DOCSLIB.ORG

THE EFFICACY of the WEEVIL Cyrtobagous Salviniae

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
THE EFFICACY of the WEEVIL Cyrtobagous Salviniae The Efficacy of the Weevil Cyrtobagous salvinae (Coleoptera: Curculionidae) as a Biological Control on Giant Salvinia (Salvinia molesta) in the Lower Colorado River Item Type text; Electronic Dissertation Authors Choi, Sangho Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 25/09/2021 14:16:59 Link to Item http://hdl.handle.net/10150/195497 THE EFFICACY OF THE WEEVIL Cyrtobagous salviniae (Coleoptera: Curculionidae) AS A BIOLOGICAL CONTROL ON GIANT SALVINIA ( Salvinia molesta ) IN THE LOWER COLORADO RIVER By Sangho C hoi ___________________________ A Dissertation Submitted to the Facul ty of the DEPARTMENT OF SOIL, WATER AND ENVIRONMENTAL SCIENCE In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2 0 0 6 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEG E As members of the Final Examination Committee, we certify that we have read the dissertation prepared by : SANGHO CHOI _______________ entitled : The efficacy of the wee vil Cyrtobagous salviniae (Coleoptera: Curculionidae) as a biological control on giant salvinia ( Salvinia molesta ) in the Lower Colorado River and recommend that it be accepted as fulfilling the dissertation requirement for the degree of Doctor of Philo sophy. __________________________________________________ 11/03/06 Kevin Fitzsimmons Date __________________________________________________ 11/03/06 Edward P. Glenn Date __________________________________________________ 1 1/03/06 Stephen G. Nelson Date __________________________________________________ 11/03/06 James Riley Date __________________________________________________ 11/03/06 Allen Matthias Date Final approval and accept ance of this dissertation is contingent upon the candidate’s submission of the final copy of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as ful filling the dissertation requirement. __________________________________________________ ___________ Dissertation Director Date Dr. Kevin Fitzsimmons 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requiremen ts for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgement of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department of the Dean of the Graduate College when in his or h er judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED :_ _Sangho Choi ____________________________ 4 ACKNOWLEDGEMENTS Without the help of numerous people, this work would not have been possible. Dr. Kevin Fitzsimmons for always being available to answer my questions and to give a good advice; Earl Andress for being willing to share the knowledge he gained over the years in field works.: Jose Louis and many of my friends (Keesung Kim, Jinsoo Jeon, Soochul Kim, and Jinhee Han) for helping me collecting samples under the severe weather conditions. Financial suuport for this project research was provided, in part, by U.S. F ish and Wildlife Service and Lower Colorado River Salvinia Task Force. Additional funding was supplied by a grant from Bureau of Reclamation. 5 DEDICATION For my family, without their love and support this work would not be a reality. 6 TABLE OF CONT ENTS Page LIST OF ILLUSTRATIONS…………………………………………………………… .7 LIST OF TABLES…………………………………………………………………… 9 ABSTRACT………………………………………………………………………… 1 0 INTRODUCTION ................................ ................................ ................................ .......... 12 RESEARCH APPROACH ................................ ................................ ............................. 20 MANAGEMENT OF GIANT SALVINIA BY BIOLOGICAL CONTROL ON THE LOWER COLORADO RIVER ................................ ................................ ...................... 25 AB ST RACT …………………………………………………………………….. 25 INTRODUCTION ................................ ................................ ................................ ...... 26 MATERIALS AND METHODS ................................ ................................ ............... 28 RESULTS ................................ ................................ ................................ ................... 35 DISCUSSION ................................ ................................ ................................ ............. 40 R EFERENCES ................................ ................................ ................................ ........... 42 LOW TEMPERATURE TOLERANCE OF THE BIOLOGICAL CONTROL AGENT Cyrtobagous salvinia e (Col eoptera: Curculionidae) ………………… …….. 44 AB STRACT …………………………………………………………………….. 44 INTRODUCTION ................................ ................................ ................................ ...... 45 MATERIALS AND METHODS ................................ ................................ ............... 47 RESULTS ................................ ................................ ................................ .................. 51 DISCUSSION ................................ ................................ ................................ ............. 54 REFERENCES ................................ ................................ ................................ ........... 55 NITROGEN AND ESTABLISHMENT OF WEEVIL POPULATIONS FOR BIOLOGICAL CONTROL O F GIANT SALVINIA ................................ .................... 57 AB STRACT …………………………………………………………………….. 57 INTRODUCTION ................................ ................................ ................................ ...... 58 MATERIALS AND METHODS ................................ ................................ ............... 59 RESULTS ................................ ................................ ................................ ................... 64 DISCUSSION ................................ ................................ ................................ ............. 68 REFERENCES ................................ ................................ ................................ ........... 69 SUMMARY ................................ ................................ ................................ ................... 70 REFERENCES ................................ ................................ ................................ ............... 77 7 LIST OF ILLUSTRATIONS FIGURE page 1 Anatomy of giant salvinia …………………………… ……………………… 13 2 Biological control agent C. salviniae for giant salvinia ……………………… 15 3 Feeding damage by weevils ……………………………………………….. 16 4 The Lower Colorado River Basin ………………………………………… 1 8 5 Distribution of gi ant salvinia in the United States ………………………… 22 6 Life cycle of Cyrtobagous salviniae ……………………………………… 31 7 Map of the release sites on the Lower Colorado River …………………… . 32 8 Map of the releas e sites on the Lower Colo rado River ………………… 32 9 Map of the releas e sites on the Lower Colorado River …………………... 33 10 Map of the releas e sites on the Lower Colorado River … …………………. 33 11 Map of the releas e sites on the Lower Colorado River … ……………… … 34 12 Map of the releas e sites on the Lower Colorado River …………………... 34 13 The number of weevils released on the river (by year) ………………… … 37 14 The number of weevils released on the river (by month ) … ………………… 38 15 The number of weevils recovered from the site (CA 02 ) … ………………… 38 16 The seasonal changes of weevil recovery ………………………………… 39 17 Salvinia and weevil hatchery in the greenhou se …………………………… 49 18 Environmental chamber …………………………………………………… . 49 19 Diagram of exp eriments ………………………………………………….. 50 20 The diagram of nitrogen fertilization procedure ………………………….. 62 21 The diagram of experimental setting … ………………………………………… 6 3 8 LIST OF ILLUSTRATIONS Continued 22 The main webpage of LCR Task Force …………………………………… 7 6 9 LIST OF TABLES TABLE 1 The average of basic water chemistry data ………………………………. 35 2 The range of basic water chemistry data ………………………………….. 36 3 Average s urvival of wee vils ( + standard deviation) at three temperature regimes …………………………………………………… ………………………….. 51 4 Average n umber of bullet hole s ( + standard deviation) per plant at three temperature regimes …………… ………………………………………………………… 5 2 5 Average s urvival of weevils at different salvinia population densities with diurnal range of 5 to 15 oC …………………………………………………………… 53 6 Basic water quality data in PVID drain …………………………………….. 64 7 Average number of weevils at each repli cate at 32 nd Ave. (inds./1 scoop) ….. 66 8 Average number of weevils at each replicate at Coco Palm (inds./1 scoop) …. 67 10 ABSTRACT The Lower Colorado River Giant Salvinia Task Force has tried a series of physical and chemical activities in an effort to control and eradicate giant salvinia ( Salvinia molesta ) since 1999. Because these efforts have not produced satisfactory results, biological control using the weevil
Load more

Recommended publications
  • (Coleoptera: Curculionidae) for the Control of Salvinia
    Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2011 Introduction and Establishment of Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) for the Control of Salvinia minima Baker (Salviniaceae), and Interspecies Interactions Possibly Limiting Successful Control in Louisiana Katherine A. Parys Louisiana State University and Agricultural and Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Entomology Commons Recommended Citation Parys, Katherine A., "Introduction and Establishment of Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) for the Control of Salvinia minima Baker (Salviniaceae), and Interspecies Interactions Possibly Limiting Successful Control in Louisiana" (2011). LSU Doctoral Dissertations. 1565. https://digitalcommons.lsu.edu/gradschool_dissertations/1565 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. INTRODUCTION AND ESTABLISHMENT OF CYRTOBAGOUS SALVINIAE CALDER AND SANDS (COLEOPTERA: CURCULIONIDAE) FOR THE CONTROL OF SALVINIA MINIMA BAKER (SALVINIACEAE), AND INTERSPECIES INTERACTIONS POSSIBLY LIMITING SUCCESSFUL CONTROL IN LOUISIANA. A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Entomology By Katherine A. Parys B.A., University of Rhode Island, 2002 M.S., Clarion University of Pennsylvania, 2004 December 2011 ACKNOWLEDGEMENTS In pursing this Ph.D. I owe many thanks to many people who have supported me throughout this endeavor.
