Mollusc killing composition containing calcium cyanamide and sodium abietate and application of mollusc killing composition

Abstract

The invention discloses a mollusc killing composition containing calcium cyanamide and sodium abietate and application of the mollusc killing composition, and belongs to the technical field of pesticides. The composition contains a first effective component calcium cyanamide and a second effective component sodium abietate, the mass ratio of calcium cyanamide to sodium abietate is 4: 1-2: 1, and the total content of calcium cyanamide and sodium abietate accounts for 20-60% of the composition. The composition can be processed into granules, water dispersible granules, wettable powder or bait and the like, and is used for preventing and treating mollusks such as snails, slugs, ampullaria gigas and the like in agricultural production. Compared with a single agent, the composition has the advantages of synergistic interaction, quick effect and persistent effect, thorough ovicidal effect, low toxicity, safety, environmental friendliness, soil improvement, yield increase and the like, can replace a high-toxicity molluscicide, and is suitable for various crops such as vegetables, rice, citrus and the like.

Description

Technical Field

[0001] This invention belongs to the field of pesticide technology, specifically relating to a composition for killing mollusks containing calcium cyanamide and sodium rosinate, and its application. Background Technology

[0002] In agricultural ecosystems, gastropods have become significant pests threatening crop yield and quality. This group primarily includes snails (Bradybaena spp., Cernuella virgata, Lissachatina fulica), slugs (Agriolimax agrestis), and golden apple snails (Pomacea canaliculata). These creatures ravage vegetables, field crops, and fruits with astonishing appetites, particularly favoring the roots, stems, buds, and flowers of crops. They pose a direct threat to vulnerable seedlings, causing leaf and stem damage, stunted growth, and reduced seedling emergence rates. In severe cases, they may bite off or completely devour seedlings, leading to gaps in the rows. Even more worrying is that the excrement and gelatinous mucus left behind by these mollusks not only contaminate crop leaves and hinder growth but also create breeding grounds for pathogens, further exacerbating crop disease risks and severely impacting the healthy growth cycle, yield, and commercial value of crops. At the same time, these mollusks have strong adaptability and reproductive capacity (for example, a single female golden apple snail can lay 2,000 to 8,500 eggs a year; a single female giant African snail can lay 800 to 1,200 eggs a year), and their populations expand rapidly, which can easily cause serious damage to agriculture and aquatic ecosystems, threaten ecosystems, and the parasites they carry may spread parasitic diseases and cause human diseases. Data shows that infestations by mollusks such as the slug (Agriolimax agrestis), giant African snail (Lissachatina fulica), similar snail (Brddybaena similaris (Ferussac)), grey snail (Bradybaena ravida (Benson)), Mediterranean white snail (Cernuella virgata), and golden apple snail (Pomacea canaliculata) can directly lead to crop yield reductions of over 40%, induce stunted seedlings and delayed growth, and extend the crop's vegetative growth period by 7-12 days (FAO, 2023). Their strong reproductive potential and wide omnivorous diet pose a potential threat to almost all crop species, causing significant harm to agricultural production. In some southern vegetable-growing areas, they have even risen from minor pests to major pests, especially in years with heavy autumn rains and high humidity, when their damage is more severe. Therefore, it is urgent to establish an environmentally friendly and economically efficient comprehensive prevention and control system to ensure the sustainable development of agriculture.

