WO2009095878A2

WO2009095878A2 - Environmentally friendly rodenticide preparation

Info

Publication number: WO2009095878A2
Application number: PCT/IB2009/050367
Authority: WO
Inventors: Massimo Tagliaro; Pierpaolo Zambotto
Original assignee: Zapi Industrie Chimiche Spa
Priority date: 2008-01-30
Filing date: 2009-01-29
Publication date: 2009-08-06
Also published as: ITMI20080142A1; WO2009095878A3

Abstract

In one aspect, the present invention relates to an environmentally friendly rodenticide preparation, consisting of a bait, preferably in paste form, containing a rodenticide active principle in association with a carrying substance, which has a baiting action, and further additional components, typically packaged in packets or in pre-measured portions, with a film made of a biopolymer, having baiting properties for the most common infesting murine species.

Description

ENVIRONMENTALLY FRIENDLY RODENTICIDE PREPARATION

FIELD OF THE INVENTION

The present invention relates to an environmentally friendly rodenticide preparation.

The invention originates in the field of products aimed at preventing and treating infestations by the murine species.

Specifically, the present invention relates to the use of a selected biodegradable material as a substitute of traditional filter paper for packing rat-poison bait in dose packets.

BACKGROUND OF THE INVENTION

The increase of the murine population and the growth of infestation in urban areas previously not affected by this phenomenon, have determined recently a rapid development of fighting systems used against murine species.

The control of the infesting murine population has assumed a more and more important role right in the urban centers, where adequate hygiene-sanitary standards must be ensured.

The problem of the murine infestations is strongly felt, because rats and mice not only live a parasitic life that impoverishes available food resources, but are also carriers of diseases injurious to humans or domestic animals.

In order to cope with this situation, there have been developed disinfestations techniques that make use of physical, electronic means and of chemical means.

The physical means include mechanical traps, glues and ultrasounds. The mechanical traps are of relative importance and are used especially for a census of species and number of appearances. It is recommended to distribute a fair amount of them along transit ways, baiting them with different food substances.

The glues are adhesive substances that can be useful in case of not massive infestations and in cases in which the use of chemical rodenticide is inadvisable. High environment temperatures and dustiness of rooms are the main disadvantages that reduce their effectiveness.

As far as the use of ultrasounds is concerned, it has been found that the murine species gets rapidly inured to the typical frequencies used, those over 20 MHz, which are not perceptible to the human ear. In addition, it has been found that the sound annoyance is more irritating for domestic animals than for rodents.

The rat genetic control is an innovative research field, since the scientists Marsh and Howard have foreseen the possibility to modify the genetic make-up of these animals. However, after the first and encouraging successes, it has been realized that a natural selection eliminates the deleterious genes quite quickly. And therefore, this is a research field still at a very early stage, with the associated problems to be solved.

Available chemical means can be subdivided into the following classes: a) repellents, b) attractants, c) chemosterilants, d) rodenticides.

The use of repellents is still being tested, although the scientific research has begun many decades ago. From among many tested substances actidione, trinitrobenzene-aniline, thiouram disulfide, hexachlorophene have proven to be particularly active. However, it appeared evident that the repellents alone did not manage to solve the problem, also because the rodents repelled from a defined area, escape to another one. The attractants are compounds with an action directly opposite to that of the above mentioned repellents. In fact, they are used to attract animals to precise places, overcoming their natural and innate suspiciousness. Generally, there are two groups of most commonly used substances: the pheromones, natural specific smells, and the compounds not connected to natural hormonal smells. The non pheromonal substances used include: vegetable oils of various kinds, sugar, molasses, glycerol, salt, sodium glutamate, etc. Besides the pheromones, other volatile substances have proven to have good attractant effectiveness and among them there is carbon disulfide, which is effective in increasing the bait consumption.

Among the chemosterilants, the use of triethylene melamine is known, which, although gives better results, has a limit of not being able to sterilize males and females at the same time. The chemosterilants have anyway the limit of not being effective after one single administration. Although capable of eliminating up to 85% of the treated murine population, and causing permanent sterility in surviving adult males, a- chlorohydrin is not active on the young prepubertal, on the females of Rattus norvegicus, and on both genders and all ages of Mus musculus.

