Wood Destroying Organisms (WDO)
Several species of fungi and insects normally infest wood, using it as food and/or shelter. The recognition and understanding of these organisms allows the selection of adequate treatments to obtain satisfactory results.
Some fungi cause wood rot, mildew, and most stains on sapwood.. These colorless microscopic plants produce threads calledhyphaeyfruiting bodies. Large numbers of hyphae produce tangled webs calledmycelium. Fruiting bodies, which are usually easy to see (dead wood conks, fungi), produce and release reproductive seedsspores. Detached spores are carried by wind or water. They can infect damp wood during storage, processing or use.Fruiting bodies are often thejust indicationthat a fungus is present.
•Foodin the form of cellulose, hemicellulose or lignin. Chemically treated wood is not a food source.
•Temperaturegenerally should be between 50°F and 90°F; ideal is around 70°F to 85°F. Wood generally below 35°F or above 100°F is safe from decay.
• Decomposition fungi require awood moisture content (M.C.) around 30%(the generally accepted wood fiber saturation point). Air-dried wood, usually with an M.C. below 19% and kiln-dried wood with M.C. 15% or less, they are generally protected from fungal damage.
•adequate oxygen- Fungi cannot live in water-saturated wood.
Fungi can be divided into two major groups based on the damage they cause.
1)Wood Destroying Fungi (Decomposed Fungi)alter the physical and chemical properties of the wood, reducing its resistance.
2)Wood stain fungi (sap stain fungi, mold fungi)just bleach the wood
wood destroying fungus
The sapwood and heartwood of most tree species are susceptible to decay.Decomposition fungi can grow inside the wood or appear on surfaces as fan-shaped stains.of thin, threadlike, cotton-like or root-like growth. The color can vary from white to light brown, bright yellow and dark brown. HeThe spore-producing bodies can be fungi, shelf-like supports, or structures with a flat, crust-like appearance.. Thin strands of fungus grow throughout the wood and digest parts like food, over time destroying the wood's strength and other properties.
White mycelium growing on wood (photo: bugginout.com)
Once started, the rate and extent of decomposition depends on how long conditions favorable for fungal growth last.Deterioration will stop when the temperature of the wood is too low or too high or when the moisture content is drier than the fungus requirements.Although,decomposition can resume when temperature and moisture content are favorable again. Early decay is sometimes accompanied by discoloration, so it can be confused with stains caused by other fungi or chemicals. Early rot is easier to see on freshly exposed surfaces of undried wood than on wood that has been exposed and discolored with age.
HeThe three main categories of wood-destroying fungi are brown rot, white rot and soft rot..
Brown rot is probably themost important causes of deterioration of softwood species used in aboveground construction. They aresometimes called "dry rot"but this is a bad term because dry wood does not rot. Black rot fungi break down cellulose for food, leaving a brown lignin residue. Black rot greatly weakens the wood before decay can even be seen. The final stage of brown rot decomposition is distinguished by:
- dark brown wood color,
- excessive shrinkage,
- cross grain break,
- dry wood that can be easily ground into a brown powder.
Brown rot fungus (www.basementsystems.com)
Some fungi can break down relatively dry wood because they have water-conducting filaments.which can transport water from moist soil to wood in woodpiles or buildings. These fungi can break down wood that is otherwise too dry for decay to occur. They are sometimes called "dry rot fungi" or "water-conducting fungi".
White rot breaks down lignin and cellulose, leaving a bleaching effect that can make damaged wood appear whiter than normal.Affected wood shows normal shrinkage and generally does not collapse or crack along the grain as occurs with brown rot damage.Rotten wood gradually loses strength, becoming spongytap.White rot fungi typically attack hardwoods.but several species also decompose softwoods.
White rot fungus (photo: sawmillcreek.org)
Soft rot usually attacks green (water-saturated) wood, causing a gradual inward softening of the surface.which resembles brown rot. The surface of the affected wood darkens and this surface layer, up to 3-4 mm deep, becomes very soft, hence the name soft rot.