    [Show full text]
  • Water Spangles (Salvinia Minima) ERSS
    Water Spangles (Salvinia minima) Ecological Risk Screening Summary U.S. Fish & Wildlife Service, December 2014 Revised, April 2018 Web Version, 8/19/2019 Photo: Kurt Stüber. Licensed under Creative Commons Attribution-Share Alike 3.0 Unported. Available: https://commons.wikimedia.org/wiki/File:Salvinia_minima_1.jpg. (April 2018). 1 Native Range and Status in the United States Native Range GISD (2018) lists Salvinia minima as native to Argentina, Belize, Bolivia, Brazil, Colombia, Cuba, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Puerto Rico, Uruguay, and Venezuela. From Howard Morgan (2018): “Native Range: Central and South America; common and wide-ranging from southern Mexico to northern Argentina and Brazil (Mickel a[n]d Beitel 1988, [Stoltze] 1983). De la Sota (1976) 1 remarked that, in Argentina, the natural range of Salvinia minima could not be precisely determined due to its frequency in the watergarden and aquarium trade.” Status in the United States GISD (2018) lists Salvinia minima as alien, invasive and established in Alabama, Florida, Louisiana, Minnesota, New York, and Texas. Howard Morgan (2018) list Salvinia minima as present in the wild in Alabama (first report in 1982), Arkansas (first report in 1998), California (first report in 2008), Florida (first report in 1930), Georgia (first report in 1936), Idaho (first report in 2004), Louisiana (first report in 1980), Maryland (first report in 1984), Massachusetts (first report in 1992), Mississippi (first report in 1999), New Mexico (first report in 1999), New York (first report in 1990), Ohio (first report in 2017), Oklahoma (first report in 1989), Puerto Rico (first report in 1998), South Carolina (first report in 1997), and Texas (first report in 1992).
    [Show full text]
  • The Adventive Status of Salvinia Minima and S. Molesta in The
    The Adventive Status of Salvinia minima and S. molesta in the Southern United States and the Related Distribution of the Weevil Cyrtobagous salviniae Author(s): Colette C. Jacono, Tracy R. Davern and Ted D. Center Source: Castanea, Vol. 66, No. 3 (Sep., 2001), pp. 214-226 Published by: Southern Appalachian Botanical Society Stable URL: http://www.jstor.org/stable/4033946 . Accessed: 29/09/2014 14:51 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Southern Appalachian Botanical Society is collaborating with JSTOR to digitize, preserve and extend access to Castanea. http://www.jstor.org This content downloaded from 158.135.136.72 on Mon, 29 Sep 2014 14:51:58 PM All use subject to JSTOR Terms and Conditions CASTANEA 66(3): 214-226. SEPTEMBER 2001 The Adventive Status of Salvinia minima and S. molesta in the Southern United States and the Related Distribution of the Weevil Cyrtobagous salviniae COLETTE C. JACONO,1 TRACY R. DAVERN,2 and TED D. CENTER2 'USGS, Florida Caribbean Science Center, 7920 NW 71st St., Gainesville, Florida 32653; 2USDA-ARS,Invasive Plant Research Laboratory,3205 College Ave., Fort Lauderdale, Florida 33314 ABSTRACT The recent introduction of Salvinia molesta constitutes a serious threat to aquatic systems in the warm temperate regions of the United States.
