Oak Tree Leaves
Accompanying photos show an oak seedling (unknown species, as it was originally planted by our crew of squirrels, who wouldn't reveal the source of the acorn) I transplanted. The seedling, now 3 or 4 seasons old, seems healthy in appearance, but two close-up photos of leaves show minimal chlorophyll, to be expected in early autumn. What is puzzling is the color of the drying leaves, something I've not observed in previous years. Is this light tan or ecru color due to the higher than normal rainfall we've been experiencing in Olney, MD (zip 20832-2130) this past summer, or does it indicate some deficiency in the plant's nutrition, also perhaps related to precipitation? I'd be very grateful for any information you can provide. Many thanks.
This looks like damage by a slug type of sawfly, a chewing insect. We cannot say which one. They chew from the epidermis and leave the lower surface intact. This is a drastic case. However, the damage has been done, they are gone, and no control is necessary. Next year this may not even be an issue.
You can monitor your tree next season in late June or July for possible damage. If you notice symptoms, you can send us photos so we can see what you are dealing with. If you catch them early enough, you may be able to handpick.