WO2024009043A1

WO2024009043A1 - Strip for protecting trees from insects

Info

Publication number: WO2024009043A1
Application number: PCT/FR2023/051040
Authority: WO
Inventors: Carlos Saiz
Original assignee: Transversal Technologies
Priority date: 2022-07-08
Filing date: 2023-07-06
Publication date: 2024-01-11
Also published as: FR3137535A1

Abstract

The invention relates to a device for preventing insects crawling on a trunk or a branch of a tree (100), the device comprising: - a deformable elongated body (7) configured to surround, in the installed state, a tree trunk (100); - an outer face covered with intermeshed electrodes (3), such that, when an insect (11) crawls over the outer face, it comes into contact with both electrodes (3); - an electrical power supply (5) with a positive pole and a negative pole respectively connected to one of the electrodes (3) of the outer face, characterised in that the elongated body (7) comprises at least one bistable spring blade (73) having two stable states, one of which is a transversely curved state, the spring blade (73) then being arranged in a straight line along a longitudinal axis corresponding to a stowed state of the device (1) and one of which is a longitudinally curved state, the spring blade (73) then being curved about a transverse axis and corresponding to an installed state of the device (1).

Description

Title: TREE PROTECTION TAPE AGAINST

THE INSECTS

Technical field of the invention

The present invention relates to the general field of protection and prevention against insects harmful to crops, in particular against crawling insects or more generally insects moving by climbing on tree trunks, and for the protection of trees such as fruit trees.

Prior art

Fruit trees are subject to attack by crawling insects, for example the ants and aphids that they breed. Aphids take sap to feed, thus weakening the tree, and are potential vectors of diseases transmitted during their bite.

It is known to use glue surrounding the trunk to protect trees, particularly fruit trees. This glue is either placed on a support strip, or directly applied to the trunk, in particular directly by hand by arborists or using a brush.

The glue surrounding the trunk prevents crawling insects from reaching the tops of the tree, where flowers and fruits develop. The insects are stuck in the glue and die. Glue has several disadvantages.

First, the glue tends to dry or harden, and more generally to lose its adhesive properties. This denaturation occurs under the effect of ultraviolet radiation, oxidation, humidity and dust deposits deposited by wind and rain running down the trunk. It is therefore recommended to reapply glue regularly to the trees.

Then the application of the glue is made painful and complex by the sticky nature of it, since it will tend to adhere to the tools and the hands of the users. Glue applied to strips is easier to renew. The hardened or denatured glue is removed with the support strip, and a new one is applied. The glue applied directly to the tree cannot be removed and is simply covered with a new layer. On young trees with thin bark, the glue can also cause ulcers which are harmful to growth and therefore to productive yield.

In particular, it is difficult to gauge exactly when said renewal must be carried out. If done too often, excessive replacement of the glue results in additional costs. If it is carried out at too long intervals, insects risk passing through and then nesting in the tops of the tree. The manufacturers recommend in the instructions to renew at least every three weeks, which can be tedious for the management of a large orchard.

The glue also diffuses synthetic molecules such as solvents, plasticizers, etc. in the rainwater that runs off it and into the atmosphere.

Furthermore, by indiscriminately killing the insects they engulf, glue or glue strips applied to trees contribute to the decline of insects and their diversity. However, it is increasingly proven that insects, even considered harmful, contribute to biotopes in ways that are sometimes imperceptible but nevertheless crucial.

Other repellents used include nets, initially designed to repel flying insects. By joining the lower edge of the net and the trunk all around, it is possible to physically prevent crawling insects from passing through the tops contained in the net. However, you must apply the net very carefully, as the slightest hole represents an entry route for insects.

We can also use chemical or biological repellents, based on pheromones or anti-feedants. However, these substances are specific to each insect or each family of insects, and they must also be reapplied regularly. Their barrier effect is also relative, since they do not physically prevent insects from accessing the tree.

Repellents other than glue are therefore expensive, specific to insect families and/or complicated to implement. Patents FR2842705 and FR3092475 describe barrier devices using electricity to repel and neutralize insects.

These devices include collars which have electrodes which are placed by tightening around the trunk, rolling the band around itself then securing.

