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WEEDS TARGETED FOR BIOLOGICAL CONTROL IN OREGON
WEED SPECIES: BIOCONTROL AGENTS:                    
  SCIENTIFIC NAME ROLE RELEASED
IN OREGON
AGENT
DISTRIBUTION
ATTACK
 RATE
CONTROL COLLECT-
ABILITY
RELEASE
QUANTITY
TIMING TECHNIQUE LIFE
STAGE
COMMENTS
Bull thistle
Cirsium vulgare
Rhinocyllus conicus seed head weevil 1979 Widespread Medium Fair Mass* 100* June* Sweep net/racquet* Adult* * Not recommended, attacks native thistles, interstate shipment prohibited.
Urophora stylata seed head gall fly 1988 Widespread Heavy Good Mass 50 galls Nov-Mar Harvest galls Larva/pupa Harvest after first killing frost, scatter galls at release site.
Canada thistle
Cirsium arvense
Ceutorhynchus litura crown/root weevil 1981 Limited Heavy Good Mass 100 Mar-Apr Aspirate from rosettes Adult Plants 1-4 inches tall best for collecting and releases.
Rhinocyllus conicus seed head weevil 1979 Widespread Heavy Fair Mass* 100* May-Jun* Sweep net/racquet* Adult* * Not recommended, attacks native thistles, interstate shipment prohibited.
Urophora cardui  stem gall fly 1980 Widespread Heavy Fair Mass 50 galls Nov-Mar Harvest galls Larva/pupa Harvest after first frost, scatter galls at release site.
Dalmatian toadflax
Linaria dalmatica
Brachypterolus pulicarius flower beetle 1992 Widespread Medium Poor Mass 100 Jun-Jul Sweep net/racquet Adult Accidentally introduced in 1950's, approved in 1992.
Calophasia lunula  defoliating moth 1982 Limited Light Fair Limited 100-200 Jun-Jul Handpick larvae Larva Occurs in Wallowa Co., release 1-2 larvae per plant.
Gymnetron antirrhini  seed head weevil 1996 Widespread Medium Fair Mass 100 Jun-Jul Sweep net/racquet Adult No need for further redistribution.
Mecinus janthinus stem boring weevil 2001 Widespread Heavy Excellent Mass 100 May-Jun Sweep net/racquet Adult Excellent biocontrol agent.
Diffuse knapweed
Centaurea diffusa
Bangasternus fausti seed head weevil 1989 Widespread Heavy Excellent Mass 100 June Sweep net/racquet Adult Best collecting at bud stage.
Larinus minutus seed head weevil 1992 Widespread Heavy Excellent Mass 100 Jun-Jul Sweep net/racquet Adult Best collecting at 20-50% bloom.
Metzneria paucipunctella  seed head moth 1981 Limited Light Poor Limited 200 March Harvest infested seed heads Larva/pupa Experimental, recovered in one county.
Pterolonche inspersa root boring moth 1997 Limited Light Poor Limited 200 Jun-Jul Egg Transfer Egg Experimental, population extremely limited.
Sphenoptera jugoslavica root boring beetle 1980 Widespread Heavy Good Mass 100 Jun-Jul Sweep net Adult Low density make hard to collect, best to sweep plants in the evening.
Urophora affinis  seed head gall fly 1975 Widespread Heavy Good Mass 100 Jun-Aug Aerial net Adult No need for further redistribution.  Gently sweep seed heads at bud stage, aspirate from net.
Urophora quadrifasciata  seed head gall fly 1979 Widespread Heavy Good Mass 100 Jun-Aug Aerial net Adult No need for further redistribution.  Gently sweep seed heads at bud stage, aspirate from net.

Eurasian watermilfoil
Myriophyllum spicatum

Euhrychiopsis lecontei stem boring weevil 2010 Unknown Unknown Unknown Unknown 500 Jul-Aug Harvest infested plants Adult/larva Limited information on distribution. Rear adults from infested material.

