Tetranychus urticae (common names include red spider mite and twospotted spider mite) is one of many species of plant-feeding mites found in dry environments, and generally considered a pest. It is the most widely known member of the family Tetranychidae or spider mites.

Description

Tetranychus urticae is extremely small, barely visible with the naked eye as reddish or greenish spots on leaves and stems; the adult females measure about 0.4 mm long.^[1] The red spider mite, which can be seen in greenhouses and tropical and temperate zones spinning a fine web on and under leaves.^[1]

Ecology

Tetranychus urticae is extremely polyphagous. It can feed on hundreds of plants, including most vegetables and food crops including peppers, tomatoes, potatoes, beans, corn, strawberries; and ornamentals such as roses.^[1] It lays its eggs on the leaves, and it poses a threat to host plants by sucking cell contents from the leaves cell by cell, leaving tiny pale spots or scars where the green epidermal cells have been destroyed.^[1] Although the individual lesions are very small, attack by hundreds or thousands of spider mites can cause thousands of lesions and thus can significantly reduce the photosynthetic capability of plants.^[1]

The mite's natural predator, Phytoseiulus persimilis, commonly used as a biological control method, is one of many predatory mites which prey mainly or exclusively on spider mites.^[1]

References