To spray or not to spray. That is the question

[Bruce L]

Gypsy moth caterpillars were devastating here last summer,trees completely stripped of their leaves,not anticipating much of a season this year because of it. Egg masses on the trees tell me it will be even worse this year. Thinking of getting the bushes sprayed with Btk,which will target and kill the caterpillars,but if the neighbors don’t do their bushes next door will it be a waste of time and money?

[wobbletop]

I'd do everything you can. I was thinking of using mineral oil on any egg masses I see.

My lures must have killed thousands of the male moths, and I killed many hundreds of caterpillars on the trees in the yard via banding.

[ennismaple]

Bruce,

If your neighbours don't spray you'll still have a benefit because the caterpillars don't move very far. We sprayed for tent caterpillars for 3 years and got through the worst of that infestation when gypsy moths hit us, with one year of overlap between the two. In 2020 we did not spray and the gyspy moth caterpillars stripped just about everything to the point where some trees put out a 2nd set of leaves. In 2021 they hit the basswood, oak and birch hard but a significant percentage of the caterpillars died before turning into moths. We are seeing very few egg masses in the woods compared to the last few years so for our property I would say we are past the peak.

My math said that if spraying meant a 0.1 Brix increase in sap sugar content that the increase in syrup made the following year justified the cost. I've heard of producers claiming their sugar content was down 0.5 Brix of more after being stripped the previous summer.

[220 maple]

Gyspy moths catch a virus and die if it is a wet Spring in our area, it’s a crazy world, I can only hope no bug or virus comes from China that kills humans? Emerald Ash bore killed multi-millions of Ash trees, then they have this bug called the Asian Long Horn beetle, it kills are money trees! Just had a thought, with all the container ships stuck of the coast maybe the new invaders will hatch and die! Before they invade our woods
Mark 220 Maple

[Pdiamond]

One can only hope!

[argohauler]

There are pheromone traps available. 1 trap is supposed to be good for 1 acre and 1000 female moths.

[wobbletop]

The store bought traps are crap. Better to make your own with a pan of soapy water and plastic cup. We had a scientist up here making lures and giving them out freely, but they were shut down for some reason (likely from BIG PESTICIDE).

edit: and the females don't fly, only the males.