NZ762115A

NZ762115A - Bait

Info

Publication number: NZ762115A
Application number: NZ762115A
Authority: NZ
Inventors: Jane Hall Donna; John Mccook William
Original assignee: Jane Hall Donna; John Mccook William
Priority date: 2019-03-19
Filing date: 2020-03-10
Publication date: 2020-03-13

Abstract

The present invention provides a bait at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent.

Description

BAIT TECHNICAL FIELD The present invention is in the field of pest control.

BACKGROUND ART Lures are used in association with pest baits to provide an olfactory attractant or cue intended to help the pest animals locate the baits and to increase bait acceptance and palatability to the pest species.

More recently, repellents have been developed for addition to baits for the purpose of deterring some non-target animals such as deer and certain birds. With some repellent products, the decline in the concentration of the repellent occurs quite rapidly.

It is a desirable aspect of many pest baits that the attractant or repellent persists until rainfall occurs but that the bait physically breaks down under rainfall. This significantly reduces the risk of non-target animals consuming the bait.

There is a need for pest baits that retain the desired effects of various active agents, such as lures or repellents, while retaining the desired weathering characteristics of the bait. Accordingly, it is an object of the present invention to go some way to achieve this outcome; and/or to at least provide the public with a useful choice.

Other objects of the invention may become apparent from the following description which is given by way of example only.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date.

SUMMARY OF THE INVENTION The applicants have inventively shown that by partially coating a bait with a coating comprising an active ingredient and an encapsulating agent, the degradative qualities of the bait can be retained, while the coating provides a convenient means to incorporate certain active agents to the bait as a whole. Furthermore, the coating can usefully delay the volatilisation of certain active agents, which allows for coordination of the useful life of a degrading bait with that of the volatile active agent.

Yet furthermore, active ingredients with limited solubility, that share solubility with the encapsulating agent, can be incorporated into the bait as a whole, within the coating.

Bait at least partially coated In a first aspect the invention provides a bait at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent.

Bait In one embodiment the bait is in the form selected from a pellet, a granule, block, or tube.

In a preferred embodiment the bait is in the form of a pellet.

In one embodiment the bait comprises a bait base material.

In one embodiment the bait base material is cereal based.

In one embodiment the bait is a plant or part thereof, selected from a vegetable or part thereof, a fruit or part thereof, or a seed.

In one embodiment the bait comprises one or more biocides.

In one embodiment the one or more biocides are selected from the group consisting of but not limited to sodium fluoroacetate, cholecalciferol, first generation anticoagulants, second generation anticoagulants, para-aminopropiophenone, norbormide, norbormide prodrugs, encapsulated sodium nitrite, or mixtures thereof.

At least partially coated In a preferred embodiment the bait is not completely coated with the coating.

In a preferred embodiment the bait is partially coated with the coating.

In one embodiment at least about 10% of the bait is coated with the coating.

In a further embodiment at least about 20%, more preferably at least about 30%, more preferably at least about 40%, more preferably at least about 50% of the surface of the bait is coated with the coating.

In a further embodiment about 20% to about 75% of the surface of the bait is coated with the coating.

In a further embodiment about 30% to about 70%, more preferably about 40% to about 60% of the surface of the bait is coated with the coating.

Coating does not prevent degradation of the of the bait In a preferred embodiment the coating does not prevent degradation of the bait.

In one embodiment degradation of the bait is due to wetting.

In a further embodiment wetting is due to the bait absorbing atmospheric moisture.

In a further embodiment the atmospheric moisture is rain water.

Encapsulating agent in the coating In one embodiment the encapsulating agent is selected from the group consisting of zein, shellac, paraffin wax, gums (e.g. guar gum), poly(vinyl acetate), lipids, glycerolipids, or a mixture thereof.

In a preferred embodiment the encapsulating agent is zein.

Active agent in the coating In one embodiment the active agent in the coating is selected from the group consisting of a volatile agent, an animal repellent, a lure, a flavour, a poison, or mixtures thereof.

In one embodiment the animal repellent is a deer repellent. In one embodiment the animal repellent is a bird repellent.

In a preferred embodiment, the active agent in the coating is an animal repellent. In a more preferred embodiment, the active agent in the coating is a bird repellent.

In some embodiments the bait, as opposed to the coating, comprises at least one active ingredient as recited above.

Active agent in coating is a volatile agent In one embodiment the active agent in the coating is a volatile agent.

In some embodiments, the bird repellent, lure, flavour, or poison is a volatile agent.

In one embodiment the volatile agent is selected from the group consisting of an animal repellent, a lure, a flavour, a poison, or mixtures thereof.

In one embodiment the animal repellent is a bird repellent. In one embodiment the volatile agent is a bird repellent.

In one embodiment the volatile agent is selected from (R)-(+)-pulegone, a blood volatile, an animal protein volatile, a garlic volatile, an essential oil volatile, a synthetic attractant, and a natural attractant.

In a preferred embodiment the volatile agent is (R)-(+)-pulegone.

Active agent in coating is an animal repellent In one embodiment the active agent is an animal repellent.

