ANDERSON COUNTY, Feb. 7, 2012—Anderson County Extension Agent Mark Price has been receiving a lot of calls about the appearing army worms. He typed up a release to share with the public about these pests.
 
“I love my job because I learn something new every day! On top of everything else we havegone through the last year, we now have an outbreak of Armyworms in January!  Yes… Armyworms! 
 
We started to get phone calls last week about these pests.  Our winter warm temperatures and good rains, is triggering armyworms to hatch.  What we are seeing is not our standard Fall Armyworms, but what is called the True Armyworm.   The easiest way to distinguish between the two species is that the Fall Armyworm has an inverted, cream-colored "Y" shape on its dark brown head. The True Armyworm doesn't have the “Y” and the head is a lighter brown.
 
From what I can read, the True Armyworm typically does not cause as much damage as the Fall Armyworm. Also Armyworms prefer to eat green growing grass, so the worms we are seeing will probably not last long.  BUT, for those of you that have Rye Grass and other cool season forages, be on the close watch. One landowner in Smith County had his rye grass field stripped before he knew what was happening.
 
Now what should we do about them?   I Do Not Know!
 
Do you spray your pastures?  My first guess is “No”.  I hate wasting money and the fewer chemical used on pastures the better!   One good freeze and they will be gone.  But, are we going to get another freeze?   We have very little for them to eat right now.  But, lawns and pastures are already starting to green up and with no hard freezes for seen in the near future, we could have the food supply they need.
 
What should we do?   A PhD friend has told me, when he does not know the answer to a question, he slowly strokes his beard, stares thoughtfully off into space [he said it makes him look smart] and then reply’s, “It depends on how the multiple variables converge”.  He said, he then hopes the subject gets changed before they figure out that he has no clue.   
 
Well folks, I am stroking my beard and thoughtfully contemplating… “We are in the middle of the winter, we should not be having to worry about this.”   Then I come to the realist answer…  “It depends on how the multiple variables converge”. 
 
Watch your pastures and lawns closely.  If you find armyworms, monitor them regularly.  If we get a hard freeze, they should be gone.  If it continues to green up, you may need to consider spraying.    
 
Only a few insecticides are labeled for use on armyworms in pastures.
Sevin 4F, Sevin XLR, Sevin 80S, Generic Carbaryl. When applied to pastures, there is a 14 day waiting period before grazing/harvest.
 
Malathion 57% and Malathion ULV. Zero days to harvest or grazing.
 
Mustang Max (9.6% zeta-cypermethrin). The first pyrethroid insecticide labeled on pastures and hay fields.  Applications may be made up to 0 days for and hay.