Walnut Husk Fly: Identification, Damage, and Limited Control

Pest ID

Small white worms between nut and green husk = walnut husk fly (Rhagoletis completa) or husk maggot (Rhagoletis suavis). Adults: light brown, two transparent wings with dark crossbars. Larvae: legless, pale yellow, up to ½".

Damage

• Larvae tunnel in husk → black, slimy, sticky husks.
• Nutmeat usually unaffected (flavor/color OK).
• Husk removal difficult; commercial value lost.

Control Reality

• Single tree: Nearly impossible. Flies come from neighbors' trees.
• Neighborhood-wide: Coordinated spraying needed.
• Insecticides: Malathion EC, Fruit & Berry Insect Spray. Timing: husk split (early autumn).
• Sanitation: Pick up & destroy infested nuts (reduces next year's population).

Homeowner Strategy

Accept some damage. Wear gloves hulling. Nutmeat is edible. Focus on sanitation.

This is a community pest, not a solo battle. Talk to neighbors about coordinated management.