GB2148686A - Device for capturing cockroaches - Google Patents

Abstract

Two types of cockroach trap are provided. One type comprises a bottom plate having an adhesive layer formed on the inner surface; a pair of side plates (3) connected to both lateral sides of said bottom plate; and a pair of end plates (4) connected to both end sides of said bottom plate, each of said side and end plates having a plurality of openings (9) which are longer in the direction normal to the bottom plate than in the direction parallel thereto. The other type is substantially the same as the first type except that an end plate (33) is connected to only one end of the bottom plate (27) and that each of said side plates consists of a wide portion (30) which is positioned close to the side where said end plate is provided and a narrow portion (28) which is positioned close to the other end where no end plate is provided. <IMAGE>

Description

SPECIFICATION Deviceforcapturing cockroaches The present invention relates to a device that capture cockroaches by stickiness whetherthey are within an open space or in a small concealed area.

A conventional device for capturing cockroaches by stickiness comprises a box-like memberwhich has a layer of adhesive agent applied to the inner surface of the bottom, an attractant provided in the center ofthe adhesive layer, and openings provided in the surrounding box walls. A cockroach entering the box through an opening is captured bythe sticky adhesive agent and is unable to escape from the box.

Conventionally, three types of openings are provided in the side walls of the cockroach trap. The first type is a generally rectangular opening which is longer in the direction parallel to the bottom member than in the direction normal thereto. The second type is in the form of an inverted triangle. The third type is an opening which is directly connected to the bottom member.

Thefirsttype of opening is so large that the user can seethe insideofthetrap and has an unpleasantfeeling after cockroaches are captured. Furthermore, dirt and dustwhich easily get into the trap through the opening adhere to the adhesive layer and accelerate the deterioration ofthe adhesive agent. The effective ingredients ofthe attractant evaporate quickly through theopening.Asanother disadvantage, the large opening permits easy access of the tentacles of a cockroach into the inside of the trap, so the cockroach easily senses the danger ofthe adhesive agent and hastily gets away from the trap.

The second type of opening also permits easy access ofthe tentacles of a cockroach into the inside of thetrapand impairs its performance bythesame reason as shown above in connection with the first type of opening.

With the third type ofopening, the adhesive layer is directly exposed to the floor on which the trap is installed, so the adhesive agent is easily sensed by a cockroach. If a large cockroach is captured by the forelegs, it will pull the device by its hind legs or escapes from the device, leaving the forelegs behind.

In orderto solve the problems with the conventional device for capturing cockroaches by stickiness, the present inventors made various studies on the be haviourofcockroaches and obtained the following observations. Being lured by the attractant in the trap, the cockroach comes close to an opening in the trap and senses firstthe exterior, then the interior of the opening bythetentacles. lfthe tentacles touches the adhesive layer, it will not enterthe device by sensing its potential danger. With the conventional device for capturing cockroaches by stickiness, it often occurs that only legs of adults or old instars of Periplaneta fulginosa Servitle are captured by the adhesive layer.

Cockroaches can easily enter a small gap (ca 5 mm) which extends vertically. They often go in and out of otherforms of small gaps.

Another defect ofthe conventional box-shaped device for capturing cockroaches by stickiness is that its height prevents installation in the gap between the floor and a refrigerator orfurniture such as a cupboard. In orderto capture cockroaches living in such gaps, three types of device have been proposed.

First type of the device consists of a thin flat sheet coated with an adhesive agent. The second type is similarto the first type exceptthatthe thin flat sheet is provided with a curved piano wire as a fixing means.

The third type is in the form of a box shape having a top sheet spaced by a small distance from the bottom member. These three types of the capturing device are sufficiently low in height to be installed within small confined areas.

However, the first type ofthe device which is in the form of a flat sheet is vulnerable to external bending or twisting forces. Furthermore, the adhesive layer is not properly protected from environments, so the device cannot be freely pushed into or pulled out of the target area without causing the adhesive layerto stickto the bottom offurniture. The stuck adhesive layer cannot be easily detached from the bottom ofthe furniture without deforming the device. The flat sheet coated with an adhesive layer is so light in weight that is slips easily by a small force. A large cockroach which is captured by only the forelegs will use its strong hind legs to drag the trap to a place which is not best fitted to the purpose of capturing cockroaches.While the cockroach is dragging the trap, the adhesive layer may sometimes foul the wall ofthefurniture. Furthermore, the device which is in the form of a flat sheet is difficult to pull out ofthe gap between the floor and the furniture by hand. The only part ofthe device that can beheld bythefingers istheadhesive layertowhich cockroaches are stuck, but this is not recommendable from a sanitary viewpoint.