[0003] According to domestic and international pesticide registration data, the active ingredients currently registered for agricultural production to control mollusks (such as snails, slugs, and golden apple snails) mainly fall into the following categories: First, inorganic compounds, such as ferric phosphate, copper sulfate, and ammonia; second, organic synthetic compounds, including triphenyltin acetate (organotin compounds), metaldehyde, carbaryl, methylcarbamate, emamectin, molluscicide, and molluscicide ethanol ammonium salt; and third, plant-derived products, such as garlic extracts (e.g., allicin, diallyl disulfide), tea saponins, and caffeine. In actual control, farmers occasionally use traditional methods, such as spreading quicklime and wood ash to form isolation zones; spreading tea seed cake, tung seed bran, and coffee grounds; and planting insect-repelling plants (such as mint and scallions) to kill or repel mollusks. However, these control agents and measures all have various negative impacts. For example, long-term use of copper sulfate can lead to copper accumulation in the soil, causing soil copper poisoning, inhibiting soil microbial activity, and disrupting the soil ecological balance. It is also highly toxic to aquatic organisms (such as fish and shellfish), easily causing water pollution. Triphenyltin acetate itself is highly toxic, difficult to degrade, and easily remains in the environment for a long time. It has significant toxicity to soil microorganisms, aquatic organisms, and non-target animals (such as fish and amphibians), and may accumulate through the food chain, posing ecological risks. Although metaldehyde has low toxicity to humans and animals, it is toxic to non-target organisms such as bees and earthworms. Long-term, large-scale use may lead to residue accumulation in the soil, affecting the stability of the soil ecosystem. Mefenamic acid, carbaryl, emamectin benzoate, spirodiclofen, and spirodiclofen ethanol ammonium salt easily remain in the soil, leading to an imbalance in the soil microbial community structure, affecting soil microbial activity, and having significant toxicity to non-target organisms such as bees, birds, and aquatic organisms, potentially causing ecological imbalance. Traditional methods used by farmers, such as the excessive use of quicklime, wood ash, and ammonia, can lead to drastic changes in soil pH, disrupting the soil microbial community structure, causing soil compaction or salinization, and affecting crop root health and soil ecosystem stability. Garlic extract is relatively environmentally friendly, but high concentrations may inhibit soil microorganisms and pose a risk to pollinating insects such as bees, so it should be used with caution. Tea saponins, tea cake, tung seed bran, and coffee grounds are derived from plants or agricultural waste and are relatively environmentally friendly, but excessive application may cause a rapid increase in soil organic matter in the short term, leading to a short-term imbalance in the soil microbial community, so they should be used in moderation. In addition, tea cake contains a certain amount of saponins, which may be toxic to aquatic organisms (such as fish), so water pollution should be avoided.

[0004] Given the toxicity of pesticides used in the control of mollusks such as snails, slugs, and golden apple snails in existing agricultural production, as well as the potential for pesticide resistance to water bodies, soil microorganisms, and non-target organisms, developing new green, environmentally friendly, low-toxicity, and highly effective drug combinations has become an inevitable choice.

[0005] This invention, through extensive indoor pesticide screening studies and field bioassays, has identified a compound composition of the inorganic compound calcium cyanamide and the plant-derived insecticide sodium pinoresinate, which demonstrates excellent control effects against mollusc damage in crops such as rice, vegetables, and medicinal herbs. Currently, there are no reports on the composition and application of calcium cyanamide and sodium pinoresinate, either domestically or internationally.

[0006] Currently, calcium cyanamide, as an alkaline inorganic compound, is mainly used in agriculture for soil disinfection, control of root-knot nematodes, and as a slow-release fertilizer. After application, it effectively inhibits soil pathogens, kills root-knot nematodes and weed seeds, slowly releases nitrogen and calcium, inhibits nitrification, and comprehensively improves nitrogen utilization. It not only provides the calcium and nitrogen needed for plant growth but also regulates soil pH, improves soil properties, accelerates the decomposition of crop straw and livestock manure, and enhances composting effects; it also promotes crop growth, tillering, quality improvement, and yield increase. As a pesticide, it has been registered for use on tomatoes and cucumbers to control root-knot nematodes and on rice to control golden apple snails. Its mechanism of action involves a chemical reaction between calcium cyanamide and water and carbon dioxide in the soil, producing calcium hydroxide, calcium carbonate, and free cyanamides (monocyanamide and dicyandiamide). Dicyandiamide has a direct toxic effect on target organisms, inhibits their growth and development, and destroys the egg structure. Monocyanamide interferes with the metabolism of target organisms by releasing substances such as formaldehyde, leading to their death. Meanwhile, the strong alkalinity of calcium cyanamide (pH approximately 12.4) can disrupt the acidic environment suitable for target organisms, and the released calcium hydroxide can raise the soil pH to a neutral or slightly alkaline state, inhibiting the survival of mollusks. For example, after application, the soil pH can increase by 7.68% to 11.18%, creating an environment unfavorable to the reproduction of mollusks. Although one domestic company has registered it for the control of golden apple snails in rice paddies, the recommended dosage of its 50% calcium cyanamide granules is (33~55) kg / mu. Such a large unit application rate and the high concentration in the water after application will cause significant damage to the rice paddy ecosystem, easily leading to aquatic organism poisoning (such as acute toxicity to non-target aquatic organisms, and ecological imbalance of rice paddy microbial and benthic communities); long-term application may lead to soil alkalization, inhibit the availability of acid-sensitive nutrients (such as iron, manganese, and zinc), induce micronutrient deficiencies, and affect the sustainability of fertility; at the same time, it will significantly increase the safety risks to crops and other plant phytotoxicity; and it will also exacerbate agricultural non-point source pollution.

