Tomato Russet Mites

Tomato russet mites are too small to see without a 14X lens, but the damage is easy to recognize.

Fruit damaged by tomato russet mites (OMAFRA) Public Domain

Symptoms of tomato russet mite infestations

​The first symptom of a tomato russet mite infestation is leaf stippling (yellow dots), which spreads to include the entire leaf. Leaves will then begin to curl and turn, you guessed it, russet colored. Stems and fruit also develop the same rough brown skin, and flower abortion is common. Symptoms usually start near the bottom of the plant and work their way up. Left uncontrolled, these pests can kill your tomato plant.

​More about mites

Mites have piercing mouthparts that are used to poke holes in a plant’s epidermis and to suck the life juices out of leaves, stems, and fruit. Like other mites, tomato russet mites (Aculops lycopersici) are more closely related to spiders than to other insects. They have eight legs and start out as an egg. These eggs are usually laid singly on the underside of leaves, in areas of new growth, cracks, or near pipes. When the eggs hatch, the larvae only have two legs. Then they go through two nymph stages. Unlike other common garden mites, tomato russet mites are in a separate family called gall mites. Gall mites are unique in that they create galls where they feed. The real problem with tomato russet mites is that they are so tiny (0.2 mm long and 0.05 mm wide); you can’t see them until the damage is extensive.

Mite controls

Mites love hot, dry conditions. They also seem to like dust, so keeping your plants relatively dust-free can reduce mite problems. Misting has also been shown to deter mites. These pests have many natural enemies, including predatory mites, predatory flies, and ladybugs. For this reason, broad spectrum pesticides should be avoided. These pests have demonstrated the ability to develop resistance to pesticides, so we don’t want to make them any more destructive than they already are! Sulfur dust and sulfur sprays can be used to get rid of mites organically.

Monitor your tomato plants weekly for signs of tomato russet mite infestation. Symptoms usually appear when the green fruit is 1 inch in diameter. Catching this pest early can save your plants!