Abstract:
A trap for attracting and killing insects utilizing carbon dioxide as the attractant. The carbon dioxide is either generated, or dispersed directly into, a trapping media. This supply of carbon dioxide bubbles through the trapping media to the surface where it diffuses into the atmosphere. Subsequently, the insects are attracted directly to the trapping media, the site of the attractant&#39;s emission, where the insect subsequently lands. The trapping media then effectuates the demise of the insect by drowning the insect or by permanently affixing the insect to the trapping media.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an insect-trapping device using carbon dioxide as the main attractant to draw insects into a trapping liquid. The insect trap specifically focuses on, but is not limited to, the attraction and containment of mosquitoes. 
     BACKGROUND OF THE INVENTION 
     The push for “environmentally friendly” insect traps correlates with the public&#39;s increased awareness of the health and environmental effects of insecticide use. The basic principle is to attract an insect to the trap where the insect is subsequently contained or destroyed. Such traps include the electrified UV lamp (where an insect is drawn toward the lamp where it is electrified) and the “lobster pot” trap (where an insect is drawn into a container which is difficult, by design, for the insect to escape). Most variances in these “environmentally friendly” insect traps regard a modification in either the attractant or the trapping mechanism used. 
     Attractants vary in effectiveness and in their specificity to certain insects. The attractant most used is color. Different insects are attracted to different colors. Flies have been found to be attracted to a yellow to yellow-green hue, while mosquitoes have an affinity to a white hue. By modifying the color of the container used for the trapping mechanism, a specificity may be obtained for a certain insect. 
     Another productive attractant is the use of odor. Odiferous attractants usually mimic those smells associated with an insect&#39;s feeding or reproductive cycle. Therefore, such stimuli prove to be highly effective. One such odor-emitting trap exhausts an odiferous mixture resembling the decomposition of matter from within its container. Although effective, the odor emitted from such traps is often repugnant to humans making them ill suited for certain applications. 
     Other insects are naturally attracted to odors which are non-offensive to humans. Mosquitoes, for instance, are attracted to carbon dioxide. This non-offensive gas is emitted from the human body, as well as other natural sources. Some prior art traps are designed utilizing this attractant. One trap utilizes a separate carbon dioxide source to naturally lure insects into the container of the trap. Once inside the container, the insect is trapped by the container&#39;s design. Subsequently, the insect flies until exhausted from trying to escape the confines of the container, whereby the insect finally succumbs falling into the entrapping liquid. 
     SUMMARY OF THE INVENTION 
     The present invention uses a means for attracting an insect directly to the entrapping liquid, whereby the insect breaks the surface layer of the liquid, due to the treatment of the liquid with a surfactant, and subsequently drowns. The present invention does not rely heavily on the design of the containment vessel in trapping the insects. Rather, the present invention relies on the properties of the entrapping liquid, itself, in combination with emitting the attractant from the liquid surface, as by bubbling the attractant into the liquid or generating it within the liquid. Thus, this method of direct attraction embodied in the present invention allows for a less confining container. 
     The principle objective of the invention is to draw the insect immediately to the entrapping liquid where the insect meets its demise directly, either through drowning or adhesion. This objective is possible because the carbon dioxide attractant is dispensed through or generated within the entrapping liquid. Thus, the carbon dioxide is released into the atmosphere at the surface level of the entrapping liquid. Preferably, the carbon dioxide is dispersed within the liquid so that numerous small bubbles are emitted over the surface area of the liquid. Therefore, when the insect is drawn to the source of the carbon dioxide, the insect will seek out the entrapping liquid. There the insect will land and subsequently drown. 
     There are several methods of generating or dispensing the carbon dioxide through the entrapping liquid so as to allow for its release at the surface of the liquid. A preferred embodiment uses a chemical reaction within the entrapping liquid to generate the carbon dioxide. A further preferred embodiment uses a dispersion nozzle in connection with an exterior carbon dioxide source to dispense carbon dioxide into the entrapping liquid. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of a preferred trap for attracting and killing insects in accordance with the present invention; and 
     FIG. 2 is a schematic view of a further preferred trap for attracting and killing insects in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, wherein like reference numerals refer to like elements throughout the several views, FIG. 1 shows a schematic view of a preferred insect trap  10  in accordance with the present invention. The insect trap  10  may be used generally to attract and trap any insect. In particular, the trap  10  may be used to trap mosquitoes, flies, midges, and other flying insects. However, the trap  10  may also attract and trap terrestrial insects such as ants and spiders. A specificity to a particular insect may be achieved by modifying the physical attributes of the trap  10  itself, or by modifying the attractant used. 
     The housing of the insect trap  10  consists primarily of a container  12 . This container  12  holds the trapping media  16 . The container  12  may be made from a variety of materials. The materials chosen often reflect the application sought. Typically, the container  12  will be made from a plastic or glass material. The defining criteria for the container  12  is that it must be capable of holding a quantity of trapping media  16 . 
