DOCSLIB.ORG

Aphid and Adelgid Pests of Conifers in Oregon J.D

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Aphid and Adelgid Pests of Conifers in Oregon J.D EC 1444 • November 1994 75¢ Aphid and Adelgid Pests of Conifers in Oregon J.D. DeAngelis his publication covers the Aphids are small, soft-bodied Aphid and adelgid life history important aphid and insects that suck plant sap from can be extremely complex, often adelgid pests of conifers in their hosts. Toxic or growth- involving more than one host TOregon, excluding those that regulating chemicals often are plant. Typically, there are several primarily feed on the roots of injected at the same time. parthenogenetic (asexual) genera- their host. Adelgids are closely related tions each year. The final genera- Conifers are plants that bear to aphids but are distinguished tion before winter may be cones as reproductive structures. from their better-known rela- sexual, and winter usually is Examples are pine, fir, spruce, tives because they feed only on spent in the egg stage. hemlock, Douglas-fir, and cedar. conifers, while aphids have host Many aphids and adelgids Aphids and adelgids can be plants in all plant families. secrete a white, waxy covering important pests in Christmas Adelgids currently are placed in from pores on the body. The wax tree plantations, conifer nurser- their own family, Adelgidae, provides protection against ies, and landscape plantings. The while aphids belong to the Identification Key lists the tree family Aphididae. Both families Jack D. DeAngelis, Extension species included in this publica- belong to the large and diverse entomologist, Oregon State tion and their pests. insect order Homoptera. University. Most Common Aphid and Adelgid Pests by Host Tree Tree Pests Douglas-fir (Pseudotsuga) Cooley spruce gall adelgid (secondary host; can reach pest status) conifer aphids (Cinara sp.) Grand fir (Abies grandis) balsam twig aphid (Mindarus abietinus) conifer aphids (Cinara sp.) balsam woolly adelgid (Adelges piceae) Noble fir (Abies nobilis) conifer aphids (Cinara sp.) balsam woolly adelgid (Adelges piceae) Pine (Pinus) conifer aphids (Cinara sp.) pine bark adelgid (Pineus strobi) Spruce (Picea) conifer aphids (Cinara sp.) spruce aphid (Elatobium abietinum) Cooley spruce gall adelgid (primary host; usually not a pest) Identification Key Important Aphid and Adelgid Pests of Northwest Conifers by Host Tree Tree and Symptoms Pests DOUGLAS-FIR (Pseudotsuga) Aphids without much waxy covering. Produce large amounts of honeydew, which may be attractive to ants and yellow jackets or covered by sooty mold ............................... conifer aphids (Cinara sp.) “Pepper” flecks (crawlers) on needles in late spring and/or white cottony tufts on needles before bud break or after about mid-June ..................................................................... Cooley spruce gall adelgid (Adelges cooleyi) TRUE FIRS (Abies) Aphids without much waxy covering. Produce large amounts of honeydew, which may be attractive to ants and yellow jackets or covered by sooty mold ............................... conifer aphids (Cinara sp.) Swelling (“gouting”) of branch nodes. Very small waxy adelgids may or may not be found. Trunk, branches, or twigs may be covered with white, waxy secretions in heavy infestations .............................................................................. balsam woolly adelgid (Adelges piceae) Twisting of new growth. Small greenish-yellow or bluish-gray aphids. Wax and honeydew may be present, causing needles to mat together ...................................................... balsam twig aphid (Mindarus abietinus) SPRUCE (Picea) Aphids without much waxy covering. Produce large amounts of honeydew, which may be attractive to ants and yellow jackets or covered by sooty mold ....................................... conifer aphids (Cinara sp.) Pineapple-shaped galls or cones on branch tips ........................... Cooley spruce gall adelgid (Adelges cooleyi) Twisting of new growth. Small greenish-yellow or bluish-gray aphids. Wax and honeydew may be present as well .................................................................................... balsam twig aphid (Mindarus abietinus) Old (more than 1-year-old) needles shed, especially on lower, shaded portions of tree. Aphids peak in