RU2208315C2 - Molluskocides with gastric effect - Google Patents

Abstract

FIELD: agriculture. SUBSTANCE: molluskocides with gastric effect comprise chelate of iron or aluminum and acceptable non- liquid carrier and their pH is above 7 ± 0.5. Method for preparing molluskocide involves stages of mixing components, their heating in the presence of steam, keeping mixture at environment temperature and forming pellets. Molluskocides exhibit the enhanced effectiveness and low toxicity as compared with the known molluskocides with gastric effect. EFFECT: improved properties of molluskocides. 23 cl, 6 tbl

Description

 The invention relates to gastric molluscicides, gastric poisons or food lures containing them, as well as their use for the destruction of mollusks, the control of mollusks and / or their inactivation, in particular slugs and snails.

 Slugs and snails are the main agricultural pests in many parts of the world. The biology of these species suggests that humid conditions are favorable for their livelihoods, such as their natural environment, where it is constantly humid, and regions with a temperate climate, especially in rainy summers and autumn. Consequently, the potential potential for damage to these species is significant.

 Different types of mollusks, which can be either terrestrial or aquatic, are very different from each other and different types of treatments are usually required to destroy them. Slugs of the species Cepaea hortensis, Theba pisana, Cernuella virgata and Achatina spp., As well as snail species Arion hortensis, Milax budapestensis, Deroceras reticulatum and Limax maximus are especially important objects. The common garden snail Helix aspersa and the field slug Deroceras reticulatum are typical garden pests in Australia. These pests can live in different parts of the world, adapting to a wide range of climatic conditions. In Australia, their numbers rarely increase to approximately 20 units per square meter. meter, but they cause damage by eating plants, with little damage due to the mucus on which they move. The Helix aspersa species is, in general, a species that feeds at night and in the daytime hides on the underside of leaves, under rocks or in cracked soils. This species develops well in humid conditions. On the other hand, there is a group of snails that were brought to Australia in the twentieth century (their number reaches 200 snails per square meter). This is the white Italian snail Theba pisana and grape or snail Mediterranean, Cernuella virgata, which can survive for a long time at high summer temperatures due to summer hibernation on weeds and racks of the fence, leaving in their shells and releasing a dense film of mucus to reduce moisture loss and as supports. These snails are of concern to Australian farmers, as they also hibernate on the ears of cereals in November and December, and when harvesting, they clog machinery and pollute the grain. As a result, grain becomes unacceptable for consumption or it is necessary to lower its quality. There are very strong fluctuations in the number of pests, and in adverse years it is not economical to harvest in large areas of crops. In cold climates in winter, the species Theba pisana also hibernates. Deroceras retlculatum slugs are found in all temperate regions of the world and are the main type of slugs found in both Australia and the UK.

 Significant damage to mollusk crops occurs in Northern Europe, the Middle East, North and Central America, Southeast Asia, Japan and New Zealand. In many cases, an increase in the status of the considered slugs or snails as pests is the result of changes either in distribution (as in the case of accidental or intentional introduction) or in agricultural practice, when new crops or processing systems can enable the population to increase the number of pests. For example, in the UK, approximately two-thirds of molluscicides are used on winter wheat and winter barley. After harvesting, a significant amount of stubble remains. In accordance with modern agricultural practice, the seeds of the next crop are sown directly in the soil, without removing the stubble of the previous crop, for example, by burning. Slugs that hide in the soil move into the sowing holes and eat new seeds from the inside, potentially damaging the entire plant. Therefore, slugs are the main agricultural pests.

 Developing ways to kill these pests is a difficult task. Methods of destruction include methods of cultivation, chemical and biological methods. Cultivation techniques in which mollusks are removed or make the habitat less acceptable are usually cheaper. Biological control by introducing natural predators is the preferred method, since, in principle, the predator can be specific to this type of snail and will not harm local snails or non-target organisms. However, in this case, very expensive testing is necessary, and after introducing the predator into the environment it is very difficult to turn the process in the opposite direction and remove it. The chemical method (the use of molluscicides) involves the use of contact or gastric poison, irritant or food depressant.

 The mollusk habitat is usually treated with molluskocide, which is then swallowed by the mollusks. Since humid conditions are favorable for most snails and slugs, any effective molluskocide should be effective under these conditions. The main requirement for widespread use in agriculture, when one treatment is preferable to several applications during the season, is the availability of appropriate resistance to water. In this case, it is desirable to have a certain balance between resistance to water and effectiveness in order to prevent the action of pellets as poison after harvest, when livestock are driven to these grazing areas. In addition, in areas with a very high moisture content, effective water resistance must be achieved so that the poison remains in the form available for swallowing for the time necessary to adequately affect the mollusks. Since moisture is of great importance for the activity of slugs and snails, the damage is likely to be more significant in heavy soils, as they retain moisture to a greater extent. However, the damage is not limited to heavy soils. The activity of slugs and snails is maintained at a high content of organic material, which is characteristic of a humid environment. Green crops and the remains of old crops used in compost often allow populations to grow rapidly. Dense deciduous plants, such as brassica and curcubitis, give a moist moist crown, under which snails and slugs thrive.

