The white pine weevil is a native North American insect that poses a serious threat to spruce and pine trees across the continent, mostly in the northern US and Canada. Management: blue spruce. This weevil attacks the terminal leader of the tree, causing significant growth loss and deformities. %���� The larva will then tunnel around the terminal leader, eating the phloem tissue and girdling the terminal shoot. In late spring to early summer, weevils become active and seek out spruce trees. Legless larvae (grubs) feed on the inner bark and cambium layers that produce tree growth. White pine weevils overwinter as adults in litter beneath host trees. The insect is sometimes referred to as spruce weevil in the western United States. 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. Adult weevils fly to the terminal shoots of host trees and feed on bark tissue. These little insects are often found on pine and spruce trees. Non-chemical options: Only the top leader and upper branches of the tree are affected by the insect. The spruce terminal weevil, also known as the white pine weevil, attacks the upper (new) growth of evergreen trees (mainly spruces in our area). 3. ��!�X��a)��x{s�۱��){b���a�||`̢�U$��0�X�1^�H�e�E�p�}:W�! Scouting for white pine weevils in the nursery by beating the tree and counting weevils that fall onto a surface. First a few trees are attacked, then the population grows rapidly, resulting in rates of 20-50% of trees attacked per year. Trees. 1), causing formation of multiple trunks and bushy-topped trees. Adults are brown, about 0.25 inch long, and covered with white and tan scales, arranged in large and small spots. White Pine Weevil “Sitka spruce weevil” (Pissodes strobi) Look For: Damage is first noticed in the summer when the spruce terminal suddenly yellows and eventually loses its needles and turns brown (Figure 1). Feeding and Larval mining on and in the terminal leader of the tree does not cause mortality, but causes unsightly growth and structural defects. 4 0 obj endobj Treatments can take care of this pest, and sometimes it can simply be pruned out. Weevils. Adults emerge in 10-15 days and continue to feed on old and new growth. It infests and kills the main shoot (terminal leader) of young trees (Fig. The white pine weevil,Pissodes strobi, is a native North American insect that poses a serious threat to spruce and pine trees transcontinentally across the northern regions of the U.S. and adjoining Canada. 2 0 obj by W. Cranshaw The white pine weevil (Pissodes strobi) produces a conspicuous injury to the terminal growth of spruce trees. Train a new leader from a lateral branch. 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. The weevil is a small insect found commonly in Bozeman, MT and SW Montana. Root collar weevils are typically pests of young plantations and can cause mortality by feeding on a tree's root collar. overwinter in leaf litter and debris around spruce trees. Full Menu+. The eggs hatch in seven to ten days. They feed on the cambium of main branches near the leader and insert eggs into the feeding cavities that are formed. The developing larvae feed in the leader until maturity in July. White pine weevil adults chew holes to feed on leaders near terminal buds causing pitch flow. 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 At about 1/4 its body length, the granary weevil's long snout extends down from its head. The lodgepole terminal weevil attacks and kills the current year’s terminal growth on immature trees 2 to 7 m high. The larvae of white pine weevil are white, legless, and approximately 0.3 inch long when fully grown. Adult white pine weevils overwinter in litter on the ground. This young Colorado Blue Spruce tree is showing the telltale symptoms of Spruce Terminal Weevil. Photo by Laurie Kerzicnik. The lodgepole terminal weevil, Pissodes terminalis Hopping, feeds in the current year’s terminal growth causing dieback, height growth loss and consequent deformity in the main stem. Pupation occurs in larval chambers made of wood chips. 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). This insect is sometimes called the lodgepole pine terminal weevil.The white pine weevil (Pissodes strobi) produces a conspicuous injury t… x��ZK��8�7���GH�"�^�H:��&�]��9${P�j�[�Jr����b�)�jXLFQ$�^���!���7o�>>���E�����v�맜m�ۛ���p�E�"��'Q� stream This young Colorado Blue Spruce tree is showing the telltale symptoms of Spruce Terminal Weevil. Indeed, the WPWs love of spruce is exemplified by its alternate common name, Engelmann Spruce Weevil. The white pine weevil (figure 1) - Pissodes strobi (Peck) (Coleoptera: Curculionidae) - is a native insect attacking eastern white pine (Pinus strobus L.).The latest cytogenetic and breeding studies indicate that two other North American pine weevil species - the Sitka spruce weevil and the Engelmann spruce weevil-also should be classified as Pissodes strobi. (266) Photo: Chuck Cornell White pine weevil chip cocoons. If the terminal leader of a Colorado blue spruce is brown and crooked like a cane, pull back a piece of the bark. Injury by white pine weevil is almost entirely limited to higher elevation areas of the state and foothill areas. The larval stage, which lives beneath the bark, is white with a distinct brown head. Healthy environments are important to healthy communities, and trees play a huge role in healthy environments. The The adults hibernate in the duff underneath host trees. $��$��q�-V��=���a��@�H�, �Gq���"��˯�7��O����Wq�W��nWipܯ^�AS>����o+�������ۛ_�q��0J�"+ˆ�,?��9Q ��D⌇yʲ< ��"�c��q���ʒe)�5�Y�D�L" ��"��H��ᨯ"Rx��)Ks�5DJ����6���%��=h�~�����Ԍ�F��1ĥpw/K�����-�f圷��+)�0ք�Ë`�z-�����. Its larvae (soft, white grubs without legs) and white pupae are similar to those of the rice and maize weevil. endobj In layman's terms, the little grubs eat the insides of the shoot until the sap can't flow anymore. This insect kills the terminal leader of Eastern White Pines. endobj The White Pine Weevil is considered the most destructive pest of eastern white pine in North America. 