late winter (February–March), decline toward summer. Small, green aphids .................................................................................................. spruce aphid (Elatobium abietinum) PINE (Pinus) Aphids without much waxy covering. Produce large amounts of honeydew, which may be attractive to ants and yellow jackets or covered by sooty mold ....................................... conifer aphids (Cinara sp.) White flocking on bark of branches and trunk. Trunk may appear “snow covered” .................................................................... pine bark adelgid (Pineus strobi) HEMLOCK (Tsuga) Aphids without much waxy covering. Produce large amounts of honeydew, which may be attractive to ants and yellow jackets or covered by sooty mold ............................... conifer aphids (Cinara sp.) Cottony tufts on bark and twigs. May seriously weaken ornamental trees ................................................................................ hemlock adelgid (Adelges tsugae) 2 water loss and predators. The When artificially presence or absence of wax injected, these substances often is a diagnostic feature can cause dramatic changes used for identification. in plant development. Aphid and adelgid identifica- Perhaps the best example is tion is difficult. The best place to the “pineapple” galls on start is with identification of the spruce that are formed by host tree since many of these growth hormones injected pests are specific to one type of by developing nymphs of host. Use the Identification Key as the Cooley spruce gall a starting point. adelgid. This pest is dis- cussed in greater detail Feeding habits and below. effects on host plants Life cycles Aphids and adelgids feed by Aphid and adelgid life piercing host tissue and with- cycles are so complex and drawing the plant’s sap through varied that we can make only straw-like mouthparts. This broad generalizations. For mode of feeding produces large example, in many species the amounts of honeydew—the feeding occurs on the secondary insect’s form changes depend- sticky, sugary liquid found host on needles or bark under a ing on host tree or season. below aphid or adelgid colonies. covering of wax. No galls are Reproduction can be complex Honeydew attracts ants, yellow formed on the secondary host. as well. At certain times of the jackets, and other scavengers Picea (spruce) normally is the year, no males are produced and and supports growth of a black primary host; and fir, larch, reproduction occurs asexually. fungus called sooty mold. Douglas-fir, hemlock, or pine is Even more strange, certain Aphids and adelgids feed on the secondary host. species sometimes give birth to needles, twigs, branches, trunks, live young and at other times and roots—in other words, lay eggs. virtually anywhere on the plant. Because these pests change However, each particular appearance from host to host species usually is confined to a Use pesticides safely! and season to season, it often is narrower range of feeding sites. better to identify aphids and • Wear protective clothing and While feeding, these pests adelgids based on the host tree. safety devices as recom- may inject toxins, growth- Generalized aphid life cycle. mended on the label. Bathe or regulating hormones, or plant Eggs overwinter on needles or shower after each use. pathogens into their host plant. bark. Young hatch in mid- Injection of plant toxins (tox- • Read the pesticide label— March, begin feeding, and emia) is observed most easily in even if you’ve used the develop into adults in April. broadleaf plants, where you pesticide before. Follow Several generations can be may find twisted, stunted closely the instructions on the produced during the warm growth above an aphid colony. label (and any other direc- months. Large colonies, often Plant viruses also can be trans- tions you have). attended by ants, develop on mitted between plants by aphid • Be cautious when you apply twigs and branches. These feeding, but this is not known to pesticides. Know your legal colonies produce copious occur in conifers. responsibility as a pesticide amounts of honeydew. Both Compounds that resemble applicator. You may be liable winged and wingless forms can natural plant growth hormones for injury or damage resulting be found in the same colony. are injected by some