Table of Contents
Subterranean and Other Termites
Termites incorporate a big and various institution of ecologically and economically important insects that feed on cellulose, principally in wooden. Worldwide there are over 2,600 species of termites; in California, there are at least 23 distinct species. Although many human beings associate termites with poor impacts, in nature they make many fine contributions to the world’s ecosystems.
In California forests, woodlands, and deserts termites normally feed on felled trees and stumps, grasses, bushes, or different pieces of useless or decaying wood. Termites can be exceptionally beneficial as they degrade woody debris, go back vitamins to the soil, and offer an energy-rich meal source to a lot of predators. Their tunneling efforts help to ensure that soils are porous, contain vitamins, and are healthy sufficient to aid plant increase. Termites not often injure or kill bushes. However, a minority of termite species can be very negative to timber in buildings, along with furniture and many different timber-based totally products. Each yr lots of housing units in California require treatment for the control of these insects.
Termites are one-of-a-kind from maximum different insects in that, like ants, bees, and wasps, they’re eusocial and stay in colonies or societies which can be enormously included. Eusocial insects are characterized via 3 tendencies: (1) Individuals of the same species cooperatively take care of immatures; (2) there’s a reproductive department of exertions with sterile individuals working on behalf of the reproductives; (3) there’s an overlap of at the least two generations in a colony so that offspring assist mother and father throughout their lifetime.
Termite colonies can vary in length from best two individuals (a mated pair or incipient colony) to masses of lots or perhaps even hundreds of thousands of individuals. Colonies comprise several bureaucracy or castes, along with larvae or immatures, workers, soldiers, nymphs, and reproductives. These castes may be prominent through physical traits.
Worker termites are wingless, tender-bodied, and mild caramel in coloration. They contain the biggest contingent in most colonies and are the people maximum frequently seen while infested wooden is examined. Workers are reproductively undeveloped. They are answerable for the care of eggs and immatures; foraging for meals; feeding and hygiene of nest pals, which include the queen; and construction and protection of safe haven tubes, galleries, and/or other colonial systems. Workers also can be concerned about the protection of the colony but are not as fierce as the infantrymen.
Soldiers can range significantly in morphology however, generally, have large, amber or brownish heads and large mandibles than workers. They guard the colony and guard it in opposition to predators.
Reproductives, or sexual adults, have yellow-brown or black bodies. At maturity, they initially have two pairs of wings of equal length and are called alates. After their swarming flight, they shed their wings and establish new colonies. The queen is the largest in bodily size, achieving mass numerous times that of employees. Her foremost function is to put eggs, sometimes lots in a single day. A king or male reproductive is usually by using her side. In the greater primitive termites, different individuals are capable of replacing kings or queens if they die.
TYPES OF TERMITES
Termite pests in California encompass subterranean, drywood, and dampwood species. Dampwood termites derive their name from the fact that they stay in wet timber, especially in stumps and fallen timber in forests. Drywood termites are not unusual and might survive in very dry conditions, even in deadwood in deserts and do now not require lots of moisture or touch with the soil. Subterranean termites are very ample in maximum components of California, even at elevations above 8,000 feet, and live and breed in soil, now and again many feet under the soil surface.
Dampwood termites are common during the state; however, due to excessive moisture requirements, they may be most customarily determined in cool, humid areas alongside the coast. They commonly infest decayed wood that stays moist both through contact with the soil or exposure to a water leak. Dampwood termites create massive, open galleries within the timber where they stay and feed. Their presence is great as a hallmark of a moisture problem or wooden decay in wooden structures.
In California, with one exception, all species of drywood termites infest dry, sound wooden—such as structural lumber, lifeless limbs on trees, application poles, decks, fences, lumber in garage, and furniture. From this infested timber, winged reproductives periodically swarm to infest additional nearby wood. Drywood termites are most time-honored in southern California, including the wilderness areas, however, they also occur along most coastal regions and in the Central Valley. Nests of most species stay totally above the floor and do no longer connect with the soil.