     The container  12  may be open-ended or closed. If the container  12  is closed, it may have small apertures in the container  12  to allow the attractant to be emitted from the openings. The apertures should also be large enough to allow the selected insect to enter the container  12 . These apertures may also be selective in allowing the insects to exit the container  12 . Therefore, the apertures may be designed for limited egress. In preferred embodiments, however, the container  12  has a large open top so that the surface of the trapping media  16  is readily accessed by insects. 
     The insect trap&#39;s container  12  may comprise a variety of colors. Altering the color of the trap allows for the attracting and trapping of specific insects. Studies indicate that certain insects are initially attracted to certain hues. For instance, the mosquito is attracted to white hues while a fly is attracted to yellow to yellowish-green hues. The use of color also aids in capturing the rays of the sun in producing indirect heat that may radiate from the insect trap. Many insects are drawn to this radiating heat because the heat is an indicator of a host organism for the insect. Thus, if the container  12  radiates heat, it may be utilized as an additional attractant in luring an insect to the trap  10 . 
     The trap container  12  may be shaped to accommodate several applications and sites for its operation. For example, the trap container  12  may be suspended off the ground by hanging, suspended off the ground by a stand, or it may be freestanding on the ground. 
     Inside the trap&#39;s container  12  is a quantity of trapping media  16 . This trapping media  16  may be a liquid, or it may be a solid. However, if the trapping media  16  is a solid, it is preferable that the solid be gas permeable and resinous. As with the trapping liquid media  16  described below, a porous solid would allow distribution of attractant in small quantities over the entire surface. A liquid trapping media  16  is usually an aqueous solution. To this liquid, a surfactant is added. The surfactant is used to lower the surface tension of the surface layer  18  of the trapping liquid  16 . Although a surfactant is preferred, any surface tension lowering chemical may be added to achieve the desired effect. The use of the surfactant allows the insect to break through the hydrogen-bonded surface layer  18 . Without the surfactant, the insect is free to move along the liquid media&#39;s surface  18 . Once the insect breaks through the surface layer  18 , it drowns because it is unable to stabilize itself upon the broken surface of the trapping liquid  16 . Preferred surfactants include dioctyl sulfosuccinate or any non-ionic, cationic, or anionic surfactant and mixtures thereof that are environmentally and toxicologically benign. A resinous solid trapping media  16  works differently. Once the insect is drawn to the solid media  16 , it will become irreversibly attached to the media  16  when it contacts the media&#39;s surface  18 . There, the insect will die of exhaustion from trying to free itself from the resinous solid. 
     An attractant  14  draws the insects to these various trapping mediums  16 . In preferred embodiments, carbon dioxide is utilized as the attractant, bubbling up through the entrapment liquid  16 . Other attractants, whether general or insect specific, may be used in conjunction with the CO 2 , or alone. General attractants often consist of various sugars. Such sugars include fructose and sucrose, among others. Lactic acid is also an exceptional general attractant. Lactic acid may be used by itself, or in combination with other general or insect specific attractants. Studies have proven that mosquitoes are highly attracted to carbon dioxide, and for this reason it is preferred. It is also possible to use general and specific attractants in combination, affording a greater response by the intended insects. However, single usage may be preferred due to cost. 
     The attractant  14  is preferably supplied within the trapping media by one of two methods. The first method, illustrated in FIG. 1, is to generate the attractant within the trapping media  16 . The second method, illustrated in FIG. 2, is to dispense or disperse the attractant inside the trapping media  36  from an outside source  40 . The preferred attractant discussed will be carbon dioxide  14 . 
     FIG. 1 illustrates the preferred embodiment for generating carbon dioxide  14  by using an acid/base reaction within the trapping media  16 . In such a reaction, either the acid or the base should have a functional group which releases carbon dioxide  14  when the acid and base react. For this reason, a preferred acid is carboxylic acid. Other acids may also be used which include acetic acid, citric acid, and tartaric acid. These acids may be placed directly within the trapping media  16  of the insect trap  10 . Thus, in a preferred embodiment, the acid is in solution within the trapping media  16 . 
     Likewise, there are numerous bases which may be utilized to generate the desired reaction and production of carbon dioxide. The preferred base is a carbonate salt  20 . When the carbonate salt  20  reacts with an acid such as those discussed infra, carbon dioxide is released  14 . Common minerals comprising the general chemical structure of a carbonate salt  20  may also be utilized as the base component in the reaction. These common minerals include limestone, baking soda, and trona, among others. 
     The carbonate salt  20  may take numerous forms. Often, the form of the carbonate salt  20  is indicative of the type of reaction desired. For example, if one wishes the reaction to take place at the surface layer  18  of the trapping media  16 , then a powderized form is desired. The forms that the base may take shape include pelletized, tablet, and powder, among others. 
     For all forms, the carbonate salt  20  may be placed into a semi-permeable container. This container allows the carbonate salt to react freely with the surrounding trapping media  16  without allowing the solid carbonate salt  20  to egress from the container. When the trapping media  16  reacts with the carbonate salt  20 , carbon dioxide gas  14  is produced, whereby the gas escapes through the semi-permeable container and bubbles up to the surface of the trapping media  18 . Such a semi-permeable container may also be selectively buoyant. The degree of submergence of the container may be altered by using various weights. 
