Delta Journal
by Bob Thomas

"Oh, no! Something else is attacking our oak trees! What’s covering the limbs with a fine sheen of silk? Will they sting? Will they kill the tree?"

Due to our experience with stinging buck moth caterpillars, this is an understandable reaction to anything strange associated with New Orleans' beloved live oak trees.

In this case, however, the culprits are very tiny, non-descript, harmless barklice (Archipsocus nomas), or psocids (members of the insect Order Psocoptera). As these little fellows go about their lives, they weave a very tight web close to the surface of their host tree that appears as a grayish sheen on the bark. They are most common in New Orleans on oak and hackberry trees. Barklice are so small that one has to get nose-to-nose with the web to observe them. They range about on the bark searching for algae, fungi, pollen grains, and the like to feed upon. They do absolutely no harm to the tree and will in no way harm people or their pets - they are not "lice" that will attack your skin.

Buck moths have made us very aware of animals that live on the bark and limbs of our trees. There is, however, a complete tree ecosystem that we should understand. There are beetles that prey on other insects, wasps that parasitize harmful caterpillars, tiny invertebrates that serve as the bottom of the food chain for who knows what, etc. Before one becomes disturbed about new discoveries, and certainly before one sprays poisons, ask the question: "I wonder what they do in nature?"