Soft rot (image: liveattack.slideshare.net)
wood stain fungus
sap coloring fungus
The fungi that stain sapwood penetrate and discolor the sapwood.Unlike mold fungus staining,sap stain cannot be removed by brushing or brushing. These fungi can become established in the sapwood of standing trees, sawn logs, lumber and lumber shortly after cutting and before they have been properly dried. Although strength is not significantly affected, woodmay not be suitable for use where appearance is important (such as siding, trim, furniture, and exterior joinery that must have a clear finish).
Fungus that stains sap (photo: entomology.ces.ncsu.edu)
Blue spot fungi are the most common of this group. They produce blueish mycelia on the bottom of the wood, giving a stain that can completely cover the sapwood or appear as spots, streaks or blotches in various shades of blue.
blue spot fungus
Blue spots aren't the only fungi that stain sap and can infect wood. The color of the stain depends on the type of fungus and the species and moisture content of the wood. There may be yellow, orange, purple or red spots.
Mold fungus (photo: themoldremediation.com)
Mold fungi first appear as green, yellow, brown, or black powdery growths on the wood surface. From himcolored spores are usually easy to remove.Although,some surface molds can cause deep stains on open pore hardwoods. Freshly cut or seasoned wood that is stacked during hot, humid weather can become visibly discolored with mildew within 5 to 6 days. these moldsdo not reduce the strength of wood; however, they can increase the wood's ability to absorb moisture., thus increasing the possibility of attack by rotting fungi.
Chemical stains can resemble those caused by fungi. Theyresult of chemical changes in the wood. Stains often occur on logs or wood during seasoning and can be mistaken for a brown sap stain caused by fungus. The most important chemical stains are thosebrown stains that can degrade the woodfor some uses. they usuallycan be avoided by rapid air drying or using relatively low temperatures during oven drying.
wood destroying insects
Several species of insects use live trees, logs, wood and finished wood products for food and/or shelter. These include various termites, ants and beetles.
Termite life stages are: egg, nymph and adult.
Castes include winged breeders, soldiers, and workers. (image: http://flrec.ifas.ufl.edu)
eastern subterranean termitesThey are social insects that live in underground colonies. FORcolony contains three castes: workers, soldiers, and winged reproductive forms (kings and queens). Each caste performs specific colony functions. The creamy-white workers wreak havoc by feeding on the wood. They also keep the colony running. The soldiers, easily recognizable by their long yellowish heads with large jaws, protect the colony from invading insects. The dark brown or black kings and queens are the reproductive part of the colony. They leave the colony in swarms between March and June. After mating, the queens are stripped of their wings as they enter the soil to start new colonies.
Winged termites are often confused with winged ants. HeThe easiest way to tell the two groups apart is to look at their antennae, or antennae.Ants have L-shaped antennae; Termite antennae are straight. Ants have narrow waists like wasps; termites have thick waists. Finally, a termite's four equally sized wings are nearly twice the length of its body. Ants' forewings are larger than their hindwings, and both are approximately the length of their bodies.
How to differentiate ants from termites (image: primepest.net)
The galleries cut out of wood attacked by termites are covered with a mixture of earth and glue.to keep the humidity high. Wood that has been infested for some time may be mostly hollow with passages and may appear rotten. By probing this wood with a screwdriver or similar tool, many of the hidden worker termites can spread out.
Wooden termite burrows are irregular in appearance and contain some mud.
exposed mud tubesthey are another sign of termites. They are a protected passageway from the land to the wood that the workers eat. Additionally, the tubes can serve as swarm outlets for winged termites. Wood embedded in soil or concrete basement floors is especially susceptible to termites.
Lama Tube (www.greenninjapestcontrol.com)
Breaking the connection between wood and soil is essential in termite control.This can be done with a chemical or mechanical barrier.
