Normally, we begin to see the first symptoms the end of June to the first part of July. Click picture for more information. 3. Larvae from the white pine weevil, Pissodes strobi, has caused damage which has become very apparent in recent weeks. White pine weevil adults chew holes to feed on leaders near terminal buds causing pitch flow. Trees. White Pine Weevil (Pissodes strobi) is a native conifer pest with a wide host appetite. The infested terminal can be clipped, and a new leader can be trained. The standard approach to manage white pine weevil is to spray insecticides in spring. Genetic resistance to this insect was demonstrated in early provenance trials in BC. The insect is sometimes referred to as spruce weevil in the western United States. <> These pictures were taken in Beaver County in early winter of 2016 on a 6-7' tall Colorado Spruce. 4 0 obj They can harm tree volume and wood quality by causing stem deformation and height loss. White pine weevil larvae kill the terminal leader and the top two to four years of growth on many varieties of spruce, as well as white and Scots pine trees. Non-chemical options: Only the top leader and upper branches of the tree are affected by the insect. White pine weevil is indigenous to North America. Root collar weevils are typically pests of young plantations and can cause mortality by feeding on a tree's root collar. Management: blue spruce. overwinter in leaf litter and debris around spruce trees. <> White pine weevil is indigenous to North America. One of the mandates of LaRueTree Certified Arborists is to inform people about trees and tree health for the benefit of homes, families and communities. It makes its living by residing in the very top of your spruce trees. Clean up duff around spruce … Its coloring is similar to the rice and maize weevils: reddish brown to black. endobj 2. endobj The adult is a small rust-colored weevil that is about 4-6 mm long. Prune out dead infested branches and destroy the branches. If the terminal leader of a Colorado blue spruce is brown and crooked like a cane, pull back a piece of the bark. As we begin this new year, I came to the realization that my informative blog posting has been lacking. Weevils. Further info can be obtained by calling LaRueTree Certified Arborists, Inc. And remember to look for the ISA Certifified Arborist designation when contacting a reputable tree service. These little insects are often found on pine and spruce trees. Feeding and Larval mining on and in the terminal leader of the tree does not cause mortality, but causes unsightly growth and structural defects. Damage from white pine weevil can be distinguished from other types of injury by the somewhat curled shape of the leader, sometimes referred to as a “shepherd’s crook” (see photo). WPW infestations start in early spring when overwintered females lay eggs just beneath the bark of terminal leaders. Scouting for white pine weevils in the nursery by beating the tree and counting weevils that fall onto a surface. If you look closely at the picture above, you can see the small entry hole where the weevil has deposited up to 100 eggs into the phloem layer of the tree. It will feed on white pine and spruce, causing the top terminal lead to die, which can disfigure an ornamental tree. The White Pine Weevil prefers to attack trees exposed to direct sunlight. The The adults hibernate in the duff underneath host trees. The presence of chip cocoons is diagnostic for white pine weevil. Eastern white pine is the insect’s preferred host, though infestations have also been reported on various other pine and spruce trees. (Moench) Voss) plantations in British Columbia (BC), Canada. %PDF-1.5 The white pine weevil often kills 2-3 years of … Lodgepole terminal weevil, Pissodes terminalis 22 Mammal damage 22 Spruce Pests 22 Spruce beetle, Dendroctonus rufipennis 22 Two-year-cycle spruce budworm, Choristoneura biennis 23 Spruce weevil, Pissodes strobi 24 Alpine Fir Pest 25 Western balsam bark beetle, Dryocoetes confusus 25 Western Hemlock Pest 25 A closely related species, Pissodes terminalis, causes similar injury to lodgepole pine in Colorado. At about 1/4 its body length, the granary weevil's long snout extends down from its head. The developing larvae feed in the leader until maturity in July. In late spring to early summer, weevils become active and seek out spruce trees. The adults normally overwinter under the canopy of the tree and emerge in the early spring (right after the snow melts or temps average in the 50’s). (261) Photo: John Davidson Feeding damage inside a terminal caused by white pine weevil. Pupation occurs in larval chambers made of wood chips. This insect kills the terminal leader of Eastern White Pines. The affected terminals wilt into a ‘shepherd’s crook’ form and the needles often become lighter colored before they ultimately die and drop. The larva will then tunnel around the terminal leader, eating the phloem tissue and girdling the terminal shoot. Not to be confused with western pine beetle, the white pine weevil infests and kills the terminal leader of young trees. Eastern white pine and Norway spruce appear to be two of its preferred hosts, although other pine and spruce, and Douglas-fir, are also suceptible. Normally, tree dieback does not extend beyond the previous year’s terminal growth. <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/Annots[ 10 0 R] /MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Females deposit eggs in the bark of the terminal growth, which hatch in 7-10 days. Although the weevil rarely kills an entire tree, it usually kills the terminal shoot and top one or two whorls of branches. Train a new leader from a lateral branch. %���� 1 0 obj Feeding and Larval mining on and in the terminal leader of the tree does not cause mortality, but causes unsightly growth and structural defects. Adult weevils fly to the terminal shoots of host trees and feed on bark tissue. First a few trees are attacked, then the population grows rapidly, resulting in rates of 20-50% of trees attacked per year. 1), causing formation of multiple trunks and bushy-topped trees. 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