The second type of the cockroach trap effectively uses the piano wire to fix the device securely in the predetermined area of installation. However, as in the case ofthe firsttype of device, the adhesive layer may foul the wall ofthe furniture and the device can be removed from thetargetarea by only holding the filthy part where cockroaches have got stuck.

The third type of the capturing device has such a small space between the top and bottom members that cockroaches have much difficulty to enter the device. It is also difficultforthe userto check visually whether cockroaches have been captured in trap.

Furthermore, this type of device which is in a box shape having both top and bottom sheets requires a materials cost at leasttwicethat necessary for making the first and second types of device.

The three types of cockroach trap shown above have one common problem: they are basically intended for use in small gaps and cannot be used satisfactorily in an open space including a large floor.

Therefore, one object of the present invention isto provide a sanitary device for capturing cockroaches by stickiness that exhibits a high capturing efficiency and which retains the effectiveness of an adhesive agentandanattractantfora prolonged period.

Another object of the present invention is to provide a sanitary device for capturing cockroaches by stickiness that can be used not only in an open space but also in a small concealed area without being bent or twisted by external forces and without causing contamination by the adhesive agent.

According to one aspect ofthe invention, a device for capturing cockroaches is provided, which comprises a bottom plate having a layer an adhesive agent formed on the inner surface for capturing cockroaches; a pairof leteral side plates connected to the lateral sides of said bottom plate, each of said lateral side plates having aflap along its lateral side and having at least one opening which provides a passage for cockroaches to enter the device and which is longer in the direction normal to the lateral sides ofthe bottom platethan in the direction parallel thereto; and a pair of end plates connected to the end sides of said bottom plate, each of said end plates having a link member on its end portions that engages said flaps and having at least one opening which provides a passage for cockroaches to enterthe device and which is longer in the direction normal to the ends of the bottom platethan in the direction parallel thereto, said device being constructed by folding said lateral side plates and said end plates at the lateral sides and ends of said bottom plate, connecting said flaps, and engaging the same with said link members atthe ends thereof.

According to another aspect ofthe invention, a device forcapturing cockroaches is provided, which comprises a bottom plate having a layer of an adhesive agent formed on the inner surface for capturing cockroaches; and a pair of side plates connected to the lateral sides of said bottom plate, each of said side plates extending to one end of said bottom plate and consisting of a wide portion having a flap at its lateral side and a narrow portion which is connected to the end of said wide portion and extending to the other end of said bottom plate, said device being constructed by folding said side plates at the lateral sides of said bottom plate and engaging said flaps with each other or bonding the same to each other.

Fig. lisa plan view ofthe blankfrom which a device for capturing cockroaches is made according to the first aspect ofthe present invention.

Fig. 2 is a perspective view of the device in its completed form.

Fig. 3 is an illustration showing the shape and size of an opening made in the device ofthe present invention.

Fig. 4 is an illustration showing how cockroaches are captured by the device ofthe present invention.

Figs. 5 to 8 are illustrations showing different embodiments of the opening made in the device of the present invention.

Fig. 9 is a plan viewofthe blank from which a device for capturing cockroaches is made according to a modified embodiment of the first aspect ofthe present invention.

Fig. loins a perspective view ofthe device in its completed form.

Fig. 11 is a plan view ofthe blankfrom which a device for capturing cockroaches is made according to the second aspect of the present invention.

Fig. 12 is a perspective view ofthe device in its completedforra.

Fig. 13 is an illustration showing how the device of Fig. 12 is installed forcapturing cockroaches.

Figs. 14 to 18 are perspective views showing different embodiments ofthe device according to the second aspect ofthe present invention.

Various embodiments of the present invention according to its first aspect are shown below. Fig. lisa plan view of the blankfor making a device for capturing cockroaches. Fig. 2 is a perspective view of the device in its completed form.The blank generally indicated at 1 is made of any material such as plastics, metals or paper. It consists of a rectangular bottom plate 2, side plates 3,3 connected to both lateral sides of said bottom plate, and end plates 4, 4which are connected to both ends of said bottom plate. Each side plate 3 is inclined on both ends and has a flap 5formed on the lateral side. Both ends of each flap 5 are spaced from the lateral side of the side plate 3 to form a gap6 therebetween.

Each end plate 4 is inclined on both lateral sides and has a link member7 connected at its end portion. The link member 7 has a slit 8 open to its end portion.

