GB2211717A

GB2211717A - Natural pest control

Info

Publication number: GB2211717A
Application number: GB8825320A
Authority: GB
Inventors: Ivan Evelin Worrall
Original assignee: NATURAL PEST CONTROL Ltd
Current assignee: NATURAL PEST CONTROL Ltd
Priority date: 1987-10-28
Filing date: 1988-10-28
Publication date: 1989-07-12
Also published as: GB8725229D0; GB8825320D0

Abstract

A package from which pest control insects can successively escape as they develop defines a compartment in which insects at a pupal or other early stage in their development are initially confined. In use, the package is placed in an environment and an escape passage for insects from the compartment is opened. As they develop, the insects escape and provide natural protection for the environment over a period of time. Prior to their escape, the insects are themselves protected by the package.

Description

NATURAL PEST CONTROL This invention relates to natural pest control, and particularly to the release of insects into an environment in which the released insects are the natural predators of the pest to be controlled. This manner of pest control is known, and has been developed as an alternative or supplement to the use of chemicals.

Chemical insecticides have the disadvantages that the pests they are intending to destroy can become immune, and can also have an adverse effect on the crop or environment they are designed to protect.

A problem with the employment of natural predators is controlling their release into the environment in a manner which achieves the desired amount of protection over a long period. Uniform distribution of the insects in the crop is important, as the range of a given insect is often limited. Spot treatments do not usually prove to be successful. Storage is another problem as the active life cycle of a particular insect can be limited. Some can be kept for limited periods at low temperatures, but long term storage is undesirable.

Protective or predator insects can be introduced into the environment to be controlled not only as adults, but also in a formative stage. The present invention is concerned primarily with the controlled release of adult insects from their formative stage into the specified environment. According to the invention, insects at a formative stage are confined in a compartment of a package disposed in the said environment, and an opening to the compartment is made which allows the escape of the insects as they develop in the prevailing conditions. Further, the invention provides an insect package comprising an housing in which the compartment is defined, and an openable closure to the compartment. Provision is also normally made for suspending the housing in the environment, for example from plants to be protected.

This enables the package to be disposed centrally within the zone in which the insects are to function, and allows the insects to escape progressively over a period which can be a number of days.

Packages of the invention afford protection for the insects confined therein in transit to their eventual region of operation, and enable them to develop and emerge naturally in the correct environment. Additionally, by being confined in the package as they develop, they are protected at this stage also from for example, air movement and their own predators, which further assures the release of the requisite number of insects into the region in which the package is disposed.

The insects in their formative stage may be introduced into the compartment of the package through the openable closure, the compartment being sealed and then reopened when the package is in situ. However, it is sometimes desirable to have a separate opening for the introduction of the insects which is permanently closed and located spaced from the eventual escape passage. In some embodiments, insects at a formative stage are attached, for example by adhesive to a closure member which is then secured over the opening with the insects on the inside. A simple strip of adhesive tape may be used for this purpose with the insects mounted on a central portion thereof, and the remainder of the adhesive surface being used to seal the surrounds of the opening.It is preferred not to use petroleum based adhesives for this purpose, but adhesives based on an 1,l,l,trichloroethane carrier is safe once the carrier has dispersed. Natural glues are also generally preferred. Some insects are not suited for such adhesive mounting, for example those which can be packaged according to the invention for release at different stages of their development. In these cases an adhesive tape closure system can still be used, but exposure of adhesive on an internal surface of the compartment should be avoided; e.g., by covering the central portion of the tape or applying adhesive to the external surface of the package around the opening.

The package itself may be made in laminar form, the main body thereof being a piece of card, with a sheet of material secured on either face thereof. An aperture is formed in the piece of card such that the sheets of material close opposite ends thereof and define the compartment thereon. An opening to the compartment can be formed by omitting or removing a portion of one of the sheets of material, and this opening may be subsequently closed after introduction of the insects by a suitable means such as one of the adhesive strip techniques described above.