Their installation, particularly on hundreds or thousands of trees in a large orchard, is tedious and time-consuming.

The repetition of the installation and tightening operations requires a significant number of manipulations, with a significant time, several seconds to tens of seconds per tree, which makes the use of these devices difficult and expensive for large orchards.

There is therefore a need for a way to prevent crawling insects from climbing trees that is durable, simple and quick to apply and, if possible, avoids killing the insects.

Brief description of the invention

In order to meet this need, the invention proposes an anti-crawling insect barrier device for a tree trunk or branch, comprising:

- an elongated and deformable body, configured to surround, in the installed state, a tree trunk,

- an exterior face covered with nested electrodes, so that when an insect walks on said exterior face, it is in contact with the two nested electrodes,

- an electrical power supply, with a positive pole and a negative pole connected respectively to one of the electrodes on the exterior face, characterized in that the elongated body comprises at least one bistable leaf spring, with two stable states, including a transversely curved state, the spring blade then being straight along a longitudinal axis, corresponding to a storage state of the device, and a longitudinally curved state, the spring blade then being curved around a transverse axis and corresponding to an installed state of the device.

The barrier device thus obtained is easy to put in place, without application of glue or other substance. The electrodes do not stick and are reusable over several years. The bistable leaf springs allow installation in a very quick movement consisting of going around the tree trunk with the elongated body, so that the bistable leaf wraps around the trunk, tilting from one stable state to another. The device may further have one or more of the following characteristics.

The electrical power supply is advantageously a box containing batteries or accumulators, and may include a control unit configured so that the electrodes deliver a non-lethal current discharge for insects, for example between 5 and 20 microamps, for a duration of between 0.05 and 0.2 seconds.

As the insects are not killed, the impact on biodiversity is negligible or zero. The insects fall and do not return to the tree, thus avoiding a rapid discharge of energy from the electrical source. We have thus measured that with a 12V 50 mAh alkaline battery it lasts long enough to stop around four million tree ants.

The device may also include a device for recharging the electrical supply comprising at least one photovoltaic panel.

Said photovoltaic panel can in particular be placed in the tree or on a dedicated support, and allows continuous recharging of the electrical supply.

The electrodes can be carried by a sheath, into which the spring blade is inserted, thus forming the elongated body.

The electrodes can be in the form of parallel longitudinal conductive strips, connected alternately to a different pole of the electrical supply.

The device may also include a thickness of deformable foam on the interior face opposite the exterior face carrying the electrodes.

This foam can be impregnated with a repellent or insecticidal substance, particularly for mealybugs.

The device may further comprise a deformable metal collar at the upper edge of the elongated body forming, in the deployed state, a protective overhang for the electrodes and for the electrical power supply. Brief description of the figures

Other advantages and characteristics will become apparent on reading the following description of the figures, including:

[Fig. 1] is a schematic representation of a tree with a device according to the invention, [Fig. 2] is a schematic sectional representation of the device on the shaft of Figure 1, [Fig. 3] is a schematic perspective representation of the device, flat for distribution and storage,

[Fig. 4] is a schematic representation of the electrical circuit formed by the electrodes and the current source, closed by an insect,

[Fig. 5] is a schematic perspective representation of a bistable leaf spring in two states of curvature,

[Fig. 6] is a schematic sectional representation of an alternative embodiment of the device,

[Fig. 7] is a schematic perspective representation of the device of Figure 6,

[Fig. 8] is a schematic representation of a barrier device equipped with a charging device.

The embodiments presented in the figures and described below are given by way of descriptive and non-limiting example. Other embodiments may be obtained by slightly modifying the features of the described embodiments or by combining features of different embodiments where possible.

Detailed description of the figures

Figure 1 is a side representation of a barrier device 1 anti-crawling insects arranged on a tree trunk 100. Alternatively, the barrier device 1 can be installed on a branch of the tree 100, for example if said branch is a graft that must be protected.

The barrier device 1 is arranged around the trunk of the tree 100, and goes around it. The barrier device 1 is wound helically around the trunk of the tree 100, and its ends overlap, one above the other and in contact along their lateral edge.

The ends are overlapped over a length of a few centimeters so that the propeller thus formed makes approximately one and a half turns. This overlap makes the probability almost zero that an insect climbing the trunk of the tree 100 will not enter contact with the barrier device 1.