In one embodiment the animal repellent is selected from the group consisting of (R)-(+)- pulegone, tannic acid, ortho-aminoacetophenone, anthraquinone, animal proteins, blood, garlic oil, or mixtures thereof.

In one embodiment the animal repellent is a bird repellent. In one embodiment the active agent is a bird repellent.

In one embodiment the bird repellent is selected from the group consisting of (R)-(+)- pulegone, tannic acid, ortho-aminoacetophenone, anthraquinone, or mixtures thereof.

In a preferred embodiment the bird repellent is (R)-(+)-pulegone.

In one embodiment the animal repellent is a deer repellent. In one embodiment the active agent is a deer repellent.

In one embodiment the deer repellent is selected from the group consisting of animal proteins, blood, garlic oil, or mixtures thereof.

Active agent in coating is a lure or a flavour In one embodiment the active agent is a lure or a flavour.

In one embodiment, the lure or flavour is selected from the group consisting of synthetic and natural attractants derived from or occurring in fish, meat, insects, or pheromones.

In one embodiment the natural attractant is selected from the group consisting of chocolate, coconut, cheese, nut fruit, fruits, berries, or an extract thereof.

In one embodiment the synthetic attractant is selected from the group consisting of synthetic compounds whose odours are known to be characteristic of fish, meat, insects, pheromones, chocolate, coconut, cheese, nut fruit, fruits, berries.

Active agent in coating is a poison In one embodiment the active agent is a poison.

In one embodiment, the poison is selected from the group consisting of sodium fluoroacetate, norbormide, norbormide prodrugs, and mixture thereof Active agent in the bait as a whole In various embodiments, the bait comprises from about 0.01% to about 1.5% w/w of the total bait weight as active agent in the coating, for example from about 0.1 to about 1.0% w/w of the total bait weight as active agent in the coating. In a preferred embodiment, the bait comprises about 0.2 % w/w of the total bait weight as active agent in the coating.

In various embodiments, the bait comprises from about 0.01% to about 0.3% w/w of the total bait weight as bird repellent in the coating, for example from about 0.1 to about 0.3% w/w of the total bait weight as bird repellent in the coating. In a preferred embodiment, the bait comprises about 0.2 % w/w of the total bait weight as bird repellent in the coating.

In various embodiments, the bait comprises from 0.1 to 0.3% w/w of the total bait weight as (R)-(+)-pulegone in the coating. In a preferred embodiment, the bait comprises about 0.2 %w/w of the total bait weight as (R)-(+)-pulegone in the coating. In a further preferred embodiment, the bait comprises 0.2 %w/w of the total bait weight as (R)-(+)-pulegone in the coating.

Delayed volatilisation of volatile agent In one embodiment the active agent is a volatile agent as described above.

In one embodiment the encapsulating agent delays the volatilisation of the volatile agent from the coating on the bait.

In one embodiment the encapsulating agent delays the volatilisation of the volatile agent from the coating such that the volatile agent remains detectable at least 1 month after the coating was first formed.

In a further embodiment the volatile agent remains detectable at least 2 months, more preferably at least 3 months, more preferably at least 4 months after the coating is formed.

In preferred embodiment the encapsulating agent delays the volatilisation of the volatile agent from the coating such that the volatile agent remains detectable at least 1 month after the bait is placed at the site where the pest is to be controlled.

In a further preferred embodiment, the active agent remains detectable at least 2 months, more preferably at least 3 months, more preferably at least 4 months after the bait is placed at the site where the pest is to be controlled.

In a preferred embodiment the coating delays volatilisation of the volatile agent but does not significantly delay degradation of the bait.

Solubility of encapsulating agent In one embodiment the encapsulating agent is soluble in a solvent.

In one embodiment the solvent is an alcohol-based solvent. In one embodiment the solvent is an aqueous alcohol or anhydrous methanol solvent.

In a preferred embodiment the alcohol is aqueous ethanol.

In a more preferred embodiment the solvent at least 50% ethanol, preferably at least 60% ethanol, more preferably at least 70% ethanol, more preferably at least 80% ethanol, more preferably at least 90% ethanol.

In a further preferred embodiment, the solvent is about 90% ethanol. In a further preferred embodiment, the solvent is 90% ethanol.

Solubility of the active agent In one embodiment the active agent is soluble in a solvent.

In a preferred embodiment the alcohol is aqueous ethanol.

Compatible solubility of the encapsulating agent and the active agent In a further embodiment the encapsulating agent and the active agent are soluble in the same solvent.

In a preferred embodiment the alcohol is aqueous ethanol.

In some embodiments the invention is useful for incorporating active agents that are otherwise challenging to incorporate into to a bait, due to their limited solubility.

These embodiments are useful for incorporating active ingredients that share solvent compatibility with the encapsulating agent.

In some embodiments the active agent is selected from the group consisting of (R)-(+)- pulegone, tannic acid, ortho-aminoacetophenone, blood, hydrolysed proteins, garlic and other essential oils, synthetic attractants, and sodium fluoroacetate.

In a preferred embodiment the active agent is (R)-(+)-pulegone and the encapsulating agent is zein.

In another preferred embodiment the active agent is norbormide or derivative thereof and the encapsulating agent is zein.

