicus are two species available. They arrive at your home in vials filled with ground-up corn.
Turn the vial over for one minute to distribute the mites evenly through the corn medium.
Put the mite-corn mixture in small paper bags or envelopes. An average-size tree requires about one-fourth of the supply. A young avocado tree that hasn't reached full size needs less. If several areas of the tree have infestations, distribute the mites among several envelopes.
Fit a branch or a couple of leaves from the infested tree into the bag. Staple the bag in a way that keeps it in place. The predatory mites have to be able to climb out of the bag and onto a section of the tree. If you have several bags, hang them evenly around the tree or in the areas where the infestation concentrates.
Inspect the new leaves that sprout after leaf drop. White spots on the underside of the foliage mean the mites are still present, weaving their protective webbing and feeding on the chlorophyll. Continue to release predatory mites once a month. The University of California Pest Management Program says that although you might not be able to control persea mites in one season, you should continue to introduce their predators into your backyard. Eventually, they'll multiply in enough numbers to provide continuous natural control of the avocado persea mite.
If the avocado leaves drop prematurely, paint the tree trunk with white latex paint to prevent sunburn. Follow the necessary steps to maintain your type of avocado tree healthy so it's always strong enough to fight pests.