# Alfalfa Cut Worms



## Vol (Jul 5, 2009)

Checked my alfalfa field this afternoon and noticed something had eaten on the leaves in small areas. Went back to the house and got my sweep net...noticed a few small aphids but probably got about 10 green cut worms about 1/4" long in 10 sweeps. My alfalfa is about 12 inches tall or more....guessing a couple of weeks away or so. I am afraid I might do more damage spraying at this point than giving the bugs part of it until I can get it cut and spray shortly after? Whats your thoughts?

Regards, Mike


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## askinner (Nov 15, 2010)

I was in the same predicament the other day Mike, I ended up spraying before cutting. I think it paid off, I wouldn't have got the yield I did had I not sprayed.
Mine was a big infestation, but if yours is only a few as you say, may just pay to spray after cutting. I did read somewhere only a few days ago, the threshold for aphids before spraying, I can't think where it was now.
I hate running over a mature stand, end up with mouldy stems in your bales that were snapped off from being run over,


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## haybaler101 (Nov 30, 2008)

Vol, you have been formally introduced the the ALFALFA WEEVIL. If only a small amount of damage and you can cut in ten days to 2 weeks, I would not spray, unless you have a big sprayer with few tracks. Weevils love 60 to 70 degree weather, a couple of 85 to 90 degree days and they will pop like popcorn and will not be a problem.


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## Vol (Jul 5, 2009)

Should one spray for weevils in the fall after removing the last cutting and again in the early spring when growth is about 3"-4"?

Regards, Mike


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## mlappin (Jun 25, 2009)

Vol said:


> Should one spray for weevils in the fall after removing the last cutting and again in the early spring when growth is about 3"-4"?
> 
> Regards, Mike


Might just be my area but we _rarely_ have to spray for weevils, for us it's not worth spraying ahead of time for something we might not even have.


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## Vol (Jul 5, 2009)

mlappin said:


> Might just be my area but we _rarely_ have to spray for weevils, for us it's not worth spraying ahead of time for something we might not even have.


I read where the weevils like to lay some of their eggs in the fall.....thought that might help partially control them for next Spring. Guess its too cold for them in your area Marty.

Regards, Mike


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## mlappin (Jun 25, 2009)

Thats quite possible, either cold enough or the freeze thaw cycle takes em out.


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## hay wilson in TX (Jan 28, 2009)

Just got to love the paraphrased quote.
[background=#ffff80]Weevils love 60 to 70º weather, a couple of 85 to 90º days eliminates the problem[/background].

Printed off the entire exchange through # 3 haybaler 101. Now I think I understand why FD 4 alfalfa will cut earlier in the spring and out yield a FD 8 alfalfa. With no new growth to eat until the temperature gets higher the AW just can not do their thing.
Thank you one and all. *J *


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## rjmoses (Apr 4, 2010)

Anybody have information on permethrin method of working and rainfasted-ness? I'm thinking of spraying for weevils this morning, but they are calling for 1" of rain tonight. But, at $70/gal, I don't want to spray if it's not a contact killer.

All I can find is "Do not...." on the label.

Ralph


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## Vol (Jul 5, 2009)

rjmoses said:


> Anybody have information on permethrin method of working and rainfasted-ness? I'm thinking of spraying for weevils this morning, but they are calling for 1" of rain tonight. But, at $70/gal, I don't want to spray if it's not a contact killer.
> 
> All I can find is "Do not...." on the label.
> 
> Ralph


Must be rainfast on contact as the chart shows a zero time to rainfastness.

http://www.agphd.com/

Regards, Mike


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## rjmoses (Apr 4, 2010)

Vol said:


> Must be rainfast on contact as the chart shows a zero time to rainfastness.
> 
> http://www.agphd.com/
> 
> Regards, Mike


According to my dealer, it needs to be dry for about an hour. So I sprayed today. we'll see what happens.

Ralph


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## askinner (Nov 15, 2010)

askinner said:


> I did read somewhere only a few days ago, the threshold for aphids before spraying, I can't think where it was now.


Here is an excellent article kindly posted by Haywilson : http://www.caes.uga.edu/commodities/fieldcrops/forages/events/FC13/03/InsectAlf.pdf Some great info in there!


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