Abstract:
Apparatus, for detecting the presence and eating activity of organisms such as termites that damage structures, includes a body; a wooden bait element controllably exposed to the organisms within a cavity of the body, and having an applied bait substance; a side wall of the body having a vertically spaced plurality of smoothly converging entrance passages for admitting the organisms, a consumable porous barrier covering each of the entrance passages. Spring tension is applied to an upper end of the bait element, an opposite end being anchored to the body. A flag member that is connected to the upper end of the bait element projects from the body when the bait element is weakened to the predetermined amount by the organisms.

Description:
BACKGROUND 
     The present invention relates to pest control, and more particularly to monitoring termite activity proximate and especially under building structures. 
     Termite infestation and damage is a continuing problem in buildings having wood structure. Traditionally, the structures are inspected only infrequently, such as in connection with a sale, at which time considerable damage may have been done, with expensive repairs being required. Termite infestation and damage is generally not readily apparent, and partial dismantling of building structures in order to locate possible infestation has to be weighed against the damage done by such dismantling and the cost of restoration. Even professional inspections are not always effective with respect to inaccessible structure. 
     Accordingly, various non-invasive devices have been developed for detecting termite activity, such devices being implanted in the ground around and/or under homes or other building structures. For example, U.S. Pat. No. 5,329,726 to Thorne et al. and U.S. Pat. No. 5,901,496 to Woodruff disclose ground-implantable devices for detecting termite activity, the devices having a perforate outer housing for permanent ground implantation, and a removable perforate cartridge having bait therein. The cartridge is removed and visually inspected for detection of termite activity. These devices of the prior art exhibit a number of disadvantages; for example:
         1. They are ineffective in that active termite infestations may be ignored because:
           a. the unit does not get proper inspections;   b. the original placement of the unit is difficult to determine;   c. an aggressive termite colony was not identified early; and   
           2. They are difficult to install and monitor, especially when implanted in crawl space under structures.       

     Thus there is a need for a device that facilitates detection and monitoring of infestation of soil environments of building structures by destructive organisms, that is both effective and easy to use, and that is inexpensive to provide. 
     SUMMARY 
     The present invention meets this need by providing a monitoring device having a direct indication of a predetermined amount of cumulative destructive activity of invasive organisms such as termites. In one aspect of the invention, an apparatus for signaling a cumulative amount of weakening of a test material resulting from exposure to a hazardous environment includes a body; a test element supported relative to the body and comprising the test material; means for controllably exposing the test element to the hazardous environment; means for applying a load force to the test element, the load force being effective for displacing a portion of the test element when there is a predetermined amount of weakening of the test element; a flag member movably supported relative to the body and coupled to the test element for movement in projecting relation to the body when the test element is weakened to the predetermined amount. The means for controllably exposing can include the body having a cavity for enclosing the test element, a side wall of the body having an opening therein for communicating with the hazardous environment. As used herein “hazardous environment” means an environment that may be deleterious to the strength of a structural material. 
     In another aspect of the invention, an apparatus for detecting the presence and eating activity of organisms that damage structures by consuming portions thereof includes the body; a bait element supported relative to the body and comprising a consumable structural material; means for controllably exposing the bait element to the organisms; means for applying a load force to the bait element, the load force being effective for displacing a portion of the bait element when there is a predetermined amount of weakening of the bait element; a flag member movably supported relative to the body and coupled to the bait element for movement in projecting relation to the body when the bait element is weakened to the predetermined amount by the organisms. 
     The exposing means can include the body having a cavity for enclosing the bait element, a side wall of the body having an entrance passage formed therein for admitting the organisms. Preferably the exposing means further includes a barrier member covering the entrance passage and being formed of a sheet of consumable porous material for excluding foreign material from the entrance passage. The consumable material of the barrier member is preferably perforated for enhanced communication of bait odor out of and of the organisms into the entrance passage. The barrier member can also act as an attractant, being selected, for example, from the group consisting of balsa wood, pine, and cardboard. Preferably the body has an outer portion to which the sheet of consumable porous material is connected and a telescopically separable core portion that supports the bait element and the flag member for facilitating removal and inspection of the bait element without disturbing the outer body and the sheet of porous material. 
     The entrance passage can extend between a first opening in an outside surface of the side wall and a second opening in an inside surface of the side wall, the first opening having a first area, the second opening having a second area being preferably less than the first area, the passage smoothly tapering between the first area and the second area for concentrating eating activity at a specific location along the bait element. The body can form an elongate housing having respective bottom and top extremities, the entrance passage being preferably one of a vertically spaced plurality of entrance passages for exposure to organisms at plural depths within the hazardous environment, a consumable porous barrier member covering each of the entrance passages. The entrance passages and the barrier member can be on a first fade of the body, the body preferably including a second face having counterparts of the entrance passages and the barrier member for exposing the bait element to organisms approaching from different directions. 
     The means for applying a load force can include a first coupling for anchoring one end to the bait element to the body, a second coupling for connecting an opposite end of the bait element, and a spring for applying tensile load to the bait element through the second coupling. The flag member can be connected to the second coupling. The bait element can be a word member having a bait substance applied thereto. 
     In a further aspect of the invention, a method for monitoring a predetermined cumulative eating activity of organisms on a bait member includes:
         (a) providing a housing body having an elongate cavity and a side wall passage;   (b) anchoring one end of the bait member to the body with the bait member extending within the cavity;   (c) connecting a flag member to an opposite end of the bait member with the flag member extending to proximate a flag opening of the body;   (d) connecting a spring member between the flag member and the housing body for tensioning the bait member;   (e) placing the housing body in a medium subject to infestation by the organisms with the side wall passage being accessible by the organisms and the flag opening being located outside the medium; and   (f) periodically observing the housing body for display to the flag member in an extended position thereof.       

