Brown Mite

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Brown Mite

Bryobia rubrioculus


In a Nutshell

  • Leaves stippled with feeding marks and pale or bronzed appearance.
  • Deformation of leaves resulting in smaller, nearly flat and stiff blades.




Damage is similar to that caused by other spider mites. All motile stages feed from the underside of leaves and remove chlorophyll from the cells. The accumulation of feeding marks causes a stippling of the upper leaf side, which may also appear pale green, silvery or or bronzed. Because nutrients are not reaching the leaf tissues, those can grow fairly small, nearly flat, with stiff blades having almost no marginal serrations. However, defoliation is less likely with this species. The bark of the tree may also show discolorations. Generally these mites are not considered major pests and low to moderate numbers can be beneficial in spring by providing mite predators with a food supply. Infestations are generally confined to a few trees.


The brown mite is the largest in size of all almond pest mites and emerges first in the spring. Adults are flattened with long front legs, their body color is a dull reddish brown with dark orange markings. Unlike other types of fruit tree mites, they do not spin webs. Overwintering eggs are red, without a stalk, and laid in masses on twigs, especially at the junction of wood growth from the two previous seasons. Eggs hatch at the same time as leaf and flower buds open, on which they will later feed. The mites are active only during the cool parts of the day or during the night, and migrate off the leaves during midday to congregate on twigs. They are not active during hotter periods of the summer. There are 2 to 3 generations per year. Residues of certain pesticides, such as synthetic pyrethroids, can negatively impact the predators of the brown mite and lead to increases in populations.

Biological Control

Several species of mites, ladybirds, minute pirate bugs, predatory mirid bugs and brown lacewing are effective natural enemies of the brown mite. However, they may not be able control brown mite populations, if not used as part of an integrated pest management.

Chemical Control

Always consider an integrated approach with preventive measures together with biological treatments if available. Winter oils should be applied during spring (“dormant treatments”), resulting in decimation of the overwintering eggs on bark and branches. If infestations are severe in summer, use commercial miticides against the pest.

Preventive Measures

Plant resistant or tolerant varieties, if available in your area. Monitor the almond plantation for symptoms of the pest. Allow low populations of brown mites in the orchard during spring to enable predator populations to increase to levels that are more effective in controlling other types of mites. Remove severely infested tree parts, if no other treatment decimates the infestation. Make sure, not to use insecticides that kill the natural enemies of the brown mite.