In an alternative embodiment, the package may take the form of a blister pack in which the blister is formed of a normally transparent material and mounted on an opaque card. In this embodiment, the closure can conveniently comprise a portion of the card bendable away from the blister to open an exit therefrom. The card may itself be formed in a plastics material, normally substantially rigid and provided with an hinged section to form the closure, but cellulose card or stiff paper card is preferably used. Such materials readily enable a closure portion thereof to be effectively permanently displaced from an opening to the compartment.

A part of the housing defining the boundary compartment in a package according to the invention is preferably formed in a transparent material such that the development of insects in the compartment can be observed.

This material may be a clear plastic sheet such as Cellophane ("Cellophane" is a Registered Trade Mark) or acetate sheeting, and in the laminated embodiment described above, an whole side of the piece of card may be covered by such sheeting. Plain paper may be used to define other boundaries of the compartment and, again in the embodiment described above, 60-80 g paper may be used as both the sheet material and with an adhesive coating as an adhesive tape for closing the opening of the compartment.

A number of packages according to the invention can be produced simultaneously, and particularly where the package is of laminar form the product is well suited to mass-production. A single piece of card may be punched to form a number of apertures therein corresponding to the number of packages to be made from it, and sheet material adhered to either face of the card to close or partially close the compartments. The card can then be scored between the apertures to render the packages readily separable from one another. Preferably, additional scorelines or perforations are included in the card such that a portion of each package can be torn away and discarded to form an opening to the compartment through which the insects may escape.Insects at their formative stage may be introduced into-the compartment as the packages are assembled, but it is preferred to form a separate opening as described above by the selective application of a sheet of material to one face of the card. In this way, insects at their formative stage can be introduced into each package at an appropriate time relative to the eventual use thereof.

The above production technique can of course be applied to any reasonable number of packages, and typically, 50 packages can be made from a single cardboard sheet of A4 size. Normally, the packages will be sold in groups of five. It should be understood though, that they can of course be made and sold singly.

As noted above, adult insects are not normally confined in the compartments of packages according to the invention. They will be introduced in one of their formative stages. Different insects and different conditions in the environment to be controlled will determine what formative stage is most appropriate for a particular application. Generally, we have found that insects can effectively be introduced into the compartment at their pupal stage, but certain circumstances will render the larval or egg stage more suitable.

One particular application contemplated for the present invention is the control of the red spider mite by means of Phvtoseiulus persimilis, which is a mite belonging to the class Arachnida and, apart from the egg, the young stages are identical to the adults except for size. These are distributed as active mites of all ages and so the adhesive mounting enclosure method is not appropriate.

Other applications of the invention are the control of the glasshouse whitefly by Encarcia formosa, the control of the leaf miner by Dacnusa sibirica and Diqlyphus isaea; and the control of aphids by Athdoletes Aphidimvza. The predator in each of these applications is introduced into packages according to the invention as pupae, and insects progressively escape from the package as they develop therefrom.

Another useful predator is Crysopa Carnea, a polyphagous insect which attacks aphids, thrips and other soft bodied insects and mites. These are packaged as eggs.

Embodiments of the invention will now be described by way of example and with reference to the accompanying schematic drawings, wherein: Figure 1 is an enlarged perspective view of a first package according to the invention; Figure 2 is a front elevation of the package of Figure 1; Figure 3 is a side elevation of the package of Figure 1; Figure 4 illustrates a strip of packages according to Figure 1; Figure 5 is an enlarged perspective view of a second package according to the invention; and Figure 6 is a side elevation of the package of Figure 5, after opening.

The package shown in Figure 1 is formed from a piece 2 of card with a sheet 4 of paper secured to the rear face, and a sheet 6 of transparent material secured to the front face. Simple adhesive securement is sufficient for this purpose, applied to the card rather than the sheets 4 and 6. Prior to securement of the sheets 4 and 6 an aperture is cut in the card bounded by walls 8. The sheet 4 does not totally close the aperture, but leaves an opening 10 as shown. This opening is closed by a length of tape 12 after introduction of insects through the opening 10 into the compartment defined by the sheets 4 and 6 and the walls 8.

