DOCSLIB.ORG

Response to Clover Root Weevil Outbreaks in South Canterbury, Otago and Southland; the Agricultural Sector and Government Working Together

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Response to Clover Root Weevil Outbreaks in South Canterbury, Otago and Southland; the Agricultural Sector and Government Working Together 117 Response to clover root weevil outbreaks in South Canterbury, Otago and Southland; the agricultural sector and government working together S. HARDWICK1, C.M. FERGUSON2, P. McCAULEY3, W. NICHOL4, R. KYTE5, D.M. BARTON2, M.R. McNEILL1, B.A. PHILIP2 and C.B. PHILLIPS1 1AgResearch Ltd, Lincoln Research Centre, Lincoln, New Zealand 2AgResearch Ltd, Invermay Agricultural Centre, Mosgiel, New Zealand 3Beef+Lamb New Zealand, PO Box 121, Wellington 6140, New Zealand 4PGG Wrightson Seeds Ltd., Private Bag 1946, Dunedin, New Zealand 5DairyNZ, 70 Forth Street, Invercargill, New Zealand [email protected] Abstract Southland in 2010 (Phillips et al. 2010) and Westland in Clover root weevil was first discovered in the northern 2012 (Ferguson et al. 2012). These isolated populations South Island in 2006, and an introduced biocontrol probably arose from inadvertent human-assisted agent the parasitoid wasp Microctonus aethiopoides, dispersal of CRW in association with farming activities was immediately released there in response. As the (Phillips et al. 2010; Ferguson et al. 2012). weevil spread southwards, ongoing releases and Adults of CRW feed on white clover leaves and can natural parasitoid dispersal generally supressed it to reduce establishment of seedlings, but it is the root- economically tolerable levels. However, mild winters feeding larvae that cause most damage by reducing in the southern South Island during 2013 and 2014 nitrogen fixation and weakening or killing plants allowed weevil populations to grow and spread quicker (Barratt et al. 1996 and references therein; Eerens et than the parasitoid. This severely impacted white clover al. 2005; Gerard et al. 2007). To maintain production, production and farm profitability in parts of South farmers may apply additional nitrogen fertiliser, grow Canterbury, Otago and Southland, thus, scientists and more non-susceptible forage plants, and/or increase industry conducted 18 months of intensive parasitoid supplementary feed (White & Gerard 2006). CRW releases of ca. 1.1 million parasitised weevils at 6000 damage was estimated to cost New Zealand agriculture sites. The parasitoid rapidly established at all 50 up to NZ$2.4 billion p.a. (Dooley & Lovatt 2013). monitored release sites and dispersed from them. The Insecticidal control is usually unfeasible and biocontrol biocontrol agent now occurs at all locations in South offered the best long-term option (Eerens et al. 2005). Canterbury, Otago, Southland, and elsewhere in New After searching for potential biocontrol agents Zealand, where clover root weevil is present. in Europe and North America (Phillips et al. 2000) and conducting bio-safety tests in New Zealand Keywords: biological control, pest spread, parasitic quarantine, the parasitoid Microctonus aethiopoides wasp, Sitona obsoletus, Microctonus aethiopoides, Loan (Hymenoptera: Braconidae) was introduced South Canterbury, Southland, Otago from Ireland in 2006 (Gerard et al. 2007, 2011). It is parthenogenetic (female only), attacks the adult Introduction stage of CRW, and each female can lay eggs in up to Sitona obsoletus (=S. lepidus) Gmelin (Coleoptera: 85 weevils. One weevil can support simultaneous Curculionidae), clover root weevil (CRW), is a development of 1-6 parasitoid larvae (Gerard et al. Palaearctic species that was first detected in Waikato, 2016). The parasitoid was first released in the North New Zealand, in 1996 (Barratt et al. 1996). By then Island, then soon afterwards in the South Island at it had already become widespread in Auckland, north Richmond in 2006 and the Rai Valley in 2007 (Phillips Waikato and coastal Bay of Plenty (Barker et al. 1996). et al. 2007). The parasitoid rapidly established and CRW continued to spread throughout the North Island began dispersing at approximately 15 km/year in at 10-70 km/year (Hardwick et al. 2004) and reached tandem with CRW (Phillips et al. 2010; Ferguson et al. the southern end of the North Island by 2005 (Gerard 2012). However, the discovery of additional isolated et al. 2009). populations of CRW that had established without the In the South Island, isolated populations of CRW biocontrol agent prompted further parasitoid releases in were discovered in Christchurch, Richmond and the North Canterbury in 2009 and Otago in 2010 (Ferguson Rai Valley in 2006 (Phillips et al. 2007), Otago in 2009, et al. 2012). At release sites, parasitoid establishment ISSN 2463-2872 (Print) ISSN 2463-2880 (Online) 118 Journal of New Zealand Grasslands 78: 117-122 (2016) was often confirmed as soon as 3 months after release, stored at 5 °C, pending distribution to farmers. On 10 and parasitism rates generally reached 70% within 12 occasions when the parasitism rate in collections was months; CRW populations and clover damage declined below 60%, weevils were exposed to parasitoids in soon after (Gerard et al. 2011; Ferguson et al. 2012). the