conifer- from pesticide use. Generalized adelgid life feeding aphids and adelgids cycle. The complete life cycle while they feed. These sub- takes 2 years and involves two stances mimic natural plant hosts, a primary host and a chemicals that regulate growth secondary host. A gall is pro- and reproduction. duced on the primary host, while 3 Pest descriptions make galls on spruce. It is, even after the adelgids them- however, the most common and selves are gone. Infestation Cooley spruce gall adelgid is the one that alternates with causes bud deformity, branch (Adelges cooleyi) has an ex- Douglas-fir. It also may persist die-back, and damage to parts tremely complex life cycle, part on Douglas-fir by reproducing of the outer bark. of which is spent on spruce parthenogenetically for many Severe infestations can leave while the other part is completed generations. the entire trunk covered with on Douglas-fir. The complete Balsam woolly adelgid waxy secretions. At this point, cycle may extend over 2 years (Adelges piceae)
Load more

Recommended publications
  • Zootaxa,Phylogeny and Higher Classification of the Scale Insects
    Zootaxa 1668: 413–425 (2007) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ ZOOTAXA Copyright © 2007 · Magnolia Press ISSN 1175-5334 (online edition) Phylogeny and higher classification of the scale insects (Hemiptera: Sternorrhyncha: Coccoidea)* P.J. GULLAN1 AND L.G. COOK2 1Department of Entomology, University of California, One Shields Avenue, Davis, CA 95616, U.S.A. E-mail: [email protected] 2School of Integrative Biology, The University of Queensland, Brisbane, Queensland 4072, Australia. Email: [email protected] *In: Zhang, Z.-Q. & Shear, W.A. (Eds) (2007) Linnaeus Tercentenary: Progress in Invertebrate Taxonomy. Zootaxa, 1668, 1–766. Table of contents Abstract . .413 Introduction . .413 A review of archaeococcoid classification and relationships . 416 A review of neococcoid classification and relationships . .420 Future directions . .421 Acknowledgements . .422 References . .422 Abstract The superfamily Coccoidea contains nearly 8000 species of plant-feeding hemipterans comprising up to 32 families divided traditionally into two informal groups, the archaeococcoids and the neococcoids. The neococcoids form a mono- phyletic group supported by both morphological and genetic data. In contrast, the monophyly of the archaeococcoids is uncertain and the higher level ranks within it have been controversial, particularly since the late Professor Jan Koteja introduced his multi-family classification for scale insects in 1974. Recent phylogenetic studies using molecular and morphological data support the recognition of up to 15 extant families of archaeococcoids, including 11 families for the former Margarodidae sensu lato, vindicating Koteja’s views. Archaeococcoids are represented better in the fossil record than neococcoids, and have an adequate record through the Tertiary and Cretaceous but almost no putative coccoid fos- sils are known from earlier.
    [Show full text]
  • Impact of Imidacloprid and Horticultural Oil on Nonâ•Fitarget
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 8-2007 Impact of Imidacloprid and Horticultural Oil on Non–target Phytophagous and Transient Canopy Insects Associated with Eastern Hemlock, Tsuga canadensis (L.) Carrieré, in the Southern Appalachians Carla Irene Dilling University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Part of the Entomology Commons Recommended Citation Dilling, Carla Irene, "Impact of Imidacloprid and Horticultural Oil on Non–target Phytophagous and Transient Canopy Insects Associated with Eastern Hemlock, Tsuga canadensis (L.) Carrieré, in the Southern Appalachians. " Master's Thesis, University of Tennessee, 2007. https://trace.tennessee.edu/utk_gradthes/120 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Carla Irene Dilling entitled "Impact of Imidacloprid and Horticultural Oil on Non–target Phytophagous and Transient Canopy Insects Associated with Eastern Hemlock, Tsuga canadensis (L.) Carrieré, in the Southern Appalachians." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Entomology and Plant Pathology. Paris L. Lambdin, Major Professor We have read this thesis and recommend its acceptance: Jerome Grant, Nathan Sanders, James Rhea, Nicole Labbé Accepted for the Council: Carolyn R.