Each side plate 3 is provided with at least one opening 9 which is longer in the direction normal to the lateral side ofthe bottom plate 2 than in the direction parallel thereto. Each end plate 4 is also provided with at least one opening 9 which is longer in the direction normal to the end portion ofthe bottom plate 2than in the other direction. A layer of adhesive agent 10 isformed on the innersurface ofthe bottom plate 2. The adhesive layer 10 is preferably covered withthe peelable paper which is peeled before use, when an attractant 11 is put in the center of the adhesive layer.

The side plates 3 and end plates 4 are folded respectively at the lateral sides and end portions of the bottom plate 2. The two side plates 3,3 are brought into contact with each other and the opposing faces of the flaps 5,5 are puttogether and the slits 8 in the link members 7 are brought into engagementwith the gaps 6, thereby constructing a device for capturing cockroaches by stickiness, which has the adhesive layerformed on the inner surface ofthe bottom plate 2 and has openings 9 made in the surrounding walls.

As shown in Fig. 3, each opening 9 made in the side plate 3 is in the form an elongated rectangle having the following dimensions: the length Ii of the axis 9b normal to the axis 9a that bisects the opening in the longitudinal direction is preferably not less than 5 mm but not more than 12 mm; the longitudinal axis 9a is inclined with respect to the line 3a (atwhich the side plate 3 is folded) at an angle e1 which is preferably in the range of 300 to 1500, typically 900 as in Fig. 3; the length 12 ofthe longitudinal axis 9a is preferably at least 1 times the length 11 of the transverse axis 9b; and the opening 9 is spaced from the fold iine3a by a distance of 5 mm or more.

The opening 9 may assume other configurations.

For example, the opening may be inclined in such a manner that the longitudinal axis 9a forms an angle 31 of 30" two 1 50" with the fold line 3a, as shown in Fig. 5.

The short sides 9', 9' of the opening need not be parallel tothefold line 3a and may assume such shapes as shown in Figs. 6 and 7. Alternatively, the long sides 9", 9" at the opening need not be parallel to each other and may assume such a shape as shown in Fig. 8.

The foregoing discussion about the size and shape ofthe opening 9 may equally apply to that made in the end plates 4.

A modified embodiment of the device according to the first aspect ofthe present invention is shown in Figs. 9 and 10. In the embodiment of Figs. 9 and 10, one side plate 3 is broader than the other side plate 3'.

One side wall of each end plate 4 has a length equal to the end portion ofthe broad side plate 3, and the other sidewall of each end plate has a length equal to the end portion ofthe narrow side plate 3'. When the device is set up, the broad side plate 3 forms a smaller angle with the bottom plate 2 than does the narrow side plate 3' as shown in Fig. 10.

In an embodiment not shown here, a device may be produced by using relatively high side plates and end plates, provided that one side plate is erected at a right angle with respect to a relatively narrow bottom plate.

This type of device is particularly suitable for capturing cockroaches living in a small concealed area.

As shown in Fig. 4, when a cockroach B climbs the one of side plates 3 of the device 1 placed on a floorA, it tries to enterthe device through an opening 9 by first putting its tentacles C into the opening. Since the opening is longer in the direction normal to the bottom plate than in the other direction, the pair of tentacles C, C cannot be easily put into the opening unless they are perpendicular to thefloorA. This causes the cockroach B to assume a posture that is generally normal to the longitudinal axis 9a ofthe opening 9. As a result, the cockroach gradually crawls upthe side plate 3 and spreads its tentacles C into the opening so that they are substantially parallel to the axis 9a.

After using the tentacles C to confirm that there is no danger on his way, the cockroach puts its head into the device th rough the opening. Since the adhesive agent 10 is in the right (or left) position, not above or below, with respect to the head of the cockroach, it senses no danger and puts its breastorabdomen pastthe opening 9. Then, in orderto keep the balance of his posture, it extendstheforelegs downwardly in the direction of gravity, whereupon the legsarestuckto the adhesive layer 10.

Being scared, the cockroach tries to escape from the trap. However, the greater part of his body is already within the device 1 and its movement is limited by the unique configuration of opening 9which is longer in the direction normal to the bottom plate than in the direction parallel thereto (i.e., the transverse axis 9b whose length Ii is in the range of 12 mm prevents the free movement of the cockroach that has approached the opening in a posture generally normal to the longitudinal axis 9a). In addition, more than half ofthe six legs of the cockroach are within the device and as it wriggles about, the hind legs are also captured bythe adhesive agent 10.