In addition to these limitations, the chemosterilants cannot be used in case of massive infestation, or where the presence of even a single Mus musculus is not tolerated.

The commonly used rodenticides can be subdivided in two categories: acute or single dose rodenticides and chronic or multiple-dose rodenticides. Natural poisons and synthetic poisons belong to the first category: the natural ones include scilliroside and strychnine, while the synthetic poisons include crimidine, sodium fluoroacetate and fluoroacetamide, zinc phosphide, norbomide, thallium sulfate and ANTU. Although the acute rodenticides are not effective as the chronic ones (anticoagulants), they can be validly used in emergency situations, when the rat population must be destroyed in the shortest possible time. However, they have many disadvantages, among which stands out the extreme dangerousness for man and non-target species and the increase of the rodents' suspiciousness.

The most effective and used instrument for fighting against rats is poisoned baits, with anticoagulant-based active principles. These baits take advantage of an action that does not occur before 2-3 days after the ingestion, independently from the quantity of the ingested food, and of a relative safety of use, as the quantity of bait necessary to cause toxic effects is such as to make unlikely lethal intoxication in people, children and domestic animals.

The anticoagulants can be subdivided, according to the action mode, into multiple dose (or first generation) anticoagulants and single dose (or second generation) ones. The first set includes the already known warfarin, coumachlor, coumatetralyl, coumafuryl, pivaldione, diphacinone and chlorophacinone; the second set includes bromadiolon, diphenacoum, brodifacoum and the most recent difethialone and flocoumafen.

The rat poison baits are products or compounds with phagocytic baiting effect; actually, they attract the targeted animal, so that the animal eats the bait. The addition of a poison makes it a poisoned bait. The bigger the bait effect and its liking, the bigger the possibility of a successful result. The bait formulations must take into account both behavioral habits and food habits of the species.

At present, there are various compounds on the market and thus an active principle can be presented in the form of cereals, powdery baits, blocks of paraffin, packets of fresh paste, of tracer powder, etc.

In order to increase the bait attraction and palatability, particular flavors, fruit, animal proteins, vegetable oils and sugar are used. Finally, other substances such as preservatives, coloring and bitter agents can be added. The cereals constitute the basis of rodents' diet in numerous environmental contexts and their use is definitely a valid baiting system. Those most advisable ones in the fight against rats are without teguments in order to facilitate complete absorption of the active principle. Actually, the use of caryopsides covered with teguments is to be avoided, since the latter, covering the seed, prevent also its complete imbibition by the active principle, making the rodent eat the seed without assuming the active principle, after having discarded the teguments.

Whole or pulverized cereals are often contained in packets of paper or plastic transpiring material, so as to facilitate a product optimal preservation, simplicity of the bait substitution and smaller risk for dispersal in the environment. The practice of packing baits in packets allows also detection of rodents' presence, since the rat must break the packet to eat the bait, and also bigger storability and duration of the bait in the environment are obtained. However, the use of rat-poison bait in the form of cereals is not without disadvantages, such as scarce uniformity of the active principle distribution and possibility of finding insect infestations. Furthermore, as it is very easy for rodents to move the grains or flakes and accumulate them in areas which can be even several meters distant from the poisoning station, serious risks of contamination intervene when operating in the presence of foodstuffs.

The flaked and pulverized bait is composed of a mixture of flaked cereals and crumbled and pulverized corn and other highly attractive food components. The used components are: flaked wheat and oats enriched with baiting substances, sugar, whole wheat, sunflower seeds. The presence of different components increases the probability that the target animal will detect among them a particularly appreciated one and begins to eat it.

Pellets are produced in a way similar to the food for zoo-technical use: by suitable production lines, the pulverized cereals and the active principle are mixed together with thickening substances and animal and vegetable proteins, and drawn. The palatability of the so obtained baits can be generally compared with that of the whole cereals, although the pellets have bigger hardness and a more uniform diffusion of the active principle in the bait with respect to the whole cereals. The product hardness satisfies the mice and rats' need for gnawing.

However, the pulverized product and the pellets are disadvantageous, because they require to be used in suitable containers, so as to avoid their dispersion in the environment. In fact, if they were used outside, the rain would make the product release the active principle, not only making the bait useless, but also polluting the ground and water tables.