Method of producing a bait at least partially coated with the bird repellent coating In a further aspect the invention provides a method for producing a bait at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent.

In one embodiment the method comprises the steps of: a) mixing the at least one active agent and the at least one encapsulating agent in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

Those skilled in the art will understand that the active agent(s) and encapsulating agent(s) can be mixed in any order.

The active agent and encapsulating agent may be any of those described previously.

In one embodiment the method comprises the step of dissolving the active agent and the encapsulating agent in the solvent.

In a further aspect the invention provides a bait produced by a method of the invention that is at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent.

In a preferred embodiment the bait is not completely coated with the coating.

In a preferred embodiment the bait is partially coated with the coating.

In one embodiment at least about 10% of the bait is coated with the coating.

In a further embodiment about 10% to about 90% of the surface of the bait is coated with the coating.

In a further embodiment about 20% to about 80%, more preferably about 30% to about 70%, more preferably about 40% to about 60% of the surface of the bait is coated with the coating.

Coating composition in liquid form In one embodiment the coating composition is in liquid form.

In one embodiment, the coating composition is in a liquid form suitable for application to a desired bait by spraying. In one embodiment, the bait is immersed in the coating composition to apply the coating composition to the bait.

In one embodiment the active agent and encapsulating agent are dissolved in an alcohol- based solvent. In one embodiment the active agent and encapsulating agent are dissolved in an aqueous alcohol or anhydrous methanol solvent. In a preferred embodiment the alcohol is aqueous ethanol.

Ratio of active agent and encapsulating agent In one embodiment the active agent and encapsulating agent are present in the coating composition at a ratio in the range of about 1:10 to about 10:1, preferably about 1:5 to about 5:1, more preferably about 1:3 to about 3:1, more preferably about 1:2 to about 2:1.

In a preferred embodiment the active agent and encapsulating agent are present in the coating composition at a ratio of about 1:1.

Concentration of active agent in the coating composition In one embodiment the concentration of active agent in the coating composition is at least about 1% w/v, preferably at least about 2% w/v, preferably at least about 3% w/v, preferably at least about 5% w/v, preferably at least about 10% w/v.

Concentration of encapsulating agent in the coating composition In one embodiment the concentration of encapsulating agent in the coating composition is at least about 1% w/v, preferably at least about 2% w/v, preferably at least about 3% w/v, preferably at least about 5% w/v, preferably at least about 10% w/v.

Coating in solid form In one embodiment the coating is in solid form.

In one embodiment the coating is formed by evaporation of at least part of the solvent from the coating composition. In one embodiment the coating is formed by evaporation of the solvent from the coating composition.

In one embodiment degradation of the bait is due to wetting.

In a further embodiment the atmospheric moisture is rain water.

Delay of volatile agent volatilisation In one embodiment the encapsulating agent delays the volatilisation of the volatile agent from the coating.

In one embodiment the encapsulating agent delays the volatilisation of the volatile agent from the coating such that volatilisation of the volatile agent remains detectable at least 1 month after the coating was first formed.

In a further embodiment volatilisation of the volatile agent remains detectable at least 2 months, more preferably at least 3 months, more preferably at least 4 months after the coating is formed.

Methods for detecting the volatilisation of the volatile agent will be apparent to a skilled worker. In one embodiment the volatilisation of the volatile agent is detected by odour. In another embodiment the volatilisation of the volatile agent is detected by high performance liquid chromatography (HPLC) or gas chromatography (GC).

In one embodiment the encapsulating agent delays the volatilisation of the volatile agent from the coating such that the volatile agent remains detectable at least 1 month after the bait is placed at the site where the pest is to be controlled.

In a further preferred embodiment, the volatile agent remains detectable at least 2 months, more preferably at least 3 months, more preferably at least 4 months after the bait is placed at the site where the pest is to be controlled.

Method of controlling pests In a further aspect the invention provides a method for controlling at least one pest, the method comprising exposing the pest to a bait according to the invention or a bait produced by the method of the invention.

In a preferred embodiment the pest ingests at least part of the bait.

In one embodiment the pest is selected from the group consisting of but not limited to deer, pigs, rabbits, cats, possums, rats, mustelids, mice, wallabies, and feral dogs.

Method of modifying behaviour In a further aspect the invention provides a method for modifying the behaviour of at least one animal, the method comprising exposing the animal to a bait according to the invention or a bait produced by the method of the invention.

In one embodiment the behaviour of the animal is modified by the volatile agent evaporating from the bait of the invention.

In one embodiment the active agent is a bird repellent, the animal is a bird, and the behaviour modification is repelling the bird. In one embodiment the bird is repelled by the bird repellent evaporating from the bait of the invention.

In one embodiment the bird is selected from the group consisting of but not limited to kea, kakapo, and kereru.

In one embodiment the active agent is a deer repellent, the animal is a deer, and the behaviour modification is repelling the deer. In one embodiment the deer is repelled by the deer repellent evaporating from the bait of the invention.

In one embodiment the behaviour modification is attracting a pest. In one embodiment the active agent is a flavour or a lure, the animal is a pest, and the behaviour modification is attracting the pest.