The device of the present invention having openings ofthe shape and size specified above is particularly effective for capturing large cockroaches such as American cockroaches and Periplaneta fuliginosa Serville whetherthey are adults or old instars. The device ofthe present invention is also effective in capturing small cockroaches such as German cockroaches and young instars ofotherspecies because theirtentacles are short and are less fit for the purpose of sensing the danger ofthe adhesive agent present on the bottom ofthe device.

Therefore, the device of the present invention is capable of effectively capturing all kinds of cockroaches. Once the cockroach is trapped by the adhesive layer on the bottom plate ofthe device, it finds much difficulty in finding the way out by putting the tentacles outofthe device through the opening which is longer in the direction normal to the bottom plate than in the direction parallel thereto unlike the opening used in the conventional device which is longer in the direction parallel to the bottom plate than in the other direction. Even if it succeeds in escaping from the adhesive layer by separating the legs stuckto the adhesive layer, the cockroach is again captured by the adhesive layer before it finds the way out.This is anotherfactorthat enhances the efficiencyofoaptur- ing cockroaches.

The use of openings 9which are longer in the direction normal to the bottom plate than in the direction parallel thereto enables the fabrication of a capturing device whose width is sufficiently small to permit installation in a small gap between two closely spaced pieces of furniture. The device needs no separate roof or canopy to conceal its interior; the device does not give any unpleasantfeeling to the user and if necessary, he can look into itto see whether cockroaches have been captured. Furthermore, the device can be kept dark so that it provides a condition liked by cockroaches. As another advantage, the device ofthe present invention permits less draft than a conventional device having a single large opening in each ofthe side plates.Therefore, dirt and dust have a smallerchanceto build on the surface of the adhesive layer, and the adhesive agent remains sufficiently effectiveforan extended period.The life of the attractant positioned in the center ofthe adhesive layer is also extended because the effective ingredients ofthe attractant are held in a favorable atmosphere.

Various embodiments of the device for capturing cockroaches according to the second aspect of the presentinventionarehereunderdescribed by referenceto Figs. 11 to 18. Fig. 11 is a planviewofthe blank making a capturing device according to this second aspect. Fig. 12 is a perspective view showing the completed form ofthe device. The device generally indicated at 21 is in the form of a thin sheet made of any material selected from among paper, plastics and metals. The blank having the shape shown in Fig. 11 is prepared by a suitable means such as a press, and folded in a predetermined mannerto make the completed form shown in Fig. 12.

As shown in Fig. 11,the blank 21 is generally in the form of a "cross" which consists of a center member 22, a pair of wings 23,23 and a wing 24. Afold line 25 is formed on both lateral sides ofthe center member 22, and anotherfold line 26 is formed between one end of the center member 22 and the wing 24. A rectangular portion defined bythefold lines 25,26 and the other end 22a ofthe center member 22 provides a bottom plate 27. Afirst side plate 28 is defined between each lateral side 22b of the center member 22 and each fold line 25.

Both wings 23,23 are shorterthan the center member 22 and integral parts thereofwhich are positioned closerto the end of the center member which is connected to the wing 24. Afold line 29 that runs across the ends 23b and 23c of each wing 23 is provided at a positionclosertothelateralside23a.

The area defined between this fold line 29 and the fold line 25 provides a second side plate 30 which is broaderthan the first side plate 28. The second side plate 30 is provided with an opening 31 which is large enough to permit free entrance of cockroaches. The area defined bythe fold line 29 and the lateral side 23a provides a flap 32.

The wing 24consists of a generally triangular end plate 33 and a rectangular link member 34. The end plate 33 has an opening 35 which is large enough to permit free entrance of cockroaches. The link member 34 has a slit 36 and borders the end plate 33 at a fold line 37.

Each ofthe openings 31 and 35 may be a single large opening of a desired shape, or at least one elongated opening of the same shape as defined in connection with the device according to the first aspect of the invention.

One end 23c ofthewing 23 is provided with a recess 38 to form a projection 32a from one end ofthe flap 32.

Anotch 39 is provided in the lateral side 23a oftheflap 32.

The bottom plate 27 has a coat of an adhesive agent 40 on its entire surface exceptforthe area which is at least 20 mm distant from the edge 22a. The adhesive layer40 is preferably covered with peelable paper which is peeled off just before use.