Carpenter ants vary in size (up to 1/2 inch long) and can range from red to black. Workers don't have wings; Breeding males and females have wings. These insects commonlybuild nesting galleries in damp wood. how notthere will often be no outward signs of damage, feeling the wood with a screwdriver helps to discover the excavated galleries. Another technique for locating hidden nests is to tap wooden surfaces with the blunt end of a screwdriver, listening for the hollow sound of damaged wood. If there is a nest nearby, carpenter ants usually respond by making a "whispering" sound similar to crinkled cellophane.
Cleaning wood carpenter ant galleries (photo: mcinroybasemsntsystems.com)
Carpenter ant galleries look smooth, sanded and clean; no slimy material as seen with termites.Shredded wood fragments, such as coarse sawdust, are discharged from the galleries through cracks or pre-existing crevices made by the ants. These accumulations are a good indication of carpenter ant activity.
Dust beetles (PPB)
Dust beetle is a term used to describeseveral species of small (1/8-3/4 inch long) wood-boring insects that reduce wood to a fine flour-like powder. Hethe larvae chew through narrow, winding tunnels in the woodwhile they feed. Infestations are discovered after observationsmall round "shot holes" in the surface of the wood and accumulations of sawdust. They are exit holes used by beetles that come out of the wood after completing their development. Newly emerged adults mate and lay eggs on or below the surface of bare (unfinished) wood. Tiny, newly hatched larvae bore into the wood and feed for 1 to 3 years, depending on the characteristics of the wood. You are more likely to see damaged holes than beetles because the adults are short-lived and mostly active at night.
The Gunpowder and Sawdust Beetle "Shot Holes" (townandcountrysolutions.com)
BothThe most common and destructive families of dust beetles in Kentucky are Lyctidae and Anobiidae..
lyctid dust beetle
Gunpowder Lithmic Beetlesattack only hardwoodsfor example, oak, ash, walnut and hickory.
Lictid dust beetle (image: publish.illinois.edu)
Lyctids rarely infest wood older than 5 years, so infestationsusually occur in new logs and lumber. In many cases, the infestation was present when the tree was felled or shortly thereafter. Typically, the infested item was constructed from untreated wood or wood that was not properly dried and stored.
Dust anobius beetle (image: itp.lucidcentral.org)
Anobius beetles canattacks hard and soft woodstherefore, infestations can be found in the same locations as Lyctid beetles, as well as instructural wood (beams, sills, beams, studs, subfloor, etc.).Maple, beech, poplar and pine are especially susceptible to attack..
Anobiids prefer to infest damp wood; therefore,infestations usually start in damp, poorly ventilated areassuch as crawlspaces, basements, garages, and utility sheds. Under favorable conditions of humidity and temperature, infestations can spread upward to walls and upper levels of the structure, and occasionally to furniture. Infestations can result from using infested wood or from beetles that fly outside. Infestations develop slowly, but wood can be re-infested year after year. Thatcan result in extensive damage.
2006. G. Thomasson, J. Capizzi, F. Dost, J. Morrell, and D. Miller Wood Preservation and Wood Product Care Training Manual (http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/20518/em8403.pdf)
Wood Preservation Category 4b Study Guide for Commercial Applicators Ohio Department of Agriculture Publication for Pesticide Regulation 08/03 (http://www.agri.ohio.gov/Public_Docs/Pest_Study_Material/4b%20Wood%20Preservation%20Study%20Guide.pdf)
These include the termites (order Isoptera), powderpost beetles (Lyctidae), false powderpost beetles (Bostrichidae), deathwatch beetles (Anobiidae), carpenter ants (Formicidae: Formicinae), and the oldhouse borer just mentioned.Is wood preservative toxic? ›
Commonly used wood preservatives are toxic. Some can irritate and burn the skin, eyes, nose and throat and cause dizziness and muscle spasms. Excessive contact, particularly with some concentrates, can cause short-term, long-term, or permanently damaging effects.What is considered a wood destroying organism? ›
Wood Destroying Organisms (WDOs) are organisms that impact the structural integrity of wood. These include carpenter ants, termites, wood-boring beetles, and dry rot. While WDOs can come in many shapes and sizes, they all damage wood through their normal life cycles and can lead to significant damage and expense.How do you get rid of wood destroying insects? ›
