GWSS Program

Glassy-Winged Sharpshooter (GWSS) Natural Enemies and Production Process

A natural enemy is an organism that lives at the expense of another organism and which may limit the population of this organism. Only a few natural enemies are biological control agents; see the biological control section for a discussion on this subject. For more information and discussion on this subject go to the California Department of Food and Agriculture’s website by clicking GWSS Natural Enemies.

Production Process

The many insects that are selected for research are easy to rear; artificial diets have been developed for hornworms, drosophila, wax moths, and cabbage white butterflies. Other insects are herbivores so only one plant needs to be produced to rear them. Even predators some parasitoids can be easy to rear as they may be reared on easy to rear alternative hosts or artificial eggs. Unfortunately such is not the case with GWSS egg parasitoids. While the wasps themselves are relatively easy to rear, obtaining a reliable year-round supply of eggs is very hard. In the field, GWSS feed on large perennial plants and switch hosts as the season changes. They can oviposit on plants on which they rarely feed and once the nymphs emerge, they frequently leave the ovipositional plant to feed on other plants. And even in the field GWSS cease to oviposit in California winters. In an attempt to rear GWSS biological control agents, we are attempting not only to duplicate field conditions but improve on them. For more information the production process go to the California Department of Food and Agriculture’s website Production Process.