The device for capturing cockroaches according to the second aspect of the present invention is constructed by the following procedure. First, the wings 23 and 24are folded at lines 25,26 and 29 until thetwo flaps 32 contact each other bytheirinnersurface. The two projections 32a are slipped into the slit36 so asto engage the second side plates 30 and the end palte 33 bythe link member 34, in such a mannerthatthe lateral sides33a ofthe end plate 33 are in contact with the inner surface of each of the second side plates 30, 30.As a result of this procedure, there is provided a cockroach trap which consists ofthe flat bottom plate 27, a pair of first side plates 28,28 that are low in height and are not connected to each other, a pair of second side plates 30,30 which are higher than thefirstside plates and are connected to each other, and the end plate 33 which closes the opening at one end of the second side plates. As shown in Fig. 12, this device is open at one end in the longitudinal direction of the bottom plate 27 and isclosedattheotherend.

In the embodiments shown above, the fold lines are preliminarily provided in the blank and the user constructs the device by himself by folding the respective portions ofthe blank. Alternatively, the device may be supplied in its completed form which is prepared by folding with a press or any other suitable positioning means.

Fig. 13 shows how the cockroach trap according to the present invention is used. The partofthetrap defined by the lowfirstside plates 28 is inserted into the gap E between a floor A and the bottom of a piece of furniture, whereas the other part of the trap defined by the high second side plates 30 and the end plate 33 is left outside of the gap. Cockroaches living in the gap E can be captured by using the open space between thefirstside plates 28.

These scuttling about on the floor A can also be captured by using the openings 31 and 35 made in the second side plates30 andthe end plate33, respectively.

The device of the present invention has high strength against external bending ortwisting forces because the first and second side plates 28 and 30 are in an erect position with respect to the bottom plate 27.

The erect side plates 28 serve as a protection against the walls of a building. They also preventthe adhesive layer40from making directcontactwith the walls.

Therefore, the device of the present invention is free from the chance of contamination ofthe adhesive layer by extraneous materials such as dust and dirt.

The edge ofthe adhesive layer 40 is at least 20 mm apart fro the open end of the bottom plate 27. Ifthe forelegs of a cockroach get stuck to the adhesive layer, its hind legs are still on the bottom plate 27, rather than on thefloorA, and so is unable to move the device.

The device ofthe present invention claims further protection from unwanted movement by cockroaches because the high second side plates 30 are in contact with the angular corner of the bottom of furniture.

Conventional cockroach trap are often moved from the intended area by cockroaches which are not completely trapped. As a result, the capturing efficiency is decreased significantly, orthe device slips to an inaccessible area. However, these problems are absentfrom the device of the present invention and it can always be held in the desired area.

The device of the present invention is open in the part above the first side plates 28, so cockroaches can have easy access to the bottom plate 27 having the adhesive layer 40. This is another reason why the device ofthe invention features high capturing efficiency. As a further advantage, the user can readily checkvisually how many cockroaches have been captured.

The high second side plates30farenotwithinthe gap E, so the user has only to hold these plates in orderto take the device out of the gap. This is also desired from a hygienic viewpoint since the user can dispose of the device without touching the adhesive layer 40 to which cockroaches have got stuck.

These advantages are more apparent in the embodiment shown in Fig. 12. The erectflaps 32 provide a handy means for holding the device. They are sufficiently distantfrom the adhesive layer 40 to avoid user's contact with the tentacles, legs or alae of a cockroach.

The second side plates 30 that are exposed fromthe gap E are connected bytheflaps 32 and the end plate 33 conceals the interior ofthe device. When the device is put into the gap E, the user does not seethe inside of the device and will have no unpleasant feeling.

The low first side plates preferably cover at least half ofthe total length of the device. It is to be emphasized here that the device of the present invention is adapted to capturing not only cock roaches living in small concealed areas but also those scuttling around on thefloorin an open space.

The device ofthe present invention is not limited to the embodiment shown in Fig. 12. The end plate 33 may be omitted as shown in Figs. 14to 16, and if they are not used, the bottom plate 27 must have margins on both ends which are not coated with the adhesive layer 40 and are at least 20 mm distant from both ends ofthe plate so that a cockroach entering the device from either end cannot extend its hind legs beyond the device when it is caught by the adhesive layer40.

Instead of combining the innersurfaces ofthe flaps 32 as shown in Fig. 12, they may be combined in an overlapping fashion as illustrated in Fig. 14. Alternatively, the flaps 32 may be engageably connected as illustrated in Fig. 15. If desired, the second side plates 30 and the flaps 32 may be connected in an overlapping fashion to form a curved contour as shown in Fig. 16. In still another embodiment, the upper edge 28a of each ofthe first side plates 28 may be inclined as shown in Figs. 17 and 18.