If you suspect your wood is infested with woodworms or wood-boring beetles, treating the wood with a borate treatment is the most effective way to kill the active pests. Remove finishes from wood that has been painted or sealed before treating. Chose a product that is borate-based for your wood treatment.Are carpenter ants wood destroying organisms? ›
Carpenter ants are capable of damaging any wood within which they nest. Carpenter ant infestation can become severe when left untreated, and, in some cases, a colony of carpenter ants can develop satellite nests.What kind of termites are in Kentucky? ›
Dampwood and drywood termites are mostly prevalent in southern states such as Tennessee and Kentucky. Like the name suggests, subterranean termites house in the soil and create tunnel systems. To access feeding sites, they build mud tunnels leading above ground.What pesticides are in wood preservative? ›
Wood preservatives containing chromated arsenicals include preservatives containing chromium, copper and arsenic. Since the 1940s, wood has been pressure treated with chromated arsenicals to protect wood from rotting due to insect and microbial agent attack and wood-boring marine invertebrates.What are the environmental issues problems of wood preservative usage? ›
Use of wood preservatives has been cited as a source of pollution in surface and groundwater in many parts of this country. Testing has documented contamination in public and private wells at levels exceeding health advisories.
Cancer. Creosote, pentachlorophenol, and arsenicals are all chemicals that constitute wood preservatives. The US Environmental Protection Agency categorizes the first two as probable carcinogens, and they label arsenicals as concrete carcinogens.What are 4 insects that damage wood? ›
Wood borers are a group of insects that eat trees, acorns and nuts. These insects create holes in wood when they exit as larvae, but don't structurally damage the wood. Common types of wood boring insects include metallic wood borers, wood wasps, bark beetles and long-horned beetles.
Your WDO Inspection – A WDO is an Inspection for Wood Destroying Organisms. This inspection is more commonly referred to as a termite inspection. It's called a WDO because termites are not the only wood destroying organisms in the world. The WDO inspector is trained to look for things that we are not.How do you remove parasites from wood? ›
Applying a 1:1 mix of white vinegar and water to the wood surface will clear woodworm infections. While they find it unpleasant, it does not kill them. However, permethrin (which usually comes as a concentrare) kills woodworms at all life stages.How do you protect trees from wood boring insects? ›
Systemic insecticides applied via trunk injection, basal bark sprays, or as a soil drench are effective against flatheaded borers and they may be the only practical method for treating tall trees.Are wood borers the same as termites? ›
Difference Between Borers and Termites
Borers cause the most damage during the larvae stage and make their nest within the timber furniture in your house. Whereas, termites build their nest elsewhere and return to the infested timber furniture whenever they are hungry.
Carpenter ants and termites both present a risk to your home, but while either can cause considerable damage to wooden structures, the termite will invoke significantly more damage than the carpenter ant and will accomplish it in a shorter period of time.What eats carpenter ants? ›
Carpenter Ants are a main source of food for young grouse and pileated woodpeckers. Smaller woodpeckers, along with some songbird species, also eat ants. Now for some not so well-known animals that eat ants: toads, frogs, lizards, and at least one species of salamander like to eat ants!How long does it take carpenter ants to destroy wood? ›
Contrary to popular belief, carpenter ants do not actually eat the wood. Rather, they hollow it out in order to nest inside, which may result in structural damage. Also unlike termites, carpenter ants generally take years to cause significant damage.What state has the worst termites? ›
- South Carolina.
Subterranean termites are much more dangerous because they cause more significant damage than drywood termites. Their colonies can develop up to 1 million strong. Subterranean termites have a soft white body with no eyes. They are typically no longer than a centimeter.What do active termite droppings look like? ›
Termite droppings typically have the following characteristics: 1mm pellets – often look like piles of salt or pepper. Black, brown, and grey in color depending on the wood eaten by termites. Pellets will be pushed out of 'exit holes' in the nest to create pile-ups.
