DOCSLIB.ORG

Orgyia Pseudotsugata

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Defoliators II ÷ Lecture outline/goals: o The budworm complex – a closer look • Eastern spruce budworm • 2-year cycle budworm • Western spruce budworm – Past and present outbreak condiEons • Blackheaded budworm o Douglas-fir tussock moth 1 Defoliator acEvity 2015 Area of defoiation (ha) Defoliators BC Canada Eastern Spruce Budworm 0 6,726,007 2-yr Cycle Budworm 46,420 46,420 Western Spruce Budworm 9,135 9,135 Blackheaded Budworm 301 301 Conifers Douglas-fir Tussock Moth 0 0 Western Hemlock Looper 0 0 Aspen Leaf Miner 942,085 942,085 Forest Tent Caterpillar 609,999 5,199,101 Hardwoods Total = 12,923,049 Budworms Family Tortricidae o Complex of species o Complicated life cycles o Diverse Hosts o Extensive distribuEons C. fumiferana C. biennis C. orae C. freemani Eastern spruce budworm (Choristoneura fumiferana) ÷ Hosts o Subalpine fir, interior spruce (all ages) ÷ DistribuEon o Boreal forest (north-eastern BC) ÷ Injury paerns o Young larvae mine needles, buds, new cones; feed on young foliage following bud burst o Older larvae may feed on old foliage if young foliage is depleted (prefer young) o Crowns of damaged trees appear reddish-brown from June to Sept o IniEal symptoms of defoliaon visible in tree tops and at branch Eps o AZer several years of defoliaon – reduced cones, growth loss, top kill or mortality (esp. immature/suppressed trees) Eastern spruce budworm (Choristoneura fumiferana) ÷ Biology/ecology o UnivolEne (overwinter as L2’s) o Larvae develop through 6 instars (L1 to L6) before pupaon; foliage webbed together during feeding o Pupaon within foliage o Female moths lay eggs in masses on the underside of needles in a shingle-like paern o Larvae (L1’s) eclose 1 – 2 weeks aer egg lay, do not feed, spin hibernacula, moult to L2 and overwinter o Larvae (L2 – L6) feed the following spring on buds, developing cones, then new foliage Choristoneura fumiferana life cycle Egg hatch/L1’s spin hibernacula: Egg lay: August L2 feeding: August May Pupation: L2 – L6 feeding: July - August May - July 2-year cycle budworm (Choristoneura biennis) ÷ Hosts o Subalpine fir, interior spruce (all ages) ÷ DistribuEon o Subalpine and boreal habitats (W. of Rockies) ÷ Injury paerns o Young larvae mine needles, buds, new cones; feed on young foliage following bud burst o Older larvae may feed on old foliage if young is depleted o Crowns of damaged trees appear reddish-brown from June to Sept (every second year) o IniEal symptoms of defoliaon visible in tree tops and at branch Eps o AZer several years of defoliaon – reduced cones, growth loss, top kill or mortality (esp. immature/suppressed trees) 2-year cycle budworm (Choristoneura biennis) ÷ Biology/ecology o SemivolEne (overwinter as L2’s, L4’s) o Larvae develop through 6 instars (L1 to L6) before pupaon o Pupaon within foliage o Female moths lay eggs in masses on the underside of needles in a shingle-like paern o Larvae (L1’s) eclose 1 – 2 weeks aer egg lay, do not feed, spin hibernacula, moult to L2 and overwinter o Early instars (L2 – L4) feed the following spring on buds, developing cones, then new foliage o L4’s also spin hibernacula and overwinter o Late instar larvae (L4 – L6) feed, complete development during spring of year 2 – Eme of most injury Choristoneura biennis life cycle Egg hatch/L1’s spin hibernacula: Egg lay: August L2-L4 feeding: August May - July L4’s spin hibernacula: July Pupation: L4-L6 feeding: June to July May - June Western spruce budworm (Choristoneura freemani formerly C. occidentalis) ÷ Hosts o Douglas fir (occasionally spruce, western larch, lodgepole pine); all ages of trees ÷ DistribuEon o Southern BC, coast, montane, Columbia forest types ÷ Injury paerns o Young larvae mine needles, buds, new cones; feed on young foliage following bud burst o Older larvae may feed on old foliage if young is depleted o Crowns of damaged trees appear reddish-brown from June to Sept o IniEal symptoms of defoliaon visible in tree tops and at branch Eps o Several years of defoliaon = reduced cones, growth loss, top kill or mortality (esp. immature/ suppressed trees) Western spruce budworm (Choristoneura freemani formerly C. occidentalis) ÷ Biology/ecology o UnivolEne (overwinter as L2’s) o Larvae develop through 6 instars (L1 to L6) before pupaon o Pupaon within foliage o Female moths lay eggs in masses on the underside of needles in a shingle-like paern o Larvae (L1’s) eclose 1 – 2 weeks aer egg lay, do not feed, spin hibernacula, moult to L2 and overwinter o Early instars (L2 – L6) feed the following spring on buds, developing cones, then new foliage Choristoneura occidentalis life cycle Egg hatch/L1’s spin hibernacula: Egg lay: August L2 feeding: August May Pupation: L2 – L6 feeding: July - August May - July Western spruce budworm outbreak history: recent changes ÷ Outbreak first recorded 1909, Vancouver Island 1000 ÷ Increasing frequency and severity ) Western spruce budworm during past century? 