laboratory to boost parasitism levels, as described During 2013-2015 in the southern South Island, in Ferguson et al. (2012). Parasitism rates in released the parasitoid’s natural spread and population growth weevils ranged from 60-90% (Hardwick et al. unpubl. failed to keep pace with those of CRW. In Otago and data). Because multiple parasitoid larvae can develop Southland, CRW outbreaks probably arose from winter in one CRW, on average about 100 parasitoids develop temperatures that were up to 2°C warmer than average from 60 CRW (Hardwick et al. unpubl. data). Also, (Anon. 2014, 2015). This favoured CRW egg and farmers were invited to collect their own parasitised larval survival, but not parasitoid population growth. In CRW from pastures at AgResearch’s Invermay campus. the springs of 2013 and 2014, many farmers in these regions reported that clover had disappeared from Industry field days their pastures, and farm profitability plummeted due to AgResearch staff contributed to workshops run by Beef reduced production and a need to apply more nitrogen + Lamb New Zealand, DairyNZ, PGGWrightsons Seeds, fertiliser. The parasitoid’s performance elsewhere, Ravensdown, Farmlands, Ballance AgriNutrients, including some parts of Otago, indicated it would Agricom and various farmer groups, by providing eventually have gained control of CRW. However, based up-to-date information on the biology, management on parasitoid dispersal rates of 15-20 km/year (Gerard and distribution of CRW and its parasitoid. They also et al. 2011; Ferguson et al. 2012), it was estimated distributed the parasitoid to the farmers most impacted this could take up to 7 years, which was economically by CRW. Usually one container of 100 parasitised untenable for farmers. In response, AgResearch, Beef + CRW was provided per farm, but multiple containers Lamb New Zealand, DairyNZ, PGGWrightson Seeds, were given to owners of large properties if the number Environment Southland and New Zealand Landcare of containers available exceeded the number of farmers Trust funded an 18 month programme of CRW present. Records were kept of the farms or localities delimitation surveys, parasitoid releases and extension, where the parasitised weevils were destined so districts to ensure that farmers in Southland and Otago had with low coverage could be targeted for subsequent access to both the parasitoid and the latest information releases. on CRW and its management. This paper builds on the work of Ferguson et al. (2012) by describing CRW CRW and biocontrol agent detection management activity during the 2014-2015 programme The methods used to detect and monitor CRW and the of parasitoid releases, and by reporting on the current parasitoid as they spread through the South Island were distribution of CRW and its parasitoid in the southern described by Phillips et al. (2010) and Ferguson et al. South Island. (2012). In brief, a Geographical Information System was used to divide the South Island into a 20 × 20 km grid, Methods and each cell in the grid was prioritised for sampling Parasitoid collection based on the area of pasture within it and results from Between late summer 2014 and winter 2015, AgResearch any previous sampling. A subset of properties that collected parasitised CRW for redistribution to farmers belonged to farmers who had received parasitised CRW in South Canterbury, Otago and Southland. Most from AgResearch were sampled to monitor parasitoid weevils (about 80%) were obtained from a farm near establishment. Researchers also took advantage of Peel Forest in Canterbury and many of the remainder sampling from other pest management programmes from AgResearch’s Invermay farm. At Peel Forest, the to monitor for the presence of CRW and its parasitoid. parasitoid had only recently become established and CRW presence was identified by sighting CRW adults there was a dense population of CRW that was highly in pasture, or by taking blower-vac samples. Parasitoid parasitised by M. aethiopoides. presence was confirmed by maintaining ca.100 CRW/ Parasitised CRW were collected by dragging a site in cages to allow parasitoid eggs and larvae to modified blower-vac (echo ES-255ES), across the develop into adults, and/or by dissecting 50-100 pasture (e.g. Phillips et al. 2000). Material from the weevils per site. mesh sock located in the air intake tube was taken to AgResearch laboratories at Lincoln or Invermay to Results extract CRW adults. A sub-sample of weevils from each Parasitoid collection and distribution collection were assessed for parasitism as described in Over the 18 month programme, a total of ca. 900 Gerard et al. (2007, 2011). The remainder were counted 000 parasitised CRW were collected by AgResearch into lots of 100, placed into 60 ml containers, and for distribution in the southern South Island, and a Response... (S. Hardwick, C.M. Ferguson, P. McCauley, W. Nichol, R. Kyte, D.M. Barton, M.R. McNeill, B.A. Philip and C.B. Phillips) 119 further ca. 250 000 were collected from the Invermay held in South Canterbury, Otago and Southland, with Agriculture Centre by farmers and associated industry most occurring in the latter two regions (Table 1). reps. These parasitised CRW weevils were released at ca.
