DOCSLIB.ORG

Lethal and Sublethal Effects of Imidacloprid on Hemlock Woolly Adelgid (Hemiptera: Adelgidae) and Two Introduced Predator Species

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lethal and Sublethal Effects of Imidacloprid on Hemlock Woolly Adelgid (Hemiptera: Adelgidae) and Two Introduced Predator Species FOREST ENTOMOLOGY Lethal and Sublethal Effects of Imidacloprid on Hemlock Woolly Adelgid (Hemiptera: Adelgidae) and Two Introduced Predator Species 1,2 1 1 3 BRIAN M. EISENBACK, SCOTT M. SALOM, LOKE T. KOK, AND ANTHONY F. LAGALANTE J. Econ. Entomol. 103(4): 1222Ð1234 (2010); DOI: 10.1603/EC09270 ABSTRACT Eastern hemlock, Tsuga canadensis (L.) Carrie`re, branchlets were systemically treated with imidacloprid and bioassayed with hemlock woolly adelgid, Adelges tsugae (Annand) (Hemiptera: Adelgidae), and predators. After 10 d, two hemlock woolly adelgid predators, Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae Sasaji & McClure (Coleoptera: Coc- cinellidae), were allowed to feed on remaining hemlock woolly adelgid for 20 d on branches systemically treated with 1, 10, or 100 ppm imidacloprid. Every 5 d, mortality, mobility (measured as ßip time), number of hemlock woolly adelgid consumed, and degree of intoxication of each individual beetle were recorded. Liquid chromatography-mass spectrometry was used to quantify imidacloprid and some of its major metabolites in hemlock wood tissues and in the predator beetles postmortem. Probit analysis of hemlock woolly adelgid mortality and imidacloprid concentrations recovered from branch wood tissues determined the 30 d LC50 to be 242 ppb. A topical application of imidacloprid to the ventral abdomen of individual beetles resulted ina6dLD50 value of 1.8 and 0.71 ng imidacloprid per beetle for L. nigrinus and S. tsugae, respectively. In no-choice tests, L. nigrinus mortality was signiÞcantly higher on hemlock branchlets treated with 100 ppm imidacloprid than on controls, but S. tsugae mortality was not. S. tsugae consumed the same number of adelgids on treated branchlets as on controls, but L. nigrinus consumed fewer adelgids from the 100 ppm branchlets than on controls. In choice tests, beetle mortality and ßip times were generally not signiÞcantly different from controls. At times, both beetle species displayed intoxication symptoms after feeding on adelgids from treated branchlets and imidacloprid was recovered from both beetle species postmortem. These results suggest that systemic imidacloprid displayed both lethal and sublethal effects on these two nontarget predators of the hemlock woolly adelgid. KEY WORDS Tsuga canadensis, Laricobius nigrinus, Sasajiscymnus tsugae, nontarget, prey-mediated effects Hemlock woolly adelgid, Adelges tsugae (Annand) avian species (Reay 1999, Yamasaki et al. 1999, Snyder (Hemiptera: Adelgidae), is an exotic invasive pest of et al. 2002, Tingley et al. 2002, Ross et al. 2003). two hemlock (Tsuga) species in the eastern United Hemlock woolly adelgid feeds on ßuids and nutri- States. Carolina hemlock, Tsuga caroliniana En- ents from parenchyma cells at the base of hemlock gelmann, is a relatively rare species conÞned to moun- needles (McClure 1987, 1991; Shields et al. 1995; tain ridges and isolated stands in the Appalachian Young et al. 1995). Infestation causes desiccation, bud highlands of western North Carolina, Tennessee, and mortality, needle loss, and a reduction of new growth Virginia. Eastern hemlock, Tsuga canadensis (L.) Car- (McClure 1987, McClure et al. 2001) and can lead to rie`re, is common along streams and cool, mountain dieback and tree death in 4Ð10 yr (McClure et al. slopes throughout eastern forests; its range extends 2001). Hemlock woolly adelgid has an anholocyclic from Maine to the southern extent of the Appalachian life cycle with two parthenogenic generations per year chain in northern Georgia and Alabama (Godman and on hemlocks. The asexual sistentes generation is Ϸ1 Lancaster 1990). Eastern hemlocks are an important mm in length and secretes a woolly white ßocculence economic (Rhea 1995, Holmes et al. 2005) and eco- or ovisac. Sistentes Þrst-instar crawlers aestivate on logical species; they provide habitats and nutrients hemlock stems throughout the summer. Breaking aes- that are beneÞcial for many aquatic, terrestrial, and tivation in the fall, they begin feeding and develop through four instars during the winter. Adults mature and lay eggs in March and April, which hatch as either 1 Department of Entomology, Virginia Polytechnic Institute and progredientes or sexuparae. Sexuparae production is State University, Blacksburg, VA 24061. initiated by high densities of sistentes that cause poor 2 Corresponding author: Department of Biology, Bryan College, host nutritional quality (McClure 1991). Sexuparae Dayton, TN 37321 (e-mail: [email protected]). 