ANSWER: The fuzzy balls are galls formed by the tree leaf in response to the feeding of the larvae hatched from an egg deposited by a tiny gall wasp in the Family Cynipidae, Genus Andricus. Here are photos of Andricus quercusflocci galls that form on leaves of Quercus alba (white oak) and Quercus prinus (chestnut oak).Click to see full answer. Likewise, what are the orange fuzzy things on leaves?– Bob. ANSWER: It is an insect infestation called wooly oak gall. The tiny insects infest some of the oak leaves in the spring and cause the leaves to grow the fuzzy tan galls on their undersides. The insects live and feed inside the galls during the summer.Also, are leaf galls harmful to humans? Although galls are unsightly, they are typically don’t cause irreparable damage to your tree. Because many galls only cause cosmetic damage, we may not recommend any specific treatment for tree galls. One may also ask, what is the fuzzy stuff that falls from oak trees? A • The “tassels” that drop from oak trees are called catkins, and they are the spent male flowers whose purpose is to shed pollen that is carried by the wind to female flowers. If pollination occurs, then the female flowers will develop into the acorns that are the seeds of the oak tree.What is a gall on a tree?Galls are abnormal growths that occur on leaves, twigs, or branches. They may be simple lumps or complicated structures, plain brown or brightly colored. There are 1500 species of gall producers, the majority of which are insects and mites. Galls affecting leaves are seldom if ever a serious problem.