|
Cryptotermes brevis |
|
Cryptotermes cavifrons |
Area of Distribution: Cryptotermes drywood termites are found mainly in
the humid coastal areas of the southern states of the United States from
Virginia to Florida, through the desert southwest, along the Pacific coast
to northern California and in Hawaii.
Cryptotermes drywood termites are sometimes discovered in other states
after being transported in furniture or other timbers.
Cryptotermes drywood termites infest the structural timbers of buildings,
furniture and other dry timbers having less than 12% timber moisture content.
This termite species require no ground contact and obtain their required
moisture intake from the timber they infest.
Cryptotermes drywood termites are sometimes called "powderpost"
termites or "furniture" termites due to their small faecal droppings
and the fact that they commonly attack timber furniture. The average moisture
content of seasoned timbers in service in the United States is 8-12%,
except along the coastal plains where the moisture level can exceed 12%.
Identification of Swarmers and Soldiers: Swarmers are about 7/16-1/2"
long including the wings, with the head width being 1/32-1/16". The
head and body are pale yellowish brown to pale reddish brown and the wings
are hardened and pigmented. The veins are pale yellowish brown in the
outer half of the wing.
The front wings have 3 dark, heavily sclerotized veins in the front half
of the wing. The median vein is un-sclerotized and runs midway between
sclerotized veins above and unsclerotized area below. The area ends near
the wing tip even if branched along its length and is not hairy. The tibia
have spines lacking along their length, apex has 3 spines.
The head of the Cryptotermes drywood termite soldier is short and thick
in front, the front surrounded by a flange and the front part nearly black.
Mandibles re-curved under front of head, with an unequal number of teeth
on each member of pair. The tibia lacks spines along length.
Identification of Timber Damage: The most obvious sign of infestation
is the piles of tiny faecal pellets ejected through temporary holes in
the infested timber. The faecal pellets are hard, elongated and oval with
rounded ends, and have six concave sides.
Cryptotermes drywood termites eat across the wood grain and make chambers
or galleries connected by tunnels. Other signs of infestation include
the presence of swarmers or their shed wings, piles of faecal pellets,
termite plugs which seal all openings in infested wood, and surface blisters
caused by older enlarged galleries very close to the wood surface. Occasionally
they may build shelter tubes constructed of pellets cemented together
to bridge over to an adjacent piece of wood.
Biology and Habits: Cryptotermes drywood termites do not live in the ground.
They obtain all the moisture required from the timber they infest. They
do not require contact with the ground and do not build mud shelter tubes.
Their colonies are located in the wood they eat and are small in size,
containing perhaps a few thousand termites. It is commonplace to have
multiple colonies in the same building.
Cryptotermes drywood termite infestations tend to be localised in buildings,
in doors, window trims, fascias, even picture frames. They eat the springwood
as well as the summerwood. The cavities they excavate in timbers are clean
and smooth, and do not contain any mud packing, in contrast with subterranean
termites.