Field bindweed
Convolvulus arvensis


Aceria malherbae  bud/leaf gall mite 1999 Limited Heavy Good Mass 1000 Jun-Sep Harvest infested plants All 1000 mites equals about 1 sandwich bag of infested plant material.
Tyta luctuosa defoliating moth 1998 Limited Unknown Unknown Limited 100 Jun-Sep Light trap Adult Difficult to collect, early August is best; release 200 larvae (2-3 larvae per square meter)

Gorse
Ulex europaeus


Exapion ulicis  seed weevil 1956 Widespread Heavy Good Mass 100 Apr-May Sweep net/racquet Adult No need for further redistribution.
Tetranychus lintearius  spider mite 1994 Widespread Light Poor Limited 500 Aug-Sep Harvest infested plants All Limited by predatory mite, ineffective agent.
Italian thistle
Carduus pycnocephalus
Cheilosia corydon crown/root fly 1991 Widespread Heavy Excellent Mass 100 Jun-Jul Harvest infested plants Pupa No need for further redistribution.
Rhinocyllus conicus seed head weevil 1979 Widespread Heavy Excellent Mass* 100* April* Sweep net/racquet* Adult* * Not recommended, attacks native thistles, interstate shipment prohibited.
Trichosirocalus horridus crown/root weevil 1994 Widespread Heavy Good Mass 100 Feb-May Sweep net/beating sheet Adult No need for further redistribution.
Leafy spurge
Euphorbia esula
Aphthona cyparissiae root/defoliating flea beetle 1989 Widespread Heavy Excellent Mass 500 Jun-Jul Sweep net Adult Often present in species complex
Aphthona czwalinae root/defoliating flea beetle 1993 Widespread Heavy Excellent Mass 500 Jun-Jul Sweep net Adult Less common, difficult to tell from and usually mixed with A. lacertosa.
Aphthona flava root/defoliating flea beetle 1989 Widespread Heavy Excellent Mass 500 Jun-Jul Sweep net Adult Less common in species complex
Aphthona lacertosa root/defoliating flea beetle 1993 Widespread Heavy Excellent Mass 500 Jun-Jul Sweep net Adult Often present in species complex, better for wetter areas.
Aphthona nigriscutis  root/defoliating flea beetle 1989 Widespread Heavy Excellent Mass 500 Jun-Jul Sweep net Adult Often present in species complex, better for drier areas.
Oberea erythrocephala root/stem boring beetle 1982 Widespread Heavy Good Mass 100 July Sweep net Adult Look for girdled upper quarter of plants.
Meadow knapweed
 Centaurea jacea x nigra
Larinus minutus seed head weevil 1992 Limited Medium Fair Limited 100 Jun-Jul Sweep net/racquet Adult Displaced by L. obtusus
Larinus obtusus seed head weevil 1994 Widespread Heavy Good Mass 100 Jun-Jul Sweep net/racquet Adult Best collected after 10% bloom.
Metzneria paucipunctella  seed head moth 1981 Limited Light Poor Limited 200 March Harvest infested seed heads Larva/pupa Occurs in Hood River and Douglas Counties, heavily parasitized.
Urophora quadrifasciata  seed head gall fly 1979 Widespread Medium Poor Mass 100 May-Jun Aerial net Adult No need for further redistribution. Gently sweep seed heads at bud stage, aspirate from net.

Mediterranean sage
Salvia aethiopis

Phrydiuchus tau root/crown weevil 1971 Widespread Heavy Good Mass 100 Oct-Nov,
July
Aspirate from plants,
Sweep net/racquet
Adult Aspirate breeding adults in fall or Sweep net/beating sheet emerging adults in summer.

