Feron atrimentum

Feron atrimentum, also known as the striped volcano gall wasp, is a species of gall-forming wasp in the genus Feron. It induces galls on blue oak leaves. Like other oak gall wasps, it has two generations: a bisexual generation, and a parthenogenic female generation. The bisexual generation produces round, 3-4 mm galls in spring that start as green or pink, and then turn brown. The unisexual generation produces conical, 4-4 mm galls in summer that are pale with red stripes.