Integrated Weed Control Project - Biological Control-
Jennifer Andreas Integrated Weed Control Project Director [email protected] (206) 205-3135 What is Biocontrol?
The intentional use of one Nematodes living organism to control/suppress another organism, such as WEEDS
Caesar, USDA ARS; bugwood.org Insects Mammals Pathogens
Piper, WSU; bugwood.org
WSU Extension Healing Hooves Integrated Weed Management
• Decision-making process
• Strategy for effective weed suppression
• Ecologically-based
• Combination of weed control methods – physical, cultural, chemical, biological Advantages • Safe – USDA APHIS approves biological control agents before introduction into U.S. • Ecologically desirable – herbicide alternative • Insects are mobile • Long-term solution
• Cost effective WSU Extension Limitations
• Long time to make impact • Subject to predators
• May not establish at Predatory mite some sites dinosaurtheory.com • Very slow approval of new agents
• No eradication Predatory insect When to use biocontrol? • Established weed infestations • Remote, inaccessible, less disturbed areas Dargatz, Jefferson CNWCB. WA • Areas not controlled by other means • Environmentally WSU Extension sensitive sites When NOT to use biocontrol? • Small or new infestations • Highly disturbed areas
Mazerolle, Air • Roads or traveled paths
• Areas unfavorable Schwarzlaender for insect • On weeds with no approved agents Mazerolle, Air Knapweeds
WSU Extension WSU Extension Spotted knapweed Diffuse knapweed (Centaurea stoebe spp. (Centaurea diffusa) micranthos) Meadow knapweed (Centaurea pratensis ) - spread by seed - ↑ soil erosion WSU Extension - ↓biodiversity - ↓quality forage
WSU Extension Knapweed Biocontrol Agents
Larva consumes Adult seeds Adults devouring diffuse knapweed
WSU Extension WSU Extension Larinus obtusus Larinus minutus - seed-head feeding weevil - seed-head feeding weevil - attacks spotted, meadow & - attacks diffuse, spotted & meadow diffuse - strong impact on diffuse in eastern WA - currently best agent for meadow - adults can defoliate plants - ↓ seed production - ↓ seed production Success with Larinus minutus !
• diffuse knapweed reduced dramatically
Before biocontrol agent release
After biocontrol agent release
WSU Extension WSU Extension Knapweed Biocontrol Agents
Adult
Cyphocleonus achates - root-feeding weevil - attacks spotted & diffuse - ↓ biomass & density WSU Extension - can kill plants - good success in Montana with L. minutus & root weevil
Larva Larval root damage
WSU Extension Additional Knapweed Agents Seed-feeders Root-feeders Sphenoptera Adult Bangasternus lays jugoslavica eggs fausti - root-feeding beetle in - seed-feeding weevil - attacks diffuse, seed- - attacks diffuse & head maybe spotted spotted - prefers hot, dry - prefers hot, dry USDA APHIS PPQ; bugwood.org environments environments
Rees, USDA ARS; bugwood Chaetorellia acrolophi & Terellia virens USDA APHIS PPQ; bugwood - seed-feeding flies - attacks spotted & diffuse Nez Perce Biocontrol Center, ID; bugwood.org - prefers cool, wet sites Agapeta zoegana - root-feeding moth - attacks spotted & diffuse USDA APHIS PPQ; bugwood.org - impact unknown Purple loosestrife
Lythrum salicaria
WSU Extension
- herbaceous perennial - aquatic, wetland sites - displace native vegetation - degrades wildlife habitat & hunting/ fishing areas - ↓ water flow
Agriculture and Agri-Food Canada;.bugwood.org Purple Loosestrife Biocontrol
Mating adults
Eggs Larva
Beetles skeletonized loosestrife in Pierce County
WSU Extension WSU Extension Galerucella calmariensis / G. pusilla - foliage-feeding beetles - highly effective - larvae & adults devour foliage - do not like tidal-influenced waters Purple Loosestrife Biocontrol
Adult Larva mining flower-head
Piper, WSU; bugwood.org
Schwarzlaender, UI
Larva mines root
Adult Coombs, ODA; bugwood.org Hylobius transversovittatus Coombs, ODA; bugwood.org - root-feeding weevil Nanophyes marmoratus - best combined with leaf beetles - bud/ flower-feeding weevil - kills small roots in 2 years with - outcompeted by leaf beetles several larvae - ↓ seed production - difficult to collect Scotch Broom