Load more

Recommended publications
  • Does White Clover (Trifolium Repens) Abundance in Temperate Pastures Determine Sitona Obsoletus (Coleoptera: Curculionidae) Larval Populations?
    fpls-07-01397 September 14, 2016 Time: 19:20 # 1 View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Frontiers - Publisher Connector ORIGINAL RESEARCH published: 16 September 2016 doi: 10.3389/fpls.2016.01397 Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations? Mark R. McNeill1*, Chikako van Koten1, Vanessa M. Cave2, David Chapman3 and Hamish Hodgson3 1 AgResearch, Christchurch, New Zealand, 2 AgResearch, Hamilton, New Zealand, 3 DairyNZ, Lincoln University, Lincoln, New Zealand To determine if host plant abundance determined the size of clover root weevil (CRW) Edited by: Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown Ivan Hiltpold, Western Sydney University, Australia in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover Reviewed by: (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white James Michael William Ryalls, clover content to investigate CRW population establishment and impacts on white clover Hawkesbury Institute for the Environment, Australia survival. Larval sampling was carried out in spring (October) when larval densities are Phil Murray, near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured Rothamsted Research – in autumn (April) and spring (September) of each year. Overall, mean larval densities Biotechnology and Biological −2 Sciences Research Council, UK measured in spring 2012–2015 were 310, 38, 59, and 31 larvae m , respectively. *Correspondence: There was a significant decline in larval populations between 2012 and 2013, but Mark R.
    [Show full text]
  • The Clover Root Weevil Invasion: Impact and Response of the New Zealand Pastoral Industry 1996-2012
    University of Kentucky UKnowledge International Grassland Congress Proceedings XXII International Grassland Congress The Clover Root Weevil Invasion: Impact and Response of the New Zealand Pastoral Industry 1996-2012 Philippa J. Gerard AgResearch, New Zealand James R. Crush AgResearch, New Zealand Colin M. Ferguson AgResearch, New Zealand Scott Hardwick AgResearch, New Zealand Mark R. McNeill AgResearch, New Zealand See next page for additional authors Follow this and additional works at: https://uknowledge.uky.edu/igc Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/22/2-13/4 The XXII International Grassland Congress (Revitalising Grasslands to Sustain Our Communities) took place in Sydney, Australia from September 15 through September 19, 2013. Proceedings Editors: David L. Michalk, Geoffrey D. Millar, Warwick B. Badgery, and Kim M. Broadfoot Publisher: New South Wales Department of Primary Industry, Kite St., Orange New South Wales, Australia This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact [email protected]. Presenter Information Philippa J. Gerard, James R. Crush, Colin M. Ferguson, Scott Hardwick, Mark R. McNeill, and Craig B. Phillips This event is available at UKnowledge: https://uknowledge.uky.edu/igc/22/2-13/4 Ecology and control of
    [Show full text]
  • Invertebrate Biosecurity Challenges in High-Productivity Grassland: the New Zealand Example
    fpls-07-01670 November 11, 2016 Time: 14:42 # 1 CORE Metadata, citation and similar papers at core.ac.uk Provided by Lincoln University Research Archive MINI REVIEW published: 15 November 2016 doi: 10.3389/fpls.2016.01670 Invertebrate Biosecurity Challenges in High-Productivity Grassland: The New Zealand Example Stephen L. Goldson1,2, Barbara I. P. Barratt3 and Karen F. Armstrong1* 1 Bio-Protection Research Centre, Lincoln University, Canterbury, New Zealand, 2 Biocontrol and Biosecurity Group, AgResearch, Canterbury, New Zealand, 3 Biocontrol and Biosecurity Group, AgResearch, Otago, New Zealand To protect productive grasslands from pests and diseases, effective pre- and at- border planning and interventions are necessary. Biosecurity failure inevitably requires expensive and difficult eradication, or long-term and often quite ineffective management strategies. This is compared to the early intervention more likely for sectors where there is public and political interest in plants