These include copper HDO (Bis-(N-cyclohexyldiazeniumdioxy)-copper or CuHDO), copper chromate, copper citrate, acid copper chromate, and ammoniacal copper zinc arsenate (ACZA). The CuHDO treatment is an alternative to CCA, ACQ and CA used in Europe and in approval stages for United States and Canada.What are the 3 classes of timber preservatives? ›
The main types of wood preservative pesticides are: 1) oil-borne, 2) water-borne, and 3) fumigants.What are the 3 main types of timber preservatives? ›
The preservatives may be water solvable salts or oil solvable salts or volatile base salts. Examples are zinc chloride, coal tar, creosote oil, and creosote petroleum blends respectively.What are 4 environmental causes of timber deterioration? ›
Thus, timber structures are also subject to decay due to a number of biological factors such as bacteria, fungi, insects and molluscs, and due to such non-biological factors as weathering, wetting and drying, chemical exposure and atmospheric con- taminants. Timber is as well susceptible to fire.What are the environmental factors that affect the degradation of wood? ›
To summarize, environmental factors such as tree species, temperature, water and nutrient conditions, insect boring, and forest disturbance affect the relative dominance of white-rot and brown-rot fungi in deadwood, and as a consequence, affect the decay type of deadwood on a variety of spatial scales.What are the hazards of treated wood? ›
The major health concern is that daily, long-term contact with arsenic leached from CCA-treated wood might lead to an increased risk of lung, bladder, skin, and other cancers or other health effects.Is chemically treated wood toxic? ›
The amount of leached chemicals generally drops quickly within a short distance from where soil is in contact with the treated wood. If you follow safety precautions around treated wood, you should not have any health effects as a result. However, you should avoid exposure to the smoke or ash from burning treated wood.How long is treated wood toxic? ›
The EPA and the U.S. Consumer Product Safety Commission (CPSC) believe that it is safe to leave old pressure-treated wood in place, stating that the toxic arsenate levels will be minimal as long as the treated wood receives a coating of pigmented, wood-penetrating oil sealant annually.What are some of the health effects from chemicals in or on wood products? ›
The main health risk is occupational asthma caused by inhalation of wood dust. Substances such as wood dusts and resins, solvents, paints, varnishes and strong detergents however, will also damage the skin. This may lead to skin soreness, blotches, cracking, itching and blisters.Which insect is most destructive to wood? ›
After termites, wood-boring beetles are the most significant wood-destroying insects. Female wood-boring beetles lay their eggs on wood that has not been seasoned or processed. However, some species do choose seasoned wood.
Termites cause more structural damage in the United States than any other insect. Subterranean species are the most destructive. They're found throughout the United States, but the Southeast and California have the heaviest infestations and sustain the most damage.Which insects cause the most damage to timber? ›
Termites. Subterranean termites – also known as white ants – cause the most damage to timber in NSW. They live underground or in mounds, and build mud tunnels so they can access timber to feed on the cellulose it contains.What does DTD mean in real estate? ›
DTD is an acronym for Document Type Definition, a document that describes the tags and hierarchy structure for a particular set of XML data such as RETML, the RETS DTD that relates to real property listings.Is mold a wood destroying organism? ›
Although mold is a type of fungus that can grow on the surface of wood, it does not acturally consume the wood, so it is not categorized as a wood destroying organism.How much does it cost to get termite inspection? ›
Termite inspection costs range from $50-$280 and typically cost $100, according to 2022 data from HomeAdvisor. Many home inspectors offer termite inspections as part of a package. Termite inspections purchased along with a general home inspection may be cheaper than standalone termite inspections.How do you know if wood borers are active? ›
- Fresh exit holes in timber - round or oval shaped with sharp edges, the holes will appear clean and fresh.
- Tunnels in the wood - also known as 'galleries' which are often hard to see.
- Bore dust - (also known as frass) caused by emerging adult beetles, usually visible below the infested timber.
