Cereal Leaf Beetle Management – Chemical or Biological? Diana Roberts (WSU Extension), Keith Pike (WSU), Terry Miller (WSU), Steve Miller (USDA-APHIS) Mike Klaus (WSDA)
CLB damage in irrigated winter wheat, Union Co., OR Picture by Gary Brown Outline • CLB distribution • Potential impact • Identification & Life Cycle • Chemical management • Biocontrols
CLB Distribution in USA • 1962 found in Michigan • Introduced from Europe 1940’s • Federal eradication & quarantine failed • Utah, Idaho, Wyoming, Montana • 1992 Idaho • 1999 Oregon & Washington • June 7 East Farms • Nine Mile Falls
CLB Hosts Oats RyeFescue Wheat Wild ryeDowny brome Barley Smooth bromeRedtop Wild oats Foxtail milletRice Quackgrass (Corn) Timothy Sorghum Rye grass Sudangrass Orchardgrass Bluegrass Canarygrass Millet
Impact - Quarantines • Immediately imposed on any county positive for CLB • Phytosanitary cert needed on all cereal grains, grass, straw, sod, and Christmas trees to Canada & California • 95% alfalfa hay excluded • From infested counties - declaring phosphine fumigant • Grain – fumigated or cleaned in <100 lb bags • From clean counties – declaring source
Colville insectary CLB crop damage Impact - Yield Loss • Most severe in spring cereals, irrigated crops • Canada • winter wheat 25% • spring oats up to 75% • USSR • 25 - 50% of crop • Nine Mile Falls 2002 • Spr wht 36 bu vs 100 avg • WSU plots 44 bu vs 60 bu
Impact – Potential Cost to WA growers • 600,000 acres spring wheat - $90 million • Conservative 30% infestation - $21 million p.a. • Insecticide $7-$10/A +$3-5/A application • Spray 50% spring wheat; $3 million p.a.
CLB Life Cycle USDA-APHIS photo Photo by G. Clevenger
Picture by Garrett Clevenger Collops hirtellus (beneficial) Adult CLB
Remember, my children are home! Please don’t spray unless you absolutely have to… CLB Management - Chemicals • Azinphos-methyl – once per season • Carbaryl (Sevin least hazardous to bees) – 2 applications only after heading • Furadan – Apply before heading, twice only/season. No forage feeding • Malathion – wheat & barley only • Karate – synthetic pyrethroid, wheat only. 0.02-0.03 lb ai/A. PHI 30 days • Warrior - synthetic pyrethroid, 0.02-0.03 lb ai/A
CLB Economic Threshold • 3 eggs or larvae per plant up to boot stage in spring cereals • 1 egg or larva per flag leaf after boot • 1 larva per flag leaf -> 5-6 bu grain loss per acre • From MT, not confirmed in WA • Winter wheat should not incur economic damage
CLB Management - Biocontrols • USDA “CLB the first instance in which a pest of an annual crop grown in a temperate continental area successfully controlled by imported natural enemies” • Most successful in the eastern US • Longer to establish in Utah
CLB Management - Biocontrols • Predators - lady bird beetles • Parasitoids - 4 introduced parasitic wasps • 3 attack larval stage • 1 attacks egg stage • Fungus - Beavaria bassiana • Suppresses population
Cereal leaf beetle larva being attacked by parasitic wasp species Tetrastichus julis. Larval parasitoid Tetrastichus julis2 generations/yr
CLB larva parasitized by T. julis Picture by Garrett Clevenger
Picture by Terry Miller Egg parasitoid Anaphes flavipes 6-8 generations/yr
CLB eggs parasitized (dark) by A. flavipes and non-parasitized. Picture by Garrett Clevenger
Nine Mile Falls Insectary Picture by Kit Cutler
2006 Parasitoid releases • 3,087 T. julis (larval parasitoid) As parasitized CLB larvae • 9,994 A. flavipes (egg parasitoid) As parasitized CLB eggs
WA Progress summary • 2000 – Hitchcox made first T. julis releases at 9-Mile • 2002 – First field insectary at Nine Mile Falls (Spokane) • 2003 – First T.j. recovery & Anaphes releases • 2004 – First Anaphes recoveries. Have 6 insectaries. • 2005 – 8 insectaries, excellent T.j. recovery, limited Anaphes recovery at 3 locations.
