Biocontrol of Rangeland Weeds TRA Pest Management Workshop, Feb 20, 11:15 am. Outline. Pest Management Workshop 2013 Bean, Rangeland Pest Control

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1 Biocontrol of Rangeland Weeds TRA Pest Management Workshop, Feb 20, 11:15 am Dan Bean Colorado Department of Agriculture Palisade Insectary Who are we? Palisade Insectary Began in the 1940 s to fight Oriental fruit moth, a project that helped peach farmers and is still going Moved to new 14,000 sq. ft. facility in 1992 Distributes over 20 biocontrol agents for the control of insect pests and weeds Is a partner in pest management Outline What is biological control? Is biological control safe? Is biological control effective? What weeds can we control using biological agents? Russian knapweed, yellow toadflax and Canada thistle; new agents for rangeland weeds. What is biological control? Biological control (biocontrol) is the use of natural enemies, including insects, mites and pathogens, to control pests, including insect pests and noxious weeds. Calophasia lunula on Dalmatian toadflax Macrocentrus ancylivorus stings host Classical Weed Biological Control The reunification of host specific natural enemies with invasive plants Tamarix spp Tamarisk 1830 Biological Control The use of natural enemies to control pest organisms Safe Effective Inexpensive Sustainable Flea beetle on leafy spurge Leaf beetle 2001 Field bindweed gall mites Macrocentrusparasitic wasp tamarisk leaf beetle collection Diorhabda carinulata 1

2 Biological Control The use of natural enemies to control pest organisms The results of weed biocontrol are a new equilibriumbetween the introduced plant and natural enemies of the plant Natural enemy added Field bindweed gall mites Macrocentrus parasitic wasp Flea beetle on leafy spurge Cultural, Mechanical Chemical, Biological long term ecological solution balance Integrated Pest Management tamarisk leaf beetle collection Weed Suppression Never Eradication! The results of weed biocontrol are a new equilibriumbetween the introduced plant and natural enemies of the plant Ecologically Based Invasive Plant Management (successional weed management) Natural enemy added 1. Site Availability 2. Species Availability 3. Species Performance long term ecological solution 1. Opens canopy (increases site availability) 2. Decreases seed production (decreases species availability) 3. Slows growth or may kill (decreases species performance) Ecologically Based Invasive Plant Management Biological Control Ecologically Based Invasive Plant Management Restoration Islands tamarisk biocontrol May open up new sites for desired plants Decreases seed production of target weeds Decreases competitive ability of target weeds 1. Site Availability 2. Species Availability 3. Species Performance 1. Site Availability 2. Species Availability 3. Species Performance 2

3 Is biological control safe? Generalists vs. Specialists: Only Specialists are used! Yes, only host specific insects are used and no record of host switches during the 65 years of weed biocontrol in NA Insect Leafy spurge flea beetles Knapweed root weevil Russian knapweed gall fly Tamarisk beetle Grasshoppers (various species) Host Plant Leafy spurge Diffuse and spotted knapweed Russian knapweed tamarisk Various crops Defoliated tamarisk in the midst of other tree species that remain untouched Moab, Utah Most plant feeding insects are adapted to a single plant species or a small group of closely related plant species. Some groups, like many grasshopper species, are generalists and feed on a wide range of plants Steps in weed biological control Is biological control effective? Identification of target/background research Overseas exploration and research to find agent or agents Quarantine work including agent cleanup and host range testing Approval from regulatory agencies (TAG, APHIS) Before After Before and after release of leafy spurge flea beetles and long horned beetles, complete control (not eradication) of leafy spurge in pasture land near Pine, Colorado Field testing including monitoring Full scale implementation years! Flea beetles leafy spurge Oberea adult What weeds can we control using biological agents? spotted knapweed Russian knapweed Providing biocontrol agents/ developing biocontrol programs (numbers are for 2010 except for J. ivannikovi which is 2012) Leafy Spurge Aphthonaspp 200,000 Oberea erythrocephala 1000 Field Bindweed Aceria malherbae 900,000 (est) Tyta luctuosa 27,410 Dalmatian toadflax Mecinus janthiniformis 11,115 Calophasia lunula 6806 Yellow toadflax Rhinusalinariae 300 Mecinus janthinus 800 Knapweeds Larinus minutus 4600 Russian knapweed Jaapiella ivannikovi 1,788 galls Musk thistle Trichosirocalus horridus 3400 Canada thistle Urophora cardui 5020 Puncturevine Microlarinus spp 4300 Tamarisk Diorhabda carinulata 300,000 3

