Some Cereal Insects

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Some Cereal Insects

• By David Bragg, PhD
• Washington State University
• Extension Entomologist

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Common wheat/cereal insects/mites anddamage they
cause

• Bird cherry-oat aphid vectors BYDV in the fall,
  moving into wheat and barley from corn as late as
  December. Also green bug aphid.
• Wheat stem saw fly causes stem to break resulting
  in blank heads.
• Wheat joint worm feeds at crowns rare in SE
  Washington.
• Pachynematus leaf saw fly increasing in low ppt.
  zone of Oregon and Washington not economic.
• Wheat leaf curl mite vectors wheat streak mosaic
  virus is this High Plains Disease of sweet corn?

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More wheat insects and mites

• Brown wheat mite rarely damages wheat but has
  damaged barley and timothy hay crops in the PNW
  Region.
• Russian wheat aphid is damaging to late seeded
  spring cereals when natural enemies lag behind
  aphid populations up to 20 bushel yield
  reductions where not controlled prior to milk
  stage. Snake River dry lands have RWA just about
  each summer.
• Wire worms (Elateridae) can reduce spring cereal
  stands and fall seeding into CRP take out w/o
  insecticide seed treatments.

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Eleodes hisperlabrus false wireworm beetle
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Bird cherry-oat aphid alates on wheat leaf
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Schizaphis graminarium green bug aphid found in
conjunction with Russian wheat aphid colonies.
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Russian wheat aphid colony
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Pachynematus saw fly larvae feed on wheat leaves
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Wheat leaf saw fly adult
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Wheat stem saw fly adult
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Wheat stem saw fly larva
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Wheat joint worm can cause losses in spring wheat
in Montana.
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Brown wheat mite feeds on leaf surface
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WHEAT STREAK MOSAIC VIRUS

• WSMV is vectored by the Wheat Leaf Curl Mite.
• Constant wheat rotations w/o a crop free period
  e.g. seeding winter wheat into green spring wheat
  or spring wheat into green winter wheat stubble.
• Cereal volunteers in non crop places can be
  bridge for mites.
• Very serious problem in Walla Walla area in 2007!
• No control other than elimination of green wheat
  plants to prevent mites from vectoring virus.

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Wheat leaf curl mite aka wheat rust mite is an
Eriophyid mite of very tiny size.
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Close up of wheat leaf curl mite under microscope
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Wheat streak mosaic virus symptoms
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HESSIAN FLY LARVAE Myetola destructor
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Hessian Fly Puparia in wheat stem above 1st node
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HESSIAN FLY MANAGEMENT

• Deep plow after harvest
• If reduced or no-till rotate cereal crops with
  other non-host crops
• Use resistant spring wheat varieties
• Use maximum rates of labeled seed treatment
  insecticides e.g. Thiomethoxam, Imidicloprid,
  Clothianidin
• If you have HF, assume it will be a continuing
  problem so choose a combo of management tools
• Dont wait for larvae too late!

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THE END!