3 Department of Chemistry, Villanova University, Villanova, PA are winged and sexual; they do not feed on hemlocks 19085. but disperse to search for suitable spruce (Picea) spe- 0022-0493/10/1222Ð1234$04.00/0 ᭧ 2010 Entomological Society of America August 2010 EISENBACK ET AL.: EFFECTS OF IMIDACLOPRID ON HEMLOCK WOOLLY ADELGID 1223 cies to complete an holocyclic life cycle (Havill and 1999). For example, in cotton, Gossypium hirsutum L., Foottit 2007). The progredientes generation is similar metabolites protect the plant from whiteßies even in body morphology to the sistentes. After hatching, after parent compound concentrations declined Þrst instar crawlers disperse, settle, and begin to feed (Nauen et al. 1999). at the base of needles. The progredientes develop Effective control of hemlock woolly adelgid can be rapidly through four instars, mature, and lay eggs. Eggs achieved when imidacloprid is applied by foliar sprays hatch into sistentes crawlers which migrate to new or through systemic trunk or soil injections (McClure growth, settle, and aestivate through the summer. et al. 2001, Doccola et al. 2003, Webb et al. 2003, Laricobius nigrinus Fender (Coleoptera: Derodon- Cowles et al. 2006). Trunk and soil injections are the tidae) and Sasajiscymnus (Pseudoscymnus) tsugae primary control techniques for hemlock woolly adel- Sasaji & McClure (Coleoptera: Coccinellidae) are two gid in large-scale injection programs in national forests predators that have been reared and released as bio- and state parks. The Great Smoky Mountains National logical control agents of hemlock woolly adelgid Park in northeastern Tennessee is an example of a (Cheah and McClure 2002, Cheah et al. 2005, Lamb et current initiative to limit hemlock decline from hem- al. 2006). L. nigrinus is native to the PaciÞc Northwest lock woolly adelgid infestation. In the park, 466,843 and is a specialist predator of hemlock woolly adelgid. S. tsugae and 7,857 L. nigrinus) have been released at It is univoltine, host speciÞc and closely synchronized 32 and 191 sites, respectively, and Ͼ140,000 hemlocks with hemlock woolly adelgidÕs life cycle (Zilahi- have been treated via soil or trunk injections of imi- Balogh et al. 2002, 2003, Mausel et al. 2010). Adults dacloprid as of 2010 (K. Johnson, personal communi- emerge from the soil and begin feeding on sistentes in cation). the fall after the adelgids break aestivation. L. nigrinus In settings where chemical and biological controls feeds throughout the winter. The adults are cold hardy are jointly applied, it is important to determine the and active at temperatures above 0ЊC (Mausel 2007). compatibility of the two control options. High-value In early spring, adults begin laying eggs; larvae develop hemlock stands are often the Þrst candidates for chem- through four instars and feed primarily on hemlock ical control, and these same stands are desired as sites woolly adelgid eggs. In late spring, larvae drop from for biological control predator releases. Often preda- the hemlock branches into the soil where they pupate tor releases are in proximity to chemically treated and aestivate through the summer. L. nigrinus can sites, occupying the same valleys or mountain ridges. survive, oviposit, and reduce hemlock woolly adelgid As predators are released into the environment, it is populations in Þeld cages during winter and spring in important to analyze factors that could affect their southwestern Virginia (Lamb et al. 2005, 2006; Flowers establishment (Mausel 2007). Subsequent relocation et al. 2006). Three generations of L. nigrinus were and dispersal of predators from release sites could recovered from release sites in eastern forests (Lamb possibly result in predators coming into contact with et al. 2006, Mausel et al. 2010). hemlock woolly adelgid on hemlocks that have been S. tsugae is a multivoltine predator that is native to chemically treated. Japan where it is found in association with hemlock Using imidacloprid to control