3 10 800 o ≈20 years between outbreaks since × 1950 o >10 years outbreak duraon 600 • Note: data reliability good due to proximity of WSBW habitat to long- term human seTlements (but only 100 yrs) 400 o Due to changing climate? • Unknown, but… 200 • Northward shiZ due to shiZing Mapped outbreak area(ha phenological window o Fire suppression? 0 • Fewer ground fires = more understory, more food Year Western spruce budworm control efforts ÷ Btk applicaon ÷ 61,966 ha treated in 2008 (largest Btk applicaon in BC) ÷ Treatment prioriEes based on: o Predicted defoliaon o PotenEal for stands to recover o Stand value (investment) o Stand structure o Wildlife habitat o Recreaon/aestheEc values 15 Blackheaded budworm (Acleris gloverana) ÷ Hosts o Western hemlock and true firs (occasionally Douglas fir); all ages of trees ÷ DistribuEon o Throughout BC (except southern Okanagan); outbreaks most severe along coast ÷ Injury paerns o Larvae feed preferenEally on young foliage in the upper crown o Older foliage consumed when young depleted; enEre trees defoliated during outbreaks o “Wasteful” feeders – enEre needles seldom consumed o Defoliaon over two or more years may lead to top kill and mortality Blackheaded budworm (Acleris gloverana) ÷ Biology/ecology o UnivolEne (overwinter as eggs) o Egg hatch and bud burst synchronized o L1’s mine needles or buds unl L2 o L3’s construct shelters by webbing together parEally eaten needles o Larvae develop through 6 instars o Pupaon occurs during July o Moths emerge in August, mate, lay eggs and die o Eggs overwinter Acleris gloverana life cycle Eggs overwinter Egg lay: Egg hatch: August May Pupation: L1 – L6 feeding: July - August May - July Defoliation history of Acleris gloverana in BC Douglas-fir tussock moth (Orgyia pseudotsugata) ÷ Hosts o Douglas fir; all ages of trees ÷ DistribuEon o Warm, dry areas of southern BC ÷ Injury paerns o Larvae feed preferenEally on young foliage in the upper crown o Mature larvae require some feeding on older foliage; enEre trees defoliated during outbreaks o ConsumpEon of new and old foliage together increases likelihood of tree mortality o ATacked trees turn reddish-brown then greyish purple from July to Sept o Secondary agents oZen associated with DFTM Douglas-fir tussock moth (Orgyia pseudotsugata) ÷ Biology/ecology o UnivolEne (overwinter as eggs) o Egg hatch and bud burst synchronized o Newly emerged larvae disperse aerially (ballooning) o Larvae develop through 4 - 6 instars o Pupaon occurs during July in cocoons partly composed of larval hairs* o Moths emerge in August; females wingless, emit pheromones o Eggs laid in frothy mass mixed with female body hairs on old cocoons o Eggs overwinter *note: tussock moth hairs are significant irritants Orgyia pseudotsugata life cycle Eggs overwinter Egg lay: Egg hatch/larval dispersal: August May Pupation: Larval feeding: July May - July Douglas-fir tussock moth populaon dynamics ÷ Intrinsic cycles – every 8 to 9 years o Delayed density dependence between DFTM and natural enemies o Generalist predators, specific parasitoids, specific NPV o Site and weather condiEons – significant DI perturbaons • Warm, dry condiEons; shallow soils 23 Silivicultural management of Douglas fir tussock moth impacts Species composiEon, planEng; promotes tree/stand resistance (see IPM lecture) Site selecEon based on risk rang SuscepEble Sites Low elevaons East slopes Warm, dry (tree stress) Ridge tops High tree density Large crowns Larval dispersal High % DF, Fir Management Favour soil moisture and nutrient cycling processes Avoid compacEon Thinning Retain slash .
Recommended publications
  • Drought and Moisture Availability and Recent Western Spruce Budworm Outbreaks in the Western United States

