Print As PDF

Effective use of Stethorus in Commercial Cannabis cultivation:

Rates with Stethorus 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

Best control of spider mites is achieved when Stethorus is used along with predatory mites (Fallacis and Persimilis). Use care when removing leaves from infested plants. Keep any leaves with Stethorus pupae in the greenhouse until adult beetles have emerged.

Stethorus is a great option for cannabis growers in the flowering stage, as this beetle is not deterred by the trichomes of the plant. Weekly applications should provide sufficient control of two spot spider mites in flower.


Stethorus punctillum is a specialized spider mite predator in the lady beetle family. Adults are tiny and oval shaped, 1/10 in. long, dark brown to black in color, with brownish-yellow antennae, mouthparts and legs. Larvae are slow moving, grey with conspicuous legs. They move from plant to plant on leaves. Eggs are yellowish ovals, laid singly in or near mite colonies. Adult beetles can fly, and have an unusually good ability to find small infestations of spider mites.

Available in 50 or 100 count 8 oz. bottle (Minimum orders of 10 bottles, due to shipping concerns).

Life Cycle

The complete life cycle takes 14-20 days at 70-80°F. Female beetles lay 3-13 eggs per day. Over their long life span (up to 2 years), females can lay over 1,000 eggs. Females must eat 20-40 spider mites per day to initiate and sustain egg laying. Larvae feed for 10-14 days, and a single larva can consume 240 spider mites as it develops from egg to adult.

Older larvae migrate down the plant to pupate. Pupae are often found along leaf veins on the undersides of leaves. Adults emerge from pupae in 6-7 days. Both larvae and adult beetles feed on all stages of mites. Adults can eat over 50 mite eggs or 10 adult mites per day. If food is scarce, they will also feed on other small arthropod eggs, aphids, nectar and pollen, and will even cannibalize their own species. 

Biological Control 

When combined with other biological control agents, such as predatory mites, Stethorus can improve the management of a variety of pest mites in greenhouses, interior plantscapes, and nurseries. Optimum conditions are moderate to high temperatures of 67-90°F. They may remain active and feed, but will not fly at temperatures below 54°F. 

Stethours in cannabis is one of your only options for spider mite control in the flowering stage, as it is not deterred by the trichomes and stickiness of the plant. 100 per week, per room, when flowering, may be your best option when it comes to biocontrol use.

Monitoring Tips:

Watch for small grey larvae and pupae on the undersides of leaves in areas with the earliest spider mite damage. After 4-5 weeks, the first adult Stethorus should be found in areas with spider mites. Two months after the first introductions, all stages of Stethorus should be present in the oldest mite infested areas.

Introduction Rates

Apply 0.5 - 1 per 10 square feet