Temperature also affects the activity level of slugs and snails. Indeed, their activity is maximum at 15-20 ^o C and significantly decreases at temperatures below 5 ^o C and above 30 ^o C. In addition, the development of slug eggs is significantly delayed at low temperatures. Most slugs and snails are species that feed on nights. Therefore, evening watering of gardens often contributes to the creation of an environment that stimulates the high nutritional activity of mollusks.

 Molluscicides used against mucus and snails can be divided into three groups. These are contact molluscicides, such as crystalline aluminum and copper sulfates, which are applied to the habitat of slugs or snails and are in place while the snail or slug moves around this area; irritating powdered molluscicides, such as silica granules, which act when snails or slugs get on the motor mucus; and gastric molluscicides, such as pellets of metaldehyde and methiocarb, which the mollusks swallow.

 Contact molluscicides are usually applied to crops by spraying or in the form of dust, and mollusks receive a lethal dose of toxin when moving around the plant. Toxin delivery to mollusks is a problem, since their relatively large size means that a large dose of toxin is needed. In addition, mollusks are relatively inactive and can remain relatively safe for a long period. These problems are further complicated by the layer of mucus that surrounds the mollusks. Irritating materials stimulate mucus secretion and can be discarded and left behind in mucus-discarded coatings. Since the mucus consists mainly of water, water-soluble contact poisons are needed that can penetrate the mucous barrier. However, the hydrophilic properties of the toxin also increase the rate at which it is diluted with rainwater and leached into the soil.

 Delivery of an effective amount of bait is also a problem. The mollusk must swallow enough poison in order for the lethal dose to be reached. In the general case, most toxic compounds are also repellents, and the combination of toxicity and repellent properties prevents the mollusk from swallowing enough poison to kill it. There are three main effects on shellfish of poisonous baits intended for swallowing. Firstly, with the help of bait, you can scare them away from the culture. Secondly, swallowing the bait can lead to a decrease in food absorption activity, and thirdly, the poison can kill the snail or slug that swallowed the bait.

 Until the mid 60s. the most effective molluskocide was metaldehyde, which is an acetaldehyde tetramer. In Europe, metaldehyde was only known as solid fuel until its molluscicidal properties were accidentally discovered (in France, farmers found dead and dried snails on tablets and around metaldehyde tablets thrown away after use in field dryers).

 At high concentrations, metaldehyde is a toxic compound, and at lower concentrations it is irritating, causing mucus secretion and gradual drying. Its disadvantage is the dependence of the maximum effect on high temperature and low humidity and the presence of a high recovery rate in mollusks due to the ability to reverse the water deficit caused by excessive mucus production stimulated by metaldehyde. Under optimal conditions, snails that are immobilized and lose moisture under the influence of metaldehyde will die if they remain in the open space under the influence of sunlight. Unfortunately, it is under humid conditions and lower temperatures, when metaldehyde is the least effective, land snails, such as Theba pisana, are most active. In addition, at higher temperatures, the snails hibernate and do not feed. There is only a very limited period of time during which the snails are fed, and the temperature is high enough for the metaldehyde to be effective.

 In the mid 60s. carbamate compounds, for example methyl carbamate, have been found to have the same mollusk toxicity as metaldehyde. Carbamate compounds inhibit cholinesterases, which are enzymes involved in the transmission of synaptic nerve impulses in a large number of animals, and their mechanism of action on insects has been well studied, especially in connection with the development of insect resistance. Methylcarbamate, which is most commonly used as a molluskocide, is methiocarb (3,5-dimethyl-1,4-methylthiophenyl-N-methylcarbamate). The effectiveness of methiocarb is less affected by low temperature and high humidity than the effectiveness of metaldehyde, which is the main advantage, since damage from pests is often found under conditions in which metaldehyde is least acceptable. However, methiocarb (an active insecticide and acaricide) is more toxic than metaldehyde to non-target organisms such as beneficial insects and earthworms. Although farmers currently tend to use methiocarb, they would prefer to do without it because of its high toxicity and because sheep often graze in places that require processing to destroy snails and slugs. For example, in South Australia there are irrigated pastures for sheep, which have recently been found to have a high distribution of conical snails Cochlicella barbara. Therefore, any effective molluskocide used under these conditions, in addition to being non-toxic to sheep, must have high resistance to water. Metiocarb is effective against Theba pisana, but in view of its insecticidal activity and toxicity to earthworms, its use for this type of snail also has serious drawbacks.

