FOR YOUR FILES: Two-Spotted Spider Mite Tech Sheet (PDF)
MITES belong to the order Acari and have four sets of legs, distinguishing them from insects, which have three sets of legs. Mites are one of the most common pests of protected crops in greenhouses and interior plantscapes. They are also found on berry and fruit crops and many woody ornamentals grown outdoors. Mites damage plants by piercing and sucking the contents of cells, which results in speckling on leaves as the cells turn yellow and die. Although most mites are on the undersides of leaves, the damage is visible on both leaf surfaces. As damage increases, the whole leaf may turn yellow and wither. 2-spotted spider mites(Tetranychus urticae), broad mites (Polyphagotarsonemus latus), cyclamen mites (Steneotarsonemus pallidus), and bamboo mites (Schizotetranychus celarius) are the most common pest mites that Sound Horticulture addresses, but we are happy to help you with whatever mite problem you are experiencing.
LIFE CYCLE: A complete 2-spotted spider mite life cycle takes about 14 days at 70°F (21°C), 33 days at 59°F (15°C) and only 7 days at 86°F (30°C). Females lay eggs on the lower leaf surface; larvae hatch from eggs in about 3 days. Nymphs pass through two more stages before becoming adults. Feeding and number of eggs laid by 2-spotted spider mite females increases as temperature rises and humidity drops. Under hot, dry conditions, 2-spotted spider mite populations can cause extensive damage and quickly get out of control. When 2-spotted spider mite populations are high, they disperse easily throughout the crop on air currents and are also carried along on workers’ clothing as they handle plants. 2-spotted spider mite diapause in response to short days, lower temperatures or a deteriorating food supply. They travel up or down the plant, away from light, searching for protected places to hibernate, such as crevices in the greenhouse structure or at the soil line at the base of posts. This phase doesn’t feed and is very difficult to control with either chemicals or biological controls.
CONTROL: Sound Horticulture offers several different predatory mites as solutions to your pest mite problem. Predatory mites feed on pest mites and sometimes on other small arthropods and pollen, depending on the species. Which predatory mite you use depends on the crop, climate, and population lever of the pest mite. Many predatory mites can be used simultaneously for greater effect and efficiency. Read the informational pages on each predatory mite listed below, and ask Sound Horticulture which one or combination is most suitable for your pest problem.
Lifestyles of Predatory Mites (PDF)
Always obtain an accurate diagnosis and ensure you are using good cultural and sanitation practices. Local extension offices will generally be able to identify your pest. Additionally, feel free to send us images and we will do our best to assist you.