    Drought and Moisture Availability and Recent Western Spruce Budworm Outbreaks in the Western United States

    Article Drought and Moisture Availability and Recent Western Spruce Budworm Outbreaks in the Western United States Bingbing Xu 1, Jeffrey A. Hicke 2,* and John T. Abatzoglou 2 1 Environmental Science Program, University of Idaho, Moscow, ID 83844, USA; [email protected] 2 Department of Geography, University of Idaho, Moscow, ID 83844, USA; [email protected] * Correspondence: [email protected]; Tel.: +01-208-885-6240 Received: 27 February 2019; Accepted: 19 April 2019; Published: 24 April 2019 Abstract: Western spruce budworm (WSBW) is a common defoliating insect that has caused extensive damage and mortality to a number of tree species across the western United States (US). Past studies have linked outbreaks of WSBW to increased moisture stress of host trees in the Northwest and decreased moisture stress in the Southwest. Our study analyzed seasonal drought stress metrics with WSBW outbreaks within Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests in the western US during 1997–2015. Superposed epoch analysis and defoliation area growth rates (representing insect population growth rates) were assessed to quantify the drought conditions associated with the initiation and continuation of outbreaks, respectively. We found that multiple years of drought occurred prior to and during outbreak initiation in the Northwest, and that outbreak initiation in the Southwest was associated with only weak drought or neutral conditions. During the outbreak continuation stage, there was a weak positive correlation between May moisture availability and defoliation area growth rates in the Southwest (R2 = 0.12), but no clear relationship was identified in the Northwest. Increased frequency of summer droughts such as these expected from climate change may increase WSBW outbreaks and promote tree dieoff.
  • The Forestry Commission's Contingency Plan

    The Forestry Commission's Contingency Plan

    Western Spruce Budworm (Choristoneura freemani), Eastern Spruce Budworm (Choristoneura fumiferana) Black-Headed Budworm (Acleris gloverana and Acleris variana) – Contingency Plan Combined Budworm: Draft contingency plan INTRODUCTION 1. Serious or significant pests require strategic-level plans developed at a national level describing the overall aim and high-level objectives to be achieved, and setting out the response strategy for eradicating or containing outbreaks. 2. The UK Plant Health Risk Group (PHRG) has commissioned, following identification by the UK Plant Health Risk Register, pest-specific contingency plans for those pests which pose the greatest risk and require stakeholder consultation. 3. The purpose of these pest-specific contingency plans is to ensure a rapid and effective response to outbreaks of the pests or diseases described. They are designed to help government agencies anticipate, assess, prepare for, prevent, respond to and recover from pest and disease outbreaks. 4. Contingency planning starts with the anticipation and assessment of potential threats, includes preparation and response, and finishes with recovery. Anticipate 5. Gathering information and intelligence about the pest, including surveillance and horizon scanning. Assess 6. Identifying concerns and preparing plans. 7. Setting outbreak management objectives Prepare 8. Ensuring staff and stakeholders are familiar with the pest. Response 9. Identifying the requirements for either containing or eradicating the pest or disease, including work to determine success. 10. The Defra Contingency Plan for Plant Health in England (in draft) gives details of the teams and organisations involved in pest and disease response in England, and their responsibilities and governance. It also 2 | Combined budworm contingency plan | Dafni Nianiaka | 24/01/2017 Combined Budworm: Draft contingency plan describes how these teams and organisations will work together in the event of an outbreak of a plant health pest.
  • Lepidoptera: Tortricidae: Tortricinae) and Evolutionary Correlates of Novel Secondary Sexual Structures

    Lepidoptera: Tortricidae: Tortricinae) and Evolutionary Correlates of Novel Secondary Sexual Structures