Specific aspects In one aspect the invention provides a bait at least partially coated in a coating comprising at least one volatile agent and at least one encapsulating agent, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

In one aspect the invention provides a bait at least partially coated in a coating comprising at least one volatile agent and zein, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

In one aspect the invention provides a bait at least partially coated in a coating comprising at least bird repellent and at least one encapsulating agent, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

In one aspect the invention provides a bait at least partially coated in a coating comprising at least bird repellent and zein, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

In one aspect the invention provides a method for producing a bait at least partially coated in a coating comprising at least one volatile agent and at least one encapsulating agent, the method comprising the steps of: a) mixing the at least one volatile agent and the at least one encapsulating agent in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

In one aspect the invention provides a method for producing a bait at least partially coated in a coating comprising at least one volatile agent and zein, the method comprising the steps a) mixing the at least one volatile agent and zein in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

In one aspect the invention provides a method for producing a bait at least partially coated in a coating comprising at least one bird repellent and at least one encapsulating agent, the method comprising the steps of: a) mixing the at least one bird repellent and the at least one encapsulating agent in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

In one aspect the invention provides a method for producing a bait at least partially coated in a coating comprising at least one bird repellent and zein, the method comprising the steps a. mixing the at least one bird repellent and zein in a solvent to produce a coating composition, b. applying the coating composition to at least part of a bait, and c. evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

In addition, where features or aspects of the invention are described in terms of Markush groups, those persons skilled in the art will appreciate that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.

As used herein “(s)” following a noun means the plural and/or singular forms of the noun.

As used herein the term “and/or” means “and” or “or” or both.

The term “comprising” as used in this specification means “consisting at least in part of”.

When interpreting each statement in this specification that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise”, “comprised”, and “comprises” are to be interpreted in the same manner.

It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

Although the present invention is broadly as defined above, those persons skilled in the art will appreciate that the invention is not limited thereto and that the invention also includes embodiments of which the following description gives examples.

DETAILED DESCRIPTION OF THE INVENTION The inventors have surprisingly found that the efficacy of an active agent coated on a bait can be maintained over a period by incorporating the active agent with an encapsulating agent.

Partial coating of a bait in the active agent and encapsulating agent still allows the bait to degrade as necessary.

Bait at least partially coated with the coating In a first aspect the invention provides a bait at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent.

Baits are substances or objects used to attract and control pests. Pests are animals that impact adversely on humans, or are a threat to protected, native, and/or endangered species. In some countries, such as New Zealand, introduced mammalian pests are a threat to native species such as plants, birds, and bats. Mammalian pests include mustelids, rodents, marsupials, felines, and rabbits. In various embodiments, the target animals are selected from the group consisting of possums, rats, stoats, ferrets, feral cats, rabbits, weasels, deer, pigs, mice, wallabies, and feral dogs.

In some instances when using baits to control animal pests, it is important that non-target animals are not attracted to the bait and/or do not ingest the bait. This may be achieved by adding a substance to the bait that repels non-target animals. It is important that this repellent substance remains repellent for the lifetime of the bait. Otherwise, baits may be deployed that are attractive or potent to non-target animals and thus pose a risk to the non-target animal.

Alternatively, it may be desirable to add a substance to the coating that attracts pests, such as a lure or a flavour, or a substance that harms pests, such as a poison.

The inventors have found that by incorporating an active agent in to a coating comprising an encapsulating agent, the active agent retains its effect for a longer time.

Encapsulation is a process in which particles or compounds are surrounded by an encapsulating agent. Suitable encapsulating agents may be palatable to a pest, and able to be applied to a surface of a bait.

It is desirable, and in some instances a requirement, that baits break down or weather appropriately in the environment. In some situations, it is preferable that the bait breaks down after exposure to rain and that if the bait contains an active agent, the active agent leaches out of the bait.

However, a bait must also be stable during storage or transportation.

The inventors have found that by at least partially coating a bait with a coating composition comprising an active agent and an encapsulating agent, the properties of the active agent can be maintained, while also maintaining desirable weathering characteristics of the bait.

In a preferred embodiment the bait is in the form of a pellet.

In one embodiment the bait comprises a bait base material.

In a further embodiment the bait base material is selected from the group consisting of cereal-based, a plant or part thereof, a seed, or a vegetable. In a preferred embodiment, the bait base material is cereal-based. Cereal-based pellet baits may comprise cereals (such as wheat, maize, oats, or barley), sugar, fats, anti-microbial agents, and flavours, in addition to one or more active agents.

When used to control pests, baits may contain one or more biocides that cause disturbance or death in the target animal. In various embodiments, the bait comprises one or more biocides. Bait biocides are selected from the group consisting of but not limited to sodium fluoroacetate, cholecalciferol, first generation anticoagulants, second generation anticoagulants, para-aminopropiophenone, norbormide, norbormide prodrugs, encapsulated sodium nitrite, or mixtures thereof, or any other suitable active agent known to a skilled worker.

In a further embodiment the bait comprises one or more biocides.

