PECAN LEAF CASEBEARER (PLC): Acrobasis juglandis (LeBaron) Order - Lepidoptera: Family -Pyralidae

DISTRIBUTION: PLCB is found in Ontario, Canada and in the United States from Vermont to Florida and North Dakota to New Mexico.

DESCRIPTION:Eggs are small (0.5-1 mm), oval, and white and are found on the undersides of leaflets. Larvae (Fig 1) have three pairs of thoracic legs and five pairs of prolegs. They are light green when young, becoming a darker jade color with shiny, dark brown heads as they age; larvae are about 16 mm long when mature. Half-grown and mature larvae are found on the undersides of leaflets in specially constructed silk cases that are 13-22 mm long. The cases are usually adorned with frass and droppings (see conical case Fig 1). Pupae are yellow-brown and about 6-9 mm long. Pupation occurs within the larval case. Adult moths (Fig 4) are 9-10 mm long and grayish brown with a patch of white and reddish scales just behind a dark band of scales that runs across the base of both wings.

HOSTS: Pecan, hickory, and walnut.

DAMAGE: During early spring small larvae attack unfolding buds and foliage. When infestations are heavy, they can keep trees partially defoliated for several weeks. Damaging infestations are cyclic. Late season larvae feed sparingly on undersides of leaflets and do little damage.

INSPECTION TIPS: Inspect twigs and damaged buds (Fig 3) and look for exposed larvae as trees begin new growth in the spring. During late Spring (Fig 1) and Summer (Fig 5), look for larvae in cases along the undersides of leaflets. Open leaflets that are bunched or damaged (Fig 2), especially if damage is associated with silk and excrement. Inspect bare root trees for small cocoons (hibernacula- Fig 6) on branches and near buds.

LIFE CYCLE: PLCB has one generation per year. Tiny larvae (2-3 mm) overwinter in silk cocoons (hibernacula – Fig 6) on twigs of the host, often near buds. In the spring they leave their cocoons and bore into nearby expanding buds. When half grown, larvae move to the undersides of leaflets and form and fasten silk cases from which to feed. Nearby leaflets are often tied down around the cases for protection and support. Pupation takes place within the larval case, and adults appear from mid-May until the first part of August. Female moths lay eggs on the undersides of the leaflets. Young larvae issuing from these eggs form small cases on the undersides of leaflets and feed sparingly until fall. As weather cools, larvae migrate from their small cases to sites where they will form their winter cocoons.

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