Patent Application
20090094884
This invention relates generally to termite stations for monitoring and/or suppressing termite infestations, and more particularly to a cartridge for placement into a termite station.
Many pests, such as subterranean termites, present threats to building structures or other wood or cellulose containing structures such as trees, fence posts and the like. In particular, while subterranean termites primarily dwell in soil and often form large colonies, the members of a colony commonly forage for food above ground, consuming food located by the foraging termites and then returning to the colony or nest site and sharing the food with their nestmates. Termites, when foraging above-ground, often leave telltale signs of infestation, such as termite tunnels visible on exterior surfaces or, where the foraging is substantially within the interior of a structure, holes visible in the outer surface of the infested structure.
In-ground and above ground control devices or systems are known for monitoring and eliminating termite infestations. In-ground devices commonly comprise a housing that is placed down into soil with a monitoring food source disposed in the housing that is edible by termites and provided to encourage termites to feed within the housing. Once active feeding is indicated by the monitoring food source, it is replaced by an edible bait matrix containing a toxicant whereby the foraging termites consume portions of the toxicant-containing bait and return portions of the toxicant-containing bait back to the nest to thereby eradicate or suppress the infestation. Other known in-ground devices have an aggregation base or other attractant disposed in the housing along with a separate toxicant containing bait whereby the termites upon entering the housing locate the aggregation base, which encourages further foraging within the housing so that the termites find and consume the toxicant-containing bait.
In contrast, above-ground termite control devices or systems consist of a housing and a bait matrix containing a toxicant disposed in the housing. These above-ground systems forego any monitoring phase and provide direct access to termites for readily feeding on a bait toxicant material. While in-ground devices are readily located at a desired location by placing the housing down into the soil, above-ground termite stations must be mounted on a structure or other mounting surface at a particular location of infestation, such as along the termite tunnel or over a hole formed by the foraging termites in the structure. Conventional above-ground termite stations typically comprise a housing containing the internal termite control components and one or more fasteners that extend through precise locating holes formed in an outer panel and an inner or base panel to secure the housing on the mounting surface.
It is also common that over time the various internal components, such as the toxicant-containing bait matrix, of the housing, whether it be an in-ground station or an above-ground station, may require replacement. In some above-ground termite stations, the entire station must be removed and a new one mounted on the mounting surface at the same or approximate location. In another known termite station, the outer cover of the station may be removed and another station stacked on top of the existing station to provide additional bait. In yet another above-ground type station the bait matrix is a loose material that is packed into the station and when additional bait is needed it is either forced in around the feeding debris within the station or the station must be cleaned before additional bait can be added. In each of these known stations, the feeding site is typically disturbed, which may cause the termites to abandon the bait holder altogether.
Typically with respect to in-ground termite stations, the toxic termite bait is applied only after contact has been established with a termite colony and termites are feeding from the station. Reasons for this include minimization of the amount of bait used, potential deterioration of bait if it is left in place for long periods of time in anticipation of prospective termite attack, minimization of the potential for unintended exposure of children and pets to the bait, etc. Therefore, it is preferable to first detect termites at the bait holder with a nontoxic medium while monitoring the site. After termites are detected, the toxic bait is placed into the housing. As a result, such systems must be inspected periodically, such as every one to three months, to determine if termites are active within the bait holder. However, to accomplish this, a baiting system must deal with several issues that left unresolved, make a baiting method and/or system less likely to succeed. For example, when inspecting the monitoring medium or the bait within the bait holder or when adding or replacing the toxic bait, the feeding site is typically disturbed. This may cause the termites to abandon the bait holder altogether.
Thus, there is a need for a termite station that permits termite detection and baiting in a manner where the transition of feeding termites from nontoxic to toxic bait or the replacement of bait is effected with minimal, if any, disturbance of the feeding site and that is simple to use.
In one aspect, a replaceable cartridge is provided for use with an apparatus for detecting and controlling termites. The apparatus comprises a container defining an interior space sized and shaped for receiving the replaceable cartridge therein. The replaceable cartridge generally comprises a generally tubular sidewall constructed of a termite resistant material and having an interior chamber. The sidewall has an upper end and an open lower end. An aggregation member is separate from the sidewall and positionable at least in part within the interior chamber of the sidewall generally adjacent the lower end thereof to at least in part close the lower end of the sidewall. The aggregation member is configured to define at least one opening through which termites enter the interior chamber of the sidewall through the lower end thereof. The aggregation member is constructed of a termite edible material. A bait matrix is separate from the aggregation member and disposed within the interior chamber of the sidewall intermediate the aggregation member and the upper end of the sidewall.
