NON SUBTERRANEAN TERMITES AND OTHER WOOD DESTROYING INSECTS
Unlike the Subterranean termite, they do not require any contact with
the soil. They live in un decayed wood with a low moisture content.
Individuals are in distinct forms or castes - reproductives, workers,
and soldiers. Each performs a separate biological function. Only the
reproductives are winged (4 wings).
Their are no workers in the drywood termite group - instead the young
reproductives and soldiers serve as workers until they mature. The vast
majority in the colony is the worker caste and the workers and the reproductives
have chewing mouthparts especially adapted for chewing wood. It is the
workers who do the wide-spread destruction. The soldiers have powerful
mandibles to attack their enemies (usually ants).
Male and Female reproductives up to 1/2 inch long.
Bodies soft and cylindrical in shape, usually pale brown in color;
six legged; they have compound eyes and chewing type mouthparts. During
the winged stage there are 4 equal size wings that extend longer than
the body by 1/8-1/4 inch.
Soldier 3/8 inch;
Wood and occasionally other cellulose materials. They eat wood in houses,
utility poles, furniture and dying trees. They can not digest the cellulose
directly. They have other microorganisms (protozoans and bacteria) in
their stomachs that help break down the cellulose which then can be
digested by their own metabolism.
They live in small social colonies in dry wood. They mate and fly
to new dry wood areas; enter a small hole in the wood and start to form
a colony.In the first year, colony size may be only around 50 . After
4 years, there may be as many as 700 individuals in one colony. At this
time, the colony may swarm to start the cycle over again. After 15 years,
the colony will have grown to approximately 3,000 individuals. They
do not need a source of water and live off of the water that is produced
from the digestion of the cellulose.
They infest dry, un decayed wood, including structural lumber as well
as dead limbs of native trees and shade and orchard trees, utility poles,
posts, and lumber in storage.
The Drywood variety have a low moisture requirement and can tolerate
dry conditions for prolonged periods. They remain entirely above ground
and do not connect their nests to the soil.
Piles of their fecal pellets, which are distinctive in appearance, may
be a clue to their presence.
From these areas, winged reproductives seasonally migrate to nearby
buildings and other structures usually on sunny days during fall months.
This type is usually found in the humid coastal and subtropical regions
(i.e. California, Hawaii, Florida, Arizona, South and North Carolina,
New Mexico, Texas, Alabama, Mississippi, Louisiana and Puerto Rico).
They usually infest attic spaces or exterior wood members exposed to
them when they swarm in early spring or summer.
Click on map for a larger picture
Typical signs of infestation include:
1. Shed wings
2. Ejected pellets
3. Galleries inside wood are typical signs of a drywood termite infestation.
4. Swarming ants are many times confused with termites, but their
differences are easy to recognize.
5. Piles of their fecal pellets, which are distinctive in appearance,
may be a clue to their presence.
The fecal pellets of drywood and dampwood termites
Picture from: © 1996
The Regents of the University of California
Fecal pellets of drywood and dampwood termites. are elongate (about
0.03 inch long) with rounded ends and have six flattened or roundly
depressed surfaces separated by six longitudinal ridges.
RECOMMENDATIONS FOR TREATMENT IN DRYWOOD TERMITES:
Treatment for drywood termites consists of:
1.Structural fumigation. This is done by a certified pest control
operator. The entire building is covered tightly with a fumigation cover
and a sulfuryl fluoride(Vikane) or methyl bromide gas is fumigated.
2.Direct Wood Treatment(Spot treatments) To prepare for use of a a
liquid, aerosol, or dust formulation, holes are drilled into the infested
timbers through the termite galleries, using a 1/2 " drill in larger
timbers and smaller drills elsewhere. Insecticide is then forced through
these holes to be dispersed through the galleries.
DRIONE DUST is labeled for such use. Dusts should be
injected in the galleries in small amounts.
Too much dust would clog the galleries, and the termites will wall off
and isolate these areas.
When treating limited infestations, aerosols like INVADER and
Drione dust may be used. If you inject a water-based insecticide in
a wooden beam..it may produce a favorable site for decay fungi. From:
UC Pest Management Guidelines-Drywood Termites, you will find information
on detection, whole structure vs. spot treatments, eliminating existing
infestations, whole structure treatments and long term preventive treatments.
DRYWOOD AND OTHER NON SUBTERRANEAN TERMITES
Because of their ability to live in wood without soil contact, non subterranean
like the drywood termite, powder post beetles, or dampwood termites,are
frequently carried in infested furniture and other wooden objects into
geographical areas where they are not normally found.
As the name implies, the drywood variety establish in dry, sound wood that may have as little as 3 percent moisture content. They are not dependent upon a constant moisture supply as are the subterranean type.
