DOCSLIB.ORG

Effect of Physiological and Behavioural Characteristics of Parasitoids on Host Specificity Testing Outcomes and the Biological Control of Paropsis Charybdis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Effect of Physiological and Behavioural Characteristics of Parasitoids on Host Specificity Testing Outcomes and the Biological Control of Paropsis Charybdis EFFECT OF PHYSIOLOGICAL AND BEHAVIOURAL CHARACTERISTICS OF PARASITOIDS ON HOST SPECIFICITY TESTING OUTCOMES AND THE BIOLOGICAL CONTROL OF PAROPSIS CHARYBDIS A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University By Tara J. Murray Lincoln University 2010 To Barbara Barratt and Kath Dickinson, outstanding scientists, inspiring mentors and patient friends - without your enthusiastic and supportive introduction to scientific research I wouldn’t have had the determination or desire to keep going when the road got rough. Things have rarely gone as planned, but thanks to you I know there are many exciting research opportunities awaiting me, and some amazing scientists that I can look forward to working with in the future. Abstract of thesis submitted in partial fulfilment of the requirements for the Degree of Ph.D. Effect of physiological and behavioural characteristics of parasitoids on host specificity testing outcomes and the biological control of Paropsis charybdis By Tara J. Murray An established host-parasitoid-hyperparasitoid system was used to investigate how the physiological and behavioural characteristics of parasitoids influence the outcomes of laboratory- based host specificity tests. The characteristics of the two pteromalid egg parasitoids, Enoggera nassaui (Girault) and Neopolycystus insectifurax Girault, were assessed and interpreted in regard to the particular host specificity testing methods used and the control of the eucalypt defoliating beetle Paropsis charybdis Stål (Chrysomelidae) in New Zealand. The physiology of N. insectifurax was examined to determine how to increase production of female parasitoids that were physiologically capable and motivated to parasitise P. charybdis eggs in laboratory trials. Neopolycystus insectifurax were found to be more synovigenic than E. nassaui . Provisioning them with honey and host stimuli for three days, and allowing females to parasitise hosts in isolation (i.e. in the absence of competition) was an effective means of achieving these goals. No-choice tests were conducted in Petri dish arenas with the four paropsine beetles established in New Zealand. All four were found to be within the physiological host ranges of E. nassaui and N. insectifurax , but their quality as hosts, as indicated by the percent parasitised and offspring sex ratios, varied. The results of paired choice tests between three of the four species agreed with those of no-choice tests in most instances. However, the host Trachymela catenata (Chapuis), which was parasitised at very low levels by E. nassaui in no-choice tests, was not accepted by that species in paired choice tests. A much stronger preference by N. insectifurax for P. charybdis over T. catenata was recorded in the paired choice test than expected considering the latter was parasitised at a high level in the no-choice test. The presence of the target host in paired choice tests reduced acceptance of lower ranked hosts. Both no-choice and choice tests failed to predict that eggs of the i acacia feeding beetle Dicranosterna semipunctata (Chapuis) would not be within the ecological host range of E. nassaui and N. insectifurax . Behavioural observations were made of interspecific competition between E. nassaui and N. insectifurax for access to P. charybdis eggs. Two very different oviposition strategies were identified. Neopolycystus insectifurax were characterised by taking possession of, and aggressively guarding host eggs during and after oviposition. They also appeared to selectively oviposit into host eggs already parasitised by E. nassaui, but did not emerge from significantly more multi- parasitised hosts than E. nassaui . Enoggera nassaui did not engage in contests and fled when approached by N. insectifurax . Although often prohibited from ovipositing by N. insectifurax, E. nassaui were able to locate and begin ovipositing more quickly, and did not remain to guard eggs after oviposition. It is hypothesised that although N. insectifurax have a competitive advantage in a Petri dish arena, E. nassaui may be able to locate and parasitise more host eggs in the field in New Zealand, where competition for hosts in is relatively low. The biology of the newly established encyrtid