Minnesota Barklice, Booklice, and Parasitic Lice

Psocodea is the order of barklice, booklice, and parasitic lice. Until recently, barklice and booklice were placed in the order Psocoptera, and parasitic lice were were separated into the orders Mallophaga (chewing lice) and Anoplura (sucking lice).

Psocodea are small, soft-bodied, scavanging insects distinguished by the following:

• small, rarely more than 3⁄16″ (5 mm) long;
• large heads and bulbous bodies;
• mouthparts optimized for chewing;
• the central lobe of the lower mouthparts (maxillae) are rod-like and are used for stability while feeding;
• swollen forehead;
• long, thread-like antennae, with 13 to 50 segments, that are swept backward;
• huge compound eyes and three simple eyes (ocelli); and
• last part of the leg (tarsus) has 2 of 3 segments.

Many are wingless. Winged species

• have four membranous wings;
• wings are held roof-like and steeply angled over the body when at rest;
• the forewing is larger than the hindwing; and
• wing veination is reduced.

There are about 11,000 species in more than 400 genera in 7 suborders of Psocodea worldwide. There are about 1,200 species in 3 suborders in about 200 genera in 43 families in North America north of Mexico. Only 15 species have been collected at Cedar Creek Ecosystem Science Reserve in Anoka, Minnesota. The total number of species in Minnesota is probably closer to 60.