Meet the Pest: Leaf Roller

Codling Moth LarvaLRX include oblique banded leafroller, Pandemis leafrollers and omnivorous leafroller

Certis Choice Solution:
 Deliver biological insecticide

Leafrollers are the second most important pest of apples in Washington state and the key pest in the apple production areas of the northeastern part of the United States. These pests, in their larval stages, damage fruit during three primary periods: 1) mid April to mid June, 2) late June to early August, and 3) late August to late September. Note that the obliquebanded leafroller has developed high levels of resistance to organophosphate insecticides in most North American apple producing areas.

It's a Huge Family

Leafrollers are members of the Tortricidae family, which include 5,000 species throughout the world. Tortricid larvae are polyphagous, feeding as leafrollers, leaf webbers, leafminers and stem, root, fruit and seed borers. Hosts include a wide variety of wood deciduous species, including cottonwood, rose, willow, alder and hawthorn. Pome and soft fruits (cherry, prune, plum and apricot) are adopted hosts.

A primary leafroller pest is the obliquebanded leafroller. It is native to and distributed throughout North America except for the arid southwest and northern Canada. It is the most important leafroller pest in the major apple producing states, including Washington, New York and Michigan.

Pandemis leafroller is a serious pest of apple, pears and some stone fruit throughout most of the United States and from Nova Scotia to southern British Columbia. In western North America, there are two species of Pandemis. P. limitata is found in southern British Columbia and P. pyrusana is found in Washington and Oregon.

Tufted apple budmoth is the key leafroller pest in Pennsylvania and northern Virginia, while the variegated leafroller is the principal leafroller pest in central Virginia. Redbanded leafroller is found in all the eastern apple-producing states, but it is less economically important than the other leafroller pests.

Omnivorous leafroller is an important pest of stone fruit and grapes in California. It is a less important pest on a variety of other hosts in Arizona, Florida, Illinois and Massachusetts.

Life History of Leafrollers

Female leafrollers lay egg masses of 50 to 200 eggs. Female obliquebanded leafrollers can lay up to 900 eggs during a seven to eight day oviposition.

Peak activity of the summer generation of adult occurs in mid- to late-August.

Hatch of the overwintering generation begins in late August and continues through September. Young larvae of the overwintering generation feed for a short time before seeking sites to construct overwintering hibernacula.

Life History of the Obliquebanded Leafroller (OBLR)

OBLR overwinter as first, second and third instar larvae within a hibernaculum located in the protected areas of the scaffold limbs, such as in small cracks and crevices or in the exfoliating bark. Young larvae of the overwintering generation become active in the spring as the young buds start to open. Most have left the hibernaculum by the half-inch green stage of apple development. The young larvae bore into developing fruit buds and later feed on expanding leaves and flower clusters. In Washington state, larvae are full grown by mid- to late May. In Michigan and New York, larvae are full grown by early to mid-June.

In Washington, the first adults of the overwintering generation can be detected in pheromone traps from late May to early June. Peak adult flight activity occurs from early to mid-June. In Michigan and New York, moths emerge from mid-June to mid-July with peak activity occurring towards the end of June.