3 0 obj Terminal weevils are found on pine and spruce throughout most regions in British Columbia. Like most weevils, the adult has a long snout-like beak from which small antennae arise. 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. 1-800-341-8733. White pine weevil is indigenous to North America. 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). The white pine weevil (Pissodes strobi) is often the most frequently discussed weevil pest of eastern white pine, however this insect can also be destructive of blue spruce. Eastern white pine is the insect’s preferred host, though infestations have also been reported on various other pine and spruce trees. 1 0 obj <>>> Removal of the infested part of the tree is important as well as future pruning and training in order to ensure a single dominant leader. Click picture for more information. The infested terminal can be clipped, and a new leader can be trained. (Spruce Trees) Terminal Weevil. April - June During this period, adult Where habitat conditions are suitable for the weevil, outbreaks develop in pine or spruce regeneration after the overstory is removed by natural (fire, windthrow, bark beetle) or man-made disturbance (harvesting). When mature, the larva is approximately 7 mm long, legless, and sli… A closely related species, Pissodes terminalis, causes similar injury to lodgepole pine in Colorado. (261) Photo: John Davidson Feeding damage inside a terminal caused by white pine weevil. Near the apex of the front wings is a large white patch. 1. Prune out dead infested branches and destroy the branches. White Pine Weevil (Pissodes strobi) is a native conifer pest with a wide host appetite. The adult is a small rust-colored weevil that is about 4-6 mm long. These pictures were taken in Beaver County in early winter of 2016 on a 6-7' tall Colorado Spruce. (\�ы It will feed on white pine and spruce, causing the top terminal lead to die, which can disfigure an ornamental tree. Eggs are laid in these holes and hatch. They can harm tree volume and wood quality by causing stem deformation and height loss. The Spruce Terminal weevil, also known as the White Pine Weevil, attacks the upper (new) growth of evergreen trees (mainly spruces in our area). The standard approach to manage white pine weevil is to spray insecticides in spring. 2. Blue spruce white pine weevil has one generation per year. (Moench) Voss) plantations in British Columbia (BC), Canada. They favor feeding on bark 7-10” below dormant terminal buds. Larvae from the white pine weevil, Pissodes strobi, has caused damage which has become very apparent in recent weeks. Normally, tree dieback does not extend beyond the previous year’s terminal growth. Normally, we begin to see the first symptoms the end of June to the first part of July. Not to be confused with western pine beetle, the white pine weevil infests and kills the terminal leader of young trees. As we begin this new year, I came to the realization that my informative blog posting has been lacking. Larvae from the white pine weevil, Pissodes strobi, has caused damage which has become very apparent in recent weeks. White pine weevil is a common pest in this area, but its damage is mostly cosmetic. Although the weevil rarely kills an entire tree, it usually kills the terminal shoot and top one or two whorls of branches. A closer view of the leader of this little spruce tree shows the entry site of the Spruce Weevil into the phloem layer of the terminal shoot. <> %PDF-1.5 The white pine weevil often kills 2-3 years of … The damage to the phloem layer is visible in this cross section of the terminal leader after it was pruned off of the tree. In late spring, new growth wilts and dies back. <> Typical damage to … The White Pine Weevil prefers to attack trees exposed to direct sunlight. <>/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>> White pine weevil is indigenous to North America. It makes its living by residing in the very top of your spruce trees. Genetic resistance to this insect was demonstrated in early provenance trials in BC. Eastern white pine is the insect’s preferred host, though infestations have also been reported on various other pine and spruce trees. Tree Pruning; Tree Removals; Its host range includes Scotch, jack, red, pitch, and eastern white pines as well as Douglas-fir and all spruces. It has irregularly shaped patches of brown and white scales on the front wings. White pine weevil damage on . Figure 1. Clean up duff around spruce … The resulting grub-like larvae are white, legless, and slightly curved. The insect is sometimes referred to as spruce weevil in the western United States. Eggs hatch in 1 - 2 weeks and the grubs tunnel downward underneath the bark. Its coloring is similar to the rice and maize weevils: reddish brown to black. From April to May, they emerge and begin feeding on terminal growth. 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. Indeed, the weevil's love of spruce is exemplified by its alternate common name, Engelmann Spruce Weevil, or simply Spruce Weevil. WPW infestations start in early spring when overwintered females lay eggs just beneath the bark of terminal leaders. 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. Females deposit eggs in the bark of the terminal growth, which hatch in 7-10 days. The presence of chip cocoons is diagnostic for white pine weevil. 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). The weevils then chew small pits in the leader and lay their eggs there in May. (265) Photo: Chuck Cornell Monitoring white pine weevil overwintering adults. Colorado Blue Spruce, Norway Spruce, Serbian Spruce, Scotch and Austrian Pines may also be attacked. Larvae of the white pine weevil kill the terminal leader and the top two to four years of growth on many varieties of spruce, as well as white and Scotch pine trees. 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