In a further embodiment the one or more biocides are selected from the group consisting of but not sodium fluoroacetate, cholecalciferol, first generation anticoagulants, second generation anticoagulants, para-aminopropiophenone, norbormide, norbormide prodrugs, encapsulated sodium nitrite, or mixtures thereof. First generation anticoagulants include warfarin, coumatetralyl diphacinone, chlorophacinone, and pindone. Second generation anticoagulants include difenacoum, brodifacoum, flocoumafen, and bromadiolone.

In various embodiments, the bait comprises a bait base material and one or more biocides.

A person skilled in the art will understand methods for producing baits, with or without biocides.

At least partially coated In one embodiment the bait is not completely coated with the coating.

In one embodiment the bait is partially coated with the coating.

In one embodiment at least 10%, preferably at least about 20%, more preferably at least about 30%, more preferably at least about 40%, more preferably at least about 50% of the surface of the bait is coated with the coating composition.

In one embodiment about 20% to about 75%, more preferably about 30% to about 70%, more preferably about 40% to about 60% of the surface of the bait is coated with the coating composition.

Coating does not prevent degradation of the of the bait In a preferred embodiment the coating does not significantly prevent degradation of the bait. In a preferred embodiment the coating does not prevent degradation of the bait.

In one embodiment degradation of the bait is due to wetting.

In a further embodiment the atmospheric moisture is rain water.

Encapsulating agent in the coating In various embodiments, the encapsulating agent is selected from the group consisting of zein, shellac, paraffin wax, gums (e.g. guar gum), poly(vinyl acetate), lipids, glycerolipids, or mixtures thereof. In a preferred embodiment, the encapsulating agent is zein.

In various embodiments, the encapsulating agent is a glazing agent. A glazing agent is a natural or synthetic substance that can provide a waxy, homogeneous coating to substances to prevent water loss from a surface and provide other protection.

In a preferred embodiment the glazing agent is zein.

Zein is a class of prolamine protein found in maize. It is usually manufactured as a powder from corn gluten meal. Zein is translucent, odourless, tasteless, hard, water-insoluble, and an edible protein.

In one embodiment the animal repellent is a deer repellent. In one embodiment the volatile agent is a deer repellent.

In a preferred embodiment the volatile agent is (R)-(+)-pulegone.

Repellents can be classified as primary and secondary repellents. Primary repellents deter non-target animals by having an unpleasant taste, look, or smell, or causing instant irritation to an animal. Secondary repellents deter non-target animals due to learned association with an unpleasant effect, such as causing illness (Sayre, Roger W. and Clark, Larry, "Comparison of Primary and Secondary Repellents for Aversive Conditioning of European Starlings" (2001). USDA National Wildlife Research Center - Staff Publications. 611.).

Some animal repellents are volatile organic compounds, that deter animals due to an unpleasant smell. However, due to this volatility, the animal repellent may lose its repellent effect within a short time. The animal repellent content in a composition may decline rapidly when the compositions held in storage, or are subject to rain.

In one embodiment the bird repellent is selected from the group consisting of (R)-(+)- pulegone, tannic acid, ortho-aminoacetophenone, anthraquinone, or mixtures thereof. In a preferred embodiment the bird repellent is (R)-(+)-pulegone.

A lure or flavour may be selected to attract a specific target pest.

In one embodiment the synthetic attractant is selected from the group consisting of synthetic compounds whose odours are known to be characteristic of fish, meat, insects, pheromones, chocolate, coconut, cheese, nut fruit, fruits, berries. These compounds will be known to a skilled worker.

In one embodiment, the poison is selected from the group consisting of sodium fluoroacetate, norbormide, norbormide prodrugs, and mixture thereof In some embodiments, the active agent present in the coating may also be present in the bait.

Active agent in the bait as a whole In various embodiments, the bait comprises from about 0.01% to about 1.5% w/w of the total bait weight as active agent in the coating. For example, the bait comprises from about 0.02 to about 1.5% w/w, or about 0.05 to about 1.2% w/w, or about 0.1 to about 1.0% w/w, or about 0.05 to about 0.2% w/w, or about 0.1 to about 0.2% w/w of the total bait weight as active agent in the coating. In a preferred embodiment, the bait comprises 0.2 %w/w of the total bait weight as active agent in the coating.

In various embodiments, the bait comprises from 0.01 to 0.3% w/w of the total bait weight as bird repellent in the coating. In a preferred embodiment, the bait comprises 0.2 %w/w of the total bait weight as bird repellent in the coating.

In various embodiments, the bait comprises from 0.1 to 0.3% w/w of the total bait weight as (R)-(+)-pulegone in the coating. In a preferred embodiment, the bait comprises 0.2 %w/w of the total bait weight as (R)-(+)-pulegone in the coating.

Delayed volatilisation of volatile agent In one embodiment the active agent is a volatile agent.

In one embodiment the encapsulating agent delays the volatilisation of the volatile agent from the bait such that the volatile agent remains detectable at least 1 month after the bait was first formed.

In a further embodiment the volatile agent remains detectable at least 2 months, more preferably at least 3 months, more preferably at least 4 months after the bait is formed.

Methods for detecting the volatilisation of the volatile agent will be apparent to a skilled worker, including but not limited to HPLC or GC detection or merely odour detection if the volatile agent has a distinctive smell. In one embodiment the volatilisation of the volatile agent is detected by odour. In another embodiment the volatilisation of the volatile agent is detected by HPLC. In another embodiment the volatilisation of the volatile agent is detected by GC.

