Spider Mite

Tetranychidae

Content coming soon for this insect guide.

Insect Profile

Beneficial Rating

-4 Pest

Active Months

JanFebMarAprMayJunJulAugSepOctNovDec

US Distribution

NortheastSoutheastMidwestSouthwestWestPacific Northwest

Habitat Preferences

gardensgreenhousesorchardsfieldshouseplants

Taxonomic Group

Mite & Spider

Family

Tetranychidae

Lifecycle

The spider mite life cycle consists of four stages: egg, larva, nymph, and adult. Under optimal conditions (around 80°F), the entire life cycle can be completed in as little as 5 to 7 days. Eggs are laid on the undersides of leaves and hatch in 1-2 days. The six-legged larva emerges and feeds for a short period before molting into the first nymphal stage (protonymph). The eight-legged protonymph and subsequent deutonymph continue to feed and grow, each stage lasting a few days. After the final molt, the adult emerges. Adult females can live for 2 to 4 weeks and lay hundreds of eggs, leading to rapid population growth.

Overwintering Strategy

Mated adult females overwinter in protected places such as under loose bark, in cracks in the soil, in leaf litter, and other plant debris.

Native Range

Eurasia

Attracted By

drought-stressed plantshot and dry conditionstomatoespeppersstrawberriescornbeanscannabis

Repelled By

cilantrodillgarlicchrysanthemumsneem oil

Organic Control Methods

Organic control of spider mites focuses on prevention and the use of natural methods. Ensuring plants are properly watered to avoid drought stress is the first line of defense. Regularly spraying the undersides of leaves with a strong jet of water can dislodge and kill many mites. Introducing or encouraging predatory mites, such as *Phytoseiulus persimilis*, is a highly effective biological control. Applications of horticultural oil, neem oil, or insecticidal soap can also be used to smother and kill mites and their eggs. These should be applied thoroughly, covering all plant surfaces.

Companion Planting

Planting cilantro, dill, garlic, and chrysanthemums can help deter spider mites. These plants either repel the mites directly or attract their natural predators. Maintaining a diverse garden ecosystem with plenty of flowering plants will also support populations of beneficial insects that prey on spider mites.