There are many facts indicating that metal salts used as contact poisons are toxic to mollusks (Glen DM, Orsman IA, "Comparison of molluscicides based on metaldehyde, methiocarb and aluminum sulphate" (Comparison of molluskocides based on metaldehyde, methiocarb and aluminum sulfate), Crop Protection, 1986, 5, 371-375). In particular, in the United Kingdom, iron and aluminum salts (Henderson et al., "Aluminum (III) and Iron (III) complexes, exhibiting molluscicidal activity", (Aluminum (III) and iron (III) complexes with molluscicidal activity) Australian Patent AU-B-22526/88). In these works, it was concluded that the effectiveness of molluskocide depends on a number of factors, but the formation of chelates using ferric iron leads to significantly better results compared to non-chelated salts. In addition, the authors of these works found that the introduction of poison into baits, such as pellets, gives significantly better results than direct application of molluskocide to the soil or applying bait to the soil of the bait in the form of a powder. Details of the bait recipe are provided without further discussion of the differences that would be expected from other recipes. Such differences are most likely related to the amount of chelate needed to effectively control the pests. In the field, the efficiency and activity of many metal salts is greatly reduced both due to dilution and due to the chemical binding of metal ions to the soil, which makes them inaccessible to toxic effects. The proposed metal-based contact poisons, such as aluminum tris (acetylacetonate) (Al (ACAC) ₃ , are expensive to manufacture and economically unsuitable for use in home gardens or for gardening and large areas. Various metal salts are sold as contact molluscides and are actually toxic, but the question is whether they are effective in the field, as contact poisons they are not persistent enough and have too high a repellent effect to use For these reasons, molluscicides intended to destroy ground objects (as opposed to water objects) are usually used as gastric poison poisons.

 Another major problem with using such gastric poisons is that they are often consumed by non-target organisms such as pets and birds, as well as by children. For normal use in agriculture and veterinary medicine, preparations are usually very diluted. However, when baits are used, this is a different case and there is always the possibility that they will be consumed by non-target organisms. Accidental poisoning of non-target organisms is especially common in the case of bait in the form of pellets designed to destroy snails and slugs. Although it is difficult to reliably explain the poisoning of dogs, cats and local animals, in Australia, according to reliable data, there are up to 10,000 poisonings in the fall with approximately 40-50% deaths. Therefore, there is a need for molluscicides that are effective against snails and slugs, but which are minimally hazardous to the environment and whose cost does not exceed the cost of existing molluscicides.

 There are a large number of published data on the evaluation of effectiveness, which indicate that iron (III) - sodium salt of EDTA (Iron (III) EDTA or iron-EDTA) is an effective contact action molluskocide. A number of iron and aluminum compounds have been studied as poisons for Deroceras reticulatum slugs (Henderson IF, Martin AP, "Control of slugs with contact-action milluscicides", An. Appl. Biol., 1990, 116, 273-278) .In these studies, two types of experiment are described, in one of which, when laboratory tests are performed, slugs are placed on a treated glass surface, and the other uses moist soil. Non-chelated salts are effective poisons when applied to a glass surface, but quickly deactivated when they are treated soil formation.The formation of chelates of both metals with organic ligands slows down the rate of decrease in activity on moist soil.This work also describes field trials in which the iron chelate, applied by scattering at a dose of 40 kg of active ingredient per hectare or as a bait formulation, applied at the rate of 1.32 kg / ha of active ingredient, was effective against Deroceras reticulatum and Anon spp. The authors concluded that “the bait formulation is apparently more effective because 586 slugs die on the surface of the active ingredient at a dose of 1.32 kg / ha within three days, while the compounding formulation applied at a dose 40 kg / ha destroys only 204 individuals on the surface in the same period. " Iron (III) - [2,4-pentanedionate] is apparently more toxic than iron (III) EDTA and although it is difficult to quantify this difference, it turned out that on wet soil after 10 days, 2,4-pentanedionate 2-3 times more toxic. A detailed description of the recipe for the bait is not given, but, most likely, the amount of chelate necessary for the effective destruction of pests is important.

 Recently, international patent application WO 96/05728 "Ingestable Mollusc Poison" (Puritch et al.) Claims stomach poison for terrestrial mollusks containing either iron (III) or iron (III) -hydroxyethyl derivative of edetic acid as the active ingredient (edetic acid). The work also showed that mixtures of iron salts such as iron (III) sulfate, iron (III) chloride or iron (III) nitrate with the disodium salt of EDTA or EDTA are toxic to slugs of the species Deroceras reticulatum. The big problem that must be overcome in the case of effective gastric molluscicides is their palatability, since in order for molluskocide to be effective, it must be swallowed by the mollusk. Although the authors stated that their formulations provide acceptable molluscocides according to their taste parameters, tests conducted by the authors of this application have shown that these formulations are acidic and therefore not likely to be acceptable in terms of taste. Apparently, the claimed effectiveness is due to the action of the formulation as a contact poison, and not as a swallowed poison. In addition, it is likely that the claimed palatability of these formulations is not associated with the introduction of a specific active ingredient, but with the components of an inert carrier.

