PSOCOPTERA.

BARKLICE & BOOKLICE. PSOCOPTERA. Barklice is a general term given to a diverse group of soft-bodied insects in the family Psosidae.

According to bug scientists, these insects first appeared in the Permian period 295–248 million years ago. So since they haven’t changed much, they must be doing something right. Also, they are not really lice… they just look like them to us humans, so we just lump them all together with a common name.


Often regarded as the most primitive of the hemipteroids, their name originates from the Greek word ψῶχος, psokhos meaning gnawed or rubbed, and πτερά, ptera meaning wings. I had to include the original Greek here as the letters are soooo cool, no? The species as a whole received their common name because they are commonly found amongst old books, where they feed upon the paste used in binding.


The ones we see in the forests here in Hong Kong typically feed on algae and lichen, using their chewing mandibles. Interestingly, the central lobe of the maxilla is modified into a slender rod, which is used to brace the insect while it scrapes up detritus with its mandibles. “Use your fork, Maximilian, not your rod” is often heard at psocopteran mealtimes.