Similar to dampwood termites, feeding by using drywood termites can cut throughout the grain of wooden leaving a characteristic sample of chambers and tunnels, a number of that are full of fecal pellets. Drywood termites often expel their fecal pellets through surface openings and they can accumulate on horizontal surfaces under the openings. These fecal pellets, that are exceptional in look with six longitudinal flattened aspects, can be the primary clue to their presence. For in addition statistics on drywood termite biology and control see Pest Note: Drywood Termites.
Subterranean termites are commonplace all through California and can be determined to infest fallen trees, stumps, or other lifeless wooden in contact with the soil within the forest, panorama, or structural lumber in our houses. The species of financial significance are within the genera Reticulitermes, Heterotermes, and Coptotermes. Other genera of subterranean termites located in California are commonly constrained to the wilderness regions within the southeastern nook of the kingdom and are generally no longer essential pests.
The maximum not unusual subterranean termites, Reticulitermes, may be encountered in nearly all areas of the kingdom, from the sand dunes of the coast to the top elevations of the mountain degrees or even in a number of the desolate tract regions. The species of Reticulitermes are the most unfavorable termites determined in California. They are small in length as compared to dampwood and drywood termites, but mature colonies can include loads of heaps of individuals.
Reproductive winged types of subterranean termites are dark brown to brownish-black with brownish-gray wings. On warm, sunny days following fall or spring rains, swarms of reproductives may be seen rising en masse from their underground nests. Soldiers are wingless with light caramel-colored bodies and long, slender amber-colored heads without eyes. Workers are slightly smaller than reproductives, wingless, and feature a shorter head than squaddies; their shade is much like that of infantrymen.
In the Sonoran Desert of southeastern California, Heterotermes aureus is the maximum damaging species of subterranean termites. This species has mild-brown winged forms that fly inside the early evening and are drawn to lighting fixtures. Another unfavorable species on this group, the Formosan subterranean termite, Coptotermes formosanus, is native to China but now mounted in California, thus far restricted to a small region close to San Diego. Unlike the native Reticulitermes but much like Heterotermes, Formosan subterranean termites swarm at nightfall and are attracted to lighting.
Termite colonies are self-perpetuating. When the colony consists of a massive wide variety of individuals, frequently heaps, a small percentage of people change into winged reproductives (alates or swarmers) that then go away the nest, flying in swarms to mate, disperse, and establish new colonies. Most of those reproductives perish throughout the flight because of predation via birds, lizards, ants, or different bugs. The time of day and year when flights occur varies with species and geographic vicinity. Reticulitermes species swarms in the course of the afternoon in either spring or fall on clean days after a soaking rain. Heterotermes aureus flies within the late afternoon or early evening in July, August, and September. Coptotermes formosanus, even though uncommon in California, flies within the late-night and is attracted to lights. In homes with heated basements, termites once in a while fly internal all through winter.
New kings and queens are winged all through their early personal life and generally fly much less than one hundred meters from their colony. Once they land on the floor they find a mate and start the look for a nesting website online. A colony starts offevolved when a mated pair constructs a small underground chamber, which they enter and seal. Soon in a while mating happens and the girl starts laying eggs.
Most species of termites have microscopic one-celled organisms, known as protists, within their intestines that assist in changing otherwise indigestible cellulose from timber into food for the colony. Both the king and queen feed the younger on predigested food, thereby transferring those intestinal protists till the new brood is able to feed themselves. Once workers are produced, the king and queen are fed by them and cease feeding on timber.
Surprisingly, termites may be lengthy lived; queens and kings may have a lifestyle span of a decade or more, even as character people can live for one to several years.