 Thus, an object of the present invention is to provide an improved gastric molluskocide containing a metal chelate that is substantially more palatable and therefore more effective. Another object of the present invention is the creation of a molluskocide of gastric action with better taste characteristics, in the presence of such positive properties as environmental safety and the absence of toxicity for non-target organisms.

SUMMARY OF THE INVENTION
The inclusion of metal chelates as an active ingredient in gastric poisons in accordance with the present invention provides significant advantages over currently used gastrointestinal molluskocides with metaldehyde and methiocarb. The present invention relates to the inclusion of complexon as a chelate ligand to act as an active ingredient in gastric poisons. The selected complexones are significantly less toxic to mammals than methiocarb or metaldehyde. Indeed, they are used for medical purposes to alleviate the symptoms of anemia. Such complexones are also often used in mixtures with trace elements in situations where a plant is deficient in iron. The effectiveness of complexones does not very much depend on temperature and humidity, while it is comparable in this indicator with methiocarb. They are neither insecticides nor acaricides and pellets based on such compounds, designed to destroy snails and slugs, will not affect earthworms or (predominantly useful) carabid beetles. The term "complex metal" is used in a broad sense and refers to a metal chelate with at least one complexon type ligand.

The term “complex” as used herein refers to an organic ligand containing at least one iminodiacetyl group —N (CH ₂ CO ₂ H) ₂ or two aminoacetyl groups —NHCH ₂ CO ₂ H that form stable complexes with most cations. Suitable chelators are chelators described in Wilkinson G., "Comprehensive Coordination Chemistry", Volume 2, Chapter 20.3, pp. 777-792, which is included in the description as a reference material.

 The complexones of the present invention are substituent-containing complexones, such as hydroxy groups, which are more strongly coordinated with the metal ion, for example, EDDHA, or complexones, which have increased stability due to the presence of an additional coordinating group, for example DPTA. As other chelates, the iron-sodium salt of ethylenediaminbis [(2-hydroxyphenyl) acetic acid] (FeEDDTA) and the sodium-salt of diethylene triamine pentaacetic acid were studied.

 The main problem that must be overcome in the case of molluscicides of gastric action is that, in order for molluscicides to be effective, they must be acceptable for mollusks in terms of taste. Shellfish should eat them in an amount sufficient to cause their death.

 In accordance with one aspect of the present invention, there is provided a gastric molluskocide comprising a metal complexon and a non-liquid acceptable carrier, wherein the molluskocide has a pH greater than 7. Preferably, the molluskocide has a pH of between about 7 and 10. More preferably, the molluskocide has a pH of about 8.

 Typically, a metal in a metal complexon is selected from the group consisting of transition metals or metals of the 13th group. Preferably, the metal in the metal complexone is selected from the group consisting of manganese, aluminum, iron, copper or zinc.

Preferably, the complex contains at least one iminodiacetyl group or two aminoacetyl groups. Preferably, the metal complex contains a hydroxy metal complex. Most preferably, the metal complex in the molluskocide is in the form of a hydroxy-metal complexon [Fe (OH) EDTA] ^2- or in the form of an oxo-dimer [EDTAFE-O-FeEDTA] ^4- .

In a preferred embodiment of the invention, the non-liquid carrier of the metal complexon is usually food for mollusks, for example cereals, that is, wheat flour, bran, flour from underground shoots or arrowroot rhizomes or rice flour; carrot; beer; rice husk crushed cuttlefish; starch or gelatin, which attract the mollusk to food lures. Non-edible carriers of interest include non-edible polymeric materials, pumice, charcoal and materials used as carriers for insecticides. The venom or bait may also contain other additives known in the art, such as mollusk phagostimulants, such as sucrose or molasses; lubricants, such as calcium or magnesium stearate, talc or silicon dioxide; binders that have suitable waterproofing properties, such as paraffin, paraffin oil, or casein; and flavoring agents, such as BITREX ^® (registered trademark), which give a bitter taste and make poison or bait less attractive to non-target organisms. Preservatives such as sodium benzoate, vitamin E, alpha-tocopherol, ascorbic acid, methyl paraben, propyl paraben or sodium bisulfite may also be included to inhibit the deterioration of the properties of the poison or bait. In addition, it is preferable when the waterproofing agent contains fatty acid alcohol in an amount of from about 1 to 5 weight. % based on the entire composition of the poison. More preferably, the fatty acid alcohol is selected from the group of C ₁₆ -C ₁₈ fatty acid alcohols. Most preferably, the C ₁₆ -C ₁₈ fatty acid alcohols comprise about 2% by weight of the total molluskocide composition, and the C ₁₆ -C ₁₈ fatty acid alcohol is HYDRENOL MY, which is a mixture of hexadecanol, heptadecanol and octadecanol.

