Adults are buff colored with dark, irregular marking on wings. The eggs are laid in masses on the tree bark and overlap each other like fish scales. They are light green when laid, but turn to creamy white by spring. The young larvae are light green with a distinct dark brown head. Mature larvae are approximately three-fourths of an inch long and vary from light to dark green with dark brown heads.
Biology and Damage
A. rosanus overwinters in egg stage. Egg hatch in late March or early April depending on spring temperatures. The young larvae move to opening buds and feed on both sides of new leaves. Sometimes they web, developing buds and young foliage to form feeding nests. The larval period is about 6-8 weeks.Pupation occur within the rolled and webbed leaves. Pupation occur at the end of May and early June(in USA). Adults emergence occurs in the second week of June, and continues usually mid- August. Adults live for 2-4 weeks. Most egg laying occurs in June and July with an average of 50 eggs per female; the egg masses usually are found on tree trunks and major branches. It feeds on a large variety of shrubs and trees. In Turkey , in spite of presence on various fruit trees there is no record that it feed on hazelnut.
Larvae feed on developing buds and immature nuts and can deform them causing direct losses. They also leaves, tender terminal growth, newly formd nuts, and catkins. After hatching, larvae fold one or more leaves together and feed on the lesf tissue inside this shelter. Foliar damage is nor serious unless the larval population is very large.
USA: Filbert leafroller. TR: Yaprakbüken