Paraffinized baits are compounds in which the active principle and other ingredients are mixed with paraffin. These compounds have been developed with the purpose of limiting the rodenticide baits perishability, especially when they are used in environments with a high humidity level.

These compounds, however, have the disadvantage of having rather low palatability for rodents. Until a few years ago, the paraffinized bait has been formulated with a classic procedure: the melted paraffin was mixed with the ingredients, then it was cast into the molds, where it hardened. The high contents of paraffin (up to 50%), the strong heating, to which the ingredients were subjected, and their not homogeneous distribution in the bait, reduce significantly its palatability.

Recently, formulating techniques have been developed that allow paraffinized baits of good palatability to be obtained: the paraffinized bait obtained by the compression technique (ovules) and the paraffinized bait obtained by the extrusion technique. By extrusion technique blocks are obtained which can be fixed within the poisoning stations and which cannot be transported easily by the rodents.

The paraffinized baits, although particularly suitable for external use, since they incorporate the active principle in the paraffin, and do not allow water to extract it, have the disadvantage of liquefying due to the exposition to the sunbeams and thus dispersing the active principle in the environment during the rains.

Track or contact powders have been conceived to be placed on the rodents' habitual paths or blown into their holes. The rodent, once covered with the powder, will undoubtedly try to clean itself using the tongue and thereby the active principle will be assumed. Although the powders are extremely efficacious in controlling the rodents, currently the system is rarely used due to high risk of environmental contamination.

The baits having gel formulation or fat baits have a good palatability and a very important quality, deriving from the fact that they cannot be transferred by the rodents.

Moreover, they keep fresh for a long time. In some cases, the fresh gel bait or fat bait can exploit the same mechanism of the powder, whereby the rat, trying to clean its hair with the tongue, swallows the active principle.

Liquid concentrate formulations are indicated for the bait formulation and are mixed with attractant substances that can vary according to the food habits of the mice and/or rats population to be fought. The liquid contains coloring agents (blue, green, red) to give color to the baits. A very efficacious and palatable formulation is the paste bait contained in packets of filter paper, that make easy the bait positioning and passage. It is a paste of a floury consistency, mixed with animal and vegetable fats to which antioxidants are added to prevent them from becoming rancid.

The paste bait contains all ingredients most palatable for rodents and by virtue of its rather oily consistency, it has optimal palatability in many situations, especially when only dry food is available. Packaging in filters or packets allows a diffusion of baiting aromas and attractant substances contained therein. The overall duration of such a compound is good, although the sachets often tend to transude excessive quantities of oil, when the temperature becomes high. This is a very frequent case within the poisoning stations during summer, when temperatures can exceed 50⁰C.

However, the paste bait has the same environmental pollution disadvantages as the pulverized baits and pellets. The packages of paste bait, typically dose packets, typically containing materials deriving from the mixture of cannabis, cellulose fibers and thermoplastic fibers, remain, in fact, dispersed in the environment after the rat/mouse has consumed the bait.

Therefore, there is currently the need to have rodenticide preparations that are formulated and packaged in such a way as to minimize the pollution risks, caused by a possible dispersion in the environment of the active principles contained therein.

SUMMARY OF THE INVENTION

A general object of the present invention is to provide a rodenticide preparation that is packaged in a manner and with materials which reduce the risks of environmental contamination by the active components having rodenticide action.

One of the principal objects of the present invention is to provide a rodenticide preparation packaged in a way such to reduce the risks of environmental dispersion and to protect the components contained therein from chemical-physical deterioration, which occurs after the preparation has been positioned in the environment.

Another object of the present invention is to provide a packaged rodenticide system which, once begun and consumed by the target species, does not leave any package residues, which can pollute the environment.

A further object of the present invention is to provide a rodenticide system in form of dose packets, having a reduced environmental impact, whose package does not impair the bait palatability for the target species.

In consideration of these objects, an environmentally friendly rodenticide preparation is therefore provided, according to a first aspect of the invention, comprising a poisoned bait comprising a rodenticide active principle and a carrying substance palatable for rodents, characterized in that said poisoned bait is packaged into a biodegradable film based on a biopolymer palatable for infesting murine species.

The Applicant has identified the possibility to use a selected biodegradable material, for example in the form of film, for packaging a rodenticide bait without impairing the palatability of the baiting component of the poisoned bait.