Indeed, in order not to come into contact with the barrier device 1, the insect must precisely follow the contact line of the extremities, without deviating from it. The longer this contact line is, the less likely it is that an insect will follow it without deviating.

Figure 2 is a sectional view of the barrier device 1. Figure 3 shows the barrier device 1 in perspective.

The barrier device 1 comprises on a front or exterior face (opposite the trunk of the tree 100) electrodes 3. The electrodes 3 are connected respectively to the two poles, positive and negative, of an electrical power supply 5 and are nested so that when an insect walks on said exterior face, it is in contact with the two adjacent electrodes, and thus closes the electrical circuit.

The insect then receives an electric shock due to the current delivered between the electrodes 3. In particular, the electrical power supply 5 is a box comprising one or more batteries or accumulators, possibly a battery or supercapacitors. A voltage of approximately 6 to 12 volts is for example maintained between the electrodes 3 in the absence of insects or elements closing the circuit.

According to a particular embodiment, the power supply 5 may include supercapacitors, which can undergo a significant number of charge and discharge cycles without undergoing degradation.

A control unit (not shown) controls the current emitted by the electrical power supply 5. In particular, by limiting the emitted current to approximately 5 to 20 microamps, and the emission duration between 0.05 and 0.20 seconds, it is possible to knock down most insects without killing them by means of a shock strong enough to paralyze them but nevertheless non-lethal.

The voltage between the electrodes 3, the current intensity and the emission duration can of course be adapted to the size and resistance to electric shock of the expected insects.

The electrodes 3 are carried by an elongated deformable body 7, configured to surround, in the installed state, the trunk of the tree 100. The elongated body 7 is here in the form of a flexible sheath 71 into which stacked bistable spring blades 73 are inserted.

A thickness of deformable foam 9 is attached to the elongated body 7, on the side placed against the trunk of the tree 100. The foam 9, by conforming to the shape of the exterior surface of the trunk, blocks the asperities which would represent a hole between the trunk and the barrier device 1, then forming a passage for insects.

The foam 9 is for example a strip of expanded polyurethane, glued to the side opposite the electrodes 3 of the elongated body 7. The foam 9 is advantageously impregnated with a repellent or insecticide, in particular targeted against scale insects, which could use the roughness of moss for nesting.

Figure 4 illustrates an example of arrangement of the electrodes 3.

The electrodes 31, 33, connected respectively to the positive and negative pole of the electrical power supply, comprise straight and parallel segments, alternating a segment of the positive electrode 31 and a segment of the negative electrode 33.

The segments have for example a width of 0.5 to 3 millimeters, and a length corresponding to the total length of the elongated body 7. The electrodes 3 are for example produced by deposition of a thin metallic layer, or by chemical or photochemical etching.

The electrodes 3 are for example made of chrome stainless steel, in order to resist degradation by oxidation, of copper or aluminum.

The electrodes 3 are close enough for an insect 11 which moves on the exterior face of the barrier device 1 to touch, when it attempts to cross the barrier device 1, two parallel segments belonging to the two electrodes 3. The insect 11 closes thus the electrical circuit, which triggers the emission of an electric current which shocks the insect 11.

Other patterns of positive 31 and negative 33 electrodes are alternatively possible, in particular with a checkerboard distribution or with strips oriented other than horizontally. As the ends of the spirally wound barrier device 1 overlap, any vertical path along the tree trunk 100 passes through the electrodes 3. The probability that an insect will avoid them and can therefore completely pass the barrier device 1 without suffering an electric shock is reduced or even zero.

Figure 5 shows a bistable leaf spring 73, in its two stable states. At the top in Figure 5, the spring blade 73 is curved in a transverse direction, and is straight in the longitudinal direction. At the bottom in Figure 5, the blade springs 73 and is straight in the transverse direction, and curved in the longitudinal direction.

Such spring blades 73 are used in particular in the context of armbands. When curved in the transverse direction, the spring blades 73 are straight along their longitudinal axis. This configuration corresponds for example to the configuration during storage.