    Zootaxa 3729 (1): 001–062 ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Monograph ZOOTAXA Copyright © 2013 Magnolia Press ISSN 1175-5334 (online edition) http://dx.doi.org/10.11646/zootaxa.3729.1.1 http://zoobank.org/urn:lsid:zoobank.org:pub:CA0C1355-FF3E-4C67-8F48-544B2166AF2A ZOOTAXA 3729 Phylogeny of the tribe Archipini (Lepidoptera: Tortricidae: Tortricinae) and evolutionary correlates of novel secondary sexual structures JASON J. DOMBROSKIE1,2,3 & FELIX A. H. SPERLING2 1Cornell University, Comstock Hall, Department of Entomology, Ithaca, NY, USA, 14853-2601. E-mail: [email protected] 2Department of Biological Sciences, University of Alberta, Edmonton, Canada, T6G 2E9 3Corresponding author Magnolia Press Auckland, New Zealand Accepted by J. Brown: 2 Sept. 2013; published: 25 Oct. 2013 Licensed under a Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0 JASON J. DOMBROSKIE & FELIX A. H. SPERLING Phylogeny of the tribe Archipini (Lepidoptera: Tortricidae: Tortricinae) and evolutionary correlates of novel secondary sexual structures (Zootaxa 3729) 62 pp.; 30 cm. 25 Oct. 2013 ISBN 978-1-77557-288-6 (paperback) ISBN 978-1-77557-289-3 (Online edition) FIRST PUBLISHED IN 2013 BY Magnolia Press P.O. Box 41-383 Auckland 1346 New Zealand e-mail: [email protected] http://www.mapress.com/zootaxa/ © 2013 Magnolia Press 2 · Zootaxa 3729 (1) © 2013 Magnolia Press DOMBROSKIE & SPERLING Table of contents Abstract . 3 Material and methods . 6 Results . 18 Discussion . 23 Conclusions . 33 Acknowledgements . 33 Literature cited . 34 APPENDIX 1. 38 APPENDIX 2. 44 Additional References for Appendices 1 & 2 . 49 APPENDIX 3. 51 APPENDIX 4. 52 APPENDIX 5.
  • Forest Insect and Disease Conditions in the Southwestern Region, 2018

    Forest Insect and Disease Conditions in the Southwestern Region, 2018

    United States Department of Agriculture Forest Insect and Disease Conditions in the Southwestern Region, 2018 Forest Southwestern Forest Health September 2019 Service Region PR-R3-16-18 In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or USDA’s TARGET Center at (202) 720- 2600 (voice and TTY) or contact USDA through the Federal Relay Service at (800) 877-8339. Additionally, program information may be made available in languages other than English. To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online at http://www.ascr.usda.gov/complaint_filing_cust.html and at any USDA office or write a letter addressed to USDA and provide in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632- 9992. Submit your completed form or letter to USDA by: (1) mail: U.S.
  • Does Wildfire Likelihood Increase Following Insect Outbreaks in Conifer Forests? 1,3, 1 1 1 GARRETT W

    Does Wildfire Likelihood Increase Following Insect Outbreaks in Conifer Forests? 1,3, 1 1 1 GARRETT W

    Does wildfire likelihood increase following insect outbreaks in conifer forests? 1,3, 1 1 1 GARRETT W. MEIGS, JOHN L. CAMPBELL, HAROLD S. J. ZALD, JOHN D. BAILEY, 1 1,2 DAVID C. SHAW, AND ROBERT E. KENNEDY 1College of Forestry, Oregon State University, Corvallis, Oregon 97331 USA 2College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331 USA Citation: Meigs, G. W., J. L. Campbell, H. S. J. Zald, J. D. Bailey, D. C. Shaw, and R. E. Kennedy. 2015. Does wildfire likelihood increase following insect outbreaks in conifer forests? Ecosphere 6(7):118. http://dx.doi.org/10.1890/ ES15-00037.1 Abstract. Although there is acute concern that insect-caused tree mortality increases the likelihood or severity of subsequent wildfire, previous studies have been mixed, with findings typically based on stand- scale simulations or individual events. This study investigates landscape- and regional-scale wildfire likelihood following outbreaks of the two most prevalent native insect pests in the US Pacific Northwest (PNW): mountain pine beetle (MPB; Dendroctonus ponderosae) and western spruce budworm (WSB; Choristoneura freemani). We leverage seamless census data across numerous insect and fire events to (1) summarize the interannual dynamics of insects (1970–2012) and wildfires (1984–2012) across forested ecoregions of the PNW; (2) identify potential linked disturbance interactions with an empirical wildfire likelihood index; (3) quantify this insect-fire likelihood across different insect agents, time lags, ecoregions, and fire sizes. All three disturbance agents have occurred primarily in the drier, interior conifer forests east of the Cascade Range. In general, WSB extent exceeds MPB extent, which in turn exceeds wildfire extent, and each disturbance typically affects less than 2% annually of a given ecoregion.
  • Monitoring Western Spruce Budworm with Pheromone- Baited Sticky Traps to Predict Subsequent Defoliation Christine G