Milk thistle
Silybum marianum

Rhinocyllus conicus seed head weevil 1979 Widespread Heavy Excellent Mass* 100* April* Sweep net/racquet* Adult* * Not recommended, attacks native thistles, interstate shipment prohibited.
Musk thistle
Carduus nutans
Cheilosia corydon crown/root fly 1991 Unknown Unknown Unknown Limited 100 July Harvest infested plants Pupa Experimental, not established on musk thistle.
Rhinocyllus conicus seed head weevil 1979 Widespread Heavy Good Mass* 100* June Sweep net/racquet* Adult* * Not recommended, attacks native thistles, interstate shipment prohibited.
Trichosirocalus horridus crown/root weevil 1994 Limited Heavy Good Mass 100 Mar, Jul Sweep net/racquet Adult Collectable in Klamath County only.
Puncturevine
Tribulus terrestris
Microlarinus lareynii  seed weevil 1963 Limited Light Fair Mass 100 Aug-Sep Aspirate Adult Susceptible to cold winters, lift stems and aspirate adults when they move.
Microlarinus lypriformis  stem boring weevil 1963 Unknown Unknown Unknown N/A 100 Aug-Sep Aspirate Adult Susceptible to cold winters, collection methods same as M. lareynii, not known to occur in OR. 
Purple loosestrife
Lythrum salicaria
Galerucella calmariensis  defoliating beetle 1992 Widespread Heavy Excellent Mass 500 May, Jul Sweep net Adult Release in one spot.
Galerucella pusilla  defoliating beetle 1992 Widespread Heavy Excellent Mass 500 May, Jul Sweep net Adult Release in one spot.
Hylobius transversovittatus  root weevil 1992 Widespread Heavy Good Limited 100 Jul-Aug Handpick Adult Can rear from infested material.
Nanophyes marmoratus  seed head weevil 1994 Widespread Medium Fair Mass 100 Jul Sweep net/beating sheet Adult Collect from off of seed heads.
Rush skeletonweed
Chondrilla juncea
Bradyrrhoa gilveolella  root boring moth 2005 Limited Unknown Unknown N/A 100-200 Jun Unknown Egg/Larva Experimental, source colony was lab reared.
Cystiphora schmidti   stem/leaf gall midge 1978 Widespread Heavy Good Mass 250 Jun-Aug Harvest infested plants Larva Place infested bouquets at release site, heavily parasitized late in season.
Eriophyes chondrillae   bud gall mite 1978 Widespread Heavy Excellent Mass 1000 Jun-Aug Harvest infested plants Adult Place galls onto uninfested plants. 
Puccinia chondrillina   leaf rust fungus 1978 Widespread Heavy Good Mass - May-Jun Harvest infested plants Spore Place infested bouquets at release site, pathogen requires moist conditions.
Russian knapweed
Acroptilon repens
Subanguina picridis gall nematode 1990 Limited Slight Fair Limited 1000 Fall Harvest infested plants/soil All Limited to wet sites, very slow spreading (about 6 inches per year).
Russian thistle
Salsola kali
Coleophora klimeschiella  leaf mining moth 1973 Widespread Medium Poor Mass 100 Aug-Sep Harvest infested plants Larva/pupa Deposit infested plant materials at site.
Coleophora parthenica  stem boring moth 1973 Widespread Medium Poor Mass 100 Aug-Sep Harvest infested plants Larva/pupa No need for further redistribution.
Saltcedar
Tamarix ramosissima
Diorhabda elongata  defoliating beetle 2003 Widespread Heavy Excellent Mass 500 Jul-Aug Sweep net/racquet Adult Interstate movement currently prohibited.  Release beetles all in one spot at site.
Scotch broom
Cytisus scoparius
Bruchidius villosus  seed beetle 1998 Widespread Heavy Good Mass 100 Apr-May Beating sheet/aspirate Adult No need for further redistribution in Willamette Valley.
Exapion fuscirostre   seed weevil 1983 Widespread Heavy Good Mass 100 Apr-May Beating sheet/aspirate Adult No need for further redistribution.
Leucoptera spartifoliella  twig mining moth 1970 Widespread Medium Poor Mass 100 May-Jun Harvest infested plants Larva/pupa Place out infested bouquets. 