In another aspect, a termite station for detecting and controlling termites generally comprises a container defining an interior space and a replaceable cartridge. The replaceable cartridge has a generally tubular sidewall constructed of a termite resistant material and an interior chamber. The sidewall has an upper end and an open lower end. An aggregation member is separate from the sidewall and positionable at least in part within the interior chamber of the sidewall generally adjacent the lower end thereof to at least in part close the lower end of the sidewall. The aggregation member is configured to define at least one opening through which termites enter the interior chamber of the sidewall through the lower end thereof. The aggregation member is constructed of a termite edible material. A bait matrix is separate from the aggregation member and disposed within the interior chamber of the sidewall intermediate the aggregation member and the upper end of the sidewall.
With reference now to the drawings, and in particular to
The base panel 25 suitably has an outer surface 35 (
With particular reference to
These base panel openings 39 are used to mount the base panel 25 (and hence the container 23) on the mounting surface M using suitable fasteners such as screw fasteners 43 (
Providing a plurality of such openings 39 in the base panel 25 allows the base panel (and hence the termite station 21) to be arranged at a desired location on the mounting surface M, such as with one or more of the openings located over an opening (not shown) formed by termites in the mounting surface, while providing sufficient additional openings through which fasteners 43 may extend through the base panel into the mounting surface at a more stable (e.g., less damaged) or stronger segment of the mounting surface. Thus, in such an embodiment the number of openings 39 exceeds the number of fasteners used to fasten the base panel on the mounting surface M by at least one. The openings 39 also allow the termite station 21 to be secured to the mounting surface M by passing the fasteners 43 through a single structural member of the container 23, i.e., the base panel 25, as opposed to multiple components thereof. For example, the lid 31 of the container 23 is free of openings that may otherwise be used as in the case with conventional designs because it is unnecessary for mounting fasteners to extend through the lid. This arrangement makes it easier to visually place the termite station 21, and in particular the base panel 25, in the desired location on the mounting surface M and also allows opening and closing of the lid 31 while the termite station remains mounted on the mounting surface, and in particular without having to loosen or remove the mounting fasteners.
The openings 39 in the base panel 25 also provide multiple entry points for the ingress and egress of termites to and from the interior space 33 of the container 31 through the base panel 25. To this end, the base panel is openings 39 are generally chamfered, or tapered outward (e.g., expanding in planar dimension) from the base panel outer surface 35 to the inner surface 37 thereof as illustrated in
Peripheral (i.e., side entry) openings 47 are formed in the end panels 27 and side panels 29 (i.e., broadly, the side) of the illustrated container 23 in spaced relationship with each other about the periphery of the container. More suitably, these peripheral openings 47 extend from the respective end panels 27 and side panels 29 to the base panel 25 (i.e., to the corners where the end panels and side panels meet the base panel), to allow termites to enter the interior space 33 of the container 23 from the sides thereof, such as along a termite tunnel formed along the mounting surface M (
As best seen in
In the illustrated embodiment (as best illustrated in
It is contemplated, however, that the access closures 50 may be formed separate from and removeably connected to the container at the peripheral openings 47, such as thermal welding, adhesive or other suitable connecting technique without departing from the scope of this invention. It is also understood that in some embodiments the access closures 50 may be refastenably connected to the container 23 (such as, for example, by adhesive, hook and loop fasteners or other suitable mechanical fasteners) so that the termite station 21 can be reconfigured and reused in treating a different termite tunnel or other infestation within the scope of this invention.
In another suitable embodiment, illustrated in
One or more raised spacing elements (e.g., nubs 49 as illustrated in
Referring back to
In other embodiments, it is contemplated that the lid 31 may instead be formed separate from the rest of the container 23 and be entirely placeable on and removable from the rest of the container. It is also understood that any suitable releasable securement arrangement other than a latch and catch arrangement may be used to releasably secure the lid 31 it its closed position and remain within the scope of this invention. While in the illustrated embodiments herein the side (i.e., the end and side panels 27, 29) of the container 23 is secured to (and more suitably formed integrally with) the base panel 25, it is contemplated that the side may instead be secured to the lid 31 and hinged to the base panel 25 for positioning along with the lid between the closed and open positions thereof to provide access to the interior space 33 of the container.
A cartridge 51 is suitably sized and configured for disposition at least in part within the container 23 and more suitably entirely within the interior space 33 of the container in the closed position of the container lid 31. With particular reference to
The aggregation member 61 in one embodiment comprises an attractant, and more suitably what is referred to herein as a non-physical attractant. A “non-physical” attractant is intended to refer herein to an attractant that does not require physical contact by a termite to induce foraging. For example, in one particularly suitable embodiment the non-physical attractant comprises a wood that has been heat treated at an elevated temperature, such as at least about 150 degrees C. (302 degrees F.) and more suitably between about 150 degrees C. and 215 degrees C. (420 degrees F.).
