This is a picture of Amphibolips quercusinanis at Leakin Park in Baltimore City, Maryland.
This is a picture of Eriophyes leionotus on a birch on the North Tract of the Patuxent Research Refuge near Fort Meade, Maryland.
This is a picture of some galls on the underside of an oak leaf at Beverly Triton Nature Park in Edgewater, Maryland.
Fairly large gall-looking mass on a Populus tremuloides. Looks like it might be composed of its leaves, or maybe it is a gall of the petiole This could be potentially caused by a number of different insects; mites, aphids, midges, etc.
Photo taken with iPhone 11
This is a picture of Pachypsylla celtidisasterisca on a hackberry leaf at Batts Neck Park on Kent Island in Stevensville, Maryland.
This is a picture of Callirhytis clavula at Batts Neck Park on Kent Island in Stevensville, Maryland.
This is a picture of Andricus dimorphus on the underside of an oak leaf at Terrapin Nature Park on Kent Island in Stevensville, Maryland.
This is a picture of Polystepha globosa on an oak leaf at Terrapin Nature Park on Kent Island in Stevensville, Maryland.