I'm wondering how this is going to affect the trees. Will the trees be at a disadvantage going into fall and winter with such little leaf surface?

Probably. Not unheard of and plants will be temporarily weakened but should recover. With our La Nina you'll want to keep hoses handy for winter watering this year.

Dan

The main problem for the trees is that they'll be entering the winter season with very low carb reserve in the root system. With the grasshoppers devouring the leaves, your trees have not been able to manufacture and store photosynthates. That's bad enough in and of itself! But they are using what little energy they have to make more leaves at the time of year when they would ordinarily be shutting down. That's a BIG double whammy.

It will be next spring and summer that will reveal the extent of the damage. It takes enormous stored energy reserves (which your trees simply do NOT have) to produce the spring flush of growth. Your trees will attempt to remetabolize (is that a word?) carbon stored primarily in the root system....at the sacrifice of that already tapped out root system.

The very best thing you can do is what you have already done...mulch and provide water if needed. I would avoid any kind of fertilizer that might force artificially rapid growth, so that the trees can begin to recover at their own rate. IF they can.

Trees, if they are reasonably healthy in the first place, can bounce back from insect defoliation, but not if it happens over and over. Since this is only the second year, I'm going with Dan on this....your trees have a pretty good chance of recovering.

Dan and Rhizo 1, thanks for your thoughts.

One apple tree is 10 years planted and otherwise healthy, still has apples on it, but just a handful of new leaves. The other 2 apples were planted 3 or 4 years ago. The other trees are spring plantings this year.

The grasshoppers did not eat the trees last year. There was apparently enough other forage for them.
This year I couldn't believe my eyes when I spotted them 7 or 8 feet up a tree! I shook them out of the London Plane at every opportunity, but they won.

I'll hope for a long fall so the trees can get something from those leaves.

Dan, thanks for the heads up that we'll have another dry, windy winter. I didn't water enough last winter and will do better this winter.

Barb

Barb, you'll definitely want to ensure these don't dry out this year, as they don't need any more stress than they already have, as rhizo detailed.

Dan

I think I would pick the apples so no more energy went into them.

Just a thought.

tj

Good point, tsuga, thanks! I'll pick them tonight.

Dan, I learned my lesson last winter. I watered a couple of times, but will up it to at least a monthly deep soaking of everything. The deciduous trees took a beating last winter and I won't let that happen again.

Thanks!

Barb

There is a spray mixture of kaolin clay and soap that works fairly well to keep grasshoppers from eating leaves. Tried it last year with caliche clay and it also seemed to work. The down side is that the clay mixture does stain the leaves.
Will look for exact recipe tonite.

Dang, I always forget to recommend "Surround", the commercial kaolin product. I really like it for plants plagued by chewing insects. The commercial product has benign additives that help keep the clay in suspension and to adhere to the leaves.

Surround has been on the market for quite a long time, mostly used by tree-fruit growers. It protects the foliage from pests and the fruit from pests AND sun scald. It's becoming more and more popular with growers of all kinds.

I picked the apples last night and there are probably 20 new leaves. You go, girl!

I'm seeing lots of bees, so I didn't do too much damage with the Sevin. Still, I hated having to resort to it. I'll try Nolo bait at the right time next year.

I can live with leaf staining. I don't care if the leaves turn purple and glow in the dark as long as they stay on the trees and out of the hoppers stomachs. Thanks, scotjute and rhizo, I really appreciate the info.

From what I've been able to gather, grasshopper infestations run 2 - 4 years, so I'm either at the tail end or have another year or two to look forward to.

Leaves are starting to turn here so I'm thinking it would be best applied next May - June?

I'll read up on Surround.