[0007] Sodium rosinate is an organic acid sodium salt compound synthesized from natural rosin through an alkaline-catalyzed reaction. It possesses strong alkalinity (pH approximately 12-13), fat solubility, film-forming properties, strong penetrating ability (it can rapidly penetrate the surface structure of insects and reach deep tissues), and emulsifying properties. Belonging to the category of plant-derived pesticides, it is registered for use on citrus trees, bayberry trees, and Dendrobium officinale to control scale insects, arrowhead scale, and citrus red wax scale, as well as for orchard sanitation. Its mechanism of action involves dissolving and corroding the waxy layer of the insect's epidermis, penetrating the insect's body, causing physiological dehydration, and achieving a contact-killing effect. Its film-forming properties hinder gas exchange in insects, leading to suffocation and death. It also has stomach poison effects, disrupting the insect's digestive system. It is characterized by high efficacy, low toxicity, no residue, and safety for humans, livestock, plants, and natural enemies. Summary of the Invention

[0008] To overcome the toxicity and potential resistance issues of pesticides used in the control of mollusks such as snails, slugs, and golden apple snails in existing agricultural production, this invention conducts in-depth research on the combination of calcium cyanamide and sodium pinoresinate. It has been found that the mixture of calcium cyanamide and sodium pinoresinate in a certain mixing ratio has a significant synergistic effect on mollusks, with complementary mechanisms of action and synergistic effects.

[0009] This invention provides a molluscicide composition containing calcium cyanamide and sodium pinoresinate, wherein the composition contains a first active ingredient, calcium cyanamide, and a second active ingredient, sodium pinoresinate; wherein the mass ratio of calcium cyanamide to sodium pinoresinate is 4:1 to 2:1, and the total weight of the two active ingredients accounts for 20% to 60% of the total weight of the composition.

[0010] Furthermore, the optimal point of the indoor toxicity curve intersection method is a mass ratio of calcium cyanamide to sodium rosinate of 3:1.

[0011] Furthermore, the composition can be formulated into agriculturally acceptable dosage forms, such as wettable powders, water-dispersible granules, pellets, and baits.

[0012] Furthermore, the composition also contains adjuvants and / or fillers permitted in pesticide formulations.

[0013] Furthermore, the additives are selected from at least one of solvents, emulsifiers, wetting agents, dispersants, binders, disintegrants, thickeners, pH adjusters, stabilizers, preservatives, antioxidants, humectants, attractants, or bait matrices; the fillers are selected from at least one of diatomaceous earth, kaolin, bentonite, silica, light calcium carbonate, talc, attapulgite, ammonium sulfate, and urea; and the attractants or bait matrices are selected from at least one of glucose, sucrose, wheat bran, corn flour, soybean meal, or rice bran.

[0014] The present invention also provides the use of the above composition for controlling molluscs in crops, wherein the molluscs are gastropod pests. The pests may be at least one of snails, slugs, golden apple snails, river snails, gray barnacles, homomorphic barnacles, giant African snails, Mediterranean white snails, and wild slugs.

[0015] Furthermore, the crops mentioned are vegetables, rice, medicinal herbs, or fruit trees.

[0016] Furthermore, the composition can be applied to crop rows, water surfaces, ground surfaces, or tree canopies by spreading, spraying, or using poison bait.