Wood is an organic material found as the primary content of the stems of woody plants (e.g., trees and shrubs). Dry wood is composed of fibers of cellulose (from about 40 percent to about 50 percent by dry weight) and hemicelluloses (from about 20 percent to about 30 percent by dry weight) held together by lignin (from about 25 percent to about 30 percent by dry weight). Wood also contains extractives, which are compounds that can be extracted using various solvents and are often less than 500 grams/mole in molecular weight. In general, these extractives constitute from about two percent to about eight percent (dry weight) of the wood components.
Cellulose is the most abundant component in wood and plays a major role in giving wood its mechanical strength. A molecule of cellulose consists of β-D-glucose units bonded with β(1→4) lingages to form a long linear chain and has a molecular weight that ranges from several thousand to many million grams/mole. The molecular chains in cellulose form elementary fibrils or micelles. The micelles align with the cellulose fibrils oriented in the same direction and are tightly packed together. Cellulose elementary fibrils are then layered together in parallel with hemicelluloses and pectins in between to form microfibrils. When the microfibrils are aggregated in larger bundles and lignin impregnated within the structure, fibrils are generated, which in turn form wood fibers.
Hemicelluloses comprise from about 20 percent to about 30 percent by dry weight. Smaller than cellulose molecules, the average molecular weight of hemicelluloses range from about 10,000 grams/mole to about 30,000 grams/mole. The composition of hemicelluloses varies between hardwoods (i.e., oak, mahogany) and softwoods (i.e., pine, cedar). The hemicelluloses of hardwoods are predominantly of glucuronoxylan (from about fifteen percent to about 30 percent) and to a minor extent glucomannan (from about two percent to about five percent). The hemicelluloses of softwoods consists predominantly of galactoglucomannan (about twenty percent) and smaller amounts of arabinoglucuroxylan (from about five percent to about ten percent).
Pectins and starch are also found in wood, but typically in minor amounts, less than about one percent each. Pectins resemble hemicelluloses in structure and are found in the middle lamella, primary cell wall and tori of bordered pits and also to a small extent in the fibril structure. Starch can be found in parenchyma cells serving as storage of nutrition for the living tree, and it consists of amylase and amylopectin.
Lignin is an amorphous polymer with a wide variation in configuration. Lignin is often considered to be the glue of the wood structure. The backbone of the lignin structure is based on three types of phenyl propane units: guaiacyl, syringyl, and p-hydroxyphenyl. Softwoods consist mainly of guaiacyl units and also to some extent of p-hydroxyphenyl units. In contrast, hardwood lignins consist of syringly and guaiacyl units.
When wood is dried, these chemical compounds that make up the structure of wood undergo various changes. In particular, according to one embodiment herein, the aggregation member 61 comprises wood dried at an elevated temperature of between about 150 degrees C. (302 degrees F.) and about 215 degrees C. (420 degrees F.), whereat these chemical changes are different from those produced by drying at lower temperature ranges, such as below about 150 degrees C. (302 degrees F.). In another exemplary embodiment herein, the aggregation member 61 comprises wood that is dried at an elevated temperature of between about 185 degrees C. (365 degrees F.) and about 215 degrees C. (420 degrees F.). In particular, it is believed that the heat-treated wood undergoes changes affecting the available space for air and moisture in the wood. In particular, the porosity and permeability of the wood is changed. The porosity defines the ratio of the volume fraction of void space within a solid. The permeability defines the rate of diffusion of a fluid through a porous body.
It is believed that after such treatment the porosity may increase as liquids and other compounds not strongly bound to the structure of the wood are removed with the heating of the wood, such as by evaporation. Taken alone, this change would indicate that such heat-treated wood would be more hygroscopic than untreated wood, as there is more available space within the wood. But this conclusion ignores the changes also made to the permeability of the treated wood. Permeability exists where cells and/or voids can interconnect to one another. For example, with a hardwood, intervessel pitting can create openings in membranes, allowing for improved permeability. It is believed that after such heat treatment, however, those membranes may become occluded or encrusted. Such occlusions decrease overall permeability. Moreover, the pits may also become aspirated, whereby the wood assumes a closed-cell structure that again decreases overall permeability. It is also believed that such heat treatment can cause substantial disconnection of adjacent microfibrils within the heat-treated wood. Whereas with living or non-heat treated wood, these adjacent microfibrils provide structures for transport of liquid through the wood via normal translaminar vascular flow of phloem and xylem tissue. With their detachment, a disconnection is created within the wood that impedes the flow of liquids, thereby decreasing hygroscopy (i.e., increasing hydrophobicity). It is also believed that the increased wood shrinkage that occurs at the heat treatment temperature can lead to increased detachment of adjacent xylem tissue cells and adjacent phloem tissue cells (i.e., vascular cells), thereby inhibiting liquid passage through normal pathways of tissue cells. As would be understood by one skilled in the art, these changes depend upon the starting porosity, permeability, and density of the wood, but it is believed that such changes are generally applicable to many wood species. Moreover, such heat treatment processes may cause other changes to the structure and nature of the wood not mentioned here without departing from the scope of the embodiments of the present invention.