DETAILED DESCRIPTION OF THE INVENTION

According to an embodiment of the invention, said biodegradable material is a thermoplastic biodegradable material, typically a biopolymer or bioplastics including vegetal components, without organoleptic properties that impair or negatively interfere with the palatability of the baiting component of the rodenticide bait.

Among the available biodegradable materials, it has been surprisingly found that using a biodegradable material based on vegetal components, for example maize starch, not only is the baiting capacity of the bait not reduced, but also an increase of the palatability of the packaged rodenticide preparation for the most common murine species is determined.

According to an embodiment of the invention said biodegradable material is chosen among biopolymers based on starch or starch derivatives. Preferable biopolymers based on starch or starch derivatives are Mater-Bi, a maize starch based biopolymer and Biophan, a biopolymer derived from a polylactic acid (PLA).

Typically, the maize starch based biopolymers, like Mater Bi, can be obtained by complexation of the starch with variable quantities of natural biodegradable complexing agents from renewable source, from synthetic or mixed source, so as to create different molecular superstructures, having a wide range of properties.

The base of these biopolymers is starch which is typically present in nature in crystalline form with linear molecules (amylose) and branched molecules (amylopectin). Beginning from breaking the starch original structure (destructuring), it is possible to obtain a new super-molecular order by forming complexes between amylose and natural or synthetic molecules. These complexes create a new crystalline order, increasing water resistance and changing the mechanical properties of the original starch, without modifying its chemical structure, but having possibility to graduate from its characteristics. Typically, the maize starch based biopolymer usable within the scope of the invention, for packaging a rodenticide preparation or composition, has one or more of the following characteristics: substantially complete biodegradability in different environments, as for example in composting and in the ground (in accordance with the European rule EN 13432 and with certification programs released by primary international bodies); workability using the same technologies of traditional plastics and with similar production rates; printability with normal inks and printing technologies, without need for corona treatment; possibility of being colored in bulk with biodegradable Master-batch; intrinsic antistaticity; possibility of being sterilized with gamma rays and opportunity of possible aromatizing with aromas liked by mice and rats in order to increase the palatability of the bait contained therein. According to one aspect, the preparation of the invention includes a biodegradable film made of a microporous and transpiring biopolymer, which wraps the baiting component, comprising at least a rodenticide active principle. According to an embodiment, said film of biodegradable thermoplastic material is microporous due to the presence of a plurality of micropores, which pass through it, providing it with transpiring properties and consequently allowing permeability to water vapor. According to an embodiment, said film in microporous biopolymer has a value of permeability to water vapor comprised between 250 and 1000g 30 μm/m2 for 24h, preferably between 500 and 800 30μm/m2 for 24h. These high values of the film permeability keep unchanged for a longer time the organoleptic properties of the packaged bait, once positioned in the environment, and avoid washing away and consequent dispersion of the active principle in the environment in case of rain.

On the contrary, the baits packaged in the dose packets in filter paper, obtained from the mixture of cannabis, cellulose fibers and thermoplastic fibers according to the prior art, are not capable of maintaining the organoleptic characteristics of the baiting component, causing a rapid reduction of palatability, with consequent reduction of the rodenticide efficiency.

Field tests have proven that already after 1 month of application, the tidbits packaged with traditional filter paper are subjected to deterioration capable of altering the organoleptic characteristics of the bait contained typically in paste, contrary to the tidbits packaged with the biodegradable and compostable film, that present reduced signs of deterioration up to 2 months after the positioning.

The poisoned bait packaged according to an aspect of the invention can be formulated in any type or formula, for example can be in form of paste, fresh bait, pellet, grains, paraffinized bait and the mixtures thereof.

According to another aspect of the present invention, the use of a biodegradable biopolymer based film, palatable for infesting murine species is provided for packaging a poisoned bait comprising a rodenticide active principle mixed with a carrying substance palatable for rodents, according to claim 13.

Further characteristics of the film are detailed in the enclosed dependent claims 14-18. The use of a film either of starch based biopolymer, or of polyacetic acid derivative, does not alter in any way the bait palatability for the target species. Laboratory studies of comparative palatability and efficiency between the baits packaged with traditional filter paper and baits packaged with the selected innovative film, have proven that there is no difference in palatability between the two different typologies of packaging.