    [Show full text]
  • Salvinia Molesta. Retrieved From
    Aquatic Plant Salvinia I. Current Status and Distribution Salvinia molesta, S. minima, S. herzogii, S. natans a. Range Global/Continental Wisconsin Native Range S. molesta: South America (Southern Brazil)1 S. minima: Central and South America2 S. herzogii: South America3 S. natans: Eurasia4 Not recorded in Wisconsin Figure 1: U.S and Canada Distribution Map5 Also reported from Virginia & Colorado6 (S. molesta, S. minima, S. herzogii, and S. natans) Abundance/Range Widespread: Tropics, subtropics Not applicable Locally Abundant: Warm temperatures, high nutrients7 Not applicable Sparse: Frost-limited Not applicable Range Expansion Date Introduced: Late 19th century8; 1930s2; late 1970s to early Not applicable 1980s9 Rate of Spread: Extremely rapid; doubling time of 2.9 days (S. Not applicable herzogii)10 Density Risk of Monoculture: High; capable of 30,000 plants/m2; can result Unknown in mats 3 feet thick9 Facilitated By: High temperatures, nutrients Unknown b. Habitat Lakes, reservoirs, wetlands, low energy systems Tolerance Chart of tolerances: Increasingly dark color indicates increasingly optimal range11,12 Preferences Low energy freshwater systems; high nutrient input (nitrogen) and high temperatures10,13; intolerant of salinity8 Page 1 of 5 Wisconsin Department of Natural Resources – Aquatic Invasive Species Literature Review c. Regulation Noxious/Regulated5: Federal Noxious Weed List; AL, AZ, CA, CO, CT, FL, MA, MS, NV, NC, OR, SC, TX, VT Minnesota Regulations: Prohibited; One may not possess, import, purchase, propagate, or transport Michigan Regulations: Prohibited; One may not knowingly possess or introduce Washington Regulations: Secondary Species of Concern II. Establishment Potential and Life History Traits a. Life History Floating leaf aquatic fern; subtle differences exist between species but in general they are very closely related13; S.
    [Show full text]
  • Salvinia Molesta D. Mitch. (Salviniaceae): Impact and Control
    CAB Reviews 2020 15, No. 033 Salvinia molesta D. Mitch. (Salviniaceae): impact and control Julie A. Coetzee1* and Martin P. Hill2 Address: 1Botany Department, Centre for Biological Control, Rhodes University, Grahamstown, P.O. Box 94, 6140, South Africa. 2Department of Zoology and Entomology, Centre for Biological Control, Rhodes University, Grahamstown, P.O. Box 94, 6140, South Africa. ORCID information: Julie A. Coetzee (orcid: 0000-0002-0364-3349); Martin P. Hill (orcid: 0000-0003-0579-5298) *Correspondence: Julie A. Coetzee. Email: [email protected] Received: 15 November 2019 Accepted: 07 July 2020 doi: 10.1079/PAVSNNR202015033 The electronic version of this article is the definitive one. It is located here: http://www.cabi.org/cabreviews © CAB International 2020 (Online ISSN 1749-8848) Abstract Salvinia molesta D.S. Mitchell (Salviniaceae) (giant salvinia), a floating aquatic fern of Brazilian origin, has been dispersed to much of the tropical and subtropical parts of the world since the mid-1900s, where it is invasive and damaging. Herbicide application and mechanical control of this weed are labor intensive and expensive, but biological control using the host-specific weevil, Cyrtobagous salviniae (Calder and Sands), provides an effective and sustainable solution. The weevil was first released as a biological control agent onto S. molesta in Australia in 1980 and has subsequently been released in further 22 countries affected by the weed. The biological control program against S. molesta has been an extraordinary success story where a single weevil species has resulted in the weed no longer being considered invasive in most countries in a relatively short time of under 3 years.
