Leafrollers on Ornamental and Fruit Trees
LeafroLLers on ornamentaL and fruit trees Integrated Pest Management for Home Gardeners and Landscape Professionals Leafrollers, the larvae of certain tortri- cid moths, often feed and pupate with- in the protection of rolled-up leaves. Several species can cause problems on fruit and ornamental trees in Cali- fornia. The fruittree leafroller, Archips argyrospila, is the most common lea- froller pest in landscapes throughout the state. It occurs on many ornamental trees—including ash, birch, California Figure 3. Fruittree leafroller larva feed- buckeye, box elder, elm, locust, maple, ing inside a leaf it has rolled, or webbed, poplar, rose, and willow—and is par- together. ticularly damaging to deciduous and live oaks. It also attacks numerous fruit and nut trees including almond, apple, apricot, caneberries, cherry, citrus, pear, plum, prune, quince, and walnut. Figure 1. Unhatched (top) and hatched (at bottom with holes) fruittree leafroller eggs. Other leafrollers include the obliqueband- ed leafroller, Choristoneura rosaceana, and the omnivorous leafroller, Platynota stul- tana, which are serious problems on fruit trees. The orange tortrix, Argyrotaenia franciscana, and apple pandemis, Pandemis pyrusana, are pests that occur through- out the year primarily on fruit trees and vines in coastal areas of California. A new invader, the light brown apple Figure 2. Omnivorous leafroller eggs. moth (LBAM), Epiphyas postvittana, re- Figure 4. Fruittree leafroller larva de- scending on its silken thread. cently has invaded the northern coastal smaller branches. At first a dark gray areas of the state, and high populations or brown “cement” coats the mass; this are found in areas with cool summers later bleaches to white.
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