hemlock woolly ad- woolly adelgid (Cheah and McClure 1995). It can feed elgid could impact predators either through direct and develop to maturity on all stages of hemlock exposure or indirectly by changing hemlock woolly woolly adelgid, and its life cycle suggests a seasonal adelgid availability, quality, or distribution. Systemic synchrony with hemlock woolly adelgid progredien- insecticides do not directly expose predators to the tes in the Þeld (Cheah and McClure 1998, 2000). S. degree that foliar applications do (Mizell and Scony- tsugae is less cold tolerant than L. nigrinus and devel- ers 1992); however, nontarget beneÞcials can come ops most rapidly at temperatures from 20 to 25ЊC into contact with systemic toxins by feeding on plant (Cheah and McClure 2000). More than 3 million S. parts, contaminated prey, or through environmental tsugae and Ͼ100,000 L. nigrinus have been released in factors such as contaminated soil (Groot and Dicke eastern forests as of spring 2009. 2002). Predator consumption of
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]
  • 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]
  • 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]
  • 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]
  • Hemlock Woolly Adelgid
    United States Department of Agriculture TECHNOLOGY TRANSFER Non-native Pest BIOLOGY AND CONTROL OF HEMLOCK WOOLLY ADELGID Nathan P. Havill Lígia C. Vieira Scott M. Salom Forest Health Technology FHTET-2014-05 Enterprise Team Revised June 2016 The Forest Health Technology Enterprise Team (FHTET) was created in 1995 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: Background image: Hemlock mortality, Jason Van Driesche, Bugwood.org Bottom left to right: HWA white ovisacs on eastern hemlock branch , Scott M. Salom, Virginia Tech; Sajiscymus tsugae, Carol Cheah, Bugwood.org; Laricobius osakensis, Ligia C. Vieira, Virginia Tech. CAUTION: PESTICIDES Pesticide Precautionary Statement This publication reports research involving pesticides. It does not contain recommen- dations for their use, nor does it imply that the uses discussed here have been regis- tered. All uses of pesticides must be registered by appropriate State and/or Federal agencies before they can be recommended. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife--if they are not handled or applied properly. Use all pesticides selectively and carefully. Follow recommended practices for the disposal of surplus pesticides and pesticide containers. In accordance with Federal
    [Show full text]
  • Biology and Evolution of Adelgidae
    ANRV297-EN52-16 ARI 21 November 2006 10:26 Biology and Evolution of Adelgidae Nathan P. Havill1 and Robert G. Foottit2 1Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut 06520; email: [email protected] 2Agriculture and Agri-Food Canada, Eastern Cereal and Oilseeds Research Centre, Ottawa, ON K1A 0C6, Canada; email: [email protected] Annu. Rev. Entomol. 2007. 52:325–49 Key Words The Annual Review of Entomology is online at Aphidoidea, complex life cycle, cyclical parthenogenesis, ento.annualreviews.org plant-insect interactions This article’s doi: 10.1146/annurev.ento.52.110405.091303 Abstract Copyright c 2007 by Annual Reviews. The Adelgidae form a small clade of insects within the Aphidoidea All rights reserved (Hemiptera) that includes some of the most destructive introduced by Agriculture & Agri-Food Canada on 09/05/08. For personal use only. 0066-4170/07/0107-0325$20.00 pest species threatening North American forest ecosystems. De- spite their importance, little is known about their evolutionary his- Annu. Rev. Entomol. 2007.52:325-349. Downloaded from arjournals.annualreviews.org tory and their taxonomy remains unresolved. Adelgids are cyclically parthenogenetic and exhibit multigeneration complex life cycles. They can be holocyclic, with a sexual generation and host alterna- tion, or anholocyclic, entirely asexual and without host alternation. We discuss adelgid behavior and ecology, emphasizing plant-insect interactions, and we explore ways that the biogeographic history of their host plants may have affected adelgid phylogeny and evolution of adelgid life cycles. Finally, we highlight several areas in which ad- ditional research into speciation, population genetics, multitrophic interactions, and life-history evolution would improve our under- standing of adelgid biology and evolution.
