Looks like some leaf-eater. Heard of any gypsy moths in your area? I've occasionally seen some kind of mass-caterpillar attack (not gypsy moths) on one of my swamp white oaks. It might be able to recover next spring.

Thank you, bengz, I cannot recall seeing gypsy moths in the area and perplexed (but pleased) that those proximal are not apparently impacted at all. These trees are under warranty for one year. So until late Jan/Feb next year, before the leaves would emerge. I am just trying to study up before engaging with the installers, so I better understand
Did your impacted white oak recover? Thank you for your message —Natalie

Yes, it recovered, and I've had another oak that got a late spring freeze and every new leaf was killed, but it did re-leaf later w/small leaves. It's up to you if you want to exercise your warranty, but it looks like it isn't the suppliers' fault that a rouge insect attack occurred. I've never seen anything quite that bad other than sawfly larvae on small dogwoods and the gypsy moth attacks on oaks in the 70s and 80s.

Thank you, bengz, I have the following response and now cannot unsee impacts in our community. Albeit less shocking because those are mature oaks and only small portion of tree is defoliated— newer tender leaves appear to be tastiest, on those, as well.

Thank you for letting me know about the oak tree. The photos are helpful. Given the lack of browned or dropped leaves, and that the leaf stem is still intact I do feel this may be pest-related. Oak trees are hosts to hundreds of species of caterpillars. Some of these caterpillars can completely defoliate a tree.

I would suspect this could likely be damage from the Orange-striped oakworm (aka OSO, a common caterpillar in our area that will feed in late Summer.). If this occured fairly recently you may be able to look for frass pellets (ie. caterpillar poop from the chewed up leaves) beneath the trees. Click here for more information and visuals on what to look for. There are other caterpillars that could be at play, but OSO is the one most frequently encountered in my professional opinion.

If this is the case, the tree should have already had plenty of time to photosynthesize and will likely not be a huge setback for the tree. It may be worth monitoring the other oaks for any caterpillars over the next few weeks. There are treatment options that can be looked into for next season as far as preventative spray applications. We use a product that includes a soil bacterium (BTK) that can be applied as a spray to the foliage. If ingested by the caterpillar, it will disrupt their digestive track and feeding ceases or is greatly suppressed. Typically this isn't needed unless: 1.) years of total defoliation continues, 2.) the caterpillar droppings get worse to where it is a maintenance concern (ie. droppings on cars, sidewalks, buildings, etc.). I hope this is helpful!

You mention an orange-striped oakworm, and I bet that's what was on my swamp white oak because I noticed they had a peculiar color. Luckily haven't seen any more for a couple yrs, tho a whitish sawfly larvae has been eating some of my red-stem dogwoods along a border stream, and those will strip an entire small tree in a week. Other sawfly species attack my pagoda dogwoods, but haven't seen them this year at least.

You do not say specifically where you live in Raleigh. We live about 20 miles east of Raleigh in near the Flowers community. For most of the summer we had very little rain, so the fact that a young tree lost it leaves is not surprising. There are many reason for one tree to loose it leaves in a dry season and other not. one at the high end of a slope and there lower down. Type of soil. Some soils retain moisture better that others. just because they are in the same yard, the soil can be dramatically different. We live in a typical addition. the street in front of our house is cut down to give a better grade for the street. What that means is that part of the yard is pure clay the type when you dig down several feet. Leach beds and septic tanks can also cause significantly diffferent soil condition. When the bury the tank the excess dirt (clay) is usually spread of the yard to get rid of it.