Bark Lice on Silver Maple: Harmless Insects Creating Silken Webbing

A homeowner observes tens of thousands of tiny, white-fuzzy-winged insects at the base of their silver maple, mostly in limb crotches. No bark or leaf damage is visible. This occurs annually.

Identification: Bark Lice (Psocids)

These are not pests. Bark lice (psocids) are scavengers feeding on lichens, fungi, dead bark, and organic debris on tree surfaces. They produce protective silken webbing with a silvery sheen on trunks and large limbs—never on twigs or leaves.

Biology and Behavior

• Common on hardwoods (especially oaks) and citrus along Gulf/Atlantic coasts
• Populations peak in fall, decline in winter cold
• Webbing is cosmetic; insects cause no harm
• Distantly related to household booklice, but stay outdoors

Management: None Needed

No control recommended. They perform beneficial cleanup. If webbing is objectionable, a strong water blast dislodges them temporarily. Insecticide use is unwarranted and harms beneficials.

Further Information

Auburn University Bark Lice Fact Sheet with photos and detailed biology.