    [Show full text]
  • HEMLOCK WOOLLY ADELGID Hemiptera: Adelgidae, Adelges
    HEMLOCK WOOLLY ADELGID Hemiptera: Adelgidae, Adelges tsugae Annand By Eric R. Day and Scott Salom DISTRIBUTION AND HOSTS: Native to Asia and westrern North America, this adelgid was first reported in eastern Virginia in the early 1950's. Since then it has spread to much of the Appalachian region of the eastern United States, see map from U.S. Forest Service on following page. DESCRIPTION OF DAMAGE: Immature nymphs and adults damage trees by feeding on storage cell near the base of needles at its attachment point to the twigs. The tree loses vigor and prematurely drops needles, to the point of defoliation, which may lead to death. If left uncontrolled, the adelgid can kill a tree in a single year. When not at serious risk to the tree, presence of the dirty white globular masses of woolly puffs attached to the twigs or base of needles reduces the value of ornamentals. IDENTIFICATION: These small insects display several different forms during their life history, including winged and wingless forms. Generally, they are brownish- reddish in color, oval in shape, and about 0.8 mm in length. Crawler stage nymphs produce white cottony/waxy tufts which cover their bodies and remain in place throughout their lifetime. The white masses are 3 mm or more in diameter. The presence of these masses on the bark, foliage, and twigs of hemlock is a sure sign of hemlock woolly adelgid. Hemlock Woolly adelgid, close up shows the newly LIFE HISTORY: There are four forms of this insect. Each form goes through six setteled immatures at the life stages (egg, four nymphal instars, and adult).
    [Show full text]
  • Hemlock Woolly Adelgid Facsheet Dec 2018
    Dr. Carole Cheah Valley Laboratory The Connecticut Agricultural Experiment Station 153 Cook Hill Road, P. O. Box 248 Windsor, CT 06095 Phone: (860) 683-4980 Fax: (860) 683-4987 Founded in 1875 Email: [email protected] Putting science to work for society Website: www.ct.gov/caes Hemlock Woolly Adelgid (HWA) and Other Factors Impacting Eastern Hemlock Introduction and Overview Adelgids are small conifer-feeding insects, related to aphids, belonging to the Suborder Homoptera (1). Hemlock woolly adelgid, Adelges tsugae Annand, (HWA), feeds specifically on hemlock species and was first described from samples originally from Oregon by P. N. Annand in California in 1924 (2). In North America, native Eastern hemlock, Tsuga canadensis (L.) Carriere and Carolina hemlock, Tsuga caroliniana Engelmann are very susceptible to HWA attack (3). Eastern hemlock is the seventh most common tree species in Connecticut and the second most abundant conifer after eastern white pine (4). In the eastern United States, this non- native insect pest was initially reported at a private estate in Richmond, Virginia in the early 1950s (5). The hemlock woolly adelgid in eastern US originated from southern Honshu island, Japan (6) and infestations have since spread widely to attack eastern hemlock and Carolina hemlock in 20 eastern states, from the southern Appalachians in the Carolinas and Georgia, through the Mid-Atlantic States, westwards to Ohio and Michigan and northwards to northern New England (7). Most recently, HWA was found in southern Nova Scotia in Canada in 2017 (8). In Connecticut, HWA was first reported to the Connecticut Agricultural Experiment Station in New Haven in 1985 and by 1997, was found throughout the state, in all 169 Connecticut towns (7).
    [Show full text]
  • Evolution of the Insects
    CY501-C08[261-330].qxd 2/15/05 11:10 PM Page 261 quark11 27B:CY501:Chapters:Chapter-08: 8 TheThe Paraneopteran Orders Paraneopteran The evolutionary history of the Paraneoptera – the bark lice, fold their wings rooflike at rest over the abdomen, but thrips true lice, thrips,Orders and hemipterans – is a history beautifully and Heteroptera fold them flat over the abdomen, which reflected in structure and function of their mouthparts. There probably relates to the structure of axillary sclerites and other is a general trend from the most generalized “picking” minute structures at the base of the wing (i.e., Yoshizawa and mouthparts of Psocoptera with standard insect mandibles, Saigusa, 2001). to the probing and puncturing mouthparts of thrips and Relationships among paraneopteran orders have been anopluran lice, and the distinctive piercing-sucking rostrum discussed by Seeger (1975, 1979), Kristensen (1975, 1991), or beak of the Hemiptera. Their mouthparts also reflect Hennig (1981), Wheeler et al. (2001), and most recently by diverse feeding habits (Figures 8.1, 8.2, Table 8.1). Basal Yoshizawa and Saigusa (2001). These studies generally agree paraneopterans – psocopterans and some basal thrips – are on the monophyly of the order Hemiptera and most of its microbial surface feeders. Thysanoptera and Hemiptera suborders and a close relationship of the true lice (order independently evolved a diet of plant fluids, but ancestral Phthiraptera) with the most basal group, the “bark lice” (Pso- heteropterans were, like basal living families, predatory coptera), which comprise the Psocodea. One major issue is insects that suction hemolymph and liquified tissues out of the position of thrips (order Thysanoptera), which either their prey.
    [Show full text]