Furthermore, such film has proved to be the most suitable for the proposed use also in relation to another biodegradable material that, contrary to the selected film, has proved to be not palatable during analogous comparative laboratory study of palatability and efficacy.

Moreover, if the rodents throw away the external wrapping to eat the bait, the use of this material has the advantage of leaving in the environment a biodegradable, environmentally friendly waste.

The rodenticide preparation of the invention has one or more of the following advantages: high palatability for the target species: better protection of the rodenticide bait from the chemical-physical deterioration in the environment to rid of rats, and in particular from humidity and from water, to obtain water impermeability; reduced use of the bait due to bigger permeability to water vapor of the identified film that assures better bait storability and consequently lower replacement frequency during rat extermination. - biodegradation of the residues of the packaging material following the bait consumption by the rodent.

According to an embodiment, said biopolymer microporous film (biodegradable thermoplastic material) has a breaking load comprised between 20 and 50 Mpa.

According to a further embodiment, said microporous biopolymer film has a gram-surface ratio ranging from 21 to 26 g/m2, preferably from 23 to 25.5 g/m2.

The principal characteristics of the traditional filter paper and of an embodiment of the film of the invention are summed up in the following:

According to an embodiment, the biopolymer film used in the field of the invention for packaging the rodenticide preparation satisfies the requirements of the compostable materials, according to the European rule EN 13432 (Requirements for composting and biodegradation recyclable packages - Experimental protocol and evaluation criteria for final acceptance of the packages) which provides for:

Biodegradability, determined by measuring the actual metabolic conversion of the compostable material into carbon dioxide. This property is valued quantitatively with a standard test method: EN 14046 (published also as ISO 14855: biodegradability in controlled composting conditions). The acceptance level is equal to 90% to be reached in less than 6 moths. - Disintegratability, i.e. fragmentation and loss of visibility in the final compost (absence of visual contamination). Measured with a composting test on the pilot scale (EN 14045). The material in question is biodegraded together with organic wastes for 3 months. Finally, the compost is sifted with a sifter having openings of 2 mm. The residues of the test material with dimensions larger than 2 mm are considered not disintegrated. This fraction must be smaller than 10% of the initial mass.

Absence of negative effects on the composting process. Requirement verified with a composting test on pilot scale. - Low levels of heavy metals (below the predetermined maximum levels) and absence of negative effects on the compost quality (example: reduction of the agronomic value and presence of ecotoxicology effects on plant growth). A test of plant growth (modified test OECD 208) is performed on compost samples, where the test material has been deteriorated. No difference with the control compost must be revealed.

Typically, other chemical-physical parameters which must not be different from the control compost after the biodegradation, are: pH; salinity; volatile solids; N; P; Mg; K.

According to an embodiment, the biopolymer film usable in the field of the invention can be produced by extrusion of a biopolymer or of a starting biodegradable thermoplastic material, for example provided in the form of pellets.

According to an embodiment, the extrusion is performed by means of bubble blowing technique, followed by coupling of opposite surfaces of the obtained thermoplastic bubble. The film blowing step is suitably performed at about 2-4 atmospheres.

Typically, the micropores of the film of the invention that are formed during the extrusion process, in particular in the bubble extrusion followed by press fit of the formed bubble.

Otherwise, the micropores of the film can be obtained with traditional microperforation techniques, for example of the type used for obtaining transpiring membranes used in the clothing industry, such as Gore-Tex. The rodenticide preparation proposed by the invention is suitable for the domestic, civil and industrial use, and is appropriate for rat extermination either on reduced or large scale. The rodenticide preparation according to the invention is suitably arranged in small heaps in places frequented by rodents, taking care to renew it before it is completely consumed, for example in the rate of 10/30 g (1 -3 single-dose sachets) per square meter of surface to protect.

The use of the bait of the invention has proven to be particularly efficacious in the fight against murine species selected from Rattus norvegicus, Rattus rattus, Mus musculus, Apodemus sylvaticus, etc.

It is advisable not to touch the product with one's bare hands, because of the rodents' suspiciousness towards the scent of man, and to use rubber or PVC gloves. The fresh bait is suitable for domestic, civil and industrial use, and is appropriate for rat extermination either on reduced or large scale, depending on the placed quantity.