Wood Destroying Fungi. The sapwood and heartwood of the most tree species is susceptible to decay. Decay fungi may grow inside the wood or appear on surfaces as fan-shaped patches of fine, threadlike, cottony growth or root-like shapes. Color may range from white through light brown, bright yellow, to dark brown.Which wood is most likely to be damaged by wood boring insects? ›
Flight holes between 3mm and 7mm. Infests seasoned and partly seasoned softwoods; pine, spruce and fir most susceptible.What disinfectant kills parasites? ›
The usual disinfectants, including most commonly used bleach solutions, have little effect on the parasite. An application of hydrogen peroxide seems to work best.Does vinegar get rid of woodworm? ›
Treating woodworms with vinegar is effective if you don't want to kill the larvae. The solution will only force them to leave the furniture. If you are searching for a non-toxic woodworm treatment, this is your choice. Mix white vinegar with water in 1:1 proportion and spray it on the furniture.
What kills woodworm? The most common insecticide used to control woodworm is Permethrin though growth inhibitors are used by some manufacturers. Permethrin is found in most woodworm killers.What are the four types of wood borers? ›
Infestations often go unnoticed until they exit the wood through tiny holes. In this post we'll take a look at four types of wood-infesting beetles: Deathwatch Beetles, True Powderpost Beetles, False Powderpost Beetles, and Old House Borers.What kills wood borer? ›
Fumigation - ProFume is a specialist fumigation treatment. It is a gas fumigant with the active ingredient Sulfuryl Fluoride. This fumigation process effectively eliminates all life stages of wood boring insect infestations.How serious are wood-boring beetles? ›
The adults are harmless; the larvae do all the damage. Since the larvae are inside the wood when they eat, they can be difficult to control. Products that contain borate are effective against wood-boring beetles because they penetrate wood, killing the larvae. They also linger to prevent another infestation.What are wood destroying insects? ›
- Carpenter Bees. Females chew round holes, but woodpeckers seeking larvae open the galleries creating even more damage. ...
- Carpenter Ants. Carpenter ants indicate a moisture problem because they nest in wood weakened by moisture. ...
- Termites. ...
- Carpenter Bees. ...
- Carpenter Ants.
- Subterranean Termites. The worst kind of termites to deal with are subterranean termites as they cause the most damage. ...
- Seasoned Timber Borers. They are the larvae of various beetles that lay their eggs on any timber surface and furniture. ...
- Timber Decay Fungi.
These insects are a group of insects that eat nuts, acorns, and trees. They don't structurally damage the wood but they create holes in the wood when exiting as larvae. Some common types of wood borers are long-horned beetles, bark beetles, metallic wood borers, and wood wasps.
So, what exactly is a wood-boring insect? A wood boring insect is a common term that covers many species of beetles that as larvae eat and destroy timbers. Wood boring insects are usually found in areas within a property that are poorly ventilated with a high humidity such as for example a sub floor crawl space.What insect is attracted to wood? ›
Wood Infesting Insects
These include roundheaded wood borers, flatheaded wood borers, and shothole borers, also called powderpost beetles. The legless, white larval stages of the first two types can be found while splitting logs. Piles of sawdust appear from small holes in logs infested by powderpost beetles.
While termites have wings of equal length, the carpenter ant's front wings are longer than the back wings. Rotting wood gives carpenter ants the perfect entry point into your home. You'll often find them in basements or around rotting wood near window sills or leaky pipes.
Wood destroying organisms are plants or animals that destroy wood that we use to build structures, structural components or furniture. Termites, powderpost beetles, wood-boring beetles, carpenter ants, and carpenter bees are just a few examples of insects that will attack structures.What chemical kills termites in wood? ›
What chemical kills termites? There are two main chemicals used to kill termites—fipronil and hexaflumuron. Fipronil is the specially designed chemical used as an active ingredient in many different liquid termiticides. In high enough concentrations, it can kill termites on contact.What parasite eats wood? ›
A woodworm is the wood-eating larva of many species of beetle. It is also a generic description given to the infestation of a wooden item (normally part of a dwelling or the furniture in it) by these larvae.What organism eats wood? ›
The most damaging animals that attack wood en structures are the termites. The beetles are the next most important group of insect which attack wood.