    Monitoring Western Spruce Budworm with Pheromone- Baited Sticky Traps to Predict Subsequent Defoliation Christine G

    United States Department of Agriculture Monitoring Western Spruce Budworm With Pheromone- Baited Sticky Traps to Predict Subsequent Defoliation Christine G. Niwa and David L. Overhulser1 Abstract A detailed procedure is described for monitoring western spruce budworm with pheromone-baited sticky traps and interpreting the results to predict defoliation the following year. Information provided includes timing of the survey, how to obtain traps and baits, how many traps are needed, trap assembly, field place- ment of traps, and how to evaluate the catches. 1 Christine G. Niwa is a research entomologist (retired), U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Forestry Sciences Laboratory, 3200 SW Jefferson Way, Corvallis, OR 97331-8550, and David L. Overhulser is an entomologist (retired), Oregon Department of Forestry, 2600 State Street, Salem, OR 97310. Forest Pacific Northwest Research Note June D E E P R A U R T LT Service Research Station PNW-RN-571 MENT OF AGRICU 2015 RESEARCH NOTE PNW-RN-571 Introduction Because outbreaks of the western spruce budworm (Choristoneura freemani Razowski (= occidentalis Freeman)) can last a decade or more, there are many occasions when knowing the future course of stand defoliation will aid in management decisions. This is particularly true whenever an insecticide treatment is under consideration. Forest Service scientists with the U.S. Department of Agriculture (USDA) have developed a technique for predicting spruce budworm defoliation.2 This technique relates the number of moths caught in pheromone-baited traps to stand defoliation the following year. Described herein are the methods for monitoring spruce budworm and procedures for evaluating trap catch to predict future impacts from this pest.
  • Choristoneura Fumiferana) Group on an Isolated Forest Island Lisa M

    Choristoneura Fumiferana) Group on an Isolated Forest Island Lisa M

    Life-history traits maintain the genomic integrity of sympatric species of the spruce budworm (Choristoneura fumiferana) group on an isolated forest island Lisa M. Lumley & Felix A. H. Sperling Department of Biological Sciences, CW 405 Biological Sciences Centre, University of Alberta, Edmonton, AB T6G 2E9, Canada Keywords Abstract Cypress Hills, Choristoneura lambertiana, Choristoneura occidentalis, hybridization, Identification of widespread species collected from islands can be challenging due to integrative taxonomy, phenology, the potential for local ecological and phenotypic divergence in isolated populations. pheromones, speciation, species delimitation. We sought to determine how many species of the spruce budworm (Choristoneura fumiferana) complex reside in Cypress Hills, an isolated remnant coniferous forest Correspondence in western Canada. We integrated data on behavior, ecology, morphology, mito- Lisa M. Lumley, Laurentian Forestry Centre, chondrial DNA, and simple sequence repeats, comparing Cypress Hills populations Canadian Forest Service, Natural Resources Canada, 1055 du P.E.P.S., P.O. Box 10380, Stn. to those from other regions of North America to determine which species they Ste. Foy, Quebec, QC G1V 4C7, Canada. resembled most. We identified C. fumiferana, C. occidentalis, C. lambertiana,and Tel: +01 (418) 648-7149; hybrid forms in Cypress Hills. Adult flight phenology and pheromone attraction Fax: +01 (418) 648-5849; were identified as key life-history traits involved in maintaining the genomic in- E-mail: [email protected] tegrity of species. Our study highlights the importance of extensive sampling of both specimens and a variety of characters for understanding species boundaries in Received: 12 May 2011; Revised: 27 June biodiversity research. 2011; Accepted: 28 June 2011.
  • An Annotated List of the Lepidoptera of Alberta, Canada

