Pecan Pest Seasonal Profiles

Mites

Pecan leaf scorch mite, Female and egg Photo by Jerry A. Payne, USDA-ARS	Pecan leaf scorch mite, damage, Photo by Jerry A. Payne, USDA-ARS

The pecan leaf scorch mite is the most important spider mite attacking pecans.

Damage: Large numbers of these tiny mites feed under thin, silken webs often found on the undersides of pecan leaves. Mites suck plant sap, causing irregular brown spots on infested leaves. Infestations often develop first along the leaf midrib. Damaged leaves appear russeted or scorched. Large infestations can result in leaf loss, especially if trees are under moisture stress

Biology: Scorch mites overwinter as adults in the rough bark of limbs. Adult females begin laying eggs in the spring. Mites can complete a generation in 5 to 15 days and are more numerous during hot, dry weather. Natural enemies of scorch mites, including predatory mite species, are important in controlling these pests.

Control: Scorch mites prefer the shady, interior portion of the tree and significant damage can occur before infestations are detected. Check water sprouts and shady, lower branches to detect early mite infestations. Mites may increase following the use of some insecticides (e.g., Sevin®) applied for hickory shuckworm, aphids or other pests. Monitor the orchard for mites when the weather is hat and dry and after insecticides are used. Spray when mites are present and damaging leaves. Mark infested trees or areas to determine if spot treatment is practical.