    [Show full text]
  • Canopy Arthropod Community Structure and Herbivory in Old-Growth and Regenerating Forests in Western Oregon
    318 Canopy arthropod community structure and herbivory in old-growth and regenerating forests in western Oregon T. D. SCHOWALTER Department of Entomology, Oregon State University, Corvallis, OR 97331-2907, UtS.A. Received June 30, 1988 Accepted October 19, 1988 SCHOWALTER, T. D. 1989. Canopy arthropod community structure and herbivory in old-growth and regenerating forests in western Oregon. Can. J. For. Res. 19: 318-322. This paper describes differences in canopy arthropod community structure and herbivory between old-growth and regenerating coniferous forests at the H. 3. Andrews Experimental Forest in western Oregon. Species diversity and functional diversity were much higher in canopies of old-growth trees compared with those of young trees. Aphid bio- mass in young stands was elevated an order of magnitude over biomass in old-growth stands. This study indicated a shift in the defoliator/sap-sucker ratio resulting from forest conversion, as have earlier studies at Coweeta Hydrologic Laboratory, North Carolina. These data indicated that the taxonomically distinct western coniferous and eastern deciduous forests show similar trends in functional organization of their canopy arthropod communities. SCHOWALTER, T. D. 1989. Canopy arthropod community structure and herbivory in old-growth and regenerating forests in western Oregon. Can. J. For. Res. 19 : 318-322. Cet article expose les differences observees dans la structure communautaire des arthropodes du couvert foliace et des herbivores entre des forets de coniferes de premiere venue et en regeneration a la Foret experimentale H. J. Andrews dans louest de lOregon. La diversit y des especes ainsi que la diversit y fonctionnelle etaient beaucoup plus grandes dans les couverts foliaces des vieux arbres que dans ceux des jeunes arbres.
    [Show full text]
  • Spruce Gall Adelgids by the Bartlett Lab Staff Directed by Kelby Fite, Phd
    RESEARCH LABORATORY TECHNICAL REPORT Spruce Gall Adelgids By The Bartlett Lab Staff Directed by Kelby Fite, PhD The Eastern spruce gall adelgid (Adelgis abietis) and the Cooley spruce gall adelgid (Adelgis cooleyi) inflict considerable injury to ornamental spruce trees throughout the Northeast and Midwest. Both insects cause the formation of cone-like galls on developing twigs, which deform, stunt and usually girdle them. Heavy and repeated infestations will seriously disfigure and weaken trees, and render them more susceptible to invasion by disease causing organisms and other insects. Eastern Spruce Gall Cooley Spruce Gall The Eastern spruce gall adelgid primarily attacks The Cooley spruce gall adelgid primarily infests blue, Norway and white spruce, causing the formation of Englemann and Sitka spruce and Douglas fir. Galls pineapple-shaped galls approximately one inch long at caused by this insect are elongated, one to three inches the base of developing twigs (Figure 1). Newly long, and occur at the tips of twigs (Figure 2). The hatched nymphs begin feeding near the base of life cycle of this insect on spruce is similar to the expanding buds in early spring. Feeding induces the Eastern spruce gall adelgid. In spring, nymphs feed formation of the galls, inside which the nymphs on the succulent new growth, causing needle continue to feed and develop. In late summer distortion and browning; however, galls do not form. (August through September), galls open and fully- In mid- to late summer (mid-July through August), grown nymphs emerge. These become winged nymphs mature to form winged adults. Adults adults, which can fly to nearby susceptible deposit eggs on twigs of either spruce or Douglas fir spruce trees.
    [Show full text]
  • PINE BARK ADELGID Hemiptera Adelgidae
    PINE BARK ADELGID Hemiptera Adelgidae: Pineus strobi (Htg.) By Scott Salom and Eric Day DISTRIBUTION AND HOSTS: The pine bark adelgid is widely distributed in North America, occurring principally throughout the native range of eastern white pine. This insect is also found on Scots and Austrian pine. DESCRIPTION OF DAMAGE: Adelgids feed on tree trunks by sucking sap from the phloem tissue. Trunks of heavily infested trees often appear white- washed from the woolly masses these tiny insects secrete over themselves for protection. Small nursery stock, ornamental trees, and trees in parks can be heavily attacked. In severe cases, feeding can cause bud proliferation and give the tops of the trees a bushy “witches broom” appearance. However, if the trees are otherwise healthy, permanent damage should not result. In eastern white pine plantations of a forest setting, repeatedly infested mature pine trees apparently suffer no serious harm. IDENTIFICATION: Adelgids are similar to aphids, except they have shorter antennae and lack cornicles (or bumps) on their abdomen. They live under a woolly mass they secrete for protection. If this mass is pulled off the trunk, black teardrop- shaped insects with short legs are revealed. When populations are high, the woolly masses coalesce into one large mass on the Pine Bark Adelgid on white pine trunks. LIFE HISTORY: Overwintering immature adelgids will begin feeding during the first days of warm weather, and secrete woolly tufts. Once these insects develop to adults (April to May), egg laying begins. Eggs hatch into crawlers, which can move to other parts of the tree or be blown to other trees.