SIGNS OF SUBTERRANEAN TERMITE INFESTATION
Signs of a subterranean termite infestation include swarms of winged reproductives inside the spring, summer, or fall, the presence of safe haven tubes, and proof of tunneling in timber. Shelter tubes (on occasion called mud tubes) are the maximum normally visible evidence of a subterranean termite infestation. These earth-hardened tubes are made with the aid of people using saliva mixed with soil and bits of wooden or maybe drywall. There are four forms of tubes:
operating tubes are made out of the nest in the soil to timber structures and they will tour up concrete or stone foundations;
exploratory and migratory tubes stand up from the soil but do not connect with wooden structures;
drop tubes make bigger from timber structures back to the soil; and
swarm tubes for new and swarming reproductive kings and queens to emerge from and fly away all through swarm season.
If you wreck termite tubes open, you can see stay employees and soldiers strolling through the tubes. The darkening or blistering of structural wooden members is any other possible indication of an infestation; wood in broken regions is normally skinny on the surface and easily punctured with a knife or screwdriver. Finding live termites foraging inside timber is a sure signal of a lively infestation.
The excavations that termites make in wooden are a hole, absolutely enclosed, more or much less longitudinal cavities. Some species deposit mild-brown excrement inside cavities. Feeding in timber by means of subterranean termites usually follows the grain of the wood; those species attack the softer springwood and depart the harder, less digestible summerwood. Many times this unique pattern of wooden damage by myself can be used to definitely distinguish subterranean termite interest from that of other species.
ECOLOGICAL AND BEHAVIORAL CHARACTERISTICS OF SUBTERRANEAN TERMITES
The ecology and conduct of subterranean termites give useful statistics for homeowners and the pest manages enterprise, providing new insights into the management of those capability pests.
Subterranean termites require wet environments. To satisfy this need, they generally nest in or close to the soil and keep some connection with the soil via tunnels in wooden or through refuge tubes. Furthermore, because of the moisture requirements of subterranean termites, they may be frequently observed in timber that has been barely decayed. Soil serves as a supply of moisture that protects termites from desiccation, shields them from predators, and may be used as a constructing fabric for refuge tubes and carton nests (Formosan subterranean termites) above the floor. Termites also can excavate passageways via the soil to attain extra meals assets.
Reproduction and Dispersal
New subterranean termite colonies are typically commenced from a preliminary male and girl pair (incipient colony). Pair formation takes place after the reproductive nuptial flight. Mated pairs normally start laying eggs right now. At the end of a yr, a colony may have grown to the best 75 people. Very few of the reproductives that fly every year ever pair up and set up a brand new colony; and only a few of the colonies set up ever reach maturity. Colonies that live on to maturity can include masses of lots of individuals and pose an extreme chance to systems.
Subterranean termite colonies may also be set up by the department of an existing colony. Colonies send employees to look for new meal resources. If a brand new deliver is discovered, then greater people are recruited to the website. After a while, a subcolony is mounted with a continuous change of foragers between this organization and the principal portion of the colony. Then for any quantity of reasons, the subcolony can be cut off from the mom colony; and the alternate of people terminated. This subcolony has the capacity of producing its own reproductives and growing rapidly as an impartial colony.
Because subterranean termites commonly do not build their nests in wooden, they need to forage for meals faraway from the nest. In most elements of us of a, foraging is basically curtailed via winter or extremely dry intervals. However, in California, they could forage 12 months-spherical, though the intensity of foraging varies with the season. The amount of timber consumed typically increases with growing temperature. Foraging is minimum from November to February, slight in spring and fall, and high, however erratic, at some point in the summer season months. During the recent summertime months of June thru September, even a moderate quantity of rain increases the wide variety of foragers above the soil floor and the quantity of wooden that a colony can devour. The most efficient situations for foraging, heat temperatures, and high soil moisture, commonly gift below and around homes.
Termites do no longer like every wood species, but the situation of the timber is greater essential in determining the probability of infestation. Decayed wood is eaten faster and preferred over sound wood. Digestion of wooden, in this situation, truly starts earlier than the termites take their first bite, since decay fungi within the timber damage down cellulose into smaller devices. Termites can digest sound timber, but decay fungi make their paintings a whole lot simpler.