Baeoanusia albifunicle Girault was assessed. It was confirmed to be a direct obligate hyperparasitoid able to exploit E. nassaui but not N. insectifurax . Field and database surveys found that all three parasitoids have become established in many climatically different parts of New Zealand. Physiological characteristics were identified that may allow B. albifunicle to reduced effective parasitism of P. charybdis by E. nassaui to below 10%. However, the fact that hyperparasitism still prevents P. charybdis larvae from emerging, and that B. albifunicle does not attack N. insectifurax, may preclude any significant impact on the biological control of P. charybdis . Overall, parasitoid ovigeny and behavioural interactions with other parasitoids were recognised as key characteristics having the potential to influence host acceptance in the laboratory and the successful biological control of P. charybdis in the field. It is recommended that such characteristics be considered in the design and implementation of host specificity tests and might best be assessed by conducting behavioural observations during parasitoid colony maintenance and the earliest stages of host specificity testing. Keywords: biological control, host specificity testing, no-choice test, choice test, parasitoid, hyperparasitoid, parasitoid behaviour, Eucalyptus , Acacia , Paropsis charybdis , Enoggera nassaui , Neopolycystus insectifurax , Baeoanusia albifunicle ii ACKNOWLEDGEMENTS This research was funded by the Foundation for Research Science and Technology through contracts to Scion (No. CO4X0302 and No. CO4X0807), and through contract CO2X0501, the Better Border Biosecurity (B3) Programme (www.b3nz.org) and was supported by the Forest Biosecurity Research Council to Scion. Additional funding was gratefully received through the following scholarships: Gordon Williams Postgraduate Scholarship in Ecological Sciences; MacMillan Brown Agricultural Research Scholarship; New Zealand Plant Protection Society Inc. Research Scholarship; Robert C. Bruce Trust Research Grant; Royal Society of New Zealand Travel Grant; Todd Foundation Awards for Excellence. I would like to thank the members of the New Zealand Farm Forestry Association and the Acacia Melanoxylon Interest Group Organisation, in particular Dean Satchell and Ian Brown, for their assistance locating and accessing field sites for insect collection. Individuals who have contributed their time and experience to help me conduct this research include Richard Parker (COHFE), Yaffa Gould and Richard Lainson (SDR Clinical Technology) for assistance with The Observer technology; Mark Kimberley (Scion) and James Ross (Lincoln) for statistical support; Geoff Tribe (Agricultural Research Council of South Africa) and Jo Berry (MAF) for providing and identifying parasitoid voucher specimens; Dave Hayes, Pam Taylor, Andrea Sharpe, Caro Gous (Scion) Diane Jones (MAF) and Kathleen Camp (University of California, Riverside) for advice and technical assistance in maintaining insect colonies. I would like to acknowledge my supervisors Bruce Chapman and Sue Worner (Lincoln University) and Sarah Mansfield (University of Sydney) for guiding me through the PhD process despite the distance, as well as Toni Withers (Scion) and Barbara Barratt (AgResearch) for their continued assistance and advice throughout this research. Finally, I would like to thank everyone at FBP, a great bunch to be ‘vital’ with, going forward. Special thanks to Damien, Michelle, Phil, fine Islay single malts, and my running shoes, for suffering most of my whinging and making for some good times between chapters. iii TABLE OF CONTENTS Abstract..................................................................................................................................i Acknowledgements ............................................................................................................ iii Table of Contents................................................................................................................iv List of Figures.....................................................................................................................vii List of Tables ........................................................................................................................x Chapter 1: Introduction ......................................................................................................1 1.1 Classical Biological Control..................................................................................1 1.2 Evaluating the Risks of Biological Control