of immediate economic and/or social value, and where associated pests are typically located above-ground on host plantings of relatively limited distribution. Here, biosecurity surveillance and responses can be readily designed. In contrast, pastures comprising plants of low inherent unit value create little, Edited by: if any, esthetic interest. Yet, given the vast extent of pasture in New Zealand and the Ivan Hiltpold, value of the associated industries, these plants are of immense economic importance. University of Delaware, USA Compounding this is the invasibility of New Zealand’s pastoral ecosystems through Reviewed by: Karl Kunert, a lack of biotic resistance to incursion and invasion. Further, given the sheer area of University of Pretoria, South Africa pasture, intervention options are limited because of costs per unit area and the potential William R.
    [Show full text]
  • Green Roofs and Urban Biodiversity: Their Role As Invertebrate Habitat and the Effect of Design on Beetle Community
    Portland State University PDXScholar Dissertations and Theses Dissertations and Theses Spring 5-26-2016 Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community Sydney Marie Gonsalves Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Biodiversity Commons, Ecology and Evolutionary Biology Commons, and the Environmental Sciences Commons Let us know how access to this document benefits ou.y Recommended Citation Gonsalves, Sydney Marie, "Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community" (2016). Dissertations and Theses. Paper 2997. https://doi.org/10.15760/etd.2998 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community by Sydney Marie Gonsalves A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Science and Management Thesis Committee: Catherine E. de Rivera, Chair Amy A. Larson Olyssa S. Starry Portland State University 2016 © 2016 Sydney Marie Gonsalves Abstract With over half the world’s population now living in cities, urban areas represent one of earth’s few ecosystems that are increasing in extent, and are sites of altered biogeochemical cycles, habitat fragmentation, and changes in biodiversity. However, urban green spaces, including green roofs, can also provide important pools of biodiversity and contribute to regional gamma diversity, while novel species assemblages can enhance some ecosystem services.
    [Show full text]
  • Severe Insect Pest Impacts on New Zealand Pasture: the Plight of an Ecological Outlier
    Journal of Insect Science, (2020) 20(2): 17; 1–17 doi: 10.1093/jisesa/ieaa018 Review Severe Insect Pest Impacts on New Zealand Pasture: The Plight of an Ecological Outlier Stephen L. Goldson,1,2,9, Gary M. Barker,3 Hazel M. Chapman,4 Alison J. Popay,5 Alan V. Stewart,6 John R. Caradus,7 and Barbara I. P. Barratt8 1AgResearch, Private Bag 4749, Christchurch 8140, New Zealand, 2Bio-Protection Research Centre, P.O. Box 85084, Lincoln University, Lincoln 7647, New Zealand, 3Landcare Research, P.O. Box 69040, Lincoln 7640, New Zealand, 4School of Biological Sciences, University of Canterbury, PB 4800, Christchurch, New Zealand, 5AgResearch, Private Bag 11008, Palmerston North, New Zealand, 6PPG Wrightson Seeds, P.O. Box 69175, Lincoln Christchurch 7640, New Zealand, 7Grasslanz Technology Ltd., Private Bag 11008, Palmerston North 4442, New Zealand, 8AgResearch, Invermay Agricultural Centre, PB 50034, Mosgiel, New Zealand, and 9Corresponding author, e-mail: [email protected] Subject Editor: Louis Hesler Received 17 November 2019; Editorial decision 8 March 2020 Abstract New Zealand’s intensive pastures, comprised almost entirely introduced Lolium L. and Trifolium L. species, are arguably the most productive grazing-lands in the world. However, these areas are vulnerable to destructive invasive pest species. Of these, three of the most damaging pests are weevils (Coleoptera: Curculionidae) that have relatively recently been controlled by three different introduced parasitoids, all belonging to the genus Microctonus Wesmael (Hymenoptera: Braconidae). Arguably that these introduced parasitoids have been highly effective is probably because they, like many of the exotic pest species, have benefited from enemy release.