As will be understood from the foregoing description, the device according to the second aspect is adapted to installation in small gap for capturing cockroaches living in that area.The device has sufficient strength to resist external twisting or bending forces. It presents no hygienic problems and will cause no contamination by the adhesive layer formed on the bottom plate. If necessary, the device can be effectively used in an open space (i.e., floor).

Experiments were conducted to determined the effectiveness ofthe device for capturing cockroaches according to the present invention.

Experiment 1 Six samples of cockroach trap were fabricated.

They were in the form of a rectangular prism. Each of the four side walls was provided with a plurality of openings; the base of each opening was 1 cm above the bottom plate, with the length ofthe longitudinal axis (12) being 3 cm and the angle (01) between the longitudinal axis and the fold line atwhich the side wall has been folded being 90 . The openings were arranged with separation, distance Ii, i.e. a distance equal to the width of openings. The total area of the openi ngs wasthesamefor each sample, and the number of cockroaches captured by each trap sample was counted.

The sampletraps were made of paperboard and measured 160 mm long,80 mm wide and 40 mm high. The width (I1) of the openings was varied at3, 5, 8,12,20 and 40 mm. The entire part of the inner surface of the bottom plate was coated with a layer of adhesive agent, and an attractantwas placed in the center of the adhesive layer. The six sample traps were placed in a room (ca.10m2) at equal spacings and equally distant from two opposing walls. Thirty adult Periplaneta fuliginosa Serville were let loose in the room, and 24 hours later, the number of cockroachescaptured in each samplewascounted.

The same experimentwas conducted with adult Blattella germanica Linne. For each species of cockroaches, five runs of experiment was conducted by changing the order of sample arrangement and the total number of the cockroaches captured was counted. The results are shown below.

Cockroaches captured Sample Width of Number of Periplaneta Blattella openings openings No. #1 (mm) Serville Serville Linne 1 3 80 3 15 2 5 48 15 18 3 8 30 24 18 4 12 2D 20 16 5 20 12 12 14 6 40 6 13 15 Total - - 87 96

As the table shows, veryfew adult Periplaneta fuliginosa Serville were captured in Sample No. 1 having openings of a width 3 mm. At leastfourtimes as many cockroaches were captured in each of the other samples. It therefore became evident that for the effective capturing of adult Periplaneta fuliginosa Serville, the width of openings must be at least 5 mm.

Comparison ofthedataforthewidths8 mm, 12 mm, 20 mm and 40 mm shows that openings whose width (li ) was in the range of 5 mm to 12 mm were the most effective in capturing cockroaches probably because these openings made cockroaches less sensitive to the danger ofthe adhesive agent. The data in the table also shows that the efficiency of capturing adult Blattella germanica Linne which were smaller than adult Periplaneta fuliginosa Serville was not highly dependent on the width (II) of openings. It is therefore clearthatthe device ofthe present invention is highly effective in capturing small cockroaches irrespective ofthewidth (II) of openings.

Experiment2 Series of experiments were conducted in the same manner as in Experiment 1. The only differences were as follows: the width (II) of openings was the same for each sample; the length (12) ofthe openings was varied at4, 8,12, 16 and 24 mm; and twenty-five cockroaches were let loose in each run. The results are shown in the following table.

cccoachas captured Sample Number of captured Periplaneta Blattalla No. length of (mm) openings fuliginosa germanic Serville Linne 7 4 30 1/2 5 12 8 8 30 1/1 8 19 9 12 30 3/2 13 18 10 16 30 2/1 24 19 11 24 30 3/1 25 20 Total - - - 77 88 As the above table shows, the number of adult Periplaneta fuliginosa Serville captured in Sample No. 8 (12/11 = 1/1)was less than a third ofthe number of cockroaches captured in Sample No. (2/1) or 11 (3/1). Sample No.9 having the I2/I1 ratio of 3/2 was less effective than Sample Nos. 10 and 11 and could capture a little more than 1.6 times as many cockroaches as captured by Sample 7. It is therefore clearthatforthe effective capturing of adult Periplaneta fuliginosa Serville,the ration 12/11 should be at least 1.5, and the ratio of 2.0 or greater is preferred.

The capturing of Blattella c'ermanica Line was not highly dependent on the ratio 12/lit.

Experiment3 Aseries of experiments were conducted asin Experiment 1, exceptthatthe distance 13 ofthe base of each opening from the bottom plate was varied at 0, 3,5,10 and 20 mm. The otherdimensions of each opening were 12 = 20 mm and Ii = 8 mm. Twenty-five cockroaches were let loose in each run. The results are shown in the following table.