To increase the density of the resulting mixture, filler is added to the carrier before the formation of the pellets to reduce the content of the mixture in the air and, therefore, reduce its losses. Preferably, the filler is either CaCO ₃ or K ₂ CO ₃ , but is not limited thereto. Typically, poison or bait as a filler contains approximately more than 1% and not more than 5% metal carbonate. When the metal carbonate is CaCO3, a concentration of 2-3 wt.% Is preferred. When the metal carbonate is K ₂ CO ₃ , a concentration of 4-5 wt.% Is preferred.

Such a metal carbonate additionally serves to establish the pH of the poison or bait, and it was found that with increasing pH, the efficiency increases. When conducting field tests using various amounts of CaCO ₃ and K ₂ CO _{3 it was} found that it is necessary to maintain a balance between the pH value and the attractiveness of the bait for mollusks. If the bait is too acidic, its effectiveness has been found to drop. On the other hand, if the bait is highly alkaline, this prevents it from being swallowed by the mollusk. Preferably, K ₂ CO ₃ together with CaCO ₃ are used as pH regulators. Gastric poison having an alkaline pH is believed to be more effective than gastric poison having an acidic pH. K ₂ CO ₃ together with CaCO ₃ , which are used as a filler and with which the pH value is set above about 8, contribute to the preparation of the complexon [Fe (OH) EDTA] ^2- or [EDTAFE-O-FeEDTA] ^4- . At pH between 7 and 10, mainly [Fe (OH) EDTA] ^2- and [Fe (III) EDTA] ^- ions are mainly present, the latter being contained in small quantities. In accordance with the work of FG Kari et al., Environ. Sci. Technol., (1995), 29, 1008, at a pH of about 8-8.5, [Fe (III) EDTA] ^- virtually nonexistent.

Preferably, the active ingredient is at least 6 wt.% Based on the entire molluskocide composition. More preferably, the active ingredient comprises from about 6 to 12% by weight of the total molluskocide composition, if the metal complex is [Fe (OH) EDTA] ^2- . More preferably, [Fe (OH) EDTA] ^2- is about 9 wt.% Based on the entire molluscocide.

 In accordance with another aspect of the invention, the complex metal contains a complex metal in combination with at least one other molluskocide. Usually another molluskocid is selected from metaldehyde or methiocarb.

 Molluscocide is preferably obtained in solid form, such as tablets, powders, granules or pellets. A person skilled in the art will understand that it is preferable to prepare the product constituting the object of the present invention in a form that can be easily used by the consumer. Pellets, for example, can be easily scattered out of the box on the treated area. Preferably, the molluskocide is in the form of pellets. More preferably, the pellets have a length of 2.5 to 4 mm. Most preferably, the pellet length is 3 mm.

In accordance with another aspect of the invention, a method for producing a gastric molluskocide in the form of pellets comprises the steps of:
(I) mixing the components to obtain a mixed composition;
(Ii) heating the blended composition for 1 to 5 minutes in the presence of steam at an ambient temperature of about 80 to 100 ^° C .;
(Iii) maintaining the blended composition at ambient temperature for 10 to 30 seconds; and
(IV) forming a mixed composition into one or more pellets.

Preferably, step (II) is carried out at a temperature of about 90 ^{° C.} for about 2 minutes, after which step (III) is carried out for about 15 seconds. Preferably, the blended composition is formed into pellets under pressure.

 The term "gastric molluskocide" is used here in a broad sense and includes molluskocide, which can be swallowed by the mollusk and can enter its stomach in an effective amount, so that the mollusk is killed and / or inactivated.

Examples
The invention is further illustrated by non-limiting examples.

When planning experiments to study the molluscicidal properties of salts of iron, copper and aluminum as a gastric molluskocide, it is necessary to take into account at least the following variables:
(I) the formulation of the bait in terms of palatability;
(Ii) soil type;
(III) the concentration of the metal complexone used;
(Iv) the type of mollusk in relation to which the molluskocide must be effective;
(V) the range of maximum daily temperature at which molluscocide should be effective.

When considering the effectiveness of molluscides based on metal complexon, it was found that there is a direct correlation between temperature and food intake by mollusks (Young CL "Metal chelates as stomach poison molluscicides for introduced pests Helix aspersa, Theba pisana, Cernurlla virgata and Deroceras reticulatum in Australia", BCPC mono ., (1996), 66, "Slug and Snail Pests in Agriculture", eds. Henderson IF, British Protection Coucil, Farnham, UK). Although the ideal temperature for food intake in the case of snails is approximately 20 ^° C, the temperature should be approximately higher than 10 ^° C, since at temperatures below this activity in food intake decreases. For the Helix aspersa species in high humidity conditions, the ideal temperature for food consumption is approximately 20-25 ^o С, while for the Deroceras reticulatum species, it turns out that the temperature should be much lower and, apparently, equal to approximately 15 ^o С at high humidity .