Bruchidius villosus - seed-feeding bruchid - ↓ seed production up to 90%
WSU Extension Cytisus scoparius Adult lays eggs into - perennial shrub developing seedpod - displace forage & native Adult Coombs, ODA species - impacts timber, rangeland Larva consume developing seed Exapion fuscirostre - seed-feeding weevil - widespread
- ↓ seed production Coombs, ODA; bugwood.org Tansy Ragwort
WSU Extension
Senecio jacobaea
- biennial, unless Lee, San Juan CNWCB mowed/cut - toxic to cattle & horses
Lee, San Juan County Noxious Weed Board Tansy Ragwort Biocontrol
Larva mining in leaf
Adult WSU Extension
Coombs, ODA Adult feeding holes WSU Extension
USDA ARS EBCL; bugwood.org Longitarsus jacobaeae - root-feeding flea beetle WSU Extension - excellent agent - widespread - Italian & Swiss strains Tansy Ragwort Biocontrol
Botanophila seneciella - seed-feeding fly - widespread
Larva consuming seeds
Larvae consuming foliage
WSU ExtensionWSU Extension
R. Lee, San Juan
Adult
Coombs, ODA; bugwood.org Adult Tyria jacobaeae (cinnabar moth) - foliage-feeding moth - effective in large numbers but plants are often able to flower Coombs, ODA; bugwood.org - non-target concerns St. Johnswort
Hypericum perforatum - perennial, rhizomatous - causes sensitivity to sun - poster child for biocontrol success - now considered mainly a roadside or wasteland weed
WSU Extension • 1 million hectares in northern California infested in 1944 Rees, USDA ARS; bugwood.org St. Johnswort Biocontrol
Monument to Eggs beetle (and researchers) Larvae in California, celebrating success Rees, USDA ARS; bugwood.com
Harris, AAFC Adult
Rees, USDA ARS; bugwood.org Chrysolina spp. - foliage-feeding beetle USDA EBCL; bugwood.org - poster child for biocontrol success! St. Johnswort Biocontrol Agrilus hyperici Adult moth - root-boring beetle - success unknown - difficult to collect in large numbers Adult beetle
larvae Larva mining root
Rees, USDA ARS; bugwood.org Aplocera plagiata - foliage-feeding moth - success unknown
- difficult to collect in large Rees, USDA ARS; bugwood.org numbers Rush Skeletonweed
Dewey, Utah State U.; bugwood.org
Chondrilla juncea - long-lived herbaceous perennial - spread by seed & vegetative regrowth - over 404,000 ha in Washington - competes with crop plants - latex hinders crop production - displaces desirable forage
Piper, WSU; bugwood.org Rush Skeletonweed Biocontrol
Eriophyes chondrillae - gall-forming mite - most effective agent - ↓ plant vigor / stunts plants - ↓ seed production - kills seedlings
Piper, WSU; bugwood.org
Puccinia chondrillina - rust fungus - effective - ↓ seed production - ↓ plant vigor
- can kill seedlings Turner, USDA ARS; bugwood.org
Piper, WSU; bugwood.org Rush Skeletonweed Biocontrol
Cystiphora schmidti Bradyrrhoa gilveolella - gall midge (fly) - root-mining moth - effective - can kill above-ground tissue - can kill rosettes and stems - establishment questionable - ↓ plant vigor - may be available for trials - ↓ seed weight & viability
Piper, WSU; bugwood.org
USFS Canada Thistle
Cirsium arvense - creeping perennial - ↓ forage - competes with crops Oregon State University
Adult
Larva inside plant University of Wisconsin WSU Extension create gall
WSU Extension
Rees, USDA ARS; bugwood.org Urophora cardui - stem-galling fly - ↓ plant vigor - works in conjunction with plant competition The Nature Conservancy Bull Thistle
Adult Cirsium vulgare Larvae consume developing seeds
Shepard, USFS; bugwood.org
WSU Extension
WSU Extension - biennial - prevalent in Harris, AAFC; bugwood.org heavily Urophora stylata disturbed - seed-feeding fly sites - ↓ seed production Colquhoun; Oregon State U Additional Biocontrol
• Biocontrol agents may be available in your area for: – gorse –bindweed – puncturevine – saltcedar – Mediterranean sage • Class A – must be controlled in Washington WSU Extension’s Role
• State-wide program
• Provide biocontrol agents free of charge to land managers
• Education to land managers
Connett, UI; bugwood.org • Expertise and on-site recommendations