Solubility In one embodiment the encapsulating agent is soluble in a solvent.

In one embodiment the active agent is soluble in a solvent.

In a further embodiment the encapsulating agent and the active agent are soluble in the same solvent.

In a preferred embodiment the alcohol is aqueous ethanol.

Active agents in the bait In some embodiments the bait, as opposed to the coating, comprises at least one active ingredient as recited above.

In one embodiment the bait comprises one or more biocides.

Method of producing a bait at least partially coated with the coating In a further aspect the invention provides a method for producing a bait at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent.

In one embodiment at least about 10% of the bait is coated with the coating. In a further embodiment at least about 20%, more preferably at least about 30%, more preferably at least about 40%, more preferably at least about 50% of the surface of the bait is coated with the coating. In a preferred embodiment the bait is not completely coated with the coating. In a preferred embodiment the bait is partially coated with the coating.

In a further embodiment about 10% to about 90% of the surface of the bait is coated with the coating. In a further embodiment about 20% to about 80%, more preferably about 30% to about 70%, more preferably about 40% to about 60% of the surface of the bait is coated with the coating.

Coating composition in liquid form In one embodiment the coating composition is in liquid form. Preferably the coating composition is in a liquid form suitable for application to a desired substrate by spraying. In a further embodiment the substrate can be immersed in the coating composition to apply the coating composition to the substrate.

In one embodiment the method comprises the step of applying the coating composition to at least part of a bait. In various embodiments, the coating composition is applied by spraying, painting, or dipping. In a preferred embodiment, the bait is coated with the coating composition by spraying. Other methods of applying the coating composition to a bait will be apparent to a person skilled in the art.

In a further embodiment the method comprises the step of evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating. The solvent is evaporated such that the bait does not lose its strength and integrity.

In one embodiment the method comprises the steps of dissolving the active agent and encapsulating agent in the solvent. Those skilled in the art will understand that active agent or encapsulating agent can be dissolved in any order, or together.

In a further aspect the invention provides a bait produced by the method of the invention.

Ratio of active agent and encapsulating agent In one embodiment the active agent and encapsulating agent are present in the coating composition at a ratio of less than 10:1, preferably less than 5:1, more preferably less than 3:1, less than 2:1.

In a further embodiment the active agent and encapsulating agent are present in the coating composition at a ratio of greater than 1:10, preferably greater than 1:5, more preferably greater than 1:3, more preferably greater than 1:2.

In a further embodiment the active agent and encapsulating agent are present in the bait, coating, and/or coating composition at a ratio in the range of about 1:10 to about 10:1, preferably about 1:5 to about 5:1, more preferably about 1:3 to about 3:1, more preferably about 1:2 to about 2:1.

In a preferred embodiment the active agent and encapsulating agent are present in the bait, coating, and/or coating composition at a ratio of about 1:1.

Concentration of encapsulating agent in the composition In one embodiment the concentration of encapsulating agent in the coating composition is at least about 1% w/v, preferably at least about 2% w/v, preferably at least about 3% w/v, preferably at least about 5% w/v, preferably at least about 10% w/v.

Coating in solid form Described herein is a coating comprising at least one active agent and at least one encapsulating agent. The coating may comprise the same active agents and encapsulating agents as previously described.

In one embodiment the coating is in solid form.

In one embodiment the coating is formed by evaporation of the solvent from the coating composition described herein.

In one embodiment degradation of the bait is due to wetting. In a further embodiment wetting is due to the bait absorbing atmospheric moisture. In a further embodiment the atmospheric moisture is rain water.

The baits produced by the method may delay volatilisation of volatile agent and the coating may not prevent degradation of the bait, as described previously.

Solubility In various embodiments, the active agent and the encapsulating agent are both soluble in the same solvent. In various embodiments, the active agent and the encapsulating agent are both soluble in a volatile solvent. In various embodiments, the active agent and the encapsulating agent are both soluble in 90% ethanol.

In one embodiment the active agent and encapsulating agent are dissolved in an alcohol- based solvent. In a preferred embodiment the alcohol is ethanol.

A person skilled in the art will understand that when the active agent is a volatile agent, the volatile agent will be retained in the coating while the solvent (e.g. ethanol) evaporates. In some instances, the volatile agent may be encapsulated by the encapsulating agent. In some instances, the volatile agent may be less volatile than the solvent used.

Method of controlling pests In a further aspect the invention provides a method for controlling at least one pest, the method comprising exposing the pest to the bait of the invention, or a bait formed by the method of the invention.

In a preferred embodiment the pest ingests at least part of the bait. Ingestion of the bait may cause discomfort or death of the pest.

Method of modifying behaviour In a further aspect the invention provides a method for modifying the behaviour of at least one animal, the method comprising exposing the animal to a bait of the invention or a bait produced by the method of the invention.

In one embodiment the bait comprises a bird repellent, the animal is a bird, and the behaviour modification is repelling the bird.

In one embodiment the bird is selected from the group consisting but not limited to kea, kakapo, and kereru.