In addition to changes in hygroscopy and hydrophobicity, wood heat-treated in this manner also includes changes associated with other chemical compounds normally bound to the cellulose materials in the wood. While not being bound to a particular theory, it is believed that as part of the heat-treatment process, the bonds normally binding these chemical compounds (e.g., volatile, semi-volatile, and naturally-extractable compounds (e.g., aromatic compounds), such as compounds derived from tannins, terpenes, and oils, among others) to the cellulose of the wood are broken, thereby allowing movement of the compounds more readily from the wood and into the area surrounding the wood (e.g., soil), as compared with conventional wood decay. As such, these chemical compounds may be extracted, or released, and more readily spread from the wood, thereby attracting termites to the wood.
Heat-treatment of wood in this manner generally proceeds as follows. First, the wood is dried to remove a substantial portion of the liquid from the wood. In one embodiment, the drying process occurs in a range from about 110 degrees C. (230 degrees F.) to about 175 degrees C. (345 degrees F.). The dried wood is then heated to and maintained at an elevated temperature, such as between about 150 degrees C. (302 degrees F.) and about 215 degrees C. (420 degrees F.), and more suitably between about 185 degrees C. (365 degrees F.) and about 215 degrees C. (420 degrees F.). It is contemplated that in other embodiments the elevated temperature at which the wood is heat-treated may exceed 215 degrees C. (420 degrees F.) as long as the temperature remains below the ignition temperature of the wood specimen to inhibit charring or burning of the treated wood. The treated wood is suitably maintained at this temperature for a time sufficient to undergo the changes described above. In one exemplary embodiment, the wood is maintained at the elevated temperature for between about two hours and about three hours. The dried wood material is then cooled by a suitable cooling method such as air cooling, liquid cooling or other know method.
In one exemplary embodiment, the dried heat-treated wood may then be partially rehydrated to increase the liquid content of the cellulose material to levels of between about one percent and about eighteen percent. In still another exemplary embodiment, the heat-treated wood may be partially rehydrated to levels of between about one percent and about ten percent. In yet another exemplary embodiment, the dried wood material may be partially rehydrated to levels of between about two percent and about ten percent. It is understood, however, that the heat-treated wood need not be partially rehydrated, such that the liquid content in the dried wood is less than about one percent, without departing from the scope of this invention.
In this experiment, samples of aspen wood heat-treated according to one suitable embodiment and conventionally-treated aspen wood were evaluated to determine Reticulitermues flavipes termite feeding preference between these wood samples.
The heat-treated wood was processed as follows. The wood was cut to a common board dimension, such as a standard 2×4 plank (i.e., cross section of about 38 millimeters (1.5 inches) by about 89 millimeters (3.5 inches)). The wood was then placed within a kiln or high temperature/pressure vessel. The temperature within the vessel was increased rapidly to about 100 degrees C. (212 degrees F.) and held until the wood uniformly reached approximately zero percent moisture content. The temperature was then steadily increased to and maintained at about 185 degrees C. (365 degrees F.) for a period of about 120 to 180 minutes. After drying, the temperature of the wood was decreased to between about 80 degrees C. (176 degrees F.) and about 90 degrees C. (194 degrees F.). A steam spray was used during the cooling period to reduce the temperature of the wood and to increase the moisture content of the wood to between two percent and about ten percent. The entire heating and cooling down process took approximately 36 hours to complete.
The conventionally-treated aspen wood was kiln dried at a temperature of about 85 degrees C. (185 degrees F.) and about 90 degrees C. (195 degrees F.) for about five to six days. After drying, the conventionally-treated aspen wood was allowed to cool to ambient.
The experiment was conducted utilizing both a choice and a no-choice laboratory bioassay. The purpose of the study was to determine the preference, based upon association and/or consumption, between the two wood samples described above. With the choice laboratory bioassay, 300 termites by weight with 20 grams (0.7 ounce) of sand at 12% moisture were added to a petri dish with an average weight across all replications of an approximately 4 gram (0.141 ounce) portion of the two types of wood located in respective opposite halves of the petri dish. The termites were placed between the portions of wood and were allowed to move to and consume the wood they preferred. After 31 days, the termites on or near each of the pieces of wood were counted. In addition, the termites were removed from the wood and the wood weighed to determine the amount consumed. This choice test was repeated seventeen times with seventeen sets of 300 termites and new wood samples.