    [Show full text]
  • Minor Insect Pests of Trees Diane G
    Minor Insect Pests of Trees Diane G. Alston Extension Entomologist Utah State University 2004 Professional Tree Care Workshops Topics • Introduction – IPM strategies • Beneficial arthropods - Conservation • Aphids • Scales • Spider mites • Cooley spruce gall adelgid • Root weevils • Leaf beetles • Earwigs • Snails/Slugs • Boxelder bug Integrated Pest Management IPM The practice of using multiple techniques to manage pests (e.g., cultural, mechanical, biological and chemical controls) while minimizing negative impacts to the environment. Use of pest controls are based on a “real need” (thresholds) Economically viable Management Strategies for Minor Insect Pests of Trees • Wait and See • Most are secondary pests and often do not increase to problem levels • Sporadic pests or populations too low to cause injury • Plants can tolerate injury • Foliar or flower feeding, bud or twig feeding • Cultural practices to keep plants healthy – resist secondary pests • Preventive tactics for annual/frequent pests • Dormant oil sprays Most insects are beneficial or have no direct impact Beneficial Insects & Mites Parasitoids Predaceous Bugs Lacewing Common Aphid Predaceous Mites Predators Lady Beetle Conservation of Natural Enemies • Provide attractive resources (food, shelter, diversity of conditions) • Many herbs (basil, coriander, thyme, dill, lavender, fennel, chamomile, etc.) • Many native and wild flowers (yarrow, columbine, mallow, penstemon, goldenrod, stonecrop, speedwell, etc.) • Avoid harmful practices (toxic insecticides, “clean farming”) Aphids
    [Show full text]
  • Insects That Feed on Trees and Shrubs
    INSECTS THAT FEED ON COLORADO TREES AND SHRUBS1 Whitney Cranshaw David Leatherman Boris Kondratieff Bulletin 506A TABLE OF CONTENTS DEFOLIATORS .................................................... 8 Leaf Feeding Caterpillars .............................................. 8 Cecropia Moth ................................................ 8 Polyphemus Moth ............................................. 9 Nevada Buck Moth ............................................. 9 Pandora Moth ............................................... 10 Io Moth .................................................... 10 Fall Webworm ............................................... 11 Tiger Moth ................................................. 12 American Dagger Moth ......................................... 13 Redhumped Caterpillar ......................................... 13 Achemon Sphinx ............................................. 14 Table 1. Common sphinx moths of Colorado .......................... 14 Douglas-fir Tussock Moth ....................................... 15 1. Whitney Cranshaw, Colorado State University Cooperative Extension etnomologist and associate professor, entomology; David Leatherman, entomologist, Colorado State Forest Service; Boris Kondratieff, associate professor, entomology. 8/93. ©Colorado State University Cooperative Extension. 1994. For more information, contact your county Cooperative Extension office. Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture,
    [Show full text]
  • About the Book the Format Acknowledgments
    About the Book For more than ten years I have been working on a book on bryophyte ecology and was joined by Heinjo During, who has been very helpful in critiquing multiple versions of the chapters. But as the book progressed, the field of bryophyte ecology progressed faster. No chapter ever seemed to stay finished, hence the decision to publish online. Furthermore, rather than being a textbook, it is evolving into an encyclopedia that would be at least three volumes. Having reached the age when I could retire whenever I wanted to, I no longer needed be so concerned with the publish or perish paradigm. In keeping with the sharing nature of bryologists, and the need to educate the non-bryologists about the nature and role of bryophytes in the ecosystem, it seemed my personal goals could best be accomplished by publishing online. This has several advantages for me. I can choose the format I want, I can include lots of color images, and I can post chapters or parts of chapters as I complete them and update later if I find it important. Throughout the book I have posed questions. I have even attempt to offer hypotheses for many of these. It is my hope that these questions and hypotheses will inspire students of all ages to attempt to answer these. Some are simple and could even be done by elementary school children. Others are suitable for undergraduate projects. And some will take lifelong work or a large team of researchers around the world. Have fun with them! The Format The decision to publish Bryophyte Ecology as an ebook occurred after I had a publisher, and I am sure I have not thought of all the complexities of publishing as I complete things, rather than in the order of the planned organization.