     If the carbonate salt  20  is in the form of a dense solid (pellet or tablet), the dense carbonate salt  20  may be added directly to a liquid trapping media  16  where the dense carbonate salt  20  should sink to the bottom of the container. There, the carbonate salt  20  reacts with the acid contained within the trapping media  16 , resulting in the steady production of carbon dioxide gas  14 , which bubbles to the surface  18 . 
     If the carbonate salt  20  is in a powder form, the powderized carbonate salt may be added directly to the surface layer of the trapping media  18 . This form allows for an optimal reaction when using a solid trapping media  16 . When the powderized carbonate salt reacts with the surface layer of the trapping media  18 , carbon dioxide  14  is produced at the surface layer  18 , whereby it elutes into the surrounding atmosphere. 
     In all of the reactions, it is preferred that the reaction not create an offensive odor to humans. By limiting the repugnancy of the odor, the applications of the trap  10  may be extended. For instance, the trap  10  may be used in close quarters with humans when the odor is non-detectable. If the reaction were to produce a repugnant odor, the applications would be limited to the outdoors and at a distance from humans. Such repugnant odors are often associated with traps  10  involving a fermentation reaction. The preferred embodiment of carbon dioxide gas production  14  does not involve a fermentation reaction. Furthermore, carbon dioxide  14  emissions are not offensive to humans, and therefore, this attractant may be utilized in both indoor and outdoor settings and in close proximity with humans. 
     FIG. 2 is a further preferred embodiment of an insect trap  30  which dispenses an attractant inside the trapping media  36  from an outside source  40 . In this embodiment, the attractant, preferably carbon dioxide  34 , is directed into the trapping media by a lumen  42  connected to the outside attractant source  40 . In one preferred embodiment, the lumen  42  is placed directly within the trapping media  36 . In this embodiment, the lumen  42  is often connected to a device which disperses the carbon dioxide gas  34 . This dispersion results in the formation of small gas bubbles  34 . Furthermore, this dispersion allows the gas bubbles  34  to be diffused along a greater surface portion within the trapping media  36  and its surface  38 . An example of such a device which disperses the carbon dioxide gas  34  is a bubbling stone  44 . This is a porous stone with a lumen running within. Such bubbling stones  44  may be in various shapes and sizes, and therefore, a stone may be selected to optimize the bubble production pattern in various container  32  shapes. For example, the bubbling stone  44  may be elongated, circular, or any other formation which creates the desired effect. 
     Another preferred embodiment for dispersing an outside attractant source is by connecting the outside source  40  to the container  32  itself. In this embodiment, the connection lumen  42  does not interact with trapping media  36  directly. Instead, the connection lumen  42  attaches to the container  32  somewhere below the surface level of the trapping media  38 . Therefore, the connection to the container  32  may be made either on the container&#39;s bottom or side. From this connection site, it may also be preferred to use a bubbling stone  44  to optimize the pattern formed by the carbon dioxide gas  34 . 
     The advantage of the dispensing mechanism embodiments is that they often do not involve a reaction of any kind within the trapping media  36 . In order to ensure unwanted side reactions which may result in odor production, inert ingredients may be used within the trapping media  36 . Therefore, these embodiments allow the insect trap  30  to be utilized in areas where humans will need to be in close proximity to the trap  30 . 
     The following are a series of experiments showing the effectiveness of both general and specific attractants in conjunction with the present invention. 
     Experiment 1 
     In a preferred embodiment of the invention, 10 grams pelletized limestone (CaCO 3 ) containing a nontoxic surfactant was introduced into a white bowl with 20 grams of citric acid (2-hodroxy-1,2,3-propanetricarboxylic acid) and 500 ml water. The surfactant used was dioctyl sulfosuccinate. CO 2  was generated by the combination and visibly evident as bubbles emanating from the liquid surface. The bowl was placed outdoors overnight next to a control (a white bowl containing 500 ml water). The following morning the bowls were retrieved and the number of drowned mosquitoes were counted. The results were: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 The preferred embodiment: 
                 75 mosquitoes 
               
               
                   
                 Control: 
                  2 mosquitoes 
               
               
                   
                   
               
             
          
         
       
     
     Experiment 2 
     5 grams of lactic acid (CH 3 CH(OH)COOH) was added to the preferred embodiment in Experiment 1. The preferred embodiment was set alongside a control as described in Experiment 1. After five minutes the bowls were retrieved, and the number of drowned mosquitoes were counted. The results were: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 The preferred embodiment: 
                 5 mosquitoes 
               
               
                   
                 Control: 
                 0 mosquitoes 
               
               
                   
                   
               
             
          
         
       
     
     Numerous characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many aspects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention. The invention&#39;s scope is defined, of course, in the language in which the appended claims are expressed.