For the no-choice bioassay, 300 termites by weight with 20 grams (0.7 ounce) of sand at 12% moisture were added to a petri dish with an average weight across all replications of an approximately 4 gram (0.141 ounce) portion of one of the wood samples. The termites were placed across from the portion of wood and were allowed to move freely within the test chamber and consume the wood. After 31 days, the termites were removed from the wood and the wood weighed to determine the amount consumed. This choice test was repeated five times with five sets of 300 termites and new wood samples for each of the two different types (heat-treated and conventionally treated) of wood samples.
With respect to consumption in the choice bioassay, the wood heat-treated at elevated temperatures realized a mean consumption rate of 19.0 milligrams per gram of termites per day (19.0 milliounces per ounce of termites per day) with a standard deviation of 2.9 over the seventeen choice tests. In contrast, the conventionally-treated wood realized a consumption rate of 15.1 milligrams per gram of termites per day (15.1 milliounces per ounce of termites per day) with a standard deviation of 5.0 over the seventeen choice tests. In the no-choice bioassay, the wood heat-treated at elevated temperatures realized a consumption rate of 42.4 milligrams per gram of termites per day (42.4 milliounces per ounce of termites per day) with a standard deviation of 1.6 over the five no-choice tests. In contrast, the conventionally-treated wood realized a consumption rate of 37.5 milligrams per gram of termites per day (37.5 milliounces per ounce of termites per day) with a standard deviation of 5.6 over the five no-choice tests. Thus, for both the choice and no-choice bioassays, the wood that was heat-treated at elevated temperatures realized greater consumption rates than the conventionally-treated wood.
Moreover, when considering association, rather than consumption, the mean number of termites over the seventeen choice bioassay tests located in the half of the petri dish including the wood that was heat-treated at elevated temperatures was 183, with a standard deviation of 34. In contrast, the mean number of termites located in the other half of the petri dish including the conventionally-treated wood was 72, with a standard deviation of 40. Of the 300 termites included in each experiment, a mean of 47 died during the experiment. This result occurred even though the wood that was heat-treated at elevated temperatures was significantly drier, having less internal moisture content, than the conventionally-treated wood. This indicates, rather unexpectedly, that the reduced moisture content of the wood heat-treated at elevated temperatures did not deter the termites from feeding on the wood and even more unexpectedly it attracted more of the termites due to the physical and/or chemical characteristics of the wood. Termites in this study demonstrated significantly greater attraction to or preference for the wood heat-treated at elevated temperatures as compared to the conventionally treated wood.
In view of the above Experiment, the increased non-physical attraction and association preference of the wood heat-treated at elevated temperatures may significantly enhance the efficacy of a termite monitoring and/or baiting station that includes such a wood. As a more particular example, the illustrated aggregation member 61 comprises a solid wood block 67 that has been heat-treated at elevated temperatures as discussed above. It is understood, though, that the heat-treated wood from which the aggregation member 61 is made may alternatively be in a mulch form, a powder form or other suitable form. The aggregation member 61 is also suitably free from toxicant. For example, the above-described heat-treated wood has no added or natural toxicants.
In other embodiments, it is contemplated that the aggregation member 61 may instead comprise a non-toxic physical attractant, i.e., an attractant that once contacted by a termite promotes further foraging by termites. Suitable examples of such physical attractants include, without limitation, paper, cardboard, wood (e.g., other than wood that has been heat-treated in as described above) and other cellulose materials. Additionally an agar matrix alone or combined with sugars (i.e., xylose, mannose, galactose) and/or purified cellulose materials may be used as the aggregation member 61 to attract termites due to its moisture content and/or feeding attractant.
The bait matrix 63 suitably comprises a non-toxic attractant and may or may not carry a toxicant for eliminating or suppressing termite infestations. As one example, the illustrated bait matrix 63 comprises a purified cellulose powder compressed into one or more tablets 69. Without toxicant added to the bait matrix 63, the bait matrix may be suitably used to monitor for the presence of termites in the area of the termite station 21. Toxicant, if added to the bait matrix 63, is suitably one or more of a delayed-action type toxicant, or an insect growth regulator, pathogen or metabolic inhibitor. One such toxic bait matrix 63 is disclosed in co-assigned U.S. Pat. No. 6,416,752 entitled “Termite Bait Composition and Method”, the entire disclosure of which is incorporated herein by reference. It is understood that other suitable known monitoring and/or toxic bait matrix materials and/or compositions may used without departing from the scope of this invention. In the illustrated embodiment, four such toxic bait matrix tablets 69 are used in the cartridge 51. However, it is contemplated that any number of bait matrices, including a single bait matrix, may be used without departing from the scope of this invention.