In one embodiment the bait comprises a deer repellent, the animal is a deer, and the behaviour modification is repelling the deer.

In one embodiment the bait comprises a flavour or a lure, the animal is a pest, and the behaviour modification is attracting the pest.

The following non-limiting examples are provided to illustrate the present invention and in no way limit the scope thereof.

EXAMPLES Materials and methods Zein F4000C was source from Flo Chemical Corporation, Ashburnham MA 01430 USA.

(R)-(+)-pulegone CAS 897 was sourced from Penta Manufacturing, New Jersey 07039 USA.

Cereal based pellets were manufactured using a 16mm diameter ring die animal feed pellet mill. The resulting pellets had a uniform surface and were free of visible dust and had a hardness of 23kg/cm measured by a Kahl Pellet Hardness Tester produced by Amandus Kahl GmbH & Co. Hamburg Germany.

HPLC used was an Agilent 1260 Infinity with a single Quadrapole Mass Spectrometer detector.

The amount of (R)-(+)-pulegone in baits was detected using High Performance Liquid Chromatography (HPLC) detector at 252nm with comparison to a standard curve.

Standards: 100mg (R)-(+)-pulegone (92%) was accurately weighed into a 100ml volumetric flask and dissolved in 100ml HPLC grade methanol (1000ppm).

This standard was diluted to make calibration points for the calibration curve. ppm ml of 1000ppm standard Area Reference points 1 ppm 0.1 3 Limit of detection ppm 1 30 1 0.001% 100 ppm 10 300 2 0.01% 1000 ppm 3 0.1% The following conditions were used for LC/MS: a) Injection volume: 1μl b) Column: PFP 7.5cm c) RT: 5.0 min d) Fragmentor: Positive 30 e) m/z: 152 f) UV 252mn g) Mobile phase: 40% MeOH: 10% CH CN: 50% H O water over 6 min contains 10mmol triethanolamine. h) Mobile phase flow rate 1.0ml/min.

To prepare the 0.2% pellet (10% coating) samples 5g pellet samples were accurately weighed into a screw cap vial and 10ml 90% ethanol was added. The samples were left to stand overnight and filtered before analysis. 0.2% Pellet: (10% coating); MULTIPLIER: 0.01; DILUTION: 0.003 To prepare blank: zein sample 5g RS5 pellet sample was accurately weighed into a screw cap vial and 10ml 90% ethanol was added. The samples were left to stand overnight and filtered before analysis.

Example 1: Manufacture of bait with zein and (R)-(+)-pulegone A coating composition of (R)-(+)-pulegone (20g) and zein (20g) dissolved in 90% ethanol (aqueous) (160g) was prepared. 16mm non-toxic RS5 cereal bait (10 kg) was partially coated with the coating composition. The cereal baits were tightly packed in a single layer in trays so that when they were sprayed with the coating composition, the ethanol could evaporate at ambient temperature. Some of the surfaces remained unsprayed leaving part of each pellet uncoated.

Control baits were prepared without coating, in which (R)-(+)-pulegone was added into the pellet mix before they were made.

Example 2: Stability The stability of the pellets from Example 1 were determined. The odour of the (R)-(+)- pulegone was still clearly detectable by HPLC four months after the coating was first applied. This compares well when bait without this coating was devoid of odour within ten days of manufacture.

The results showed the stability of the extraction in the laboratory and that the (R)-(+)- pulegone in the test pellets remained at the original level for 2 months.

Example 3: Weathering A simulated rainfall trail was conducted using a calibrated sprinkler system, a rain gauge and a bait tray which was divided into two with standard non-toxic pellets on half of the tray and pellets partially coated in (R)-(+)-pulegone and zein on the other half of the tray. Excluding the addition of (R)-(+)-pulegone and a partial coating of zein to the test pellet, the pellet bait formulation and manufacturing method used for the two types of bait was identical.

The bait used (RS5) is normally very hygroscopic and readily absorbs water when exposed to rain or even heavy dews. Simulated rainfall trials are routinely used and found to be useful for measuring the effects of rainfall on various bait parameters such as size, hardness and poison retention (Bowen LH, Morgan DR and Eason CT 1995. Persistence of 1080 in baits under simulated rainfall. New Zealand Journal of Agricultural Research 38(4):529-531).

The rates of disintegration of standard and zein-coated baits were compared visually to determine whether the zein helped baits to either repel water or reduce the rate of degradation.

Bait was subjected to three minutes of continuous simulated rain which thoroughly wet the exterior of the pellets. The sprinkler was then turned off and all baits were carefully examined in an effort to detect the presence of zein on the test baits or to find any indication that some parts of the test pellets were resisting water. There was no sign of either, both the test baits and the standard baits were uniformly wet.

Rainfall was then turned on for a further 45 minutes, taking total cumulative rainfall to 5mm. At the end of this period all pellets from both groups were uniformly affected by rain with the bait exteriors having become soft and mushy. Surface erosion had begun on all surfaces of both bait types.

There was no sign of the zein having reduced water uptake in any area of the pellets.

While some of the zein coated pellets had appeared slightly darker (as if lacquered) prior to the rainfall commencing, it had not been possible to positively determine where the zein started and finished on the coated pellets.

