Common names: Phytoseiid Mite, Predaceous Mite
Scientific name: Order Araci, family Phytoseiidae, Phyoseiulus persimilis, Galandromus occidentalis
Identification: Look like pest mites but move faster and have fewer hairs. They are red and about half the size of a pinhead. Adults are very small, nymphs are smaller and lighter in color. Mites are not insects; they are related to spiders. Adults have four pair of legs and two body regions.
Biology and life cycle: Females emerge from overwintering in tree bark or soil litter to lay eggs on leaves among prey. Eggs hatch in three or four days. Nymphs molt several times and become adults in five to ten days.
Habitat: Plants infested by spider mites, thrips, and fungus gnats. Strawberries, blackberries, raspberries, tomatoes, orchard crops, onions.
Feeding habits: Effective predators of troublesome spider mites, especially the twospotted mite, European red mite, and citrus red mite. Some feed on pollen, thrips, and fungus gnats.
Economic importance: One of the most successful commercially available biological control agents. Used to control plant-eating mites. Release two mites per square foot or two for each small plant. In the field use 1,000 to 10,000 per acre.
Natural control: None needed.
Organic control: None needed.
Insight: The predatory mite is orange in the adult stage and pale salmon in its immature stage. Unlike the two-spotted spider mite (which is red), it does not have spots. Predatory mites have pear-shaped bodies, and their front legs are longer than those of pest mites. Beneficial mites move about quickly when disturbed or exposed to bright light and multiply much faster than pest mites. Females lay about fifty eggs a day; each mite eats from five to twenty eggs or mites per day. Release predatory mites at the first sign of spider mite damage. If there is more than one spider mite per leaf, you will probably need to reduce the populations of pest mites with seaweed spray.