Identification of the two-spotted spider mite on sugar beet

Two-spotted spider mites can cause defoliations under severe infestations of sugar beet. Natural predators are often used for control.

Scientific name: Tetranychus urticae

Two-spotted spider mites are small, round, yellowish-brown in appearance and have two dark spots on the abdomen.

They invade crops from their overwintering hosts on parachutes of silken threads blown in the wind. As such, they generally appear first on headlands.

Symptoms are yellow spots on the leaf surface and a dark colouration underneath, often with webs visible. They are visible with the naked eye. Damaged leaves die and defoliation can occur in severe infestations.

Two-spotted spider mites are favoured by warm, dry weather. Control is usually by natural predators.