     The method can further include interposing a consumable porous barrier between the medium and the side wall passage for preventing the medium from contacting the bait member. 
    
    
     
       DRAWING 
       These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where: 
       FIG. 1 is a side view of a termite monitoring apparatus according to the present invention; 
       FIG. 2 is a top view of the apparatus of FIG. 1; 
       FIG. 3 is a lateral sectional view on line  3 — 3  of FIG. 1; and 
       FIG. 4 is a plan sectional view on line  4 — 4  of FIG. 1. 
     
    
    
     DESCRIPTION 
     The present invention is directed to a device and method for detecting and monitoring the activity of invasive destructive organisms such as termites. With reference to FIGS. 1-4 of the drawings, a monitoring apparatus  10  includes a generally cylindrical housing body  12  having an elongate main cavity  14  for receiving a test element  16 , a plurality of entrance passages  18  being formed in one or more side walls  20  of the body  12  for admitting the organisms (not shown). The test element  16  is typically in the form of a cardboard strip or rod, wooden rod or dowel, which can be impregnated or coated with a suitable attractant such as phermone, the element  16  thus also being sometimes referred to herein as a bait element. A stop member  22  is attached at a bottom extremity of the bait element  16  for anchoring engagement proximate a lower extremity of the main cavity  14 . Also, a flag member  24  is connected to a top extremity of the bait element  16  by a flag fitting  26 , the flag member  24  being axially movable from a first position as shown by solid lines to a second position as shown by broken lines in FIG. 3. The flag member  24  extends within a flag cavity  28  that forms an enlargement of the main cavity  14 , the cavity  28  extending to the top of the housing body  12 . An upper portion of the flag cavity  28  is enlarged, forming a spring cavity  30  for accommodating a stop ring  32  that projects laterally from the flag member, and a compression spring  34  that is interposed between the stop ring and a bottom extremity of the spring cavity  30  for biasing the flag member toward the second position thereof, the stop ring  32  abutting a main cap  54  (further described below) that forms an upper extremity of the spring cavity  30  in the second position of the flag member  24 . Thus, when a predetermined amount of weakening of the test element  16  occurs, the element fractures in tension, whereupon the flag member  24  snaps to the second position thereof in projecting relation to the housing body  12 , being viewable from a distance as a direct indication of the corresponding cumulative consumption of the element  16 . 
     The stop member  22  and the flag fitting  26  can be attached to the test element  16  by any suitable means, such as by an adhesive, and/or by a coupling pin (not shown) that projects laterally through the element  16  and opposite walls of the stop member (and the flag fitting). As shown in FIG. 3, the stop member  22  is retained against upward movement by an anchor ledge  36  that projects inwardly within the main cavity  14  of the body  12 . 
     A preferred configuration of the entrance passages  18  has each passage formed with a large outwardly facing first opening  38  and a much smaller second opening  40  into the main cavity  14 , the passage  18  being smoothly inwardly tapered from a first area corresponding to the first opening  38  to a second area corresponding to the second opening  40  for focusing invasive activity at a particular location along the test element  16 . 
     A principal feature of the present invention is that each entrance passage  18  is covered by a porous barrier member  42  that is easily consumed by invasive organisms seeking access to the bait element  16  after the apparatus  10  is imbedded in soil that may contain the organisms. Thus the first openings  38  of the entrance passages  18  can be quite large without being blocked by pebbles or clods of the soil. More particularly, it is expected that the invading organisms will not entirely consume the portions of the barrier member  42  that cover the first openings  38 , the barrier member being at least partially effective in excluding the soil particles from the entrance passages  18 . Further, the soil particles that do get in the passages are likely to fall below the second openings  40  without blocking them. Moreover, the enhanced area of the first openings  38  serves to enable the passage of gaseous attractant matter through the porous barrier member  42  at a rate at least as great as that permitted by the smaller area of the second openings  40 . As shown in FIG. 1, each of the first openings  38  can have a rounded rectangular of other non-circular shape for more fully utilizing the area of the side walls  20  of the body  12 . Further, the barrier members are preferably perforated as indicated at  43  for enhanced communication of gaseous attractant into the soil, and for facilitating entry of termites or other invasive organisms. As best shown in FIG. 4, the barrier members  42  are retained in respective side walls  20  of the body  12  by pairs of flange portions  44 , the barrier members being inserted (or removed for replacement) from the top of the body  12 . 