    [Show full text]
  • Cyrtobagous Salviniae (Coleoptera: Curculionidae) Successfully Overwinters in Texas and Louisiana
    92 Florida Entomologist 86(1) March 2003 CYRTOBAGOUS SALVINIAE (COLEOPTERA: CURCULIONIDAE) SUCCESSFULLY OVERWINTERS IN TEXAS AND LOUISIANA P. W. TIPPING AND T. D. CENTER USDA-ARS Invasive Plant Research Laboratory, Ft. Lauderdale, FL 33314 Salvinia molesta D. S. Mitchell, an invasive structive methodologies like Berlese funnels usu- floating fern, has invaded 12 states in the U.S. and ally extract 5-10 times more adults than hand is now well established in Texas and Louisiana searching (Tipping, unpublished data) so the wee- (Jacono 1999). This plant quickly colonizes the vil density may have been up to 90 adults in the surface of slow moving, fresh water bodies caus- sampled area at one site. ing severe ecological and economic problems Further sampling was halted during the win- (Harley & Mitchell 1981). Successful biological ter and resumed on March 25-27, 2002. Two of the control programs targeting this weed have been four release sites yielded adult C. salviniae during conducted in at least 13 countries worldwide us- hand searches with three and four adults found at ing a small weevil, Cyrtobagous salviniae Calder those sites. It is unknown if these weevils were and Sands (Coleoptera: Curculionidae) (Julien & the original adults or progeny from the October, Griffiths 1998). This species was first collected in 2001 release. Sands et al. (1986) found that adults southeastern Brazil in 1979 (Forno & Bourne held under constant temperatures of 23, 27, and 1984) and, after extensive host range testing, was 31°C lived an average of 163.1, 116.9, and 101.5 released in Australia in 1980 where it reduced a days, respectively.
    [Show full text]
  • Forest Health Technology Enterprise Team Biological Control of Invasive
    Forest Health Technology Enterprise Team TECHNOLOGY TRANSFER Biological Control Biological Control of Invasive Plants in the Eastern United States Roy Van Driesche Bernd Blossey Mark Hoddle Suzanne Lyon Richard Reardon Forest Health Technology Enterprise Team—Morgantown, West Virginia United States Forest FHTET-2002-04 Department of Service August 2002 Agriculture BIOLOGICAL CONTROL OF INVASIVE PLANTS IN THE EASTERN UNITED STATES BIOLOGICAL CONTROL OF INVASIVE PLANTS IN THE EASTERN UNITED STATES Technical Coordinators Roy Van Driesche and Suzanne Lyon Department of Entomology, University of Massachusets, Amherst, MA Bernd Blossey Department of Natural Resources, Cornell University, Ithaca, NY Mark Hoddle Department of Entomology, University of California, Riverside, CA Richard Reardon Forest Health Technology Enterprise Team, USDA, Forest Service, Morgantown, WV USDA Forest Service Publication FHTET-2002-04 ACKNOWLEDGMENTS We thank the authors of the individual chap- We would also like to thank the U.S. Depart- ters for their expertise in reviewing and summariz- ment of Agriculture–Forest Service, Forest Health ing the literature and providing current information Technology Enterprise Team, Morgantown, West on biological control of the major invasive plants in Virginia, for providing funding for the preparation the Eastern United States. and printing of this publication. G. Keith Douce, David Moorhead, and Charles Additional copies of this publication can be or- Bargeron of the Bugwood Network, University of dered from the Bulletin Distribution Center, Uni- Georgia (Tifton, Ga.), managed and digitized the pho- versity of Massachusetts, Amherst, MA 01003, (413) tographs and illustrations used in this publication and 545-2717; or Mark Hoddle, Department of Entomol- produced the CD-ROM accompanying this book.