The baits were then left to dehydrate in the open air to later determine whether there was any visible sign of zein on drying and to assess whether the odour of (R)-(+)-pulegone remained.

After three days the baits were re-examined, and all had firmed considerably but lost some form. No sign of zein was present although a strong odour of (R)-(+)-pulegone was still present in the test baits.

Based on these results, the partial addition of zein to cereal pellets used for pest control helps to retain the olfactory cue provided by (R)-(+)-pulegone whereas zein appears to not impede the breakdown of cereal baits under rainfall.

It is not the intention to limit the scope of the invention to the abovementioned examples only. As would be appreciated by a skilled person in the art, many variations are possible without departing from the scope of the invention.

INDUSTRIAL APPLICATION The bait and methods of the invention have utility in the field of pest control for many agricultural, horticultural, and conservation applications, such as providing conservationists a useful means of controlling animal pests while retaining desired weathering characteristics of the bait.

Claims

We claim:

1. A bait at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent.

2. A bait according to claim 1, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

3. A bait according to any one of the preceding claims wherein the coating does not significantly prevent degradation of the bait.

4. A bait according to any one of the preceding claims wherein the encapsulating agent is selected from the group consisting of zein, shellac, paraffin wax, gums (e.g. guar gum), poly(vinyl acetate), lipids, glycerolipids, or a mixture thereof.

5. A bait according to any one of the preceding claims wherein the encapsulating agent is zein.

6. A bait according to any one of the preceding claims wherein the active agent is selected from the group consisting of a volatile agent, an animal repellent, a lure, a flavour, a poison, or mixtures thereof.

7. A bait according to any one of the preceding claims wherein active agent is a volatile agent.

8. A bait according to any one of the preceding claims wherein volatile agent is selected from the group consisting of an animal repellent, a lure, a flavour, a poison, or mixtures thereof.

9. A bait according to claim 8 wherein the volatile agent is selected from the group consisting of (R)-(+)-pulegone, a blood volatile, an animal protein volatile, a garlic volatile, an essential oil volatile, a synthetic attractant, and a natural attractant.

10. A bait according to claim 6 or 8 wherein the animal repellent is a bird repellent, and the bird repellent is selected from the from the group consisting of (R)-(+)-pulegone, tannic acid, ortho-aminoacetophenone, anthraquinone, or mixtures thereof.

11. A bait according to claim 10 wherein the bird repellent is (R)-(+)-pulegone.

12. A bait according to claim 6 or 8 wherein the flavour or lure is selected from the from the group consisting of synthetic and natural attractants derived from or occurring in fish, meat, insects, or pheromones.

13. A bait according to claim 6 or 8 wherein the poison is selected from the from the group consisting of sodium fluoroacetate, norbormide, norbormide prodrugs, and mixture thereof.

14. A bait according to any one of claims 7 to 13 wherein the encapsulating agent delays the volatilisation of the volatile agent from the coating on the bait.

15. A bait according to any one of the preceding claims wherein the bait comprises one or more biocides.

16. A bait according to claim 15 wherein the one or more biocides are selected from the group consisting of sodium fluoroacetate, cholecalciferol, first generation anticoagulants, second generation anticoagulants, para-aminopropiophenone, norbormide, norbormide prodrugs, encapsulated sodium nitrite, or mixtures thereof.

17. A method for producing a bait at least partially coated in a coating comprising at least one active agent and at least one encapsulating agent, the method comprising the steps of: a) mixing the at least one active agent and the at least one encapsulating agent in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

18. A method for controlling at least one pest, the method comprising exposing the pest to a bait according to any one of claims 1 to 16 or a bait produced by the method according to claim 17.

19. A method for modifying the behaviour of at least one animal, the method comprising exposing the animal to a bait according to any one of claims 1 to 16 or a bait produced by the method according to claim 17.

20. A bait at least partially coated in a coating comprising at least one volatile agent and at least one encapsulating agent, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

21. A bait at least partially coated in a coating comprising at least one volatile agent and zein, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

22. A bait at least partially coated in a coating comprising at least bird repellent and at least one encapsulating agent, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

23. A bait at least partially coated in a coating comprising at least bird repellent and zein, wherein from about 10% to about 90% of the surface of the bait is coated with the coating.

24. A method for producing a bait at least partially coated in a coating comprising at least one volatile agent and at least one encapsulating agent, the method comprising the steps a) mixing the at least one volatile agent and the at least one encapsulating agent in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

25. A method for producing a bait at least partially coated in a coating comprising at least one volatile agent and zein, the method comprising the steps of: a) mixing the at least one volatile agent and zein in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

26. A method for producing a bait at least partially coated in a coating comprising at least one bird repellent and at least one encapsulating agent, the method comprising the steps a) mixing the at least one bird repellent and the at least one encapsulating agent in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.

27. A method for producing a bait at least partially coated in a coating comprising at least one bird repellent and zein, the method comprising the steps of: a) mixing the at least one bird repellent and zein in a solvent to produce a coating composition, b) applying the coating composition to at least part of a bait, and c) evaporating at least part of the solvent from the coating composition on the bait to produce a bait at least partially coated by the coating.