Hickory

Hickory petiole galls produced by Phylloxera subelliptica (family Phylloxeridae) are appearing on hickory in southwest Ohio.  The single-chambered, ball-like galls range in size from 1/4 - 1/2" in diameter and arise from leaf petioles as well as along leaf midveins.  They may occur singly or in clusters to hang grape-like from their namesake host.  The galls range in color from solid greenish-white to bi-color forms involving splashes of reddish-pink.  Fully mature galls split open at to release the phylloxeran adults through a longitudinal slit.  Spent galls either dry out to...