At the upper left hand side of the package as shown, a further cut is made in the card, after securement of the sheets 4 and 6, to form a hook 14 upon which the package may be suspended in the environment to be controlled. Adjacent the upper edge of the package, the card 2 and the sheets 4 and 6 are formed with perforations to enable the upper portion to be removed to reveal an opening or escape passage at the top 16 of the compartment. Thus, once installed, insects may develop from pupae or their other formative stage at the bottom of the compartment, and progressively escape through the top.

The embodiment illustrated is particularly suitable where insects at their formative stage are first mounted on the adhesive tape 12, which is then applied as shown in the drawing, to confine the insects within the compartment. It will though, be appreciated that the provision of the removable section of the package to reveal the escape opening may be foregone if the package is effectively inverted; i.e., the opening to be closed by the tape 12 disposed at the top rather than the bottom of the compartment. In this arrangement, the insects in their formative stage can be introduced freely into the compartment, and the closing tape 12 merely removed when the package is disposed in the environment to be controlled.In this arrangement though, care must be taken to avoid exposure of adhesive on the tape 12 within the compartment to which the insects may attach themselves and thus be removed from the package with the tape when the compartment is opened.

The package illustrated will typically have overall dimensions of 3 cm x 4.5 cm based on a card thickness of at least 1500 microns. The dimensions are of course not critical, and can be modified to suit the size, storage and development of different insects and different quantities thereof. The package might also be made of a plastics material, and a variety of mechanisms may be adopted to form the opening or openings required. A package might also be re-usable in some forms, although it will normally be disposable.

Figure 4 illustrates a strip of five packages according to the invention. After securement of the sheets 4 and 6, holes are punched to form the hooks 14, and the divisions 18 between adjacent packages partially cut to enable them to be readily separated. Similarly, perforations will be formed along a line 20 to enable an opening to be revealed at the top 16 of the compartment as described above in due course. The adhesive tape 12 is not yet applied, and the packages may be "loaded" with insects at an appropriate time prior to their use.

Insects may be delivered loose to the respective compartments, and the adhesive tape then applied. If the tape exposes adhesive inside the compartment, then the insects will normally adhere thereto as the packages are transported to their eventual site. Conveniently, the required quantity of insects can be mounted on an adhesive coated portion of the tape 12 prior to its application.

Once the packages are installed, and the escape opening for the insects revealed, the insects will progressively develop and leave the compartment. Their rate of development and escape from the package can be monitored through the transparent sheet 6. This enables a user to ensure the substantially continuous presence of the required insects in the environment by replacing a package when it is empty.

Figures 5 and 6 illustrate an embodiment of the invention in the form of a blister pack. The blister 22 is defined in a preformed sheet 24 of transparent plastics material such a 250 micron PVC sheet, mounted on a backing card 26. The card 26 is typically 620 micron card, suitably treated to enable it to be heat sealed to the sheet 24 around the periphery of the blister or bubble 22.

As with the package of Figures 1 to 4, the laminate of the card 26 and sheet 24 away from the bubble 28 is formed with an hook 28 from which the package may be suspended in the environment to be treated.

The card 26 is slit along the line 30 such that the part 32 may be bent away from the bubble 22 to expose an exit therefrom, as shown in Figure 6. The sheet 24 is cut to expose a tab 34 of the card 26 for this purpose.

The heat sealing referred to above can be selective such that there is no bond between the part 32 and the sheet 24 to facilitate this step. The stiffness of the card 26, and the bond elsewhere can be sufficient to retain the insects in the bubble prior to opening, although a light bend can be formed if desired, which can easily be broken at the appropriate time. Of course, other closure and access systems of the bend described above in connection with the package of Figures 1 to 4 may be used in this embodiment if desired. The card 24, particularly if it is of a plastics material, can be formed with a line of weakness; eg, at 36 to define the nature of the exit opening exposed.