By way of example, the compositions of the invention find application in the disinfestation of the main murine species, with particular reference to the rodents which occupy chiefly the urban and agricultural-zootechnical environments and which belong to the Muridae and Cricetidae families, Microtinae subfamily.

The following examples are provided for merely illustrative purpose of the present invention, and must not be understood as limiting the protection scope.

EXAMPLE 1

Formulation of a rodenticide composition in fresh paste Vegetable flours 39,1615-48,1615 % baiting substances 12,500% natural and/or chemical preservatives and stabilizers 2,075% animal or vegetable fat 25,000% sweeteners 11 ,2625% pure rat-poison active principle/association of rat-poison not anticoagulant active principles 1 ,00-10,00% denatonium benzoate 0,001%

EXAMPLE 2

Formulation of a rodenticide composition in fresh paste vegetable flours 49,1565% baiting substances 12,500% natural and/or chemical preservatives and stabilizers 2,075% animal or vegetable fat 25,000% sweeteners 11 ,2625% pure anticoagulant rat-poison active principle

/association of anticoagulant active principles 0,005% denatonium benzoate 0,001%

EXAMPLE 3

Formulation of a rodenticide composition in fresh composite paste vegetable flours 39,1565% baiting substances 12,500% natural and/or chemical preservatives and stabilizers 2,075% animal or vegetable fat 25% sweeteners 11 ,2625% pure anticoagulant rat-poison active principle/association of anticoagulant active principles 0,005% denatonium benzoate 0,001 % Whole and/or shattered decorticated cereals, and/or puffed cereals, seeds 10%

EXAMPLE 4

Formulation of a rodenticide composition in fresh composite paste vegetable flours 39,1565 baiting substances 12,500% natural and/or chemical preservatives and stabilizers 2,075% animal or vegetable fat 25,000% sweeteners 11 ,2625% pure anticoagulant rat-poison active principle/association of anticoagulant active principles 0,005% denatonium benzoate 0,001% Whole and/or shattered decorticated cereals, and/or puffed cereals, granulated and/or cubed fruit and vegetables 10%

EXAMPLE 5 Formulation of a rodenticide composition in pellet whitebeam 82,869-73,869% ligand 3% calcium carbonate 10% propylene glycol 1 % chemical and/or natural stabilizers 0,03% possible natural and/or chemical insecticide substance 0,1% natural and/or chemical preservatives and stabilizers 2,000% pure rat-poison active principle/association of rat-poison not anticoagulant active principles 1 ,00-10,00% denatonium benzoate 0,001%

EXAMPLE 6

Formulation of a rodenticide composition in pellet vegetable flours 83,864% ligand 3% lnerts 10% propylene glycol 1% possible natural and/or chemical insecticide substance 0,1% natural and/or chemical preservatives and stabilizers 2,03% pure anticoagulant rat-poison active principle/association of anticoagulant active principles 0,005% denatonium benzoate 0,001%

EXAMPLE 7

Formulation of a rodenticide composition in grains

Whole and/or shattered decorticated cereals, 80,005-89,005% material edible by mice and rats 6,814% sweetening substances 0,005% natural and/or chemical preservatives and stabilizers 2,05% propylene glycol 1 % possible natural and/or chemical insecticide substance 0,125% pure rat-poison active principle/association of rat-poison not anticoagulant active principles 1 ,00-10,00%% denatonium benzoate 0,001%

EXAMPLE 8

Formulation of a rodenticide composition in grains Whole and/or shattered decorticated cereals, 90% material edible by mice and rats 6,814% sweetening substances 0,005% natural and/or chemical preservatives and stabilizers 2,05% propylene glycol 1% possible natural and/or chemical insecticide substance 0,125% pure anticoagulant rat-poison active principle/association of anticoagulant active principles 0,005% denatonium benzoate 0,001 %

EXAMPLE 9

Method for preparing a rat-poison composition in fresh paste, according to an embodiment of the invention. Tools used for the preparation of the formulate:

Calibrated scales

Storage silos for fiore flour

Pneumatic pump

Measuring device Working mode:

The operator provides himself with means for personal protection, such as polyethylene gloves, overalls, dust mask and makes sure that all the safety, active and passive devices are operative.