Most subterranean termite species devour wood at approximately the identical fee, however, 3 factors could make a few species potentially more voracious and destructive than others. These factors encompass the environment in which they stay (termites devour more timber while conditions are top-rated over a longer time frame), the size of the bugs (larger insects devour more timber), and the number of insects (larger colonies devour greater wood).
One of the leader ways of shared feeding is referred to as trophallaxis or the mutual change of intestine contents between colony individuals. Trophallaxis additionally lets in the green use of vitamins, the popularity of colony participants, distribution of chemical compounds involved in caste regulation, and the switch of cellulose-digesting protozoans. Many individuals of a termite colony can not feed themselves, in order that they depend upon different colony participants to feed them. This conduct also facilitates the transfer of toxicants utilized in baits and other pesticides (see Management segment underneath).
The nest device of subterranean termites in California consists of a network of galleries that increase into the ground and may expand into extra spacious chambers. The foraging territories of colonies of pest species can include a single foraging website or many websites around an unmarried building, and the scale of the populations utilizing these territories can range from a few tens of heaps to hundreds of heaps of individuals. A home with a footprint of 2400 rectangular toes ought to have several termite colonies with hundreds of lots of foragers searching for meals and safe haven (for examples of subterranean foraging territories in California see Haverty, et al. 2010 or Potter 2011 in References.
MANAGEMENT OF SUBTERRANEAN TERMITES
It is unlikely that homeowners could be able to execute subterranean termite control on their very own. However, it’s miles essential for owners to have a few familiarities with inspection procedures, reduction of conducive conditions, and remedy strategies. Successful termite control calls for special skills and understanding, which include running expertise for building construction. Information on termite biology and identity can assist a homeowner to recognize and pick an appropriate method of control. Of path, homeowners can replace termite broken wooden and correct conditions conducive to subterranean termite infestation on their very own; but, packages of registered insecticides are exceptionally regulated and require an authorized pest manage expert to perform the inspection and control program.
Multiple colonies of the same termite species or several extraordinary species can infest a constructing. A professional inspection and an incorporated method to control are required. A mixture of techniques, which includes habitat amendment, removal of extra moisture, elimination of infested timber from the shape, exclusion of termites from the building by using physical and/or chemical way, and the use of chemical strategies to wreck present colonies will probably be vital.
An inspection by means of a certified pest management professional is needed earlier than any remedies may be done. Most owners might be unaware that a subterranean termite problem exists till a widespread finding takes place. For example, an infestation is located in the course of inspection in an actual estate transaction, broken timber is uncovered at some point of a room redecorate, a shelter tube appears on an interior or exterior wall, or the unexpected look of thousands of flying insects in a lavatory or kitchen. These conditions are common due to the cryptic and secretive existence habits of subterranean termites hidden in the back of partitions or buried away in crawlspaces and beneath slab foundations.
This Pest Note and different assets found on the Internet display snapshots and images of termites, shelter tubes, and damage that house owners can reference if they suspect an infestation or in the event that they want more details about the termite inspection manner earlier than contacting a pest manipulate professional. However, due to the fact the telltale symptoms of subterranean termites frequently occur in darkish and someday risky locations (attics or tight crawlspaces that have nails, dust, or status water), it is encouraged which you contact a licensed expert for inspection and next treatment.
Springtime, specifically a warm, sunny day following rain, is the optimal time for subterranean termite swarming conduct and, as a minimum for quick moments in the course of the day, a risk to look live termites and possibly a particular area wherein they are rising from in the home. Since most soil around a home has buried cellulose debris (roots, stumps, or fence posts), locating swarming termites in your backyard doesn’t always imply your property has termites.
Homes that have had a record of subterranean termite troubles may be specifically at risk of reinfestation and must be inspected by way of an expert each numerous years. California, like most states, has nonprofit associations that offer contact records for authentic pest manipulate specialists in your vicinity.