In preparation or manufacture of the embodiment of Figures 5 and 6, insects at their pupal or other formation stage are introduced into the bubble 28 of the sheet 24 prior to its mounting on the card 26. In use, the package is suspended or otherwise placed in the environment to be treated, and the part 34 then bent away from the bubble to expose the exit, enabling the insects to progressively escape as they develop.

Also as with the previously described embodiment, packages according to Figures 5 and 6 can be produced and marketed in strip or sheet form. In all embodiments of the invention the use of a transparent material facilitates the identification of a particular package with its contents by writing or other indicia on the backing card. The blister pack of Figures 5 and 6 has the advantage of not restricting the dimensions of the compartment to the thickness of the backing card. Thus, a thinner card can be used in a package of otherwise similar overall dimensions which defines a compartment with a greater depth, for example 2 or 3 mms. Typical dimensions of the backing card are around 50 mm x 40 mm, and they will normally be marketed in sheet form as a batch of ten packages. Sheets comprising much greater numbers of packages can of course be manufactured, using a plastics sheet moulded with the appropriate number of "blisters" thereon. The slits 32 in the backing card 26 will be cut before the sheet is mounted thereon, and the batch laminate cut or partially cut as desired thereafter.

Claims

1. An insect package for use in natural pest control comprising an housing defining a compartment for the storage of insects at a formative stage, and an openable closure to the compartment, which closure covers an opening for permitting escape of insects emerging from their formative stages in the compartment.

2. A package according to Claim 1 wherein the housing defines a closable opening for insertion of insects at their formative stage into the compartment.

3. A package according to Claim 2 including a member having an adhesive surface for closing the opening which adhesive surface is exposed within the compartment for the adherence thereto of insects at their said formative stage.

4. A package according to any preceding Claim wherein at least a part of the housing defining the boundary of the compartment is formed in a transparent material to afford observance of insects in the compartment.

5. A package according to Claim 4 in the form of a blister pack wherein the blister is formed of said transparent material and mounted on an opaque card.

6. A package according to Claim 5 wherein said closure comprises a portion of the card bendable away from the blister to open an exit therefrom.

7. A package according to any of Claims 1 to 4 wherein the housing comprises a piece of card, with an aperture therethrough covered at either end to define the compartment.

8. A package according to Claim 4 and Claim 7 wherein an end of said aperture is covered by a sheet of said transparent material.

9. A package according to Claim 8 wherein a said opening is formed in the covering of the other end of said aperture.

10. A package according to any preceding Claim including means for suspending the housing.

11. A package according to Claim 5 or Claim 7, and Claim 10 wherein the suspending means comprises an hole in the piece of card.

12. A package according to any preceding Claim wherein the openable closure is a removable portion of the housing.

13. An insect package substantially as described herein with reference to Figures 1 to 4 or Figures 5 and 6 of the accompanying drawings.

14. An assembly of packages according to any preceding Claim separably attached to one another.

15. An assembly according to Claim 14 of packages according to Claim 5 comprising a sheet of card with a sheet of transparent plastics material mounted thereon and forming a plurality of discrete blisters, means being provided for dividing the card and sheet between the blisters to separate the assembly into a plurality of packages.

16. An assembly according to Claim 14 of packages according to Claim 7 comprising a card with a plurality of said apertures therethrough, and sheets of material on either side of the card covering the apertures, means being provided for dividing the card between the apertures to separate the assembly into said plurality of packages.

17. A method of controllably releasing insects into an environment comprising the disposal in said environment of at least one package according to any of Claims 1 to 13 with insects in their formative stages in the compartment thereof; and opening the closure to the compartment to permit escape of insects therefrom as they develop in appropriate environmental conditions.