The inert raw materials, which constitute the compound, are weighed. All other weighed raw materials are put into the mixer:

Vegetable flours

Baiting substances Stabilizers

Animal or vegetable fat or animal fats or other vegetable oils

Sweeteners

The active principle coloring agents, preservatives and possible aroma contained in the compound, are weighed and transferred to a kneader, together with the denatonium benzoate.

After the mixer basin has been filled, mixing begins. Mixing continues until a paste of homogeneous coloring and consistence and without lumps is obtained.

The ready paste is controlled as to quality, and, if in conformity, it is sent to be packaged on measuring devices.

Then, the bait is packaged using single-dose sachets made with biodegradable and compostable material.

EXAMPLE 10 Method for preparing a rat-poison composition in pellet, according to an embodiment of the invention.

Tools used for the preparation of the compound: Calibrated scales Pelleting machine Working mode:

The inert raw materials, which constitute the compound, are weighed. All other weighed raw materials are then put into the mixer:

Flours Stabilizers Thickening agents lnerts supports Excipients

The active principle, coloring agents, preservatives and other components contained in the compound are weighed and transferred to the mixer.

The mixing continues until a mixture of homogeneous coloring and consistence is obtained. Afterwards, the mixture is pelleted. Once cooled, the pellet is controlled as to quality, and, if in conformity, it is sent to be packaged on the measuring devices.

Then, the pellet is packaged using the single-dose sachets of biodegradable and compostable material.

EXAMPLE 11

Method for preparing a rat-poison composition in grains, according to an embodiment of the invention.

Tools used for the preparation of the compound:

Calibrated scales

Rotating mixer for cereals

Working mode: The operator provides himself with means for personal protection, such as polyethylene gloves, overalls, dust mask and makes sure that all the safety, active and passive devices are operative.

The inert raw materials, which constitute the compound, are weighed.

The following liquid raw materials are put in the tank of a compressed air sprayer, creating thus a homogeneous liquid premix:

Liquid active principle

Denatonium benzoate

Excipients

Liquid preservatives The mixing is started and then the already weighed raw materials are put into the mixer in the following order:

Whole and/or shattered decorticated cereals,

Sweetener

Color Possible aroma

Possibly present natural and/or chemical insecticide

Powder preservatives

Homogeneous liquid premix

The mixing continues until a mass of grains having a homogeneous coloring is obtained.

The final compound is controlled as to quality, and, if in conformity, it is sent to be packaged on measuring devices. Then, the grains are packaged using single-dose sachets made of biodegradable and compostable material.

Example 12

A comparative test of palatability/attractiveness has been performed using A) a poisoned bait (containing 0.0025% bromadiolon and 0.0025% diphenacoum) in paste packaged in a film of a conventional type, and B) a bait (likewise containing 0.0025% bromadiolon and 0.0025% diphenacoum) packaged with a film made in essentially transparent Mater-Bi.

The two baits contained the same baiting component in the same quantity, mixed closely with the two rat-poison active principles.

A test has been performed on the considered baits "A" and "B", to value the rodenticide palatability by means of spontaneous assumption after repeated administration of the two baits to the same animals.

For this purpose, the considered substances in known quantity have been given to 10 rats (5 males and 5 females) and 10 mice (5 males and 5 females), introducing them into single farming cages in two different containers called container "A" and container "B".

Every 24 hours for 5 days, the considered substances and the remaining ones have been weighed and substituted with the fresh ones, inverting the position of the containers.

The animals have been weighed daily during the pre-test and test.

During the examination the remaining baits have been weighed daily and moreover, further to a visual check, the presence or absence of baits packaging film is reported, so as to understand if it can interfere with the palatability of the considered substance.

The analysis is composed of two steps, whose duration is as follows: step I - 3 days step 11 - 5 days

For a total of 8 days. On the basis of the results obtained during the examination, the considered substance "A" has turned out to be palatable, the considered substance "B" has turned out to be palatable.

In fact, the daily consumption of the two baits turns out to be similar and slightly bigger for the bait B, and the absence of the packaging film in both bait types in most findings makes us presume that it does not interfere with the baits palatability.

CONCLUSIONS

On the basis of the results obtained during the analysis, the considered bait "A" has turned out to be palatable, the considered bait "B" has turned out to be palatable.

