Hessian Fly Potential

— Written By N.C. Cooperative Extension

Hessian Fly Potential


by:  Steve Gibson, Extension Agent; Agriculture 


 One of my October habits is to check volunteer wheat for Hessian fly infestation.  I started last week and yesterday (Thursday) made a  quick sweep across the Cleveland County area.  I checked 13 fields that had some volunteer wheat and in every case but two found either larvae or puparia on the first plant I pulled up.  This is the most I have ever found; in some years I have not found any.            

 Does this mean we will have Hessian fly problems on our planted wheat?  I certainly hope not.  Even though the infestation is there already it all depends now on the weather.  If we have a mild November and December and the gnat-like adult flies are able to mate and lay eggs I feel we definitely have the potential for a major and damaging infestation. 

On the other hand if we have a type of late Fall with regular below freezing nights, we may be ok.So what can you do?              

First I encourage you to get out and pull up some of the volunteer wheat in your fields.  Look for abnormal looking plants or tillers and pull back the leaves, removing the leaf and leaf sheath.  You should be able to see either the cream white colored legless larvae (about1/5” long) or the slightly larger brownish puparia.  Make sure you do have volunteer wheat since this is the primary plant host.  If you know what to look for this will help you later to determine if the pest pressure is still present closer to planting time.                       

Second, we do have 4 resistant varieties you can use.  They are Roane, Nuese, P26R12 and P26R15.                   

Third, I would not be in any great hurry to plant this year if the weather remains warm.  Many specialists and seed company reps and myself believe waiting till November to begin wheat planting is advisable for several reasons.  Our historical fly-free date is October 20th. but as you well know we do seem to be in a trend of warmer Falls and early Winters.  I will never forget losing a variety demonstration that was planted in late November to Hessian fly.  There were surrounding fallow fields with lots of volunteer wheat and we did not have any cold weather till the following January.                       

Fourth, if systemic insecticide seed are available (Gaucho or Cruiser) they definitely should be used on the earliest plantings.                       

 Fifth, when our planted wheat has emerged look very carefully at the plants.  I will do the same and if eggs are being laid hopefully we can have a field meeting so you will know how to react to prevent infestation and damage.  If any of you know of some early planted and emerged wheat please let me know.

            For us this is a rare insect pest for wheat but we have had several years in my 30 seasons with scattered completely ruined fields and one year when essentially all the wheat in the Newhouse area was devastated.