2006 • CLB became obvious in wetter dryland areas • Stevens, Spokane, Whitman, Columbia, Walla Walla • Have 10 insectaries • Older insectaries imploding • Excellent T. julis spread to farms • Redistributed our own T.j. to other insectaries • No Anaphes recovery Picture by Kit Cutler
T. julis pre-release recovery at Washington field insectaries 2004 - 2006
My big question from last year: What level of T. julis parasitism is needed in farm fields to obviate spraying? What we know: • CLB females lay about 200 eggs each • Each parasitized CLB releases 5 T. julis wasps (2005 WA data) Picture by Garrett Clevenger CLB larva parasitized by T. julis
Making farm spray recommendations When field has infestation economic threshold and T. julis present: • 50% parasitism • 25 CLB females → 5,000 eggs • Vs. 50x5=250 Tj • Next season 200 CLB:1 Tj wasp • Tough call – recommend spray affected areas/borders & monitor • 75% parasitism • 13 CLB females → 2,600 eggs • Vs. 75x5 = 375 Tj • Next season 7 CLB: 1 Tj wasp • Recommend not spray – most of damage done • >90% parasitism • 5 CLB females → 1,000 eggs • Vs. 90x5 = 450 Tj • Next season 2CLB:1 Tj wasp • Recommend not spray
Parasitism of the cereal leaf beetle. In press. E. Evans et al. Utah State University.
Nine Mile Falls (Significant) Deep Creek (significant) 2006 T.julis parasitism levels at WA insectaries plotted against time Colville (NS) Peone Prairie (NS)
Insecticides tested in 2006 • Untreated check • Warrior/pyrethroid - standard • Success/spinosad - larvicide - (Dow, product selective for CLB) • Beleaf/flonicamid – prevents insect feeding - (FMC, product selective for aphids) • Fulfill/pymetrozine - acts on ingestions and contact - (Syngenta, product selective for aphids). The latter two are not currently registered on small grains; the work here is to confirm that the products are non-toxic to CLB parasitoids, as a first step in justifying label expansion.
Biocontrol Success in WA My job • Will depend on: • Ability of biocontrols to establish • Ability to increase insectaries across region • Continued funding • Cooperation among agencies and farmers • Short term fixes (spraying insecticides, including for aphids) will adversely affect biocontrols • Recommend buffer strips, increase each year • Direct seeding beneficial to larval parasitoid Your job!
Plans for 2007 Kit Cutler – Nine Mile Falls • Phase out older insectaries • Nine Mile Falls • Colville • Peone Prairie • Extend into Yakima, Kittitas Counties • Timothy is sold on looks? • Retest soft insecticides • Work with growers to plant oats as a trap crop/modified insectary • Between winter & spring wheat Rick, Richard, & Gary Seitters - Colville
Lacey Jones ‘05, ‘06 Kathlene Peck ‘05 Thank you! Laurie Stone ‘04 Also: Mike Gould ‘03 Sally Hubbs ‘06 Moose Sanders ‘06
If you want to save money on CLB management in the long term: • You will need to withstand a certain amount of white leaves • Short term fixes (spraying insecticides, including for aphids) will adversely affect biocontrols • If you spray, use buffer strips and increase each year • Direct seeding beneficial to larval parasitoid • Please call me when you find CLB in your fields!! Picture by John Aeschliman
Questions? Contact Diana Roberts WSU Extension 509-477-2167 email@example.com Website: http://www.spokane-county.wsu.edu/