07/07/2026
Southeast Texas Garden Minute-July -Bark Lice
Plant issue of the week: Bark Lice Identified on several of our trees throughout the county. A recent influx of calls about webbing suddenly appearing on the trunks and limbs of larger oak trees prompted further investigation into the issue. The culprit behind all this webbing is actually a beneficial insect called bark lice. (pscocptera) With a name like bark lice, it may sound like a terrible insect, but it is actually considered a beneficial insect. Bark lice are considered a beneficial insect due to the fact that are considered a beneficial decomposer. They feed on fungi, algae, dead organic plant tissue, and other materials found on the trunk of the tree. Bark lice have a unique feature on movement by the way that they move in a gregarious herd type of formation throughout the tree surface. They tend to move from different parts of the tree in large groups. Eggs are laid in groups and usually protected from predators by silken webbing. This webbing also allows the insect to move freely about the surface of the tree and provides protection to adults as well. Adults can be identified by shiny black wings and grow to ¼ inch long. Nymphs hatching from the eggs will resemble the tiny wingless adults. Most species will develop through six stages(instars)of growth into adults. Nymphs may appear as dark grey and have a pale band between abdomen segments. The insects may first appear as early as April with the webbing to follow by early summertime months. This webbing can sometimes consume the entire tree or only portions such as the trunk or limb scaffolding. Left undisturbed, these insects will eat and remove the webbing before populations begin to decline by the end of the summer. This webbing causes no potential harm to the tree and Bark Lice are considered beneficial insects, so no immediate action is needed for control.
For more information:
[email protected]
409 835 8461
Jefferson County AgriLife Extension-Horticulture