One of the common symptoms of drywood attack is the accumulation of tiny, straw-colored fecal pellets inside or beneath infested furniture. These pellets sift from small holes in the surface of infested wood or are pushed out through small round openings maintained by the termites for this purpose. The hard fecal pellets have six distinct, concave surfaces. Presence of pellets does not prove damaged wood is currently infested, as pellets continue to sift from furniture for many years after termites are controlled or die. However, large, consistent accumulations of pellets are a convincing sign the termites are still active.
If the furniture is untreated, use TIMBOR or BORACARE.
Spray and allow it to penetrate the wood.
It will last the life of the wood and kill the active beetles.
If the wood is painted or varnished, you will need to strip the finish to use either one of these products.
Drywood Termites and Powder post beetles can be killed by either extreme heating or freezing. It would need 1.5 hours in a heated chamber of 150 degrees F or4 hours in a chamber of 140 degrees F. You can also use freezing temperatures to kill these insects.
Exposure at 156 degrees F for four days will kill them.
You will need to take care that either extreme of temperature would not damage the article.
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Winged dampwood termites
They don't require contact with the soil in order to obtain moisture, but wood with a high degree of moisture is needed. They are usually associated with wood decay. Because of their high moisture requirements, they most often are found in cool, humid areas along the coast.
Pacific dampwood termites (at times called a "rotten wood termite") is a major
pest at low altitudes along the coastal areas of California, Washington
Winged reproductives are dark brown with brown wings. Soldiers have a flattened brown or yellowish brown head with elongated black or dark brown mandibles. Nymphs are cream-colored with a characteristic spotted abdominal pattern caused by food in their intestines.
Dampwood termites nest in wood buried in the ground.
In nature, they are commonly found in tree stumps and fallen tree branches. In your home the most likely areas to find them would be an older wood deck, leaky roof eaves, leaky showers or tubs, or substructures with inadequate ventilation or plumbing leaks.
The Dampwood termite is much larger than the drywood and subterranean, measuring in at 3/8 to 3/4 of an inch. They can swarm periodically throughout the year and it is common to see the swarming reproductives caught in spider webs next to exterior lights since they are instinctively attracted to light.
The work of the colony is done by the immature soldiers or reproductives, there is no worker caste.
Swarms are small.
They produce a fecal pellet similar to the drywood termite's, but it is slightly
larger and has a more irregular shape. Damage in wood can be identified
by a velvety appearance in the galleries.
They produce distinctive fecal pellets that are rounded at both ends, elongate, but lacking clear longitudinal ridges common to drywood termite pellets; flattened sides are noticeable.
The Nevada dampwood termites are slightly smaller and darker than the Pacific species; reproductives are about 3/4 inch long.
The Nevada dampwood termite occurs in the higher, drier mountainous areas of the Sierras where it is an occasional pest in mountain cabins and other forest structures; it also occurs along the northern California coast. It differs from the Pacific dampwood in being subterranean in "habit". It attacks only moist wood. This termite is of horticultural importance because it frequently attacks the underground parts os shrubs an young trees. It occurs often in citrus groves.It is also found in fence posts, baseboards and door frames of buildings. Flights occur in July and August in evenings after rains.
The Florida dampwood termite is found in the extreme southeastern counties of Florida and in the keys. It lives naturally in damp( but solid) logs near salt water, and is common pest of buildings in this limited area. It is not subterranean by nature, although it may enter logs beneath the soil.
Control of Dampwood Termites:
Chemical treatment may be not necessary for the control of dampwood
termites. Since the dampwood termite requires wood with a high moisture
content, correction of the moisture source is necessary. This normally
means replacing the existing infested and saturated wood in conjunction
with elimination of the moisture source.
Common correction methods:
Increase the ventilation in the affected area, reducing the moisture and repair leaky showers and plumbing.
Make sure you have proper drainage.
Construction needs to be designed to avoid contact of wood and soil.
If the damp wood is not accessible to be removed, treatment of the soil with
an effective insecticide or termite baiting systems would be necessary.
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POWDER POST BEETLES
Picture courtesy : UC Riverside
In this section we will discuss four types of Powderpost beetles
in four families: Lyctidae, Bostrichidae, Anobiidae, and Cerambycidae. Adults
do little damage, it is the larvae that does the major part of the damage.They
go through a complete metamorphosis: adults, eggs, larvae and pupae.
True Powderpost Beetles(Lyctidae):
The adults are very small, less than 1/4" in size. They are
flattened and reddish-brown to black in color. Larvae are white, cream colored,
shaped with dark brown heads. Larvae create tunnels in the wood and become
pupae. As adults they bore out through the wood, pushing a fine powdery dust
out.The shape of their holes are round ,about 1/32-1/16 pinholes.