Slender-flowered thistle
Carduus tenuiflorus


Cheilosia corydon crown/root fly 1991 Widespread Medium Fair Mass 100 Jun-Jul Harvest infested plants Pupa No need for further redistribution.
Rhinocyllus conicus seed head weevil 1979 Widespread Heavy Good Mass* 100* April* Sweep net/racquet* Adult* * Not recommended, attacks native thistles, interstate shipment prohibited.
Trichosirocalus horridus crown/root weevil 1994 Widespread Heavy Good Mass 100 Feb-May Sweep net/beating sheet Adult Douglas County only
Spotted knapweed
Centaurea stoebe
(C. maculosa)
Agapeta zoegana root boring moth 1987 Widespread Heavy Good Limited 50-100 July Light trap Adult Low density make hard to collect.
Bangasternus fausti seed head weevil 1989 Widespread Heavy Good Mass 100 Jun-Jul Sweep net/racquet Adult Best collected at bud stage.
Chaetorellia acrolophi seed head fly 1993 Limited Light Fair Limited 100 Jun-Jul Aerial net Adult Gently sweep seed heads at bud stage, aspirate from net.
Cyphocleonus achates root weevil 1993 Limited Heavy Fair Mass 50-100 Sept. Handpick adults Adult Disperse at release site.
Larinus minutus seed head weevil 1992 Widespread Heavy Excellent Mass 100 Jun-Jul Sweep net/racquet Adult Best collected after 10% bloom.
Larinus obtusus seed head weevil 1994 Widespread Heavy Excellent Mass 100 Jun-Jul Sweep net/racquet Adult Best collected after 10% bloom.
Metzneria paucipunctella  seed head moth 1981 Widespread Light Fair Limited 200 March Harvest infested seed heads Larva/pupa May contain pest mites, do not store.
Sphenoptera jugoslavica root boring beetle 1980 Widespread Heavy Fair Limited 100 Jun-Jul Sweep net Adult Low density make hard to collect.
Terellia virens seed head fly 1993 Limited Medium Good Limited 100 Jun-Jul Aerial net Adult Body light green. Gently sweep seed heads at bud stage, aspirate from net.
Urophora affinis  seed head gall fly 1975 Widespread Heavy Good Mass 100 Jun-Aug Aerial net Adult No need for further redistribution. Gently sweep seed heads at bud stage, aspirate from net.
Urophora quadrifasciata  seed head gall fly 1979 Widespread Heavy Good Mass 100 Jun-Aug Aerial net Adult No need for further redistribution. Gently sweep seed heads at bud stage, aspirate from net.
St. Johnswort
Hypericum perforatum
Agrilus hyperici  root/stem boring beetle 1986 Limited Heavy Excellent Mass 50-100 Jun-Jul Sweep net/beating sheet Adult Best collected at 25-50% bloom, agent best at drier sites
Aplocera plagiata  defoliating moth 1989 Widespread Medium Poor Mass 100-200 Jun-Jul Beating sheet/racquet Larva Release 2-3 larvae per square meter.
Chrysolina hyperici   defoliating beetle 1947 Widespread Heavy Excellent Mass 100 Jun-Jul Sweep net Adult Adapted to wetter sites, no need for further redistribution.
Chrysolina quadrigemina   defoliating beetle 1948 Widespread Heavy Excellent Mass 100 Jun-Jul Sweep net Adult Adapted to drier sites, no need for further redistribution.
Tansy ragwort
Senecio jacobaea
Botanophila seneciella  seed head fly 1966 Widespread Light Poor Mass 100 August Harvest infested seed heads Larva No need for further redistribution.
Longitarsus jacobaeae  root/defoliating flea beetle 1971 Widespread Heavy Excellent Mass 100-200 Oct-Nov Vacuum Adult Most effective agent, no need for further redistribution.
Tyria jacobaeae defoliating moth 1960 Widespread Heavy Excellent Mass* 250-500* Jun-Jul* Handpick* Larva* * Not recommended for Eastern Oregon where it feeds on some native plants (Senecio spp.).  
Yellow starthistle
Centaurea solstitialis
Bangasternus orientalis  seed head weevil 1985 Widespread Light Poor Limited 100-200 May-Jun  Sweep net Adult Out competed by other agents, hard to find.
Chaetorellia australis  seed head fly 1988 Widespread Heavy Excellent Mass 100 May-Jun Aerial net Adult No need for further redistribution. Gently sweep seed heads at bud stage, aspirate from net.
Eustenopus villosus seed head weevil 1990 Widespread Heavy Excellent Mass 100 Jun-Jul Sweep net Adult Best collected at 5-10% bloom
Larinus curtus seed head weevil 1992 Widespread Heavy Excellent Mass 100 Jul-Aug  Sweep net Adult Limited distribution in W. OR. Interstate movement not permitted due to diseased populations.
Urophora sirunaseva  seed head fly 1985 Widespread Light Poor Limited 100 May-Jun Aerial net Adult No need for further redistribution. Can also move with bouquets of infested seed heads in March.
Yellow toadflax
Linaria vulgaris
Brachypterolus pulicarius flower beetle 1992 Limited Medium Fair Limited 100 Jun-Jul Sweep net Adult No need for further redistribution. Accidentally introduced in 1950's, approved in 1992.
Gymnetron antirrhini seed head weevil 1996 Widespread Medium Fair Mass 100 Jun-Jul Sweep net Adult No need for further redistribution.
Mecinus janthinus stem boring weevil 2001 Unknown Unknown Unknown Unknown 100 May-Jun Sweep net/racquet Adult Importing strain adapted to L. vulgaris.
NOTES:












WEED DISTRIBUTION    Latest reported general distribution of target weeds:  Yellow - Limited, Red - Abundant, Gray - Not detected  (Each map is a link to ODA's Weed Mapper site: www.weedmapper.org where additional weed information is presented.)
AGENT DISTRIBUTION   Distribution of agent on host in infested counties:  Widespread > 50%, Limited < 50% .
ATTACK RATE    Percent of plants or plant parts attacked by biocontrol agents under typical conditions:  Heavy > 70%, Medium > 30%, Light > 10%, Slight < 1%.
CONTROL   Observed reduction of target weed populations density or seed production:  Poor - Little change <10%, Fair - Some noticeable change >10%, Good - Significant control <90% reduction, Excellent - Near total control >90%.
COLLECTABILITY    Availability of biocontrol agents for redistribution:  Mass - Available for mass collection, Limited - Available only in limited numbers or difficult to collect, N/A - Not available at this time.
RELEASE QUANTITY    Recommended minimum number of biocontrol agents to establish a new colony.  Generally, when readily available, releasing greater numbers improves outcome.
TIMING    Optimum time of year to collect biocontrol agents for redistribution. For some species, special sorting techniques can be employed, see comments or contact state cooperators (listed below).
TECHNIQUE    Preferred methods for collecting from well-established sites:  Aerial net - Sweep more fragile insects with light weight net.  Aspirate - Use specialized insect aspirator to suck biocontrol agents into collection vial.  Beating Sheet - Use a specialized 3x3 foot canvas sheet and frame to catch biocontrol agents as they are knocked off host plant, then collect with an aspirator.  Hand pick - Manually pick each insect off plant or ground with hands or forceps.  Harvest - Manually collect infested plant material, seed heads, galls etc., see comments.  Light Trap - Use a specialized ultraviolet light source to attract night flying insects (mostly moths) to an adjacent white sheet or funnel trap.  Racquet - (i.e. badminton) Tap plants 2-3 times to dislodge agents into sweep net.  Sweep net - Use a heavy duty canvas insect net to sweep infested plants directly or to catch agents dislodged from shaken plants.  Vacuum - (i.e D-Vac) Use a self-powered suction machine to pull biocontrol agents from infested plants, especially rosettes.
STAGE    Life stage of biocontrol agent best suited for collection and successful establishment.
For questions about specific collecting techniques, contact one of the following:
Eric Coombs, ODA Biological Control Entomologist - Email: ecoombs@oda.state.or.us  Phone: 503-986-4624


Gary Brown, PPQ Oregon Domestic Programs Coordinator - Email: gary.w.brown@aphis.usda.gov  Phone: 503-326-2814 ext 239


Colin Park, PPQ Oregon Domestic Programs Technician - Email: colin.g.park@aphis.usda.gov  Phone: 503-326-2814 ext 227