    [Show full text]
  • Note Biological Control of Salvinia Molesta: Population Dynamics Of
    J. Aquat. Plant Manage. 55: 46–49 Note Biological control of Salvinia molesta: Population dynamics of Cyrtobagous salviniae in Lake B. A. Steinhagen ABHISHEK MUKHERJEE*, ALLEN KNUTSON, AND KEVIN HEINZ INTRODUCTION following spring. Similarly, efforts to establish C. salviniae at Lake Caddo in northeastern Texas have not been successful. The floating fern, Salvinia molesta D. S. Mitchell (Salvinia- Caged populations of C. salviniae monitored at Lake Caddo ceae) is an important aquatic weed worldwide and is an during the winters of 2010 to 2011 and 2013 to 2014 suffered invasive weed in the tropical and subtropical regions of 100% mortality, indicating that overwintering mortality was Africa, Asia, North America, South America, and Oceania limiting successful establishment at this site (Obeysekara et al. (Julien et al. 2009). Biological control of S. molesta with the 2015). These observations suggest a lack of cold tolerance of C. use of Cyrtobagous salviniae Calder and Sands (Coleoptera: salviniae might be an important limiting factor for biological Curculionidae) provides the most effective and inexpensive control success in temperate locales of Texas and Louisiana. control of S. molesta (Chikwenhere and Keswani 1997; Julien However, very little is known about the overwintering biology et al. 2009) in many situations. This semiaquatic weevil was of C. salviniae in these temperate regions of the United States. collected from Brazil and was first released in Australia in To better understand how cold could influence reproduction 1980 (Room et al. 1981). Cyrtobagous salviniae has provided and survival, we investigated the seasonal population dynam- spectacular control in Australia (Julien et al. 2012), and to ics of C.
    [Show full text]
  • A Guide to Mass Rearing the Salvinia Weevil for Biological Control of Giant Salvinia
    A Guide to Mass Rearing the Salvinia Weevil for Biological Control of Giant Salvinia A Guide to Mass Rearing the Salvinia Weevil A Guide to Mass Rearing the Salvinia Weevil for Biological Control of Giant Salvinia Allen Knutson and Julie Nachtrieb Project Coordinators Chapter Authors Chapter 1 Giant Salvinia, Salvinia Weevil, and Biological Control of Giant Salvinia Allen Knutson and Abhishek Mukherjee Chapter 2 Water Quality Parameters Important to Growing Giant Salvinia Allen Knutson Chapter 3 Rearing the Salvinia Weevil for Biological Control of Giant Salvinia at the U.S. Army Corps of Engineers Lewisville Aquatic Ecosystem Research Facility Julie G. Nachtrieb Chapter 4 Rearing the Salvinia Weevil in Outdoor Tanks at Caddo Lake, Texas Patrick Ireland, Allen Knutson, and Lucas Gregory Chapter 5 Rearing the Salvinia Weevil in the Greenhouse Lee J. Eisenberg and Seth J. Johnson Chapter 6 Rearing the Salvinia Weevil in Ponds Dearl Sanders, Wendell Lorio, and Keith Whitehead Texas A&M AgriLife Extension Service Special Publication ESP-475 A Guide to Mass Rearing the Salvinia Weevil Table of Contents List of Figures .........................................................................................................................iv List of Tables ............................................................................................................................v List of Acronyms and Abbreviations ........................................................................................v Preface ....................................................................................................................................vi
    [Show full text]
  • Giant Salvinia Including an Aquatic INVASIVE SPECIES FACT SHEET Grasshopper (Paulinia Acuminate De Geer), the Pyralid Moth (Samea Multiplicalis Guenee)
    MANAGEMENT Biological Control: A few biological control agents exist for the potential control of giant salvinia including an aquatic INVASIVE SPECIES FACT SHEET grasshopper (Paulinia acuminate De Geer), the pyralid moth (Samea multiplicalis Guenee). The moth and the grass- hopper were primarily investigated in Australia and currently are not approved for use in the United States. Herbivo- Giant Salvinia (Salvinia molesta D. S. Mitchell) rous fish including the grass carp (Ctenopharyngodon idella Val.), and tilapia (Oreochromis niloticus Trewavas); the last has shown promise as a biological control agent (Table 1). However, the salvinia weevil (Cyrtobagous salviniae Calder Description, Distribution, and Management and Sands) is the most notable and only organism that has demonstrated success in giant salvinia control. Both adult and larval damage can reduce giant salvinia infestations when conditions are optimal for weevil growth. Optimal condi- Ryan M. Wersal and John D. Madsen, PhD, GeoResources Institute, Mississippi State University tions include water temperatures between 61 and 86°F. Water temperatures outside this range results in decreased weevil performance. Similarly, feeding and larval damage depend on levels of nitrogen in plant tissues; low levels of plant nitrogen result in low densities of the salvinia weevil. Mechanical Control: Manual (hand pulling) or mechanical (wire nets and floating booms) control of giant salvinia is only INTRODUCTION practical during the early stages of growth (Table 1). After giant salvinia is established in a given area, increased bio- Giant salvinia (Salvinia molesta D.S. Mitchell) is an aquatic fern native to southern Brazil. Giant salvinia is free-floating mass and rapid growth makes harvesting and hand pulling unfeasible.