Agents.................................................2 1.3 Host Specificity Testing of Parasitoids....................................................................4 1.4 Improving Host Specificity Testing.........................................................................5 1.5 Study System in Which to Examine Host-Specificity Testing................................8 1.6 Thesis Goals...........................................................................................................12 Chapter 2: Insect Cultures & Preparing Parasitoids for Experimental Trials ...........14 2.1 Introduction............................................................................................................14
Load more

Recommended publications
  • Paropsine Beetles (Coleoptera: Chrysomelidae) in South-Eastern Queensland Hardwood Plantations: Identifying Potential Pest Species
    270 Paropsine beetles in Queensland hardwood plantations Paropsine beetles (Coleoptera: Chrysomelidae) in south-eastern Queensland hardwood plantations: identifying potential pest species Helen F. Nahrung1,2,3 1School of Natural Resource Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia; and 2Horticulture and Forestry Science, Queensland Department of Primary Industries and Fisheries, Gate 3, 80 Meiers Road, Indooroopilly, Queensland 4068, Australia 3Email: [email protected] Revised manuscript received 17 May 2006 Summary The expansion of hardwood plantations throughout peri-coastal Australia, often with eucalypt species planted outside their native Paropsine chrysomelid beetles are significant defoliators of ranges (e.g. E. globulus Labill. in Western Australia; E. nitens Australian eucalypts. In Queensland, the relatively recent (Deane and Maiden) Maiden in Tasmania), resulted in expansion of hardwood plantations has resulted in the emergence unpredicted paropsine species emerging as pests. For example, of new pest species. Here I identify paropsine beetles collected C. agricola (Chapuis) was not considered a risk to commercial from Eucalyptus cloeziana Muell. and E. dunnii Maiden, two of forestry but became a significant pest of E. nitens in Tasmania the major Eucalyptus species grown in plantations in south-eastern (de Little 1989), and the two most abundant paropsine species Queensland, and estimate the relative abundance of each (C. variicollis (Chapuis) and C. nobilitata (Erichson)) in paropsine species. Although I was unable to identify all taxa to E. globulus plantations in WA were not pests of native forest species level, at least 17 paropsine species were collected, about there (compare Selman 1994; Loch 2005), nor were they initially one-third of which have not been previously associated with considered pests of E.
    [Show full text]
  • Alien Dominance of the Parasitoid Wasp Community Along an Elevation Gradient on Hawai’I Island
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln USGS Staff -- Published Research US Geological Survey 2008 Alien dominance of the parasitoid wasp community along an elevation gradient on Hawai’i Island Robert W. Peck U.S. Geological Survey, [email protected] Paul C. Banko U.S. Geological Survey Marla Schwarzfeld U.S. Geological Survey Melody Euaparadorn U.S. Geological Survey Kevin W. Brinck U.S. Geological Survey Follow this and additional works at: https://digitalcommons.unl.edu/usgsstaffpub Peck, Robert W.; Banko, Paul C.; Schwarzfeld, Marla; Euaparadorn, Melody; and Brinck, Kevin W., "Alien dominance of the parasitoid wasp community along an elevation gradient on Hawai’i Island" (2008). USGS Staff -- Published Research. 652. https://digitalcommons.unl.edu/usgsstaffpub/652 This Article is brought to you for free and open access by the US Geological Survey at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in USGS Staff -- Published Research by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Biol Invasions (2008) 10:1441–1455 DOI 10.1007/s10530-008-9218-1 ORIGINAL PAPER Alien dominance of the parasitoid wasp community along an elevation gradient on Hawai’i Island Robert W. Peck Æ Paul C. Banko Æ Marla Schwarzfeld Æ Melody Euaparadorn Æ Kevin W. Brinck Received: 7 December 2007 / Accepted: 21 January 2008 / Published online: 6 February 2008 Ó Springer Science+Business Media B.V. 2008 Abstract Through intentional and accidental increased with increasing elevation, with all three introduction, more than 100 species of alien Ichneu- elevations differing significantly from each other. monidae and Braconidae (Hymenoptera) have Nine species purposely introduced to control pest become established in the Hawaiian Islands.