4 Pest Management Workshop 2013 Bindweed mites are microscopic and cause the leaves to curl into galls field bindweed Diffuse and spotted knapweed biological control Cyphocleonus achates prefers spotted, will hit diffuse larvae feed on roots Tamarisk biological control Larinus minutus Diorhabda carinulata eggs adults feed on foliage Larvae Knapweeds (diffuse and spotted) pupae 4

5 Pest Management Workshop 2013 Mortality egg mass Tamarisk Mortality in Western Colorado Percent Mortality Flume Larva Diorhabda carinulata Yellow toadflax biological control Knowles Saltcreek 2 Bedrock SY Burned SY Unburned Site Adult Tamarisk mortality at six field sites in western Colorado measured over three seasons. Sites were defoliated by beetles for the first time in either 2007 or 2008 and all sites had been defoliated at least four times by Of the ten sites in this study four have had no mortality and are not shown. Mecinus janthinus a stem boring weevil on yellow toadflax this species was collected on both yellow and Dalmatian toadflax in Europe. The Dalmatian toadflax weevil was later found to be a separate species, now named Mecinus janthiniformis. numerous releases on yellow toadflax in Colorado were probably the Dalmatian toadflax weevil, which would explain why they never did well on yellow toadflax. The CDA has a program to establish and release the yellow toadflax weevil. Since 2009 we have received and released over 1,000 adult weevils, through the USFS, from established populations in Montana. So far we have three sites where they are established. gall Russian knapweed biological control adult fly Jaapiella ivannikovi is looking like a promising agent. This fly lays eggs in shoot tips and stops growth and flowering. The flies were obtained from Rich Hansen, USDA APHIS in Ft. Collins. 5

6 Larvae pupate within galls 2 mm A gall may contain up to 30 larvae of the gall fly. They are small but very effective in stopping shoot growth. Adults emerge about 2 weeks after gall formation. Adults are about the size of a fruit fly. The Russian knapweed gall fly program 1,800 Russian knapweed galls were released this year. This number was divided into 63 open field releases. Five releases were made in the Arkansas Basin; more releases are needed next season considering the massive infestations in the basin. 1. We harvested about 1,700 galls from the Insectary garden in We did more than 63 open field releases in We monitored 12 field sites in We plan to add at least 8 more monitoring sites and release at least 2,000 galls in 2013 Canada thistle biological control Puccinia punctiformis (F. Strauss) Rohl. First plant pathogen suggested as biological weed control agent (1893) Occurs throughout range of C. arvense Naturalized in N. America Obligate rust pathogen Autoecious Brachy-form (aeciospores morphologically indistinguishable from urediniospores) Heterothallic Restricted host-range (only C. arvenseas as host in nature) Causes systemic disease that ultimately kills C. arvense patches Systemically diseased shoot with haploid spermagonia (yellow pustules) and dikaryotic aecia (brown pustules) resulting from fertilization of spermagonia 6

7 Monitoring sites needed for release and evaluation of biological controls by the CDA 1. Russian knapweed infestations, 2 acres or more, need to set up long term monitoring and release of gall flies and possibly other agents as they became available 2. Canada thistle infestations, half an acre or more where no spraying is planned. We will set up monitoring site and release Canada thistle rust, which is host specific and already found in the US. Russian knapweed monitoring Please contact Dan Bean at (970) or write to dan.bean@state.co.us Dr. Dana Berner, USDA ARS Thanks to: Everyone at the Palisade Insectary Cooperators, including land owners willing to let us monitor our work Dr. Dana Berner of the USDA ARS for the Canada thistle rust slide Bob Hammon, CSU Extension for arranging the program 7