    [Show full text]
  • Clover Root Weevil (Sitona Lepidus) – a Threat to the Sustainability of White Clover in New Zealand Pastures?
    Proceedings of the New Zealand Grassland Association 59: 23–27 (1997) 23 Clover root weevil (Sitona lepidus) – a threat to the sustainability of white clover in New Zealand pastures? B. WILLOUGHBY and P. ADDISON AgResearch, Ruakura Research Centre, PB 3123, Hamilton Abstract This paper summarises events following the first recognition of S. lepidus and presents some interim Clover root weevil (Sitona lepidus) is established population data from a Waikato study site. Available in Auckland, Waikato and Bay of Plenty provinces. information about the potential pest status of this insect A pasture survey in 1997 estimated that the rate of is discussed within the context of the role of white its spread at about 35 km annually. Adults feed on clover as the key to profitability in New Zealand’s the foliage and larvae on roots and nodules of pastoral industries. white clover. Pasture populations appear to be 10 times higher in New Zealand than in the UK. New Arrival and spread Zealand’s temperate climate and high clover content in pastures may offer a very favourable environment Sitona lepidus was confirmed as present in New Zealand for S. lepidus, with serious implications for New in March 1996 although it was retrospectively Zealand’s pastoral farming. determined to have been present in 1995 (Barker et al. 1996). The identification arose when weevils of Keywords: clover root weevil, pasture pests, Sitona reproductive phenology inconsistent with that of S. lepidus, Trifolium repens, white clover discoideus were collected from pastures near Hamilton. The identity of the weevil was confirmed by New Zealand Introduction (G.
    [Show full text]
  • 8 March 2013, 381 P
    See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/273257107 Mason, P. G., D. R. Gillespie & C. Vincent (Eds.) 2013. Proceedings of the Fourth International Symposium on Biological Control of Arthropods. Pucón, Chile, 4-8 March 2013, 381 p. CONFERENCE PAPER · MARCH 2013 DOWNLOADS VIEWS 626 123 3 AUTHORS, INCLUDING: Peter Mason Charles Vincent Agriculture and Agri-Food Canada Agriculture and Agri-Food Canada 96 PUBLICATIONS 738 CITATIONS 239 PUBLICATIONS 1,902 CITATIONS SEE PROFILE SEE PROFILE Available from: Charles Vincent Retrieved on: 13 August 2015 The correct citation of this work is: Peter G. Mason, David R. Gillespie and Charles Vincent (Eds.). 2013. Proceedings of the 4th International Symposium on Biological Control of Arthropods. Pucón, Chile, 4-8 March 2013, 380 p. Proceedings of the 4th INTERNATIONAL SYMPOSIUM ON BIOLOGICAL CONTROL OF ARTHROPODS Pucón, Chile March 4-8, 2013 Peter G. Mason, David R. Gillespie and Charles Vincent (Eds.) 4th INTERNATIONAL SYMPOSIUM ON BIOLOGICAL CONTROL OF ARTHROPODS Pucón, Chile, March 4-8, 2013 PREFACE The Fourth International Symposium on Biological Control of Arthropods, held in Pucón – Chile, continues the series of international symposia on the biological control of arthropods organized every four years. The first meeting was in Hawaii – USA during January 2002, followed by the Davos - Switzerland meeting during September 2005, and the Christchurch – New Zealand meeting during February 2009. The goal of these symposia is to create a forum where biological control researchers and practitioners can meet and exchange information, to promote discussions of up to date issues affecting biological control, particularly pertaining to the use of parasitoids and predators as biological control agents.
