Insects of Wood Products
FIELD GUIDE TO INSECTS AND DISEASES OF ARIZONA AND NEW MEXICO FORESTS
Termites
Order Isoptera

Hosts:  Most tree species

Figure 172. Figure 172. Castes (queen, soldier and worker) of termites.

Symptoms/Signs:  Termite damage is honeycomb in shape and follows the grain of wood. There are three types:

  • Drywood termites. Coarse sand-like fecal pellets found outside of finished wood.
  • Dampwood termites. Typically colonize dead and down trees and untreated wood in contact with the ground.
  • Subterranean termites. Presence of mud shelter tubes on wood, walls and tree trunks.

Biology:  Termites are eusocial insects that have well developed caste systems. Caste consists of primary reproductives, supplementary reproductives, workers, and soldiers. Only the reproductives have wings and they form large flight swarms outside the colony. As their name implies, workers perform most of the work for the colony. They are generally pale in color, lack compound eyes, and have small mandibles. Soldiers are sterile adults with greatly enlarged and armored heads and mandibles. Their sole duty is defense of the colony against invaders. The conversion of cellulose to smaller units by protozoa and bacterial organisms in the guts of termites allow them to digest cellulose from wood and other plants.

Figure 173. Figure 173. Damage to sign post caused by termites.

Effects:  Termites can be extremely destructive to structures built out of wood. Even houses with a cement block foundation are at risk because subterranean termite tunnels can cross over the cement to wood framing. Damp wood termites attack wood that has high moisture content and do not require contact with the ground.

Similar Insects and Diseases:  Termites are sometimes referred to as “white ants”; however they can be differentiated from ants by their soft body, light color, straight beadlike antennae, and broad connection between the thorax and abdomen. Ants are hard bodied, darker in color, elbowed antennae, and have a narrow “waist.”

References:  15, 24