     A drain opening  46  is provided at the bottom of the main cavity  14  as shown in FIG. 3 for draining moisture that might otherwise accumulate therein, the opening  46  being recessed above a bottom extremity of the housing body  12  for spacing soil therefrom when the apparatus  10  is in use. Moisture released into the soil from the opening  46  creates an environment that is attractive to termites. As shown in FIG. 4, at least a lower portion of the main cavity  12    14  optionally extends laterally as indicated at  12 ′   14 ′ by a sufficient distance from the anchor ledge  36  for allowing the test element having the stop member  22  thereon to be lowered through the flag cavity  28  into the main cavity  14 , and moved laterally into engagement with the anchor ledge  36 , the anchor ledge  36  being open toward the enlarged cavity portion  12 ′   14 ′. 
     Preferably the second openings  40  of the entrance passages  18  in respective side walls  20  of the body  12  are at corresponding locations along the test element  16  for further concentrating invasive activity at those locations, thereby further accelerating fracture of the test element  16  to more effectively and repeatably indicate a degree of infestation as the predetermined weakening of the test element  16 . 
     The apparatus  10  also includes a skirt member  48  for facilitating imbedded placement of the housing body  12  vertically oriented and at a desired depth in soil. The skirt member also collects condensation, which typically occurs between the soil and the skirt-member. The skirt member  48  is generally circular, having an outwardly and downwardly extending main portion  49  for directing the condensation away from the housing body  12 , and a downwardly projecting flange portion  50  for imparting stiffness to the skirt member, which is also formed with a central opening for passage of an upper portion of the housing body  12 . The outwardly directed condensation advantageously creates an enlarged moisture barrier around the housing  12 , thereby enhancing the attraction of termite activity to the monitor apparatus  10 . 
     The body  12  is formed with an outwardly projecting skirt lip  52  which rests on the skirt member  48 , the skirt member resting on the ground and being retained on the body  12  against the lip  52  by the weight of the body  12  and the other components of the apparatus  10 . A main cap  54  covers the top of the body  12  and the barrier members  42  for shedding moisture that might fall on the apparatus  10 , the main cap  54  having a central opening  55  for exposing the flag cavity  28 , the flag member  24  extending partway through the opening  55  in the first position thereof. The main cap is upwardly convex for enhancing the shedding of moisture, and for smoothly deflecting passing objects such as lawnmowers and the like that may be used in the vicinity of the apparatus  10 . The flag member  24  is exposed by extending through the main opening  55  in the second position thereof, upward movement of the flag member being limited by the stop ring  32  contacting the underside of the main cap  55 . In the exemplary configuration of the apparatus  10  as shown in the drawings, the housing body  12  is generally triangular in cross-section. Of course, there can be other numbers of the side walls  20 , with square and other polygonal cross-sectional shapes being contemplated. 
     Preferably the housing body  12  is separable, including a core portion  12 ′ that holds the test element  16  together with the flag member  24  and its associated hardware, the designation  12  pertaining to an outer body portion having the flange portions  44  and the lip  52  formed thereon. As shown in FIGS. 3 and 4, the first openings  38  are formed in the core portion  12 ′. Also, a bail member  56  is pivotally connected at the top of the core portion  12 ′ for facilitating removal thereof axially from the top of the body  12  when the main cap  54  is removed, the cap  54  having snap-engagement with a cap lip  58  that is spaced above the skirt lip  52  on the outer body  12 . Thus the core portion  12 ′ can be removed from the main body portion  12  and inspected without disturbing either the body  12  or the barrier members  42  that are retained thereby. As further shown in FIG. 4, the enlarged cavity potion  14 ′ can extend through a side wall  20 ′ of the core portion  12 ′, the side wall  20 ′ not having the vertically spaced entrance passages  18  formed therein. However, the main body portion  12  is provided with counterparts of the flange portions  44  and the barrier member  42  facing the side wall  20 ′. In the alternative of the housing body  12  having the core portion  12 ′ being integrally formed, the enlarged cavity portion  14 ′ can be open to the outside, being covered by one of the barrier members  42 . 
     Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, The housing body  12  can have a generally circular cross-section, a single tubular member being substituted for the barrier members  42 . Also, the stop member  22  can be configured for snap-engagement with the anchor ledge  36 , the body  12  being formed without the enlarged cavity portion  14 ′. Therefore, the spirit and scope of the appended claims should not necessarily be limited to the description of the preferred versions contained herein.