    [Show full text]
  • Hemiptera: Adelgidae)
    The ISME Journal (2012) 6, 384–396 & 2012 International Society for Microbial Ecology All rights reserved 1751-7362/12 www.nature.com/ismej ORIGINAL ARTICLE Bacteriocyte-associated gammaproteobacterial symbionts of the Adelges nordmannianae/piceae complex (Hemiptera: Adelgidae) Elena R Toenshoff1, Thomas Penz1, Thomas Narzt2, Astrid Collingro1, Stephan Schmitz-Esser1,3, Stefan Pfeiffer1, Waltraud Klepal2, Michael Wagner1, Thomas Weinmaier4, Thomas Rattei4 and Matthias Horn1 1Department of Microbial Ecology, University of Vienna, Vienna, Austria; 2Core Facility, Cell Imaging and Ultrastructure Research, University of Vienna, Vienna, Austria; 3Department of Veterinary Public Health and Food Science, Institute for Milk Hygiene, Milk Technology and Food Science, University of Veterinary Medicine Vienna, Vienna, Austria and 4Department of Computational Systems Biology, University of Vienna, Vienna, Austria Adelgids (Insecta: Hemiptera: Adelgidae) are known as severe pests of various conifers in North America, Canada, Europe and Asia. Here, we present the first molecular identification of bacteriocyte-associated symbionts in these plant sap-sucking insects. Three geographically distant populations of members of the Adelges nordmannianae/piceae complex, identified based on coI and ef1alpha gene sequences, were investigated. Electron and light microscopy revealed two morphologically different endosymbionts, coccoid or polymorphic, which are located in distinct bacteriocytes. Phylogenetic analyses of their 16S and 23S rRNA gene sequences assigned both symbionts to novel lineages within the Gammaproteobacteria sharing o92% 16S rRNA sequence similarity with each other and showing no close relationship with known symbionts of insects. Their identity and intracellular location were confirmed by fluorescence in situ hybridization, and the names ‘Candidatus Steffania adelgidicola’ and ‘Candidatus Ecksteinia adelgidicola’ are proposed for tentative classification.
    [Show full text]
  • Adelgid and Scale Insect Guilds on Hemlock and Pine
    ADELGID AND SCALE INSECT GUILDS ON HEMLOCK AND PINE MARK S. McCLURE Connecticut Agricultural Experiment Station Valley Laboratory, P.O. Box 248, 153 Cook Hill Road Windsor, CT 06095 U.S.A. INTRODUCTION Five piercing and sucking insects which were accidentally introduced from Asia during this century, together with one native species, have become very serious pests of two important forest tree species in the northeastern United States. Two armored scales, Fwrinia atma Ferris and Nuculaspis tsugae (Marlatt), and an adelgid, Adelges tsugae Annand, attack eastern hemlock, Tsuga canadensis Carriere (Fig. 1). A margarodid scale, Matsucoccus resinosae Bean and Godwin, and two adelgids, Pineus bwmeri Annand and Pineus coloradensis (Gillette), attack red pine, Pinus resinosa Aiton (Fig. 2). In Japan, their homeland, F. mema and A? tsugae are common inhabitants of two native hemlocks, Tsuga diversifolia Masters and Tsuga sieboldii Carriere. However, these scales seldom attain injurious densities in Japan. Both scales were introduced accidentally into the vicinity of New York City about 80 years ago and have since become serious pests of T. canadensis in several northeastern states (Fig. 3). Both scales feed together on the needles of hemlock by sucking cell fluids from the mesophyll. In the United States their densities often increase rapidly to levels which cause needles to discolor and drop prematurely and branches to die. Many ornamental and forest trees have been killed in 10 or fewer years after infestation. Adelges tsugae is probably also native to Japan, where it is a harmless inhabitant of T. diversifolia and T. siebokiii. This adelgid was first noticed in North Amerifa 70 years ago on Tsuga heterophylla Sargent in British Columbia.