    [Show full text]
  • Coleoptera: Chrysomelidae) and the Paropsine Threat to Eucalyptus in New Zealand
    Biological Control of Paropsis charybdis Stål (Coleoptera: Chrysomelidae) and the Paropsine Threat to Eucalyptus in New Zealand A Thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy in the University of Canterbury by Brendan Dene Murphy New Zealand School of Forestry University of Canterbury 2006 TABLE OF CONTENTS ABSTRACT v ACKNOWLEDGEMENTS vi ERRATA vii CHAPTERS Chapter 1. Biological Control of Paropsis charybdis Stål and the Paropsine Threat to Eucalyptus in New Zealand.................................................................................................... 1 Chapter 2. The Collection, Importation, and Release of Tasmanian Enoggera nassaui for Biological Control of Paropsis charybdis............................................................................. 8 Chapter 3. Molecular Detection of Enoggera nassaui Strains using the Mitochondrial DNA Gene, Cytochrome Oxidase I ............................................................................................... 22 Chapter 4. Field and Bioassay Assessment of the Host Range .................................................. 32 Chapter 5. Phylogenetic Reconstruction of Tasmanian Chrysophtharta ..................................45 Chapter 6. Assessment of Paropsine Fecundity as an Indicator................................................. 59 Chapter 7. Testing the Parasitoid Host Range and Reproductive Output Hypotheses against Dicranosterna semipunctata ...............................................................................................
    [Show full text]
  • Trees for Farm Forestry: 22 Promising Species
    Forestry and Forest Products Natural Heritage Trust Helping Communities Helping Australia TREES FOR FARM FORESTRY: 22 PROMISING SPECIES Forestry and Forest Products TREES FOR FARM FORESTRY: Natural Heritage 22 PROMISING SPECIES Trust Helping Communities Helping Australia A report for the RIRDC/ Land & Water Australia/ FWPRDC Joint Venture Agroforestry Program Revised and Edited by Bronwyn Clarke, Ian McLeod and Tim Vercoe March 2009 i © 2008 Rural Industries Research and Development Corporation. All rights reserved. ISBN 1 74151 821 0 ISSN 1440-6845 Trees for Farm Forestry: 22 promising species Publication No. 09/015 Project No. CSF-56A The information contained in this publication is intended for general use to assist public knowledge and discussion and to help improve the development of sustainable regions. You must not rely on any information contained in this publication without taking specialist advice relevant to your particular circumstances. While reasonable care has been taken in preparing this publication to ensure that information is true and correct, the Commonwealth of Australia gives no assurance as to the accuracy of any information in this publication. The Commonwealth of Australia, the Rural Industries Research and Development Corporation (RIRDC), the authors or contributors expressly disclaim, to the maximum extent permitted by law, all responsibility and liability to any person, arising directly or indirectly from any act or omission, or for any consequences of any such act or omission, made in reliance on the contents of this publication, whether or not caused by any negligence on the part of the Commonwealth of Australia, RIRDC, the authors or contributors. The Commonwealth of Australia does not necessarily endorse the views in this publication.
    [Show full text]
  • Biological Control of Paropsis Charybdis
    No. 227, July 2012 ISSN 1175-9755 BIOLOGICAL CONTROL OF PAROPSIS CHARYBDIS Paropsine beetles (Coleoptera: Chrysomelidae) is not always easy to locate in Tasmania) from which we are extremely diverse and abundant in their native could obtain larvae for experiments. Australian range but have emerged as significant defoliators only since the expansion of managed The next step was to locate Eadya paropsidis. Flying adults plantation forestry, particularly when host trees are were caught “on-the–wing” in E. nitens plantations in planted outside their native range. Since its arrival in northern Tasmania in December 2011 and brought back New Zealand in 1916 Paropsis charybdis has effectively to the laboratory in Hobart for testing. Using a sequential prevented the commercial viability of several favoured no-choice testing method to observe individual females, 9 Eucalyptus species, including Eucalyptus nitens, until the of 10 of the female wasps attacked P. agricola larvae, then successful introduction of the egg parasitoid Enoggera 7 of those 9 also attacked P. charybdis larvae. nassaui (Hymenoptera: Pteromalidae) in 1988. Scion entomologists have been involved intermittently in the Those P. charybdis larvae attacked were quickly shown search for classical biological control agents for Paropsis to be a suitable physiological host for E. paropsidis charybdis for nearly fifty years, and this appears set to development; parasitoid larvae emerged from the continue for at least another two years. paropsine larvae they had killed, and were significantly larger from P. charybdis than from P. agricola. Paropsis charybdis is bivoltine in New Zealand. The Unfortunately over the whole experiment only 8% first generation of eggs are laid in spring from October of E.