In fact, the daily consumption of the two baits turns out to be similar and the absence of the packaging film in both bait types in most findings show that presumably it does not interfere with the baits palatability. EXAMPLE 13

In a further comparative analysis performed on the two baits of the type described in the example 12, the two packages were left outside for a 70-day period, under high humidity conditions. At the end of the test period, the two packaged baits A and B have been picked up.

It has been observed that the bait A) packaged in dose packets (filter paper with plastic materials) of the prior art was in bad conditions with the two rat-poison active principles deteriorated and with a reduced palatability of the baiting component. Conversely, the bait B) packaged with a film of Mater-Bi (thickness of 40 μm) transpiring (80Og 30μm/m2 for 24h) to water vapor and substantially waterproof, not only has preserved the original palatability characteristics, but has also presented the active principles strength almost unaltered.

Claims

1. Environmentally friendly rodenticide preparation comprising a poisoned bait comprising a rodenticide active principle and a carrying substance palatable for rodents, characterized in that said poisoned bait is packaged into a biodegradable film based on a biopolymer palatable for infesting murine species.

2. Environmentally friendly rodenticide preparation, according to claim 1 , characterized in that said biopolymer palatable for infesting murine species is based on, or is, a starch derivative.

3. Environmentally friendly rodenticide preparation, according to claim 1 or 2, characterized in that said biopolymer palatable for infesting murine species is selected from Mater-Bi, Biophan and mixtures thereof.

4. Environmentally friendly rodenticide preparation, according to any of claims 1- 3, characterized in that said biodegradable film based on a biopolymer palatable for murine species is a transpiring biodegradable film, due to the presence of a plurality of micropores that cross it.

5. Rodenticide preparation, according to claim 4, characterized in that the transpiring biodegradable film has a water vapor permeability value ranging from 250 to 1000g 30 μm/m2 for 24h.

6. Rodenticide preparation, according to claim 5, characterized in that the transpiring biodegradable film has a water vapor permeability value ranging from 500 to

800 30 μm/m2 for 24h.

7. Environmentally friendly rodenticide preparation, according to any of claims 1-

6, characterized in that said biodegradable film based on a biopolymer palatable for murine species is waterproof.

8. Environmentally friendly rodenticide preparation, according to any of claims 1-

7, characterized in that said biodegradable film based on a biopolymer palatable for murine species has a thickness comprised between 10 and 100 μm.

9. Environmentally friendly rodenticide preparation, according to any of claims 1 -

8, characterized in that in said poisoned bait the rodenticide active principle is mixed with the carrying substance palatable for rodents and with other optional additives.

10. Environmentally friendly rodenticide preparation, according to any of claims 1-9, characterized in that it is packaged in pre-measured portions or dose packets.

11. Environmentally friendly rodenticide preparation, according to any of claims 1 -10, characterized in that said bait is in the form of paste or fresh bait.

12. Environmentally friendly rodenticide preparation, according to any of claims

1-11 , characterized in that said rodenticide active principle is a multiple dose anticoagulant chosen from the group consisting of warfarin, coumachlor, coumatetralyl, coumafuryl, pivaldione, diphacinone chlorophacinone and mixtures thereof or a single dose anticoagulant chosen from among bromadiolon, diphenacoum, brodifacoum, difethialone, flocoumafen and mixtures thereof or mixtures of multiple dose anticoagulant with a single dose one.

13. Use of a biodegradable film based on a biopolymer palatable for infesting murine species for packaging a poisoned bait comprising a rodenticide active principle mixed with a carrying substance palatable for rodents.

14. Use according to claim 13, wherein said biopolymer palatable for infesting murine species is based on, or is, a starch derivative.

15. Use according to claim 13 or 14, wherein said biopolymer palatable for infesting murine species is selected from Mater-Bi, Biophan and mixtures thereof.

16. Use according to any of claims 13-15, wherein said biodegradable film based on a biopolymer palatable for murine species is transpiring to water vapor due to the presence of a plurality of micropores that cross it.

17. Use, according to any of claims 13-16, wherein said transpiring biodegradable film has a water vapor permeability value comprised between 250 and

1000g 30 μm/m2 for 24h.

18. Use, according to any one of claims 13-17, for packaging paste baits in the form of pre-measured portions or dose-packets.