    [Show full text]
  • Sitona Lepidus Gyllenhal Newly Established in New Zealand: Assessment of Distribution in the North Island
    Pasture Pests and Beneficials 266 SITONA LEPIDUS GYLLENHAL NEWLY ESTABLISHED IN NEW ZEALAND: ASSESSMENT OF DISTRIBUTION IN THE NORTH ISLAND GARY M. BARKER1*, PAUL J. ADDISON1, ALAN C. FIRTH1 and BARBARA I.P. BARRATT2 1AgResearch, Ruakura Agricultural Research Centre, Private Bag 3123, Hamilton 2AgResearch, Invermay Agricultural Centre, Private Bag 53002, Mosgiel *Currently Landcare Research, Private Bag 3127, Hamilton ABSTRACT Sitona lepidus has recently established in New Zealand, being first recognised in pastures in the vicinity of Hamilton (Waikato) in March 1996. The distribution of this species in the North Island was ascertained from retrospective examination of curculionid samples collected from pastures during the period February 1995 to March 1996, and from a contemporary field survey of curculionids from pastures during March- April 1996. Collectively, these surveys provided coverage of the North Island from Te Hana, Northland to Masterton, Wairarapa. S. lepidus was confirmed as being widespread in the Auckland, north Waikato and coastal Bay of Plenty regions, but was not found south of these regions. Keywords: Sitona lepidus, pasture, distribution INTRODUCTION The genus Sitona Germar (Coleoptera: Curculionidae, Brachycerinae) has a natural Holarctic distribution and comprises a large number of species. Some are pests of forage and grain legumes, with several species being widely distributed and naturalised beyond their natural range. Sitona discoideus Gyllenhal has become widely distributed in New Zealand since first being reported in Napier in 1974 (Esson 1975). It rapidly became established in lucerne (Medicago sativa L.) crops throughout New Zealand, causing considerable crop losses (Kain and Trought 1982; Goldson and French 1983). This species also occurs widely in New Zealand in non-agricultural habitats, where other Medicago species are the primary host plants (Barker and Addison unpublished).
    [Show full text]
  • Searching for Clover Root Weevil (Sitona Lepidus) Resistance/Tolerance – a Progress Report J.P.J
    Searching for clover root weevil(Sitona lepidus) resistance/tolerance (J.P.J. Eerens et al.) 177 Searching for clover root weevil (Sitona lepidus) resistance/tolerance – A progress report J.P.J. EERENS1, B.M. COOPER2, B.E. WILLOUGHBY1 and D.R. WOODFIELD3 1AgResearch Ruakura, Private Bag 3123, Hamilton 2AgResearch, Kerikeri Research Station, P.O. Box 23, Kerikeri 3AgResearch Grasslands, Private Bag 11008, Palmerston North [email protected] Abstract exposed the New Zealand pastoral agriculture industry to a serious threat (Barratt et al. 1996). There was The decimation of white clover in Waikato and little published information applicable to New Zealand Bay of Plenty pastures owing to the invasion clover even though CRW can be found in North America and root weevil (CRW) initiated an extensive screening from the Arctic circle to the Mediterranean in Europe of legume germplasm to identify plant material and east to the Indian subcontinent (Gerard et al. that could survive and remain productive under 1999). In many of the countries where CRW is endemic, high CRW pressure. A total of 50 000 plants from several Sitona species compete for oviposition sites 275 lines and six species, were planted on seven and food (Murray 1996). In most areas with similar commercial farms and evaluated for tolerance/ environmental conditions to New Zealand, intensive resistance to CRW under conventional farming pastoral farming is more biased towards grass practices. Plant productivity and level of CRW monocultures with higher application rates of mineral damage were both highest on white clover. nitrogen. In addition, various diseases, parasites and Significant CRW damage was also observed on predators may suppress CRW populations in areas red clover and caucasian clover, but not on birdsfoot where it is endemic (Phillips et al.