    [Show full text]
  • No Slide Title
    Tachinidae: The “other” parasitoids Diego Inclán University of Padova Outline • Briefly (re-) introduce parasitoids & the parasitoid lifestyle • Quick survey of dipteran parasitoids • Introduce you to tachinid flies • major groups • oviposition strategies • host associations • host range… • Discuss role of tachinids in biological control Parasite vs. parasitoid Parasite Life cycle of a parasitoid Alien (1979) Life cycle of a parasitoid Parasite vs. parasitoid Parasite Parasitoid does not kill the host kill its host Insects life cycles Life cycle of a parasitoid Some facts about parasitoids • Parasitoids are diverse (15-25% of all insect species) • Hosts of parasitoids = virtually all terrestrial insects • Parasitoids are among the dominant natural enemies of phytophagous insects (e.g., crop pests) • Offer model systems for understanding community structure, coevolution & evolutionary diversification Distribution/frequency of parasitoids among insect orders Primary groups of parasitoids Diptera (flies) ca. 20% of parasitoids Hymenoptera (wasps) ca. 70% of parasitoids Described Family Primary hosts Diptera parasitoid sp Sciomyzidae 200? Gastropods: (snails/slugs) Nemestrinidae 300 Orth.: Acrididae Bombyliidae 5000 primarily Hym., Col., Dip. Pipunculidae 1000 Hom.:Auchenorrycha Conopidae 800 Hym:Aculeata Lep., Orth., Hom., Col., Sarcophagidae 1250? Gastropoda + others Lep., Hym., Col., Hem., Tachinidae > 8500 Dip., + many others Pyrgotidae 350 Col:Scarabaeidae Acroceridae 500 Arach.:Aranea Hym., Dip., Col., Lep., Phoridae 400?? Isop.,Diplopoda
    [Show full text]
  • VINEYARD BIODIVERSITY and INSECT INTERACTIONS! ! - Establishing and Monitoring Insectariums! !
    ! VINEYARD BIODIVERSITY AND INSECT INTERACTIONS! ! - Establishing and monitoring insectariums! ! Prepared for : GWRDC Regional - SA Central (Adelaide Hills, Currency Creek, Kangaroo Island, Langhorne Creek, McLaren Vale and Southern Fleurieu Wine Regions) By : Mary Retallack Date : August 2011 ! ! ! !"#$%&'(&)'*!%*!+& ,- .*!/'01)!.'*&----------------------------------------------------------------------------------------------------------------&2 3-! "&(')1+&'*&4.*%5"/0&#.'0.4%/+.!5&-----------------------------------------------------------------------------&6! ! &ABA <%5%+3!C0-72D0E2!AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!F! &A&A! ;D,!*2!G*0.*1%-2*3,!*HE0-3#+3I!AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!J! &AKA! ;#,2!0L!%+D#+5*+$!G*0.*1%-2*3,!*+!3D%!1*+%,#-.!AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!B&! 7- .*+%)!"/.18+&--------------------------------------------------------------------------------------------------------------&,2! ! ! KABA ;D#3!#-%!*+2%53#-*MH2I!AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!BN! KA&A! O3D%-!C#,2!0L!L0-H*+$!#!2M*3#G8%!D#G*3#3!L0-!G%+%L*5*#82!AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!&P! KAKA! ?%8%53*+$!3D%!-*$D3!2E%5*%2!30!E8#+3!AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!&B! 9- :$"*!.*;&5'1/&.*+%)!"/.18&-------------------------------------------------------------------------------------&3<!