 For the convenience of experimental work, species Theba pisana and Helix aspersa are used. Applicants have already shown that metal complexones are effective against Deroceras reticulatum and Limax maximus (Young CL "Metal chelates as stomach poison molluscicides for introduced pests Helix aspersa, Theba pisana, Cernurlla virqata and Deroceras reticulatum in Australia", BCPC mono., (1996) 66, Slug and Snail Pests in Agriculture, eds. Henderson IF, British Protection Coucil, Farnham, UK). In ongoing trials, all snails can be counted, while the slugs apparently manage to hide. It is possible that slugs die and decompose, but cannibalism cannot be ruled out. Indeed, cannibalism among slugs has been described (South A., "Terrestrial Slugs: Biology, Ecology and Control", (1992), Ch. 11, Chapman & Hall, London) and cases of cannibalism among slugs have been reported even with food (Airey WJ , "Laboratory studies on damage to popato tubers by slugs" / J. Mollusc. Stud., (1987), 53, 97-104).

For research using snails Helix aspersa conduct two types of experiments. The first “screening” experiments were carried out in order to evaluate whether a compound or mixture of compounds exhibits noticeable molluscicidal activity. Tests are carried out in "test plots", with each plot consisting of a container of approximately 500 cm ³ and a total internal surface of 300 cm ³ . On the lid of each container, approximately 10 small air holes are made with a diameter of 0.2 mm. Fresh carrot slices are used as an alternative food.

 The second group of experiments involves the use of repeated "test plots" of various sizes. Each "site" in this group consists of a plastic tray measuring 250x300 mm, containing a 15-20 mm layer of wet pot mix. Each pallet is covered with a glass plate. Black polyethylene is placed on the glass plate, which covers 65-70% of the upper part of the pallet so as to provide a shelter for snails. About 50 g of fresh carrot slices are placed on top of the wet pot mix in one corner of each pan.

 In experiments with Theba pisana, small "sections" are used consisting of approximately 1.5 L polyethylene food containers. About 10 very small air holes with a diameter of about 0.25 mm are made in the lid of each hole. In all tests, humidity is maintained at about 100% by adding water to the potted mixture as needed. These containers are used because it is believed that eggs may be present in the soil and, if trays are used, as in the case of Helix aspersa, great care must be taken to exclude the introduction of these snails to areas where they were previously absent.

 The gastric venom metal complexone is usually introduced into the carrier, with which it forms a bait. In the present invention, the carrier is based on wheat flour / bran and is a common carrier that is used in lures around the world. The well-known attractiveness of bran / wheat flour lures in industry makes it unnecessary to conduct additional experiments in this area.

 Two different inert carriers are used in the experiments, and these carriers differ in the ratio of wheat flour to bran, and the amount of bran used is in the range from 0 to 45% based on the weight of the carrier. The carrier is mixed with a small amount of oatmeal (lubricant), a small amount of sugar (1-2%), filler and mold inhibitor. Control processing includes providing snails with carrots as food.

Typically, the following compositions are used [Fe (OH) EDTA] ^2- :
670 g / kg of wheat flour (in case of low bran content) or 380 g / kg of wheat flour (in case of high bran content);
160 g / kg of bran (in case of low bran content) or 315 g / kg of bran (in case of high bran content);
20 g / kg oat oat flour (with a high content of bran);
20 g / kg calcium stearate;
90 g / kg iron-sodium EDTA;
20 g / kg CaCO ₃ ;
5 g / kg K ₂ CO ₃ ;
20 g / kg sodium benzoate;
0.2 g / kg BITREX ^® (trademark, denatonium benzoate); and
40 g / kg of liquid paraffin.

 There are a large number of variables that need to be considered when evaluating pellets to destroy snails or slugs. Field trials are often difficult to control and often difficult to make clear conclusions. For poorly set or poorly controlled experiments, extensive statistical analysis can be used. However, a series of simple experiments in which variables are controlled lead to unambiguous results without the need for a detailed statistical analysis. It was decided to compare the effectiveness of pellets in laboratory conditions, which well simulate controlled field conditions, but do not cause problems arising from incomplete collection and counting of dead objects or uneven distribution of snails in the test area. Daytime temperature or daylight hours are not controlled, despite the fact that these factors are known to some extent affect the activity of food intake by snails and slugs, but their role is small compared to the influence of temperature.

In examples 1 and 2, the effect of adding to the composition of the bait K ₂ CO ₃ (as a pH regulator) in various concentrations was studied. The effectiveness of various formulations containing aluminum and iron (II) chelates was also evaluated.

 The following formulations are used.

