Bark Lice (The Beneficial Insect)

Quick Facts

Common Name:

Bark lice

Genus / Species:

Archipsocus nomas and Cerastipsocus venosus

Type of Beneficial:


Type of Metamorphosis:

Immature stages similar in appearance to adults (i.e., simple metamorphosis)

Beneficial Stage(s):

Immature stages (known as nymphs) and adult stage


Fungi, algae, dead bark, and other organic materials on tree trunks and large limbs


Occur across the Galveston-Houston region; Archipsocus nomas is common and Cerastipsocus venosus is occasionally encountered

BarkLice Webbing Maas Nursery

I was sitting in (Boss Man) Jim Maas’s office having our weekly meeting about things to do for the newsletter and social media updates. The phone rang! He answered, it was the ever so popular question  we get this time of year.”What is this WEB like thing on my tree? It looks ghostly. How do I remove it? Can I spray it with insecticide?”

People assume it must be bad and immediately want to turn to insecticide to rid the trees of this ugly webbing. 

The name itself “bark lice” is very misleading. It isn’t a lice at all, it doesn’t even look like lice. Bark lice, are small soft-bodied insects resembling aphids.   The species of bark lice most commonly encountered in the Galveston-Houston region is the brownish-colored and gregarious Archipsocus nomas. The webbing in this region usually happens in late summer months, when humidity is at its highest. 

Reasons Bark Lice are Beneficial. 

  • They are natural scavengers 
  • They consume fungi, algae, dead bark 
  • They are Bark Maids ( they help clean the bark of undesirable inhabitants.)
  • They do not harm YOUR trees ( they don’t eat leaves or the Bark) 
  • They are short-lived and only come to clean things up. 


So have no fear, consider yourself blessed that nature is taking care of your trees for you. This truly is a beneficial insect…