    [Show full text]
  • Gumleaf Skeletoniser Biocontrol: a Lesson in Patience
    THE JOINT FORCES OF CSIRO & SCION Lisa Berndt, Michelle Watson and Tara Murray Ensis Forest Biosecurity and Protection BiologicalBiological controlcontrol ofof gumleafgumleaf skeletoniser,skeletoniser, paropsisparopsis andand buddleiabuddleia March 2007 THE JOINT FORCES OF CSIRO & SCION Gumleaf skeletoniser Uraba lugens (Nolidae) • Australian eucalypt defoliator • In Auckland since 2001 • Spreading to Waikato, Northland, BOP • Threat to plantations, amenity trees, public health • Attacking new host plant species THE JOINT FORCES OF CSIRO & SCION GLS biocontrol • 4 potential parasitoids identified • ERMA permission to import 2004 • Develop rearing & host testing methods 2004-2007 (2 species) Eriborus sp. Photos: Geoff Allen & John Barran Euplectrus sp. Cotesia urabae Dolichogenidea eucalypti THE JOINT FORCES OF CSIRO & SCION Success: rearing • Rearing method finally successful • Solving mating problems key THE JOINT FORCES OF CSIRO & SCION Success: host testing • Methods developed • Nearly complete for two species • Nine more species to test • Strong preference for uraba THE JOINT FORCES OF CSIRO & SCION Paropsis biocontrol • Major eucalypt pest • Previously controlled by parasitoid Enoggera nissaui • Biocontrol disrupted by hyperparasitoid in North Island since 2002 Enoggera nassaui on P. charybdis egg • Second parasitoid (Neopolycystus insectifurax) not as effective • Most plantations sprayed annually now THE JOINT FORCES OF CSIRO & SCION Paropsis charybdis Current research • PhD student Tara Murray (2nd year) • Studying biology of hyperparasitoid
    [Show full text]
  • To Obtain Approval for New Organisms in Containment
    APPLICATION FORM Containment To obtain approval for new organisms in containment Send to Environmental Protection Authority preferably by email ([email protected]) or alternatively by post (Private Bag 63002, Wellington 6140) Payment must accompany final application; see our fees and charges schedule for details. Application Number APP203338 Date 28 July 2017 www.epa.govt.nz 2 Application Form Approval for new organism in containment Completing this application form 1. This form has been approved under section 40 of the Hazardous Substances and New Organisms (HSNO) Act 1996. It only covers importing, development (production, fermentation or regeneration) or field test of any new organism (including genetically modified organisms (GMOs)) in containment. If you wish to make an application for another type of approval or for another use (such as an emergency, special emergency or release), a different form will have to be used. All forms are available on our website. 2. If your application is for a project approval for low-risk GMOs, please use the Containment – GMO Project application form. Low risk genetic modification is defined in the HSNO (Low Risk Genetic Modification) Regulations: http://www.legislation.govt.nz/regulation/public/2003/0152/latest/DLM195215.html. 3. It is recommended that you contact an Advisor at the Environmental Protection Authority (EPA) as early in the application process as possible. An Advisor can assist you with any questions you have during the preparation of your application including providing advice on any consultation requirements. 4. Unless otherwise indicated, all sections of this form must be completed for the application to be formally received and assessed.
    [Show full text]
  • The Influence of Induced Host Moisture Stress on the Growth and Development of Western Spruce Bud Worm and Armillaria Ostoyae on Grand Fir Seedlings
    AN ABSTRACT OF THE THESIS OF Catherine Gray Parks for the degree of Doctor of Philosophy in the Department of Forest Science, presented on April 28, 1993. Title: The Influence of Induced Host Moisture Stress on the Growth and Development of Western Spruce Budworm and Armillaria ostoyae on Grand Fir Seedlings. Abstract Approved: John D. Waistad This greenhouse study evaluates the influence of separately and simultaneously imposed water stress, western spruce budworm (Choristorneura occidentalis Freeman) defoliation, and inoculation with the root pathogen, Armillaria ostoyae (Romagn.) Herink, on the growth and biochemical features of Abies .grandis (Dougl.) Lindi. Seedling biomass, plant moisture status, bud phenology, and allocation patterns of phenolics, carbohydrates, and key nutrients (nitrogen, phosphorus, potassium and sulfur) are reported. Hypotheses are developed and testedon the impacts of water-stress, defoliation, and root inoculation, on westernspruce budworm growth and development, and Armillaria ostoyae-caused mortality and infection. Western spruce budworm larvae fedon water-stressed seedlings had higher survival rates, grew faster, and produced largerpupae than those fed on well- watered seedlings. There is no clear reason for the positive insectresponse, but changes in foliage nutrient patterns and phenolic chemistryare indicated. Insect caused defoliation has been earlier reported to enhance successful colonization of Armillaria spp. on deciduous trees in the forests of the northeastern United States. The positive response of the fungus was attributed to a weakened tree condition. Conversely, although this study conclusively found water-limited trees to have increased susceptibility to A. ostoyae, defoliation significantly lowered Armillaria-caused infection and mortality. The decline in infection success is attributed to defoliation-caused reduction in plant water stress and an alteration of root carbohydrate chemistry.