The illustrated cartridge holder 65 comprises a cup portion 71 configured generally as a pair of cylindrical cups 73 (e.g., each having a closed end 75, an open end 77 and a side wall 79 extending therebetween) with overlapped segments so that the cup portion defines a generally 8-shaped bait matrix pocket 81. The pocket 81 is suitably sized and configured for at least receiving, and more suitably for receiving and retaining, the bait matrix 63 therein and more suitably for receiving and retaining one or more of the illustrated circular tablets 69 therein. For example, the figure 8-shaped pocket 81 of
A plurality of projections, such as in the form of ribs 83 in the illustrated embodiment, are disposed lengthwise along the inner surface of each cup side wall 79 to extend laterally inward of the pocket 81 formed by the generally cylindrical cups 73. For example, the ribs 83 illustrated in
Still referring to
Suitable spacing structure is provided to space at least a portion of the aggregation member 61 from the base panel 25 in what is referred to herein as an operating configuration (
As best seen in
As best seen in
With reference again to
To use the termite station 21 for monitoring and/or treating against termite infestation, the lid 31 is opened and the cartridge 51 is removed from the container 23. The cartridge cover 101 (if present) is removed from the cartridge 51 to ex pose the aggregation member 61 and bait matrix tablets 69. The cartridge 51 is re-inserted, open end first, into the container 23 so that the aggregation member 61 now faces the base panel 25 and is otherwise spaced from the base panel by the standoff elements 99 (broadly, spacing structure) and the bait matrix tablets 69 are spaced from the base panel by spacing elements 49 as illustrated in
In operation, with the termite station 21 configured in its operating configuration, as termites approach the base panel 25 from outside the container 23, either from behind the base panel or from the sides of the container, they quickly enter through the openings 39 formed in the base panel or through the peripheral openings 47 formed in the end and/or side panels 27, 29 where the corresponding access panels removed. The placement and arrangement of the aggregation member 61 relative to the bait matrix 63 (i.e., nearer to the base panel 25, end panels 27 and side panels 29 than the bait matrix) results in the termites first encountering the aggregation member after entering the interior space 33 of the container. Where the aggregation member 61 is a non-physical attractant, such as the previously described heat-treated wood block 67, the termites may even be lured or drawn by the aggregation member into the termite station 21. The termites, induced by the aggregation member 61 to forage further within the container 23, ultimately discover and are induced to consume the bait matrix 63.
Where the bait matrix 63 is free from toxicant and is used instead for monitoring, the termites leave visual evidence of attacking the bait matrix, such as exploratory tunnels built by termites as they consume the bait material so that signs of termite infestation are left on the surface of the material, or mud tubing constructed across the surface of the material or into the cup portion of the cartridge holder. By adding toxicant to the bait matrix 63, foraging termites ingest the toxicant-containing bait and return portions of the bait to the nest through the pre-existing network of passageways, thereby effectively treating against the infestation.
It is expected that over time the need to replace to the cartridge 51 will arise, such as following long periods of non-infestation and exposure to environmental conditions, or following prolonged periods of infestation in which a substantial amount of the bait matrix 63 (e.g., the tablets 69 of the illustrated embodiment) is consumed. The cartridge 51 may be replaced by opening the lid 31, removing the old cartridge (e.g., as a single unit) and inserting a new one that includes a new aggregation member 61 and new tablets 69. Alternatively, if a new aggregation member 61 is not needed, just the bait matrix 63 (e.g., the tablets 69) may be replaced in the old cartridge 51 and the old cartridge reinserted back into the container 23. Because the aggregation member 61, bait matrix 63 and holder 65 are held in assembly as a single unit, the entire cartridge 51 is readily replaced without having to reach into the termite station 21, i.e., only the cup portion 71 of the holder 65 need be grasped and pulled outward to remove the cartridge from the container 23.
In use, the station 221 is at least partially received within a cavity accessible to termites, while still being accessible above ground by a user. The cavity may be a subterranean cavity, or may be a cavity within a wall or other framework of a building or other above ground structure. The cavity may be formed in the soil, or the cavity may be formed in a paving material, such as concrete or asphalt, with soil beneath the paving material. Preferably, the station 221 is substantially entirely received within the cavity such that only the top surface 226 and lid 231 are accessible from above ground. However, in some situations, the station 221 may be nearly entirely on top of the ground, such as when the cavity is very shallow.
The housing 223 is suitably formed from a durable, corrosion resistant material, as for example, an acrylic or high strength plastic. Although shown as having a generally cylindrical shape, the housing 223 may be any other suitable shape, such as a rectangular box. In one suitable configuration, the housing 223 has a maximum height of less than about 18 inches (457 mm) and maximum diameter or width of less than about 12 inches (305 mm), and more suitably the housing 223 has a maximum height of less than about 9 inches (229 mm) and maximum width of less than about 4 inches (102 mm).
