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Past Successes at FDWSRU

Your Input is NeededCommunicate to regulators theUrgency toRelease safe plant pathogens forEffective biological control of invasive weeds andDemand benefit-versus-risk based regulation

• Obligate systemic rust fungus

• Host specific• Systemic infections give

rise to spindly, pale shoots that die after producing infective spores

• Naturalized in N. America

• Field tests underway in MD and PA

Canada thistle Cirsium arvense

Pathogen Puccinia punctiformis

Pathogen Puccinia crupinae

Yellow starthistleCentaurea solstitialisPuccinia jaceae Released 2003

Musk thistleCarduus nutansPuccinia carduorium Released 1985

Dr. Dana K. BernerDr. Dana K. BernerLead Scientist, Plant Lead Scientist, Plant PathologistPathologistDana.Berner@ars.usda.govDana.Berner@ars.usda.gov301-619-7316301-619-7316

Dr. Douglas G. LusterDr. Douglas G. LusterPlant PhysiologistPlant PhysiologistDoug.Luster@ars.usda.goDoug.Luster@ars.usda.govv301-619-7344301-619-7344

Dr. William L. BruckartDr. William L. BruckartResearch Plant PathologistResearch Plant PathologistWilliam.Bruckart@ars.usda.William.Bruckart@ars.usda.govgov301-619-2846301-619-2846

CLASSICAL BIOLOGICAL CONTROL OF INVASIVE CLASSICAL BIOLOGICAL CONTROL OF INVASIVE WEEDS BY PLANT PATHOGENSWEEDS BY PLANT PATHOGENS

USDA, ARS, Foreign Disease-Weed Science Research Unit (FDWSRU)USDA, ARS, Foreign Disease-Weed Science Research Unit (FDWSRU)

• Obligate systemic smut fungus

• Host specific• Stops weed-seed

production• Plant test list

submitted to APHIS

Pathogen Microbotryum silybum

Milk thistleSilybum marianum

Russian thistle/tumbleweedSalsola tragus

• Obligate rust fungus

• Host specific• Debilitates

overall weed health

• Plant test list submitted to APHIS

Pathogen Uromyces salsolae

Common crupinaCrupina vulgaris

• Obligate rust fungus• Host specific• Debilitates overall

weed health• Plant test list

submitted to APHIS

Rush skeletonweedChondrilla juncea Puccinia chondrillina Released 1978

Current Advanced Pathogens

• Facultative parasitic fungus

• Host specific • Kills weed seedlings

and mature plants• Plant test list

submitted to APHIS

Pathogen Colletotrichum gloeosporioides f.sp. salsolae

Fungus sporesFungus sporesNo seedsNo seeds

Diseased flower headsDiseased flower heads