Introduction to defoliating insects - PDF document

Forest Health Protection Introduction to Defoliating Insects Chewed, mined, and missing foliage gible, some may cause signi�cant damage to individual trees. A few defoliators are important forest pests that can kill trees across large landscapes during outbreaks. Most of the important defoliating insects in conifers are the General Features • Generally, high levels of defoliation will occur for several consecutive years before trees are killed. ’s foliage, and their feeding loca tions and life cycles are timed accordingly. Figure 1. Photo: Ladd Livingston, Idaho Department of Lands, Bugwood.org. Figure 3. Western tent caterpillar is Photo: South - western Region, USDA Forest Service. Figure 2. Western spruce budworm is another Photo: Sco Tunnock, USDA Forest Service, Bugwood.org Forest Health Protection Table 1. Defoliator HostFeeding occurs Phyllocnistis populiella Thyridopteryx ephemeraeformis a Caloptilia negundella a Archips negunanus Chrysomela scripta Douglas-�r, true �rs, and spruce Orgyia pseudotsugata ) a Malacosoma americanum Chokecherry, fruit trees, and other hardwood trees and shrubsSpring to midsummer Xanthogaleruca luteola Kaliofenusa ulmi Hyphantria cunea Malacosoma disstria a Coleotechnites Ponderosa pine, pinyon pine, white �r, and blue spruce Generally, late summer to late spring; some variation with Archips semiferana Coloradia pandora Neophasia menapia Neodiprion Zadiprion a Malacosoma tigris Tiger moth ( Lophocampa . Ponderosa pine, pinyon pine, Douglas-�r, white �r, and junipers a Archips cerasivorana Western pine budworm Choristoneura lambertiana ponderosana ) Western pine tussock moth ( Dasychira grisefacta Western spruce budworm (�g. 2 Douglas-�r, true �rs, spruce Choristoneura occidentalis ) Western tent caterpillar (�g. 3) Malacosoma californicum ) a Introduction to Defoliating Insects - page 2