Walnut Shoot Moth – Acrobasis demotella

Walnut Shoot Moth (Acrobasis demotella)

Latin Name: Acrobasis demotella

Common Name: Walnut Shoot Moth

Appearance:

Eggs:

Elliptical, ivory white, convex above flattened below, with an epithelial pattern on the surface; 0.28 by 0.71

Larva:

• Dark purple-brown, 17 mm long when mature, with 1.39 to 1.52 mm wide head capsules.
• Dark brown patches on a reddish-brown to brown head.
• Yellow-brown thoracic shield with dark brown lateral borders.
• Pinacula is a pale brown to brown integument with the same color or darker than the surrounding integument.

Pupa:

Reddish-brown as well as 7.5 to 8.5 mm long. Distally, the head is tiny and rounded. The prothorax and mesothorax are wrinkled.

Adult:

Brownish grey moth with a 20 to 24 mm wingspan. Brownish grey background with three contrasting reddish-brown patches basally, medially, and distally on forewings). Females have a deeper pink or reddish suffusion on their head and thorax than males.

Host Plants:

Walnut, hickory, pecan. Black walnut

Territory: It is found in North America and throughout the range of its hosts,

Damages caused by Walnut Shoot Moth:

Early-stage larvae bore into growing terminal-bud clusters in the spring, unfolding buds. It can destroy all buds in a collection, resulting in blunt shoots or forked crowns. Nodes that have been infested may be entirely hollow. Repeated assaults on young black walnut trees cause forking, branching, slowed growth, and eventually misshape trees, lowering their value as timber.

Description about Leafminers:

Leafminer adults are tiny flies with yellow areas on their thorax, legs, and abdomen. They are 0.1 inches (2.5 mm) long, black to blue, and have yellow portions on their thorax, legs, and stomach. There is frequently a visible yellow patch towards the base of the wings. The white eggs are hidden behind the leaf’s epidermis and hatch in 4 to 6 days. Maggot larvae are typically buried between leaf surfaces in the mines where they feed; they range in color from yellow to white, are 0.25 to 0.33 inches long, flat at the back end and pointed in front, and are 0.25 to 0.33 inches long, blunt at the back end and pointed in front. Pupation is carried out underground or in mines. During the summer, the life cycle lasts around 23 days

Life history and Habit:

 

Females lay eggs singly on the undersides of growing leaflets, generally near the basal half’s lead midrib. Newly hatched larvae leave the egg chorions and build trumpet-shaped frass “plastered” enclosures onto a silken framework. Larvae overwinter in hibernacula, emerge in the spring at the period of bud swell, and feed on increasing buds as third-instar larvae. Shoot tips that extend beyond the larval tunnels wilt and perish. By late April and mid-June, mature (fifth-instar) larvae have finished eating in shoots and have exited through entry holes. Mature larvae pupate in slender cocoons made of soil particles just below the soil surface. There has been a record of one generation every year.