    [Show full text]
  • Cooley Spruce Gall Adelgid
    Cooley Spruce Gall Adelgid Mary Ridout, Graduate Student Plant Science 464, Fall 2007 Figure 1. Infested white spruce at the University of Idaho Plant Science Farm Cooley spruce gall adelgid damage was found on a White spruce (Picea glauca) at the University of Idaho Plant Science farm just outside Moscow, Idaho. The diagnosis was made from the observation of galls at or near the terminal ends of the branches (see Figure 1). Only new growth from the current year was affected. Galls were first observed early in the summer on terminal new growth as soft swollen tissue surrounding the needles. Some of these galls were green; others were beginning to turn a brownish purple. Figure 1 shows the appearance of the gall in late summer and fall. The plant itself was growing well, but damage from previous infestations was visible in slightly distorted growth caused by the loss of the terminal branch ends which induced lateral bud formation and branching and thereby formation of “shrubby” branches and asymmetrical growth habit. Spruce galls are caused by the Cooley spruce gall adelgid (Adelges cooleyi). A small aphid-like insect, the Cooley spruce gall adelgid alternates its life cycle between Picea species and Douglas Fir (Pseudotsuga menziesii). Galls, however, are only formed on spruce. While most commonly found on Colorado blue spruce, adelgids will also infest white, Engelmann, Norway, and Sitka spruce. Reproductive female adelgids over-winter on the undersides of the branches. When spring comes, they emerge and move to the new growth at the branch terminals where they lay their eggs at the base of the needles.
    [Show full text]
  • Biological Control of Hemlock Woolly Adelgid
    Forest Health Technology Enterprise Team TECHNOLOGY TRANSFER Biological Control BIOLOGICAL CONTROL OF HEMLOCK WOOLLY ADELGID TECHNICALCONTRIBUTORS: RICHARD REARDON FOREST HEALTH TECHNOLOGY ENTERPRISE TEAM, USDA FOREST SERVICE, MORGANTOWN, WEST VIRGINIA BRAD ONKEN FOREST HEALTH PROTECTION, USDA FOREST SERVICE, MORGANTOWN, WEST VIRGINIA AUTHORS: CAROLE CHEAH THE CONNECTICUT AGRICULTURAL EXPERIMENT STATION MIKE MONTGOMERY NORTHEASTERN RESEARCH STATION SCOTT SALEM VIRGINIA POLYTECHNIC INSTITUTE AND STATE UNIVERSITY BRUCE PARKER, MARGARET SKINNER, SCOTT COSTA UNIVERSITY OF VERMONT FHTET-2004-04 U.S. Department Forest of Agriculture Service FHTET he Forest Health Technology Enterprise Team (FHTET) was created in T1995 by the Deputy Chief for State and Private Forestry, USDA, Forest Service, to develop and deliver technologies to protect and improve the health of American forests. This book was published by FHTET as part of the technology transfer series. http://www.fs.fed.us/foresthealth/technology/ On the cover Clockwise from top left: adult coccinellids Sasajiscymnus tsugae, Symnus ningshanensis, and Scymnus sinuanodulus, adult derodontid Laricobius nigrinus, hemlock woolly adelgid infected with Verticillium lecanii. For copies of this publication, please contact: Brad Onken Richard Reardon Forest Health Protection Forest Health Technology Enterprise Morgantown, West Virginia Team Morgantown, West Virginia 304-285-1546 304-285-1566 [email protected] [email protected] All images in the publication are available online at http://www.forestryimages.org and http://www.invasive.org Reference numbers for the digital files appear in the figure captions in this publication. The entire publication is available online at http://www.bugwood.org and http://www.fs.fed.us/na/morgantown/fhp/hwa. The U.S.
    [Show full text]