Description:

Numerous species of mites have been found on pecan leaves.  Of these, seven species are common.  All have eight legs but are tiny and difficult to see without magnification.  The most common damaging species, the pecan leaf scorch mite, a spider mite, is greenish in color and may be found congregating near the mid-rib of leaflets (Figure 5). 

Damage:

Mites destroy leaflet tissue by their feeding, causing leaflets to have a scorched appearance.  Fresh scorch injury appears as dark brown blotches (Figure 6).  Severely injured leaflets turn entirely brown and drop. Damage most often begins along the mid-rib and spreads outward toward the leaf margins.  Damage to a tree usually begins on the lowest branches in the interior of the tree and progresses upward through the tree. Damage is most severe in late summer and fall.

Seasonal History:

When to Control:

Materials used for aphid control sometimes keep mite populations suppressed.  In late season, however, mite populations can become so heavy that these materials will not provide good control.  Some insecticides, which kill beneficial organisms but not mites, can actually cause mite problems to increase. Specific controls should be applied when mites and mite damage appears frequently and generally on the foliage of low limbs (in 25% of leaves sampled).  Spot treatments are often possible.