# Reseeding after armyworms



## Virginiagal (Apr 24, 2017)

I came home after a few days away and about 30% of the lawn on one side of the sidewalk was gone. It's army worms. I treated with bifenthrin. I will be reseeding (it's more like a renovation than an overseed in the affected area). My question: how do I protect the new seedlings? I assume I've killed the active larvae. But the worms will be hatching again from eggs. According to VA Tech and TV news and reports from neighbors on NextDoor, the worms are a big problem for the area this year. Even if I've gotten rid of my worms, moths in the general area can lay eggs most anywhere and I could have the worms again. If my neighbor has worms, they can crawl on over to my yard. I'm going to have baby grass and want to protect it. Do I just keep spraying bifenthrin until frost? How often?


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## g-man (Jun 15, 2017)

I think imidacloprid should protect you


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## Cluelessone (Sep 23, 2020)

I'm going with beneficial nematodes, as I'm in the same boat but really hesitate to spray insecticides due to my dog. Pray for me.


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## Easyluck (Feb 5, 2019)

g-man said:


> I think imidacloprid should protect you


I've seen this recommended as a preventative here and in other threads but the label doesn't list armyworms. I see cutworm (suppression). Have you had success using imidacloprid against armyworms?


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## g-man (Jun 15, 2017)

Page 8

https://extension.tennessee.edu/publications/documents/pb1342.pdf


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## Easyluck (Feb 5, 2019)

Triple crown is a combo product. It contains bifenthrin, zeta-cypermethrin and imdiacloprid. The first two list armyworms on the label as a stand alone product. Are you sure it's the imdiacloprid that is working?


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## g-man (Jun 15, 2017)

I don't have armyworms. The first two products will kill the large stuff, the imdiacloprid should cover the larva stage that virginagal asked about. Another option is grubex but it is very slow to move thru the soil profile.


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## Easyluck (Feb 5, 2019)

I've done bit of research and haven't read or heard that imdiacloprid will control fall armyworms in the larvae stage. I kindly ask for any references you have.

In my lawn, based on anecdotal evidence, I did not get control of fall armyworms using imdiacloprid. Perhaps coverage was bad or it wash away or the residual value wore off. All possibilities.

On July 5th I sprayed cyzmic cs (lamda-cyhalothrin) and imdiacloprid. The next morning I watered it in with 0.5 inches. July 27th I sprayed bifenthrin and watered it in 12 hours later.

After seeing several post about armyworms I checked my lawn and found a bunch of tiny armyworms on August 18th (44 days post imdiacloprid application). I sprayed bifenthrin that morning.

On August 26th, I found several adult armyworms after observing some minor damage. This time I went with trichlorfor and chlorantraniliprole (24 hour grub killer and grub ex).

I know chlorantraniliprole can take 2-4 weeks before the plant is protected so on September 2nd I sprayed cyzmic cs to help bridge the gap.

Did anyone have luck controlling fall armyworms with imdiacloprid this season?

Next season I'll be using chlorantraniliprole in April and perhaps again in July.


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## g-man (Jun 15, 2017)

The large army worms you are seeing eating your grass; they could come some other areas/lawns/towns/state. They move around looking for food. The healthy green lawns that have leaves full of moisture/nutrients are their main target. The neighbors that let the lawn go dormant, yeah those they likely skip.

Cyzmic/Bifen are contact kills for the armyworms. The leaves have to have the product "painted" on them when the armyworms show up. The applications in July (and more so if you water them in, why?), wont help you in 18Aug.

I think (going from memory), that the chlorant... (grubEx), does translocate from the soil to the leaves, so small animals eating the leaves should be impacted. Enough to kill them, I do not know. I think imidacloprid does that too ( think that's how the treat ash trees), but I'm not sure or how effective it is.

Here is a google search results of armyworms + imidacloprid for university publications: 
https://s3.wp.wsu.edu/uploads/sites/2071/2013/12/Armyworms-and-Their-Management.pdf
https://archive.lib.msu.edu/tic/turfx/article/1998jan6.pdf
https://www.nepjol.info/index.php/jpps/article/download/36479/28475/


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## Easyluck (Feb 5, 2019)

I know watering in a contact insecticide is not best practice. However I mixed it with systemic fungicides. (Sorry should have mentioned that) So by spraying in the evening and watering in the morning, I was hoping to achieve multiple purposes.

Also most contact insecticides recommend a higher rate of water when treating for thatch insects, especially in taller turf. So part of my thinking was rather than increasing carrier volume, I could water in to help move the product to the thatch.

Even still why did I have tiny armyworm larvae (less than 1/10 of an inch) 44 days post imdiacloprid application? I believe it's because imdiacloprid does not control armyworms.

It's possible adjacent lawns had armyworms that relocated. Adjacent lawns are mostly broadleaf lawns growing in shade. Unlikely but definitely possible.

I treat my hackberry tree with imidicloprid in the spring to control aphids. Works great.

Thanks for the links.

The first link says to check the label. Label does not list fall armyworms.

The second link states "it is not very effective at controlling caterpillars (sod webworms, cutworms, armyworms)

The third link isn't working for me.

Chlorantraniliprole is not harmful bees. Whereas imdiacloprid is extremely harmful. Both translocate to the leaves. I have not done research to say whether either insecticide is harmful to animals that eat the plants.

Here is NC states recommendation for control, dated August 31st, 2021.

https://ncturfbugs.wordpress.ncsu.edu/2021/08/31/fall-armyworm-qa/


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## Virginiagal (Apr 24, 2017)

@Easyluck So, would you recommend using something now as a preventative or just wait to see if worms show up again and do the bifenthrin again then? What kind of worm hunting do you do? I'm thinking maybe I would do a soapy water test each week and see if it brings anything up. If the moths fly away and don't lay eggs here again, I may be in the clear. Cold weather is coming.


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## Easyluck (Feb 5, 2019)

Either way you need to continue to monitor for armyworms and in the short term spray bifenthrin or similar if and when you see armyworms reappear.

If you apply grub ex today, it could take up to 4 weeks before seeing the benefits of it controlling armyworms.

Can't predict the weather so that is totally your call.


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## Easyluck (Feb 5, 2019)

Also go around your property and look at fence post, swing sets, playgrounds etc. I found a bunch of armyworm eggs on my property. Especially underneath my deck along the joist. Just snapped this picture. That is the remnant of armyworm eggs. And looks like I have more eggs in the cycle! 2nd picture. If I see eggs I squish them. And I've sprayed the deck as well.


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## g-man (Jun 15, 2017)

I'm not sure why it is not opening for you. This is a table in that report that compares multiple options. This was with corn, but it shows imidacloprid to be around 67% effective vs the control. Chlora... (grubEX) was around 97% effective, so a better choice.


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## Easyluck (Feb 5, 2019)

I see now. My browser settings were preventing it from showing up.

In the study they applied 5 different insecticides using a foliar application. So does that mean imdiacloprid provided 67% control as a contact application?


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## Lawn Whisperer (Feb 15, 2021)

A local lawn care professional mentioned that they treated for armyworms in a neighboring town; and this and other armyworm threads had me check my lawn. Sure enough, I have them in my lawn.

https://thelawnforum.com/viewtopic.php?p=436999#p436999


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## Virginiagal (Apr 24, 2017)

I decided to use Grub Ex. I'll be keeping an eye out for the worms in case the Gub Ex hasn't taken effect or if there are worms too big for it to kill.


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## Lawn Whisperer (Feb 15, 2021)

Mowed the lawn early in the AM with a lower HOC and aeration hoping to mechanically kill any armyworms feeding on leaves. Also placed a bug zapper to kill the mature moths.


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