    [Show full text]
  • Ichneumon Sub-Families This Page Describes the Different Sub-Families of the Ichneumonidae
    Ichneumon Sub-families This page describes the different sub-families of the Ichneumonidae. Their ecology and life histories are summarised, with references to more detailed articles or books. Yorkshire species from each group can be found in the Yorkshire checklist. An asterix indicates that a foreign-language key has been translated into English. One method by which the caterpillars of moths and sawflies which are the hosts of these insects attempt to prevent parasitism is for them to hide under leaves during the day and emerge to feed at night. A number of ichneumonoids, spread through several subfamilies of both ichneumons and braconids, exploit this resource by hunting at night. Most ichneumonoids are blackish, which makes them less obvious to predators, but colour is not important in the dark and many of these nocturnal ones have lost the melanin that provides the dark colour, so they are pale orange. They have often developed the large-eyed, yellowish-orange appearance typical of these nocturnal hunters and individuals are often attracted to light. This key to British species is a draft: http://www.nhm.ac.uk/resources-rx/files/keys-for-nocturnal-workshop-reduced-109651.pdf Subfamily Pimplinae. The insects in this subfamily are all elongate and range from robust, heavily- sculptured ichneumons to slender, smooth-bodied ones. Many of them have the 'normal' parasitoid life-cycle (eggs laid in or on the host larvae, feeding on the hosts' fat bodies until they are full- grown and then killing and consuming the hosts) but there are also some variations within this subfamily.
    [Show full text]
  • 100 Years of the Eucalyptus Tortoise Beetle in New Zealand Toni Withers and Elise Peters
    Professional papers 100 years of the eucalyptus tortoise beetle in New Zealand Toni Withers and Elise Peters Abstract Arrival and spread The eucalyptus tortoise beetle, Paropsis charybdis, The eucalyptus tortoise beetle, Paropsis charybdis, has been one of the most successful insect pests to was first located at Coopers Knob on Banks Peninsula in invade New Zealand. One hundred years have now 1916 (Thomson, 1922). Clark (1938) speculated that ‘the passed, and yet this pest continues to cause anxiety insect was probably imported in the egg or early larval to forest managers and impact the growth of eucalypt stages upon young eucalypt plants, although possibly plantations. Research shows there are serious cost hibernating adults may have entered the country implications for plantation managers if they neglect under the bark of imported Australian hardwoods.’ All to manage tortoise beetle outbreaks across multiple we know for sure is that the pest established quickly seasons. Many attempts have been made to control in Canterbury. Those founding individuals arrived this insect pest with biological control agents imported without any of the natural enemies that regulate their from its native Australia, with some success. number in Australia. Scion is hoping to introduce yet another natural In New Zealand, the only insects since observed enemy in 2018, a braconid parasitoid that targets the attacking tortoise beetle larvae are some predatory larval life stage. The importance of integrating aerial pentatomids (bugs) (Valentine, 1967). So with spray technologies with biological control agents to conditions perfect for its rapid population growth, minimise negative impacts on these beneficial insects the eucalyptus tortoise beetle spread steadily through cannot be under-estimated.
    [Show full text]