When curved in the longitudinal direction, the spring blades 73 tend to form a loop, and to exert an elastic force winding the spring blade 73 on itself. This configuration corresponds to the configuration when the barrier device 1 is in place around the tree 100. The elastic force winding the spring blade 73 pressing said barrier device 1 against the trunk of the tree 100.

The spring blades 73 are in particular made of so-called spring steel, austenitic and stainless, for example of the stainless steel 1.4310 type.

Several leaf springs 73 can in particular be stacked in the same sheath 71 in order to form the elongated body 7, with a greater elastic force.

Different sizes of elongated bodies 7 and therefore different sizes of barrier devices 1 can be proposed to surround trunks or branches of different sizes.

Figures 6 and 7 show a particular embodiment of barrier device 1 which further comprises a flange 13 on its upper edge.

The collar 13 is for example made of aluminum, with sufficient fineness to allow its deformation. The collar 13 is shown unfolded in Figure 6, which is a sectional view of the barrier device 1 similar to Figure 1. The collar 13 is in the form of a deformable metal sheet folded in a zigzag. The collar 13 is initially substantially flat, particularly when the elongated body 7 is in storage configuration and substantially linear.

When the elongated body 7 is wrapped around the tree trunk 100, the collar 13 is deployed, and in particular forms a fan-shaped protective overhang for the electrodes 3.

The collar 13 thus makes it possible to protect the electrodes from precipitation and runoff flowing down the trunk, and therefore to extend the life of the barrier device 1.

Figure 8 is a schematic representation of a barrier device 1 attached around the trunk of a tree 1.

The barrier device 1 here further comprises a device 15 for recharging the electrical power supply 5, in particular in the form of a photovoltaic panel, connected to the electrical power supply 5 and supplying it with electric current for its recharge.

The photo voltaic panel 15 can in particular be installed in the branches of the tree or on a dedicated post. A single photovoltaic panel 15 can be connected to several barrier devices 1 in several nearby trees 100.

The barrier device 1 according to the invention makes it possible to protect the tops of the trees 100 in an economical way, in particular compared to glue which must be regularly renewed, and ecologically, due to lower rejections and preservation of insects which may not not be killed. The installation of the barrier device 1 with electrodes 3 is easier and faster, and potentially less messy than the application of glue.

Claims

1. Anti-crawling insect barrier device for tree trunk (100) or branch, comprising:

- an elongated and deformable body (7), configured to surround, in the installed state, a tree trunk (100),

- an exterior face covered with nested electrodes (3), so that when an insect (11) walks on said exterior face, it is in contact with the two electrodes (3),

- an electrical power supply (5), with a positive pole and a negative pole connected respectively to one of the electrodes (3) of the exterior face, characterized in that the elongated body (7) comprises at least one bistable leaf spring (73) , with two stable states, including a transversely curved state, the spring blade (73) then being straight along a longitudinal axis, corresponding to a storage state of the device (1), and a longitudinally curved state, the spring blade (73) then being curved around a transverse axis and corresponding to an installed state of the device (1).

2. Device according to claim 1, characterized in that the electrodes (3) are carried by a sheath (71), into which the leaf spring (73) is inserted, forming the elongated body (7).

3. Device according to the preceding claim, characterized in that the sheath (71) comprises a plurality of bistable spring blades (73), stacked in the sheath (71).

4. Device according to one of the preceding claims, characterized in that the electrical power supply (5) is a box containing batteries or accumulators.

5. Device according to one of the preceding claims, characterized in that it further comprises a device for recharging (15) the electrical supply comprising at least one photovoltaic panel.

6. Device according to one of the preceding claims, characterized in that the electrodes (3) are in the form of parallel longitudinal conductive strips, connected alternately to a different pole of the electrical supply (5).

7. Device according to one of the preceding claims, characterized in that it further comprises a thickness of deformable foam (9) on the interior face opposite the exterior face carrying the electrodes (3).

8. Device according to the preceding claim, characterized in that the foam (9) is impregnated with a repellent or insecticidal substance, particularly for mealybugs.

9. Device according to one of the preceding claims, characterized in that it further comprises a deformable metal collar (13) at the level of the upper edge of the elongated body (7) forming, in the deployed state, a protective overhang for the electrodes (3) and the power supply (5).