Cockroaches captured Sample Distance Ni-er of Periplaneta Slattella No. #3 (mm) fuliginosa gernaflica Serville Linne 12 0 30 6 12 13 3 30 9 17 14 5 30 20 22 15 10 30 22 21 16 20 30 17 18 Total - - 74 90 As the above table shows, Sample No.14(13 = 5 mm) captured more than twice as many cockroaches (adult Periplaneta fuliginosa Serville) as captured by Sample No.13(13 = 3 mm). Sample No.15(13 = 10 mm) was more effective. A cockroach has its head parallel to the bottom plate when it enters the device through an opening. In orderto preventthe cockroach from sensing the danger of the adhesive layer on the bottom plate, the opening must be distant from the bottom plate by at least 5 mm. The efficiency of capturing adult Blattella germanica Linne is not highly dependent on 13, except that Sample No. 12 using 13 = 0 mm was the least effective. The reason would be that a cockroach easily senses the danger of the adhesive layer by direct contact with its tentacles or legs.However, Blattella germanica Linnewhich is weakerthan Periplaneta fuliginosa Serville is unable to escape from the trap once it gets stuck to the adhesive layer, and this would be the reason why the numberof adult Blattella germanica Linne captured in Sample No. 12 is notappreciablysmallerthan the numbers attained by the other samples.

Experiment4 A series of experimentswere were conducted as in Experiment 3, except that 0, was varied at 0,15,30,45 and 90 . The other dimensions of each opening were asfollows: 13 = 5 mm, I1 = 8mm,thetotal length of 12 = 40 cm. The results are shown in the following table.

Cockroaches captured Sample e1 ) Periplaneta I Blattella fuliginosa germanica Serville Linne 17 0 7 12 18 15 10 13 19 30 19 18 20 45 22 20 21 90 21 21 Total - 79 88 As the above data shows, Sample Nos. 19,20 and 21 using #1 of 300 or more were appreciably more effective than Sample Nos. 17 and 18 (s 150) in capturing adult Periplaneta fuliginosa Serville. This could be explained as follows: as61 becomes smaller, a cockroach entering through an opening has a greater ease in detecting the adhesive layer by the tentacles; furthermore, the inclination of the head of the cockroach with respect two the bottom plate is small enough for the cockroach to move backward by sensing the danger of the adhesive layer positioned below its head in the direction of its advancement.A similartendencywas observed with adult Blattella germanica Linne, butthe capturing efficiency was not highly dependent on 01. As a conclusion, high capturing efficiency is obtained if 91 is in the range of 300 to 1500 (including symmetrical shapes).

ExperimentS Six samples of cockroach trap were prepared. They were in the form of a triangular prism. Ten openings were made only in one of the opposing rectangular side plates. Each opening was made 1 cm (13) distant from the bottom plate; its length (12)was 30 mm; its width (1, ) was 8 mm; its inclination (0, ) was 90 ; and the distance between each opening was 8 mm. The angle between the bottom plate and each ofthe end plates was fixed at 90". The angle between the perforated rectangular side plate and the bottom plate was varied at 15,30,45,60,90 and 1200.

Each sample was made of cardboard, and its bottom plate measured 160 mm long and 80 mm wide. An adhesive layer ways applied tothe entire part ofthe inner surface ofthe bottom plate, and an attractantwas placed in the center ofthe adhesive layer. The number of cockroaches captured in each of the six sampleswas counted as in Experiment 1.The results are shown in the following table.

Cockroaches captured Sample lingl b-tw en perforated Sn. rectangular side plate Periplaneta Blattella aed hottol pelt. () foliginosa geraanica Serville 22 1 3 5 23 3 18 20 24 45 20 17 25 60 16 19 26 90 19 20 27 120 5 8 Total - 81 89 Astheabove date shows, Sample Nos. 23to26 were most effective in capturing both species of cockroaches.Sample No.22 wherein the perforated side plate was inclined at 150 with respect to the bottom plate was far less effective probably because cockroaches entering the trap through openings could easily detectthe dangerofthe adhesive layers which were almost in front oftheirface. When, on the other hand,the perforated side plate was inclined at an angle greaterthan 900 with respectto the bottom plate as in the case of Sample No. 27, cockroaches had to climb the side plate upside down, butthis was a most difficult thing to do for the cockroaches.

