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Effective use of Encarsia in Commercial Cannabis cultivation:

Rates with Encarsia in cannabis seem to vary a little from what the traditional, registered rates would indicate. Instead of treating in meters, and as a row crop, we recommend that each plant have direct attention paid to them, for optimal results. The climate fluctuation and temperature and humidity variations, along with the plant’s rapid growth pattern, necessity to ensure proper air movement, and hairiness/stickiness of the plant all combine to make cannabis a complex and difficult crop to treat.

For Commercial Cannabis Rates, please fill out our Commercial Cultivation Inquiry for a discrete, personalized Chemical-Free Pest Management plan.

For Best Results

The whitefly species in a crop must be correctly identified to make sure it is a species that Encarsia can control, which will also help determine appropriate release rates. Eliminate whitefly from alternate plant sources, such as weeds, previous crops, and/or cuttings before Encarsia releases begin. High whitefly populations hinder movement of the parasite as does the presence of excessive amounts of honeydew. Remove whiteflies and honeydew by spraying with water or insecticidal soap.


Encarsia is a tiny parasitic wasp that parasitizes whiteflies. It was the first biological control agent developed for use in greenhouses. Adults are black with a yellow abdomen, less than 1 mm long. Even though they are wasps, they do not sting. Larval stages live entirely inside immature whiteflies, which darken and turn black as the parasites develop inside.

Available as 1,000 count pupae on cards.

Biological Control 

Encarsia are effective controls for greenhouse whitefly on greenhouse cucumbers, tomatoes, peppers and poinsettias. They can control silverleaf and sweet potato whitefly, but only under optimum management, using high release rates.

Optimum conditions are temperatures over 61°F. When daytime temperatures are less than 64°F, Encarsia activity is sharply reduced, making them less effective.

Do not attempt to use Encarsia if high whitefly populations are already established. The predatory ladybug Delphastus avoids feeding on the whiteflies that have been parasitized by Encarsia and also feed on whitefly eggs, therefore can be used in conjunction with Encarsia. The predatory bug Dicyphus hesperus, and the parasitic wasp Eretmocerus californicus may also be used in conjunction with Encarsia.

Life Cycle

The complete life cycle takes about 28 days at 70°F. Temperature greatly affects development rates; larval development takes 15 days at 77°F and 45 days 59°F. Encarsia populations are all female. Sometimes males do occur, but they are not functional.

Eggs are laid in 2-week old whitefly scales (2nd and 3rd whitefly stages), one egg per whitefly. Each female lays up to 10 eggs per day, for a lifetime average of 200 eggs.

Larvae develop inside the whitefly scale for about 10 days at around 70°F. They then pupate for another 10 days, when adults emerge by chewing a hole in the top of the scale. Adults are most active for about 10 days, but can live up to 30 days. In addition to parasitizing them, Encarsia kill whitefly scales by feeding on the host directly. They also feed on whitefly honeydew.

Introduction Rates 

Apply 0.1 - 1 per square foot