Formulations AE were prepared based on FeSO ₄ + Na ₂ EDTA + K ₂ CO ₃ ;
Formulation A: 0.65% Fe in the form of Fe (II) EDTA + 4.8% K ₂ CO ₃ , pH = 9.5;
Formulation B: 0.65% Fe in the form of Fe (II) EDTA + 2.0% K ₂ CO ₃ , pH = 7.8;
Formulation C: 0.55% Fe in the form of Fe (II) EDTA + 1.0% K ₂ CO ₃ , pH = 6.8;
Formulation D: 0.70% Fe as Fe (II) EDTA + 2.0% K ₂ CO ₃ , pH = 6.5;
Formulation E: 1.80% Fe in the form of Fe (II) EDTA + 4.5% K ₂ CO ₃ , pH = 7.0;
FJ formulations are aluminum chelate formulations:
Formulation F: 1.1% A1 in the form of potassium aluminum salt EDTA;
Formulation G: 0.55% A1 in the form of the potassium-alumina salt of trans-1.2-diaminocyclohexane-N, N, N ', N'-tetraacetic acid;
Formulation H: 0.61% A1 in the form of a potassium aluminum salt of 1,6-diaminohexane-N, N, N ', N'-tetraacetic acid;
Formulation I: 1.1% A1 in the form of an aluminum-potassium salt of 1,3-diamino-2-hydroxypropane-N, N, N ', N'-tetraacetic acid;
Formulation J: 1.2% A1 in the form of a potassium-alumina salt of 1,2-diaminopropane-N, N, N ', N'-tetraacetic acid.

Example 1
In this example, snails of the species Helix aspersa are used. The tests are carried out at a temperature range of 18-29 ^o With the use of formulations with a high content of bran. Dead snails are removed and their number is calculated after 7 days. The results are presented in table 1.

Example 2
In this example, snails of the species Theba pisana are used. The tests are carried out at a temperature range of 18-23 ^o C and using formulations with a high content of bran. Dead snails are removed and their number is calculated after 7 days. The results obtained are presented in table.2.

conclusions
The results obtained in example 1 show that formulations having a higher pH value are much more effective than formulations with a lower pH value, and that the A1EDTA formulation has at least the same efficacy as formulation I containing Fe (Ii) EDTA. Example 2 shows that iron (II) formulations are much more effective than aluminum formulations.

 The following examples compare the efficacy of iron (III) EDTA and iron (II) EDTA formulations having different pH values with the efficacy of Zeneca (UK product containing 4% metaldehyde) and PBI (UK product containing approximately 3% metaldehyde).

Example 3
In this example, snails of the species Helix aspersa are used. The tests are carried out at a temperature range of 18-26 ^o With and using formulations with a low content of bran. Dead snails are removed and their number is counted after 8 days. The results are presented in table.3.

 The following formulations are used.

9.0% Fe (III) EDTA, pH = 7.5
Recipe K 8.9% Fe (II) EDTA; K ₂ CO ₃ , pH = 5.6
Formulation L 8.7% Fe (II) EDTA; K ₂ CO ₃ , pH = 5.7
Formulation M 8.6% Fe (II) EDTA; K ₂ CO ₃ , pH = 6.2
conclusions
The data of Example 3 show that iron (II) EDTA formulations with a set pH are at least as effective as iron (III) EDTA formulations and that metal chelate formulations are more effective than any formulations containing metaldehyde.

 The following examples compare the effectiveness of iron (II) EDTA formulations having different pH values with the effectiveness of aluminum-EDTA formulations having different pH values.

Example 4
In this example, snails of the species Helix aspersa are used. The tests are carried out at a temperature range of 17-20 ^o C and using formulations with a low content of bran. Dead snails are removed and their number is calculated after 7 days. The results are presented in table 4.

 The following formulations are used.

Formulation N 8.0% Fe (OH) EDTA, pH = 1.3
Formulation O 8.0% Fe (OH) EDTA, pH = 7.8
Formulation P 7.7% Fe (OH) EDTA, pH = 10.0
Formulation Q 7.6% Fe (OH) EDTA, pH = 10.3
Formulation R 0.78% A1 as A1EDTA, pH = 9.37
Formulation S 1.04% A1 as A1EDTA, pH = 6.80
Formulation T 1.11% A1 as A1EDTA, pH = 8.63
Formulation U 0.62% A1 as A1EDTA, pH = 6.85
conclusions
The results obtained in example 4 show that the degree of damage to the mollusks depends on the selected metal and its amount used in the formulation, as well as on the pH of the formulation.

 The following examples compare the efficacy of the Fe (III) EDTA oxodimer with the efficacy of DEFENDER Petrepel (metaldehyde), Blitzem (1.5% metaldehyde), BAYSOL (2% methiocarb, a product from Bayer), which are common pellets on the Australian market for killing snails and slugs.

Example 5
In this example, snails of the species Helix aspersa are used. Tests are carried out at a temperature range of 11-16 ^o C. The dead snails are removed and their number is calculated after 7 days. The test uses eight "test plots". The results obtained are presented in table.5.

conclusions
The results obtained in example 5 show that the formulation containing the oxodimer is much more effective than other molluskocide varieties sold on the Australian market.

 The following example shows the effectiveness of Fe (III) EDTA at various pH values.