They attack hardwoods depositing their eggs. They can attack bamboo(technically
a grass),but because of the large pores they will attack. Their diet
is starch, sugar and protein in the sapwood of hardwoods Wood that is
less than 6% moisture content is seldom attacked .The life cycle averages
one year to complete .This wood-boring beetle is the most widespread
in the United States. Many times infestations are built into structures
from infested lumber .They can re infest.
Lycid damage is characterized by:
Presence of extremely fine, flour like powder falling from the surface holes.
The frass left by other wood borers usually contains pellets, has a course texture and a tendency to stick together.
When inspecting damage, be sure to distinguish old damage from active beetle infestations.
Recently formed holes and frass(sawdust like) are light in color and clear in appearance....old holes and frass are dark in color.
False Powderpost Beetle(Bostrichidae)
They are larger than other families of powderpost beetles...so their exit holes are larger. These holes do not contain frass,but the galleries do.
The frass is tightly packed, tends to stick together and is meal like( contains no pellets)
The adults are 1/8-to 1-inch long, cylindrical, and reddish
brown to black. The adults bore into the wood in order to lay eggs, leaving
a hole larger that 1/8 inch, usually in wood less than 10 years old.
are curved and wrinkled. Their diet is dependent on the starch in the wood, they
are more common in softwood ,but can attack hardwoods. They require 6-30%
moisture content in the wood, and complete the average life cycle in one year.
Most of the hardwoods attacked are not those commonly found used for interior
floors,woodwork or trim. Most of this species does not re infest wood
after it is seasoned, so the damage is limited to that inflicted by
However the speed of the damage can be considerable.
Most of the time they do not re infest wood after it has been seasoned. They
are often found in oak, firewood and furniture.
Anobiid Powderpost Beetle (Anobiidae)- Furniture and Deathwatch
The funiture beetle is found mostly in the eastern half of the United States and it infests structural timbors as well.
The Death-watch beetel is found trhroughout the United States. It attacks building timbers in poorly ventilated areas where moisture tends to collect.
The name"Death watch" comes from the ticking sound that the adult makes inside infested wood that is audible during a still night. It is a mating call.
The insect is a common pest in the southeastern United States in crawl space timbers. Infestations can become so severe, that loss of structural strength to sills , joists, and subflooring occurs.
The Adults are 1/8-1/4 inch long. They are red to dark brown
in color and their shaped is usually oval. The adults lay their eggs in the
cracks and crevices of seasoned wood. As soona as they hatch, larvae burrow ito the wood where they live and tunnel for a year or more.
The larvae form tunnels in both softwoods
and hardwoods They require 13-30% moisture content.
The larvae are slightly
curved and wrinkled, with tiny hairs on the body.
Their holes are round,1/16-1/8 inches. They can digest
cellulose from the wood. They are inclined to the softwoods ,for this reason
they are common in crawl spaces and basements ,infesting the pine used as
The powder outside the holes (frass) is fine to coarse, many
times with small pellets. The life cycle averages 1-3 years.
reinfest crawl space areas that are poorly ventilated and humidity is absorbed
in the wood.
Old House Borer(from the family Cerambycidae)
Picture courtesy : UC Riverside
The Old House Borer is one of the most common from this family,
with it's larvae hollowing out galleries in seasoned softwood(pine). It is
found in older buildings, but is more frequent in newer buildings,(in houses
less than 10 years old).The adults are brownish-black to black, slightly
flattened and about 3/4-1 inch long.
The average life cycle is usually one
to three years, but can take up to twelve years if nutritional and environmental
conditions are unfavorable. Because of the long life cycle, reinfesting the
wood it may take years before you see any structural damage .
The exit holes
are about 1/4-3/8-inch in diameter, but damage may have occurred for several
years before spotting such holes. They are able to digest cellulose.
has been infested with fungi, the larval development is faster. Their powder
(frass) in the tunnels are like sawdust ,tightly packed.
INSPECTION FOR WOOD BORING BEETLES:
Inspect periodically all exposed wood surfaces and probe them for evidence of internal damage.
Evidence of attack is more common in attics, crawl spaces , unfinished basements and storage areas.
To be certain that the infestation is active(not old damage or old frass), there should be fresh frass the color of newly sawed wood, or live larvae or adults in the wood.
CONTROL AND RECOMMENDATIONS:
The first thing to do
is reduce the moisture content, to a proper ventilation to less than 20%.Moisture meters can be used to determine the moisture level in the wood. Central heat,vapor barriers and good ventilation can help control moisture.
If practical..remove infested wood. If not,use residaul borate insecticides.
Recommended products are two borate
TIMBOR is a powder that mixes
with water. One lb.is mixed with one gallon of water and sprayed to the surface
area of in infestation. When sprayed it penetrates the entire wood, where
it will remain for several years .An alternative to Timbor is:
BORACARE. Boracare is a liquid borate that
penetrates faster initially than the Timbor for first few hours but is equal in efficiency and results afterwards.
Timbor is considerabley cheaper per gallon use.