    [Show full text]
  • Giant Salvinia Weevils in Outdoor Ponds
    How to Rear Giant Salvinia Weevils in Outdoor Ponds Charlie Wahl, Lori Moshman and Rodrigo Diaz Department of Entomology LSU AgCenter How to Rear Giant Salvinia Weevils in Outdoor Ponds Charlie Wahl, Lori Moshman and Rodrigo Diaz Department of Entomology, LSU AgCenter Background on Giant Salvinia and salvinia leaves are typically about half the size of giant salvinia leaves (Figures 3 and 4). Trichomes on giant the Salvinia Weevil salvinia leaves fuse together to form an egg-beater shape Giant salvinia, Salvinia molesta Mitchell, is a floating (Figure 5), while trichomes on common salvinia leaves do aquatic fern that has become one of the worst invasive not fuse together (Figure 6). weeds in the southeastern United States (Figure 1). This The salvinia weevil, Cyrtobagous salviniae Calder and plant is native to southern Brazil, Argentina and Uruguay Sands, is a South American beetle that is a specialist and is considered an invasive species in several tropical feeder on salvinia. The salvinia weevil was first intro- and subtropical countries (McFarland et al. 2004). Giant duced into Australia in the 1980s, and it has successfully salvinia is of great economic and ecological importance managed giant salvinia infestations (Room et al. 1981). in Louisiana because of its ability to form extensive mats Weevils collected from this Australian population were of vegetation in lakes, ponds, reservoirs and bayous. The released in Texas and Louisiana in 2001 and have result- dominant or tertiary growth stage of giant salvinia is a ed in successful establishment of the weevil in southern densely packed mat of individual plants that can be easily regions of the states (Flores and Carlson 2006).
    [Show full text]
  • Notes Mass-Rearing Cyrtobagous Salviniae for Biological Control of Giant Salvinia: Field Release Implications
    J. Aquat. Plant Manage. 51: 122–126 Notes Mass-rearing Cyrtobagous salviniae for biological control of giant salvinia: Field release implications JULIE G. NACHTRIEB* INTRODUCTION material. This led to delays in rearing and subsequent release as the insect colonies typically did not build up Giant salvinia (Salvinia molesta Mitchell), a free-floating sufficiently large populations for field releases until Sep- aquatic fern native to South America, is considered one of tember or October. In fact, during the 6 yr of pond rearing, the world’s worst weeds (Harley and Mitchell 1981). field releases occurred only 1 time, following a mild winter, Infestations across the globe typically form dense mats, due to difficulties in achieving weevil densities appropriate which clog waterways and impact recreational activities, for collection and release. The 1 time that weevil popula- irrigation, drainage, flood mitigation, hydroelectric pro- tions were satisfactorily high, approximately 146,000 adult duction, and mosquito control, alter water quality, and weevils were collected from 1 rearing pond from late July to displace native vegetation (Tipping 2004). In the United late August 2005 (Harms et al. 2009). Due to overwintering States, infestations have been noted in Louisiana, Texas, difficulties while using ponds, it was determined that this Alabama, Arizona, California, Florida, Georgia, Hawaii, was not the optimal method for weevil rearing in north Virginia, Mississippi, South Carolina, and North Carolina Texas, and other rearing techniques were attempted. (USGS 2005). Since 2008, weevils have been reared in outdoor, Biological control of giant salvinia using the salvinia aboveground culture boxes in which it is easier to protect weevil (Cyrtobagous salviniae Calder and Sands) (Coleoptera: plants and weevils during winter.
    [Show full text]