Example 6
In this example, snails of the species Helix aspersa are used. The tests are carried out at a temperature range of 14-19 ^o C and using a formulation based on wheat flour. Dead snails are removed and their number is calculated after 7 days. Four “test plots” are used in the test. The results obtained are presented in table.6.

 The following formulations are used.

Formulation V 8.5% Fe (III) EDTA, 1.08% citric acid; pH = 6.14
Formulation W 8.5% Fe (III) EDTA; pH = 6.68 Formulation X 8.6% Fe (III) EDTA, 0.62% Na ₂ CO ₃ ; pH = 7.58
Formulation Y 8.55% Fe (III) EDTA, 1.23% Na ₂ CO ₃ ; pH = 8.01
Formulation Z 7.76% Fe (II) EDTA; pH = 4.92
conclusions
The results show how the degree of damage to the cochlea changes with a change in the metal ion and pH, which affect the palatability of the bait recipes. In general, the higher the alkaline pH, the formulations of the bait of a particular metal chelate have, the more attractive they are and provide a higher degree of snail damage.

 A person skilled in the art will understand that the described invention may be modified or modified. It should be understood that the invention includes all such variations and modifications. The invention also includes the steps, features, compositions and compounds listed or named in the description, separately or together, and all and any combination of two or more of these steps or features.

Claims (23)

 1. A gastric molluskocide containing a metal complexon, wherein the metal is selected from the group consisting of iron and aluminum, and an acceptable non-liquid carrier, said molluskocide having a pH value of 7 ± 0.5 or higher.  2. Molluscocide gastric action according to claim 1, characterized in that it has a pH value of from 7 to 10.  3. The gastric molluskoid according to claim 1, characterized in that it has a pH value of 8 ± 0.5.  4. Gastric molluskocide according to any one of claims 1 to 3, characterized in that the metal complexon contains at least one iminodiacetyl group or two aminoacetyl groups.  5. Molluscocide gastric action according to any one of claims 1 to 4, characterized in that the metal complexon is a hydroxymetal complexon. 6. Gastric molluskocide according to claim 5, characterized in that the hydroxymetal complexone is [Fe (OH) EDTA] ^-2 .  7. Gastric molluskocide according to any one of claims 1 to 6, characterized in that the non-liquid carrier contains food for the mollusk, a filler, a phagostimulator for mollusks, a lubricant, a waterproofing agent, a flavoring agent, a preservative and / or a pH regulator. 8. The gastric molluskocide according to claim 7, characterized in that the filler is selected from CaCO ₃ and K ₂ CO ₃ .  9. Gastric molluskocide according to claim 7, characterized in that the waterproofing agent is a fatty acid alcohol and is present in an amount of from 1 to 5 wt.% Based on the entire molluscocide. 10. The gastric molluskocide according to claim 9, characterized in that the fatty acid alcohol is selected from the group of alcohols C ₁₆ -C ₁₈ fatty acids. 11. Gastric molluskocide according to claim 10, characterized in that the alcohol C ₁₆ -C ₁₈ fatty acid is approximately 2 wt.% Based on the entire molluscocide. 12. The gastric molluskocide according to claim 11, wherein the C ₁₆ -C ₁₈ fatty acid alcohol is a mixture of hexadecanol, heptadecanol and octadecanol. 13. The gastric molluskocide according to claim 7, characterized in that the pH regulator is K ₂ CO ₃ .  14. Gastric molluskocide according to claim 1, characterized in that the metal complexon is at least 6 wt.% Based on the entire molluscocide. 15. The gastric molluskocide according to claim 14, characterized in that the metal complexon is at least about 6-12 wt.% Based on the entire molluscocide, if the metal complexon is [Fe (OH) EDTA] ^-2 . 16. The gastric molluskoid according to claim 15, characterized in that [Fe (OH) EDTA] ^-2 is approximately 9% by weight based on the entire molluskoid.  17. The gastric molluskocide according to claim 1, characterized in that the active ingredient comprises a metal complexon in combination with at least one other molluscocide. 18. A method of producing a molluskocide of gastric action according to claims 1-17, which includes the stage (a) of mixing the components to obtain a mixed composition; (b) heating the mixture composition for 1-5 minutes in the presence of steam at an ambient temperature of approximately 80-100 ^o C; (c) maintaining the mixed composition at ambient temperature for 10-30 s; and (g) forming the mixed composition in one or more pellets. 19. The method according to p. 18, in which stage (b) is carried out at a temperature of approximately 90 ^o C for approximately 2 minutes  20. The method according to claim 19, in which stage (C) is carried out for approximately 15 C.  21. The method according to claim 20, in which stage (g) is carried out under pressure.  22. Pellets of a molluskocide of gastric action, obtained by the method according to p. 18, and the size of the pellets is approximately 2.5-4 mm  23. Gastric molluskocide pellets according to claim 22, wherein the pellet size is approximately 3 mm.

Images