    An Annotated List of the Lepidoptera of Alberta, Canada

    A peer-reviewed open-access journal ZooKeys 38: 1–549 (2010) Annotated list of the Lepidoptera of Alberta, Canada 1 doi: 10.3897/zookeys.38.383 MONOGRAPH www.pensoftonline.net/zookeys Launched to accelerate biodiversity research An annotated list of the Lepidoptera of Alberta, Canada Gregory R. Pohl1, Gary G. Anweiler2, B. Christian Schmidt3, Norbert G. Kondla4 1 Editor-in-chief, co-author of introduction, and author of micromoths portions. Natural Resources Canada, Northern Forestry Centre, 5320 - 122 St., Edmonton, Alberta, Canada T6H 3S5 2 Co-author of macromoths portions. University of Alberta, E.H. Strickland Entomological Museum, Department of Biological Sciences, Edmonton, Alberta, Canada T6G 2E3 3 Co-author of introduction and macromoths portions. Canadian Food Inspection Agency, Canadian National Collection of Insects, Arachnids and Nematodes, K.W. Neatby Bldg., 960 Carling Ave., Ottawa, Ontario, Canada K1A 0C6 4 Author of butterfl ies portions. 242-6220 – 17 Ave. SE, Calgary, Alberta, Canada T2A 0W6 Corresponding authors: Gregory R. Pohl ([email protected]), Gary G. Anweiler ([email protected]), B. Christian Schmidt ([email protected]), Norbert G. Kondla ([email protected]) Academic editor: Donald Lafontaine | Received 11 January 2010 | Accepted 7 February 2010 | Published 5 March 2010 Citation: Pohl GR, Anweiler GG, Schmidt BC, Kondla NG (2010) An annotated list of the Lepidoptera of Alberta, Canada. ZooKeys 38: 1–549. doi: 10.3897/zookeys.38.383 Abstract Th is checklist documents the 2367 Lepidoptera species reported to occur in the province of Alberta, Can- ada, based on examination of the major public insect collections in Alberta and the Canadian National Collection of Insects, Arachnids and Nematodes.
  • Western Spruce Budworm

    Western Spruce Budworm

    Pest Profile Photo credit: (Left) William M. Ciesla, Forest Health Management International, Bugwood.org; (Right) William M. Ciesla, Forest Health Management International, Bugwood.org Common Name: Western Spruce Budworm Scientific Name: Choristoneura freemani Order and Family: Lepidoptera, Tortricidae Size and Appearance: Length (mm) Appearance Egg The eggs are oval and light green. The adult female deposits about 150 eggs in masses of 25 to 40 eggs on the underside of the host tree needles. The eggs overlap one another like shingles. The eggs are the size of a pinhead. Larva Mature: The larvae go through six instars or stages between successive 25-32mm molts with the first instar occurring between hatching and the first molt. When the caterpillars first hatch, they are yellow-green with brown heads. The newly hatched larvae create a structure made of silk under bark or lichen and spend the winter in these structures. In the next three instars, the larvae have black heads and collars with orange or cinnamon-brown bodies. The fifth instar larvae have reddish-brown heads that are marked with black triangles and collars. The body is a pale olive-brown marked with small-whitish spots. The mature caterpillars have tan or light chestnut-brown heads and collars. The body is olive or reddish- brown with large ivory-colored areas. Adult Length: 13 mm Both sexes of the adults are similar in appearance; however, the Wingspan: female can be larger. The wings can be variable in color and can 22-28 mm range from a gray or orange brown with the wings possibly being banded or streaked.
  • DISTURBANCE HISTORY and ITS INFLUENCE on DROUGHT TOLERANCE of INTERIOR DOUGLAS-FIR (Pseudotsuga Menziesii Var

    DISTURBANCE HISTORY and ITS INFLUENCE on DROUGHT TOLERANCE of INTERIOR DOUGLAS-FIR (Pseudotsuga Menziesii Var

