What is this web in our sweet gum tree?
It appears you have fall webworm (Hyphantria cunea) on your sweet gum tree. Thank you for the good photo. According to sources, this will not cause any long term damage to your tree.
NC state provides this explanation:
"Established trees can tolerate losing a considerable amount of foliage, particularly in late summer and fall. The injury caused by fall webworm feeding is considered cosmetic, only affecting the appearance of the tree, not the tree’s health. In most cases there is no need to do anything about fall webworms. The exception is young, recently planted trees which can be completely defoliated by webworms. In this situation it is usually beneficial to treat or physically remove webworms before significant leaf loss occurs."
This site will provide you with specifics:
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