In view of the results of Experiments 1 to 5, the opening 9 made in the cockroach trap according to the best embodiment of the present invention should have the following dimensions: the axis (9b) of the opening perpendicularto the axis 9a is not shorter than 5 mm and not longer than 12 mm; the length of 9a isat least 1.5 times as long as the length of 9b; the axis9a is inclined with respecttothe line3a (at which the side plate 3 is folded) at an angle (61) in the range of 30 to 1 50"; the opening is distantfrom the bottom plate by at least 5 mm; the perforated side plate is inclined from the bottom plate at an angle in the range of 30 and 90 ; an adhesive layer is formed on the inner surface of the bottom plate. What is most importantforthe purposes ofthe present invention is that the opening is longer in the direction normal to the bottom plate than in the direction parallel to the bottom plate, and that the width ofthe opening (the length of each side which is parallel to the bottom plate) is not shorterthan 5 mm and notlongerthan 12 mm.

Claims (16)

1. A device for capturing cockroaches, which comprises a bottom plate having a layer of an adhesive agentformed on the innersurfacefor capturing cockroaches; a pair of lateral side plates connected to the lateral sides of said bottom plate, each ofsaid lateral side plates having a flap along its lateral side and having at least one opening which provides a passage for cockroaches to enter the device and which is longer in the direction normal to the lateral sides of the bottom plate than in the direction parallel thereto; and a pair of end plates connected to the end sides of said bottom plate, each of said end plates having a link member on its end portions that engages said flaps and having at least one opening which provides a passage for cockroaches to enter the device and which is longer in the direction normal to the ends of the bottom plate than in the direction parallel thereto, said device being constructed by folding said lateral side plates and said end plates respectively atthe lateral sides and ends of said bottom plate, connecting said flaps, and engaging the same with said link members at the ends thereof.

2. A device according to Claim 1 wherein said flaps are interconnected in such a mannerthat their inner surfaces contact each other, the connected flaps engaging said link members to form a grip.

3. A device according to Claim 1 wherein said opening hasawidth in the range of5to 12 mm and a length which is at least 1.5 times as great as said width,

4. A device according to Claim 1 wherein the distance between the lower side of said opening and the lateral side of the bottom plate to which the perforated side plate is connected is at least 5 mm.

5. A device according to Claim 1 wherein the longitudinal axis of said opening is inclined with respectto the lateral side of said bottom plate at an angleof30to 150 .

6. A device according to Claim 1 wherein the layer of said adhesive agent is covered with peelable paper which is peeled from said adhesive layer before use, when an attractant is put on said adhesive layer.

7. Adeviceforcapturing cockroaches,which comprises a bottom plate having a layer of an adhesive agentformed on theinner surface for capturing cockroaches; and a pair of said plates connected to the lateral sides of said bottom plate, each of said side plates extending to one end of said bottom plate and consisting of a wide portion having a flap at its lateral side and a narrow portion which is connected to the end of said wide portion and extending to the other end of said bottom plate, said device being constructed by folding said side plates at the lateral sides of said bottom plate and engaging said flaps with each other or bonding the same to each other.

8. A device according to Claim 7 which further includes an end plate connected to the end of said bottom plate which is close to said wide portions, said end plate having a link memberwhich is connected to its end portion and is engageable with said flaps, said end plate further having at least one opening that provides a passage for cockroaches to enter the device.

9. A device according to Claim 7 wherein each of said side plates has in its wide portion at least one opening that provides a passage for cockroaches to enter the device.

10. A device according to Claim 7 wherein the narrow portion of each of said side plates is at least halfoftheentire length ofsaidside plate.

11. A device according to Claim 7 wherein said adhesive layer is covered with peelable paper which is peeled from said adhesive layer before use, when an attractant is put on said adhesive layer.

12. A device according to any one of Claims 7,8 and 11 wherein said adhesive layer is formed at least 20 mm apart fro an open end of the device where no end plate is connected to said bottom plate.

13. A device according to Claim 8 or 9 wherein said opening is a single relatively large opening.

14. A device according to Claim 8 or 9 wherein said opening is longer in the direction normal to the bottom plate than in the direction parallel thereto.

15. A device according to Claim 14wherein said opening has a width in the range of 5 to 12 mm and a length which is at least 1.5 times as great as said width, the distance between the lower side of said opening and the lateral side of the bottom plate to which the perforated plate is connected is at least 5 mm, the longitudinal axis of said opening being inclined with respect to the lateral side of said bottom at an angle of 30 to 1500.

16. A device according to Claim 8 wherein said flaps are interconnected in such a manner that their inner surfaces contact each other, the connected flaps engaging said link memberto form a grip.