The housing 223 includes at least one opening 247 passing through the side wall 229 to permit the ingress and egress of termites into and out of the interior space 233 of the housing. In the illustrated configuration, the side wall 229 has several vertical elongated openings 247 therein extending substantially the entire length of the side wall. As used herewith, vertical is used in reference to the preferred orientation of the station 221 with the top surface 226 facing in an upward direction. It is contemplated however, that other shapes and orientations for the openings may be used. For example, the openings may be horizontal elongated openings, or may be circular openings randomly placed or formed in a repeating pattern. Additionally, there may be openings in the bottom surface 225 of the housing 223 leading to the interior space 20. In an alternate version, the openings are formed only in a lower portion (e.g., the lower half) of the side wall 229 of the housing 223 such that an upper portion (e.g., the upper half) of the side wall near the top surface 226 of the housing is imperforate.
In one embodiment, as shown in
In another embodiment (not shown), the aggregation base 250 can be received directly within the cavity. In this embodiment, the housing 223 and associated lid 231 are not used. For example, when the aggregation base 250 is to be used in a more durable environment where there is little possibility that sidewalls of the cavity will collapse around the aggregation base 250, such as in paving material, the aggregation base can be placed directly into the cavity. The replaceable cartridge 251 may then be positioned in the cavity adjacent to, and preferably directly above, the aggregation base 250. A suitable cap (not shown), designs of which are known in the art, can then be placed over the cavity to secure the aggregation base 250 and cartridge 251 within the cavity. However, in the above embodiments, the aggregation base 250 is located in the cavity or housing in a substantially stationary manner so that there is minimal disturbance to the aggregation site and the termites while the cartridge 251 is being inspected, removed, and/or replaced.
In the illustrated example, the aggregation base 250 is formed in a generally cylindrical shape such that an outer surface of the aggregation base faces the interior of the side wall 229 of the housing 223 or cavity when placed in service. Other versions of the aggregation base may have different geometric shapes suitable for use depending on the cavity into which the base is received. In an embodiment of the aggregation base 250 to be received within the interior space 233 of the housing 223, the aggregation base suitably has a shape similar to the shape of the housing with a width slightly less than an inner width of the housing so that the aggregation base may be removably received in a snug fitting relationship within the housing.
As illustrated in
Referring now to
The sidewall 265 of the cartridge 251 is suitably free of openings so that the termites passing through the openings 247 in the housing 223 are directed down toward the aggregation base 250 so that the initial aggregation site is formed in the aggregation base. The open upper end 262 is suitably closed using a lid 301. Accordingly, the cartridge 251 is designed such that termites entering into and exiting the interior chamber 258 will do so through the open lower end 264. Moreover, the cartridge 251 is configured to be replaceably received within the housing 223 adjacent the aggregation base 250, such that the cartridge may be removed, inspected, and/or replaced without disturbing the aggregation base, thereby preserving any aggregation site formed by the termites in the aggregation base, such as within the void 252. In one suitable configuration, the cartridge 251 and the lid 301 are made of termite resistant material, such as plastic, but it is understood that other suitable materials can be used. For example, the cartridge and lid can be made from a transparent plastic.
The lid 301 of the cartridge 251 may have at least one opening 270 (see
Referring again to
In use, the cartridge 251 is placed on top of the aggregation base 250 which places the wood panel 267 adjacent to the aggregation base. In one suitable configuration, the wood panel 267 is formed from the same material as the aggregation base 250, such as wood or heat-treated wood. It is understood, however, that the wood panel and aggregation base can be formed from different materials without departing from the scope of this invention. The wood panel 267 provides a termite edible material that attracts the termites from the aggregation site within the void 252 in the aggregation base 250 upward to the interior chamber 258 of the cartridge 251 and into close proximity to the bait matrix 263. It is understood that the cartridge 251 can be used with other types of termite stations including above-ground stations, e.g., the above-ground station 21 of
In operation, a cavity of appropriate dimensions can be made in the soil for positioning of the station 221 therein. Typically, the aggregation base 250 and the cartridge 251 are placed inside the housing 223, and the housing 223 is then inserted or pressed into the cavity until the top surface 226 of the housing is near the soil surface. Alternatively, the aggregation base 250 can be placed directly into the cavity and the cartridge 251 then placed into the cavity adjacent the aggregation base. As termites approach the outside of the housing 223, they pass through the openings 247 in the housing and move inside to find the aggregation base 250, which is a potential food source. If the termites enter through the openings 247 and contact the cartridge 251 above the aggregation base 250, the imperforate sidewall 265 of the cartridge directs the termites down along the elongate openings to the aggregation base 250. The channels 254 in the aggregation base 250 encourage the termites to enter the aggregation base and begin to use the internal void 252 created by the base as an aggregation site. The void 252 creates a stopping area in the center for aggregation. Once inside the void 252, the termites will move toward the top of the aggregation base 250 and into the cartridge 251. The termites pass into the interior chamber 258 of the cartridge 251 through openings defined by the spacing between the spokes 267b of the wood panel 267 or by eating through the wood panel.
