Yellow Starthistle Status of Biological Control Agents of Yellow Starthistle

Biological Common name First Status control agent release Urophora 1969 Never established in USA. jaculata Urophora YST1 gall 1984 Widely established, present at most YST sirunaseva infestations in CA & OR; a few sites in WA, ID. Bangasternus YST bud weevil 1985 Widespread in CA, OR, WA & ID, orientalis but low numbers. YST peacock fly 1988 Prefers bachelor button; established at a few australis sites in CA; widespread in OR, WA, ID. Eustenopus YST hairy weevil 1990 Well established in CA; widespread in OR, WA; villosus a few sites in ID, UT. curtus YST flower weevil 1992 Established at a few sites in CA, WA, ID; widespread in OR. Unapproved accidental introduction: Chaetorellia YST false 1991 Widely established in CA & OR, and spreading succinea peacock fly into WA, ID & NV. Currently being evaluated for nontarget impacts. 1 YST = yellow starthistle

Urophora Bangasternus Eustenopus Larinus curtus Chaetorellia sirunaseva orientalis villosus succinea Occurrence of Yellow Starthistle by Township 1997 Eustenopus villosus yellow starthistle hairy weevil

Chews into unopened flower buds and lays egg Larvae eat developing seeds & receptacle One generation per year Adults emerge from seedhead in 4 weeks Chaetorellia succinea false peacock fly

UNAPPROVED

Can oviposit and develop on in laboratory. Did not attack safflower plot near dense fly population in Napa county. Found in 1 of 47 private safflower fields (on Cargill 44; 0.2 - 5.0% infestation). Not found in survey of 25 species of native thistles.

Balciunas and Villegas. 2001. Environ. Entomol. 30: 953-963. Balciunas and Villegas. in press. Chaetorellia succinea false peacock fly

UNAPPROVED INSECT

Can develop on native plant americana

Balciunas and Villegas. in press. Yellow Starthistle, Myrtle Creek, OR, 6/91

grazed by cattle Yellow Starthistle, Myrtle Creek, OR, 7/95

Eustenopus villosus no grazing Oregon (E. Coombs) At sites near Medford, The Dalles, and Umatilla County the weed is nearly gone. Not all sites are being controlled. But, those spots where there is good competition from native species and where the ground has remained undisturbed are starting to show good control.

Idaho (L. Wilson, T. Prather, C. Kuykendall) All are established and spreading. Chaetorellia succinea is the most common fly. Eustenopus villosus is the most abundant weevil. About 70% of susceptible seedheads are infested.

Washington (G. Piper) Eustenopus villosus is being distributed. Placer County YST seedhead insects 100 90 80 B. orientalis 70 U. sirunaseva 60 50 E. villosus 40 L. curtus 30 C. succinea 20 10 Heads w/ 1 or more sp 0 1995 1996 1997 1998 1999 2000 2001 Year CDFA data

Yolo County Sonoma County

100 100 90 90 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 1995 1996 1997 1998 1999 2000 2001 1995 1996 1997 1998 1999 2000 2001 Year Year Placer County

30,000 100 YST seedhead insects 90 25,000 80 70 20,000 60 Seeds/sq meter 15,000 50 40 Heads w/ 1 or more sp 10,000 30 20 5,000 10 0 0 1995 1996 1997 1998 1999 2000 2001 Year CDFA data

Yolo County Sonoma County

30,000 100 30,000 100 90 90 25,000 25,000 80 80 70 70 20,000 20,000 60 60 15,000 50 15,000 50 40 40 10,000 10,000 30 30 20 20 5,000 5,000 10 10 0 0 0 0 1995 1996 1997 1998 1999 2000 2001 1995 1996 1997 1998 1999 2000 2001 Year Year Placer County Impact of

2500 30 YST seedhead insects

25 2000 Seedlings/sq. meter 20 1500 Adult plants/sq. m 15 1000 Heads/ sq. meter 10 Seeds/head 500 5 1000 Seeds/sq m 0 0 1995 1996 1997 1998 1999 2000 2001 Year CDFA data

Yolo County Sonoma County

2500 30 2500 30

25 25 2000 2000

20 20 1500 1500 15 15 1000 1000 10 10

500 500 5 5

0 0 0 0 1995 1996 1997 1998 1999 2000 2001 1995 1996 1997 1998 1999 2000 2001 Year Year Future Agents for Yellow Starthistle

• Rust pathogen awaiting APHIS approval: Puccinia jaceae var. solstitialis • Quarantine testing of Ceratapion basicorne • Foreign evaluation of agents that attack the roots and leaves of young plants: Flea - Psylloides sp. nr. chalcomera - Russia Blister mite - Aceria “solstitialis” - Rosette-boring fly - Botanophila turcica - Lace bug - Tingis grisea - Turkey Seedhead weevil - Larinus filiformis - Turkey Soil borne pathogens - France root crown weevil Ceratapion basicorne

Abundant in Turkey

Can oviposit on safflower Does not prefer safflower Poor development on safflower Field tests in Turkey & Greece

L. Smith, USDA-ARS, Albany, EBCL & collaborators Ataturk University, Erzurum, Turkey (Ceratapion yellow starthistle field test) 3/7/02 Cat (1850 m), 3/29/02 Askale (1630 m), 4/27/02

YST - Turkey - California

Safflower - oleic Horasan (1500m), 5/27/02 - linoleic Flea beetle - Psylloides sp. nr. chalcomera - Russia

Population from yellow starthistle in Russia attacks only yellow starthistle. Blister mite - Aceria “solstitialis” - from Turkey Rosette-boring fly Botanophila turcica from Greece

Attacks rosettes in late winter. Same nominal species attacks Carthamus lanatus in France (CSIRO project). Lace bug - Tingis grisea - from Turkey Seedhead weevil - Larinus filiformis - from Turkey Russian thistle Salsola tragus (type A, B, C) S. australis S. iberica S. kali S. pestifer

Barbwire thistle Salsola paulsenii lax and spinosa

Chenopodiaceae Aceria salsolae on Salsola tragus

Infested plant Healthy cutting from Greece

Future Agents for Russian thistle

• Blister mite, Aceria salsolae • Gall midge, Desertovelum stackelbergi • Seed-feeding caterpillar, Gymnancyla canella • Plant bug, Piesma salsolae

• Fungus, Colletotrichum gloeosporioides • Rust fungus, Uromyces salsolae

R. Sobhian, USDA-ARS, European Biological Control Lab, France W. Bruckart, USDA-ARS, Frederick, MD