    [Show full text]
  • Chapter 9. Microctonus Parasitoids and New Zealand Weevils: Comparing Laboratory Estimates of Host Ranges to Realized Host Ranges
    __________________________________ ASSESSING HOST RANGES OF PARASITOIDS AND PREDATORS CHAPTER 9. MICROCTONUS PARASITOIDS AND NEW ZEALAND WEEVILS: COMPARING LABORATORY ESTIMATES OF HOST RANGES TO REALIZED HOST RANGES B. I. P. Barratt AgResearch Invermay, Private Bag 50034, Mosgiel, New Zealand [email protected] FORAGE WEEVIL PESTS IN NEW ZEALAND AND THEIR PARASITOIDS The pest weevils Sitona discoideus Gyllenhal and Listronotus bonariensis (Kuschel) have been the targets of recent biological control programs in New Zealand forage crops. Two species of Microctonus parasitoids (Hymen.: Braconidae: Euphorinae) were introduced to control these pests. For these parasitoids, retrospective laboratory host range testing and field studies were carried out in order to test the degree to which laboratory data can predict field host ranges. THE PEST WEEVILS Sitona discoideus in alfalfa Alfalfa is an important forage crop in low rainfall areas of New Zealand, particularly the eastern and central rain shadow areas of the South Island and parts of the North Island. Alfalfa out-produces grass pasture in the 300-800 mm rainfall zone (Douglas et al., 1987). However, in the last 20 years, alfalfa production has declined, partly because of increased pressure from exotic pests (Douglas et al., 1987). Sitona discoideus was first discov- ered in New Zealand in 1974 (Esson, 1975). Originating from the Mediterranean region, S. discoideus feeds on legumes in the genus Medicago. Adults feed on foliage, but the larvae are the most damaging stage, feeding within the root nodules of plants and reducing the ability of the plant to fix nitrogen. High densities of newly emerged adult S. discoideus can severely defoliate an alfalfa crop (Goldson et al., 1984).
    [Show full text]
  • Forest Health Technology Enterprise Team
    Forest Health Technology Enterprise Team TECHNOLOGY TRANSFER Biological Control September 12-16, 2005 Mark S. Hoddle, Compiler University of California, Riverside U.S.A. Forest Health Technology Enterprise Team—Morgantown, West Virginia United States Forest FHTET-2005-08 Department of Service September 2005 Agriculture Volume I Papers were submitted in an electronic format, and were edited to achieve a uniform format and typeface. Each contributor is responsible for the accuracy and content of his or her own paper. Statements of the contributors from outside of the U.S. Department of Agriculture may not necessarily reflect the policy of the Department. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture of any product or service to the exclusion of others that may be suitable. Any references to pesticides appearing in these papers does not constitute endorsement or recommendation of them by the conference sponsors, nor does it imply that uses discussed have been registered. Use of most pesticides is regulated by state and federal laws. Applicable regulations must be obtained from the appropriate regulatory agency prior to their use. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish and other wildlife if they are not handled and applied properly. Use all pesticides selectively and carefully. Follow recommended practices given on the label for use and disposal of pesticides and pesticide containers. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status.
    [Show full text]
  • Weevils As Targets for Biological Control, and the Importance of Taxonomy and Phylogeny for Efficacy and Biosafety
    diversity Article Weevils as Targets for Biological Control, and the Importance of Taxonomy and Phylogeny for Efficacy and Biosafety Barbara I. P. Barratt 1,2,* ID , Matthew J. W. Cock 3 ID and Rolf G. Oberprieler 4 1 AgResearch Invermay, Mosgiel PB 50034, New Zealand 2 Better Border Biosecurity (B3), Lincoln 7608, New Zealand 3 CAB International, Bakeham Lane, Egham, Surrey TW20 9TY, UK; [email protected] 4 Commonwealth Scientific and Industrial Research Organisation, Australian National Insect Collection, G.P.O. Box 1700, Canberra A.C.T. 2601, Australia; [email protected] * Correspondence: [email protected]; Tel.: +64-3-489-9059 Received: 3 July 2018; Accepted: 21 July 2018; Published: 25 July 2018 Abstract: Curculionidae are a large mainly herbivorous family of beetles, some of which have become crop pests. Classical biological control has been attempted for about 38 species in 19 genera, and at least moderate success has been achieved in 31 % of cases. Only two weevil species have been considered to be completely controlled by a biological control agent. Success depends upon accurately matching natural enemies with their hosts, and hence taxonomy and phylogeny play a critical role. These factors are discussed and illustrated with two case studies: the introduction of the braconid parasitoid Mictroctonus aethiopoides into New Zealand for biological control of the lucerne pest Sitona discoideus, a case of complex phylogenetic relationships that challenged the prediction of potential non-target hosts, and the use of a mymarid egg parasitoid, Anaphes nitens, to control species of the eucalypt weevil genus Gonipterus, which involves failure to match up parasitoids with the right target amongst a complex of very closely related species.
    [Show full text]