Moths - Big Time!

15 years ago

In eastern Mass - I applied Scotts Step 3 (feed + insect, which is bifenthrin 0.086%) about 8 days ago, before going on vacation.

Needless to say the lawn has grown like gangbusters with the rain and cooler temps we've had - but just mowing the lawn this evening for the first time since fertilizing, and I have a TON of little white moths - they fly for only a few feet, if that, as they feel me coming.

I've had these before over the years, but never this many.

Is this sod web worm? If so - is it possible/common for lawns to have sod web worms but NOT be a problem? I know that almost all lawns have grubs, but it doesn't mean it's always at damaging levels. I'm wondering if the same applies to sod web worms. OR - with those - if you have them at all - you've got trouble?

Second question on this is: if I applied Scott's Step 3 - should I just assume that this will kick in and treat the moths/eggs/new larvae that they are dropping as they fly? I haven't used Scott's 4-step program in a few years, but I have in the past and it seemed pretty fool-proof, if you follow the instructions. I know there are a few on this forum that may sneer at the notion of using Scott's 4-step, but for now I'm just trying to figure out what's going on with my moths! :)

Any general quick lesson on what these moths are all about is greatly appreciated. I can supply more info if needed...

Thanks!

Sort by:Oldest

Comments (3)

philes21
15 years ago
My thoughts are off the cuff.....not to be considered as 'carefully thought out, backed with evidence'...because they are not.

But I have made your mistake, in prior years. In one sense frustrating, in another sense, it seemed not to matter.

That chemical (and I don't know that one. I only know Grub-X, which I assume to be similar) is persistent, and will stay in the soil. It kills larvae (we call them grubs) when the larvae are zero to four weeks old. At that stage, the larvae (grubs) are weak, but later they will become stronger. If, (and it's a big IF) the grubs make it, survive, to five weeks old, the grubs will in fact become moths, and those moths will fly away, and those moths will lay eggs, at the same time every year.

You put your stuff down four weeks late. Maybe only three weeks late. Maybe (it could happen) only two weeks late. In any event, you were late, as far as this year's crop of larvae was concerned: they were already big enough that the chemical won't kill them. Every one of them will become moths.

All is not lost: that chemical (if you don't core-aerate) will stay with the soil, and will prevent any LATER crops of larvae from maturing: those larvae will be killed, when they are very young. That chemical is claimed to last for a year: in my experience, it will last for two years.

So you lost this crop of larvae: they will become moths. But later crops of larvae will die. The moths floating around now will surely lay eggs. Those eggs will hatch, but the larvae will die, rather than become grubs, and then later, moths. All because you put that chemical down on the lawn. Nice work, btw, my compliments.

But this very first crop of moths? You were a tad late.

Don't worry about it.

Keep us advised, let us know how it turns out.
grasswhisperer
Original Author
15 years ago
Philes21 - Your explanation makes perfect sense - thank you so much for taking the time to write that out.

I won't enter "panic mode" just yet!

Best -
Brad in MA.
Related Discussions
I need I.D. for a moth (I guess is a moth)
Q
Comments (3)
Interestingly, I just came across one of these today, but didn't get a photo. It moved quickly and heavily, almost like a grasshopper. Thanks for the post and reply.
...See More
Big moth
Q
Comments (3)
That looks a lot like the mature form of a Tobacco Hornworm. Just Google it and you'll find plenty of info on the particulars. Yes, they're pretty huge. I found some on my tomato plants this summer and kept them in a bottle with some tomato leaves and dirt. It was pretty awesome to watch it eat day to day, then burrow in soil when it was ready to pupate. A few weeks later we were greeted by a moth just like yours. Keep an eye on any tomato plants around next year and you may find some of its offspring munching away.
...See More
A really big moth!
Q
Comments (2)
Ventral (underside) view of male (wide-feathered antennae) Polyphemus moth (Antheraea polyphemus). One of the more common "silk" moths.
...See More
Good moth or bad moth?
Q
Comments (7)
floral, knowing where cymraes is located isn't particularly important in this instance. The Tobacco hornworm, Manduca sexta, is found in the eastern part of the country; Manduca quinquemaculata, the Tomato hornworm is typically found west of the Rocky Mountains. I don't have any doubt that one of those is the moth in question, and that cymraes has been finding those big green caterpillars on his tomato plants. I don't worry when I see the moths, cymraes, but I sure do keep a close watch on my tomatoes for their eggs and hornworm caterpillars.
...See More
paulinct
15 years ago
I hate to disagree with Philes, but the insecticide that you applied was not directed at grubs, but rather some more common insects, and will kill off your moths very soon. Yes, grub control products have a small range of effectiveness, but what you applied does not. So don't worry about the moths! You haven't made any mistake, and they will all be gone soon.

Cheers,
Paul