Biological control (using predatory and parasitic insects control pest insects) has been the main method of insect control in avocado orchards since the first plantings in California. Currently we are focused on using an arborial species of the Green Lacewing, Chrysoperla rufalabris, to control in avocado thrips.
We were successful with this predator for several years by releasing 10,000 lacewing eggs per acre every other week from flower initiation until the fruit were about 3/4 inch long. If the population of thrips is low or even moderate, this quantity of lacewings has been sufficient to control the thrips, but if the thrips are in high numbers per acre (many thrips per leaf on the flush leaves and many flush leaves per acre) then the large number of lacewings needed would probably not be economical compared to the use of a pesticide.
It is important to make successive releases of the lacewing eggs so that wave after wave of predators are searching the tree to find newly developing pockets of thrips and destroy them.
The lacewing eggs come glued to a card, which is then cut into 30 individual squares with 100 eggs per sqare. By stapling one square to each tree, you will be releasing 10,000 per acre if you have 100 trees per acre. It takes about an hour to staple the squares to 100 trees, but the first acre may take longer until you develop your technique. For more details, see Lacewing Release Instructions.