The station 221 can be inspected periodically for evidence of termite infestation by visually examining the cartridge 251 for signs of infestation. Inspection of the station 221 can be performed weekly, bi-weekly, monthly, etc. as needed or desired. An inspection is performed by removing the lid 231 and visually inspecting the cartridge 251 and/or the aggregation base 250 for termite attack. Because of the nature of termite attack against a cellulosic material, such as the bait matrix 263, visible signs or evidence of such attack will invariably be left on the monitors. This evidence can include, for example, exploratory tunnels built by termites as they consume the material in such a way that telltale signs of termite infestation are left on the surface of the material and/or mud tubing constructed over and across the interior surface of the housing 223 or cartridge 251. Such signs of infestation would be obvious to anyone skilled in the art of termite damage detection. If termite attack is discovered, the station 221 is baited by replacing the cartridge 251 with a non-toxic bait matrix 263 with a cartridge having a toxic bait matrix therein. If no termite attack is discovered, the cartridge 251 having a non-toxic bait matrix is returned to the housing 223. The lid 231 is replaced and the station 221 is inspected again after the appropriate interval.
Termites consuming the aggregation base 250 will discover and transition to feeding upon the nearby wood panel 267 and then onto the bait matrix 263 in the cartridge 251. This can be for one or more reasons. If the bait matrix 263 is of a consistency more preferred by termites than the aggregation base 250 and/or wood panel 267, then termites may cease consuming the aggregation base and/or wood panel and transition to consuming the bait matrix 263 before the entire aggregation base and/or wood panel is consumed. If termites continue to consume the aggregation base 250 and/or the wood panel 267, the termites will still transition in the normal process of termite foraging to consuming the bait matrix 263 when the aggregation base 250 and/or wood panel 267 is entirely consumed. The termites may also consume the aggregation base 250, wood panel 267, and bait matrix 263 simultaneously. Because the bait matrix 263 is near the aggregation base 250 and wood panel 267 and is of a nature preferably consumed by termites, the termites invariably consume the bait matrix.
Once termites have been discovered attacking the station 221, the station is baited with the bait matrix 263 containing a toxicant. That is, the cartridge 251 having the non-toxic bait matrix 263 is removed and replaced with a cartridge having a bait matrix with toxicant therein. The toxicant-containing bait matrix 263 can be in the form of purified cellulose toxicant delivery tablets. One suitable termite bait composition is described in co-assigned U.S. Pat. No. 6,416,752 entitled “Termite Bait Composition and Method”, the disclosure of which is incorporated herein in its entirety by reference. The toxicant in the bait matrix 263 is preferably of the delayed-action type, or an insect growth regulator, pathogen or metabolic inhibitor. Preferably, it comprises a nontoxic bait composition to which the pesticide toxicant is added. Any suitable termite pesticide composition may be used in connection with the present invention.
The removal, inspection and/or replacement of the cartridge 251 within the housing 223 does not substantially disturb the pre-existing network of access galleries or passageways previously established between the termite colony or nest and the aggregation site in the aggregation base 250 since the aggregation base is not displaced during removal and substitution of the cartridge. Thus, the disturbance of the aggregation site in the aggregation base 250 is minimized thereby reducing the likelihood that the termites will abandon the feeding site (i.e., the station 221). Also, communication and access between the toxicant containing cartridge 251 and the termite colony is quickly reestablished upon substitution of a cartridge with a non-toxic bait matrix 263 with a cartridge having a toxic bait matrix. Foraging termites ingest the toxicant-containing bait matrix 263 and also return portions of the toxic bait to the nest through the pre-existing network of passageways.
The station 221 is inspected at regular intervals (e.g., every 15 to 120 days) to assess the extent of termite consumption of the bait matrix 263. When the bait matrix 263 in the cartridge 251 has been substantially consumed, more bait can be added by removing the lid 301 and inserting more bait into the cartridge or, more preferably, simply by replacing the cartridge with a new baited cartridge. Thus, during normal inspection and/or replacement of cartridge 251, the aggregation base 250 is not removed and disturbance to the aggregation site is minimized. It may be necessary to periodically replace the aggregation base 250 (e.g., once a year to freshen up the aggregation base). “Freshening up” the aggregation base 250, however, is not usually done while termites are actively feeding from the site.
When introducing elements of the present invention or the embodiment(s) thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
As various changes could be made in the above products and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/979,761 filed Oct. 12, 2007, the entirety of which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 60979761 | Oct 2007 | US |