    DISTURBANCE HISTORY AND ITS INFLUENCE ON DROUGHT TOLERANCE OF INTERIOR DOUGLAS-FIR (Pseudotsuga menziesii var. glauca (Beissn.) Franco) IN THE CARIBOO-CHILCOTIN REGION OF BRITISH COLUMBIA, CANADA by Neil P. Thompson B.Sc., University of Maine, 2013 THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN NATURAL RESOURCE AND ENVIRONMENTAL STUDIES UNIVERSITY OF NORTHERN BRITISH COLUMBIA August 2017 © Neil P. Thompson, 2017 Abstract: Disturbance—the death of trees due to external forces such as wildfire or windstorms— drives forest stand dynamics and shapes ecosystems. Natural disturbances arising from the interaction of climate, topography, and established tree species have often occurred with some regularity, resulting in apparently perpetual renewal of particular forest structures. Minor changes in climate can have profound impacts on these disturbance regimes, breaking historically observed cycles and introducing novel stand conditions. Long-term historical baselines are critical to understanding such changes. Observational records are often inadequate, especially in western North America, where 400 year-old stands are common but reliable data are generally unavailable prior to the 20th century. I use tree ring analysis to investigate the history of Douglas-fir beetle and western spruce budworm infestations, and the influence of partial disturbances on the drought tolerance of surviving trees, developing baseline understanding of disturbance interactions in interior British Columbia. No evidence is found of any outbreaks of western spruce budworm or Douglas- fir beetle that exceed the magnitude of outbreaks in the early 21st century, suggesting that recent outbreaks represent historically high levels of insect activity. Both natural and anthropogenic partial disturbances are demonstrated to positively affect the drought tolerance of surviving trees in old-growth remnants and younger managed stands, respectively.
  • UNIVERSITY of CALIFORNIA RIVERSIDE Transcriptome

    UNIVERSITY of CALIFORNIA RIVERSIDE Transcriptome

    UNIVERSITY OF CALIFORNIA RIVERSIDE Transcriptome Analyses of Ascovirus Genome Expression in Lepidopteran Larvae and Host Responses A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Microbiology by Heba Ahmed Hamed Mohamed Zaghloul June 2018 Dissertation Committee: Dr. Brian A. Federici, Chairperson Dr. Ayala L.N. Rao Dr. Adler R. Dillman Copyright by Heba Ahmed Hamed Mohamed Zaghloul 2018 The Dissertation of Heba Ahmed Hamed Mohamed Zaghloul is approved: Committee Chairperson University of California, Riverside ACKNOWLEDGEMENT I would like to thank my major professor Dr. Brian Federici for his guidance and support over the past five years. I have learned much from his research experience and wisdom. He constantly encouraged me during my graduate studies, research, and this dissertation. My discussions with him were always fruitful. His wide knowledge in different areas of science is impressive. I will always be proud that I have been one of his students. Also, I would like to extend my thanks to my dissertation committee members, Dr. Ayala L. N. Rao and Dr. Adler R. Dillman. Your guidance, discussion and feedback were of great importance to my completion of this work. Moreover, I would like to thank present and previous Federici lab members for their help and guidance with mastering different methods and techniques as I carried out my research. I especially thank Robert Hice and Peter Arensburger for their continuous support, guidance, discussions and feedback over the years that helped me develop several skills. In addition, I extend my gratitude to Dennis Bideshi, Hyun-Woo Park and Stephanie Nanneman.
  • Giovanny Fagua González

    Giovanny Fagua González

    Phylogeny, evolution and speciation of Choristoneura and Tortricidae (Lepidoptera) by Giovanny Fagua González A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Systematics and Evolution Department of Biological Sciences University of Alberta © Giovanny Fagua González, 2017 Abstract Leafrollers moths are one of the most ecologically and economically important groups of herbivorous insects. These Lepidoptera are an ideal model for exploring the drivers that modulate the processes of diversification over time. This thesis analyzes the evolution of Choristoneura Lederer, a well known genus because of its pest species, in the general context of the evolution of Tortricidae. It takes an inductive view, starting with analysis of phylogenetic, biogeographic and diversification processes in the family Tortricidae, which gives context for studying these processes in the genus Choristoneura. Tectonic dynamics and niche availability play intertwined roles in determining patterns of diversification; such drivers explain the current distribution of many clades, whereas events like the rise of angiosperms can have more specific impacts, such as on the diversification rates of herbivores. Tortricidae are a diverse group suited for testing the effects of these determinants on the diversification of herbivorous clades. To estimate ancestral areas and diversification patterns in Tortricidae, a complete tribal-level dated tree was inferred using molecular markers and calibrated using fossil constraints. The time-calibrated phylogeny estimated that Tortricidae diverged ca. 120 million years ago (Mya) and diversified ca. 97 Mya, a timeframe synchronous with the rise of angiosperms in the Early-Mid Cretaceous. Ancestral areas analysis supports a Gondwanan origin of Tortricidae in the South American plate.