Building layout may make contributions to the possibility of termite invasion. Identify and accurate any structural deficiencies that entice or promote subterranean termite infestations. Ideally all substructural wooden beneath the constructing must be kept at least 12 inches above the soil. Consult neighborhood constructing codes for precise, minimum distances from wooden to the soil. Stucco siding that reaches the ground might also sell termite infestations when you consider that termites might tour between the stucco and the inspiration unseen. Keep foundation regions well ventilated and dry. Reduce chances of infestation via eliminating any wood in touch with the soil. Inspect porches and other structural or basis wood for symptoms of termites. Look for tree stumps, saved lumber, untreated fence posts, and buried scrap timber close to the shape which can make contributions to a termite infestation.
Replacing Lumber in Structures
Structural lumber in homes is generally Douglas-fir, hemlock, or spruce. Of those substances, Douglas-fir is fairly proof against termites, whereas the opposite two are not. Lumber utilized in foundations and other timber in touch with the soil need to be chemically dealt with or clear proof against termites and rot to help protect towards termite damage in areas in which constructing designs need to be altered or concrete can not be used. When using certainly resistant wood species, we recommend which you request documentation from suppliers to authenticate resistance tiers said on labeling. If susceptible wood is used above the handled wooden, however, subterranean termites can build their safe haven tubes over chemically handled timber and infest untreated wood above.
Use handiest outdoors-grade, pressure-dealt with lumber for regions that are exposed to weather; in any other case, the chemical in the lumber can also leach from the wooden. All topical treatments that will be exposed to climate should actually have a sealer coat to prevent leaching into the soil following rain.
Controlling Subterranean Termites
Subterranean termites in structures can’t be controlled the use of techniques that are appropriate for dry wood termites, including fumigation, warmth remedy, freezing, and termite electrocution devices, due to the fact the reproductives and a large majority of the termites are focused in nests near or underneath floor level out of reach of these control techniques. The number one techniques of controlling these termites are insecticides, either carried out to the soil adjacent to the structure, without delay to nests via shelter tubes or through bait stations. To facilitate manipulate of subterranean termites, wreck their safe haven tubes each time possible to interrupt get entry to wood substructures.
Liquid packages of pesticides are most often used for subterranean termite manage and applied to the soil both in drenches or with the aid of injection. There are no dependable over-the-counter termite control products available for the general public in California; all-powerful products are for professional use best.
Pest management experts are provided unique education due to the hazards involved in making use of insecticides to the soil around and underneath buildings. Applications within the incorrect location can reason insecticide infection of heating ducts and/or harm to radiant warmness pipes or plumbing used for water or sewage under the dealt with constructing. Soil type, weather, and alertness strategies have an effect on the mobility of pesticides in the soil; soil-applied insecticides need to no longer leach through the soil profile to contaminate groundwater or run off to infect surface water.
Recently, active components used to manipulate subterranean termites in soils were widely categorized as repellent or nonrepellent. Subterranean termites can hit upon repellent pesticides, typically pyrethroids; and they’re repelled without receiving a dose that could kill them. Because of this poor reaction, termiticide products containing repellent active elements were phased out.
Newly delivered chemical compounds are available which might be much less toxic to human beings and different mammals than the older insecticides but stay exceptionally poisonous to insects. These pesticides, such as chlorantraniliprole, fipronil, and imidacloprid are nonrepellent to termites and had been proven to be effective in killing termites at low dosage charges beneath California’s climatic situations. Depending on the label language, these materials are used as barriers as described above and also as nearby treatments, targeting nests at once thru safe haven tubes.
Subterranean termite baits, which can be gradual-performing pesticides consumed during feeding and shared inside the colony, are commercial to be had in California. Generally, bait is introduced inside a cellulose or timber matrix infused with the active factor and established underground at ordinary periods around a shape. Commercial bait products are also to be had for above-ground use, where there may be no soil for in-floor station installation. This method of controlling termites is very appealing because it doesn’t require good sized website online instruction, inclusive of trenching, or widespread application of insecticides to the soil or shape, and due to the fact the only baits use insect growth regulators (IGRs) to suppress or spoil the whole colony. IGRs have very low toxicity to human beings and their pets. The simplest bait merchandise, however, is to be had for professional use most effective.