[0017] Beneficial effects: Calcium cyanamide reacts with water to form and free cyanamide The high pH value of the pesticide and the toxic effect of cyanamide can rapidly destroy the respiratory epithelium and enzyme system of mollusks. Its efficacy against golden apple snails and other insects (over 90%) has been verified in the field. Sodium rosinate, a natural rosin acid-base saponification product, has good fat solubility, film-forming properties, and emulsifying properties. It has strong contact, fumigation, and spreading effects, and strong adhesion and penetrability. It can corrode the body wall of pests and dissolve the mucus layer of mollusks, leading to dehydration and suffocation. It also has good penetrability to egg sacs, compensating for the insufficient egg-killing effect of calcium cyanamide. The combination of these two pesticides can achieve full life-cycle coverage of "rapid-acting (sodium rosinate) + sustained-acting (calcium cyanamide)" and "adult snails + juvenile snails + egg sacs." Indoor initial screening showed a synergistic effect coefficient of 10%~30% (Colby method). The synergistic effect of the two pesticides shortens the lethal time by 30%~50%. Field trials have shown that the combination... The value is reduced by 40% compared to single agents. The combination has low resistance and recurrence risk. Neither of the two components is a neurotoxin and there is no cross-resistance with mainstream agents such as metaldehyde and molluscicide, which can delay resistance. The plant-derived characteristics of sodium rosinate make it friendly to non-target natural enemies, reducing recurrence. It is environmentally safe and eco-friendly. Calcium cyanamide is eventually degraded into urea and ammonium bicarbonate, which can also be used as nitrogen fertilizer. Sodium rosinate is easily photodegraded and leaves no soil residue. Its toxicity to fish and bees is 1-2 orders of magnitude lower than that of molluscicide. The combination can reduce the dosage of each agent by 50%-80%, further reducing the environmental burden. At the same time, the combination has crop health and yield-increasing effects. Calcium cyanamide has multiple functions such as acidification, calcium supplementation, control of root-knot nematodes, root rot, rust and white mold, and promotion of straw decomposition. Sodium rosinate also has a concurrent effect on fungi such as rice blast and sheath blight, which can achieve the integration of "killing mollusks + disease prevention + soil improvement", meeting the needs of green prevention and control.

[0018] The industry pain points that the composition containing calcium cyanamide and sodium rosinate provided by this invention can solve are mainly: poor low-temperature activity of metaldehyde and ineffectiveness against eggs; high toxicity of molluscicide to aquatic organisms and lack of alternatives in restricted and prohibited areas; increased resistance to single agents with long-term use and few varieties to rotate; and conventional agents have no soil improvement added value and require farmers to invest multiple times. The core basis for choosing this combination in actual agricultural production is as follows: Both individual agents are effective against mollusks and have been verified in the field; the combination exhibits no cross-resistance, with synergistic and complementary mechanisms; calcium cyanamide rapidly destroys mollusc cell membranes through its strong alkalinity and cyanamide toxicity, and acts on the cellular respiratory chain; sodium pinoresinate accelerates dehydration through osmotic pressure imbalance and also acts on oocysts, enhancing ovicidal effects; it has low environmental toxicity, complying with the "two reductions" policy; calcium cyanamide also has fertilizer effects, making it easier for farmers to accept and promote; the raw material cost is low, as both calcium cyanamide and sodium pinoresinate are bulk chemical raw materials, and the cost per acre of the combination is 20%~30% lower than the traditional molluscicide / metaldehyde solution, with stable supply, facilitating industrialization. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the embodiments.

[0020] Example 1: Indoor toxicity test of a pesticide composition of calcium cyanamide and sodium rosinate against snails and golden apple snails.

[0021] Test reagents: Sodium rosinate powder (content ≥99%) and calcium cyanamide powder (analytical grade, nitrogen ≥19.5%) were used. The test insects were snails collected from vegetable fields (identified as *Brddybaena similaris* (Ferussac)) and golden apple snails collected from rice paddies.

[0022] Experimental Methods: Targeting the simultaneous contact, fumigation, and stomach poison mechanisms of the pesticide, a combined indoor toxicity test was conducted on snails. The original pesticide and the mixed pesticide were prepared into five different concentration gradients using deionized water, based on the results of preliminary tests, with deionized water serving as a blank control. Cabbage slices were immersed in the corresponding concentration of pesticide solution for 10 seconds, then removed and air-dried until no visible water remained. Simultaneously, the entire rearing chamber, except for the top, was covered with filter paper (the filter paper was immersed in the corresponding concentration of pesticide solution for 5 seconds, removed, air-dried, and then used to cover the interior of the rearing chamber). The soaked and dried cabbage slices were placed in a sealed cubic plastic rearing chamber, and then 10 healthy small snails (shell height 15-20 mm) that had undergone indoor acclimatization for 3 days were introduced into the chamber. At 24h, 48h, and 72h, the number of dead and surviving snails was determined by touch reaction; a fine needle was used to gently prick the shell opening of the snail, resulting in the snail contracting its body or expelling a small amount of mucus, while dead snails showed no reaction. Each treatment was repeated three times. The test temperature was controlled at 25±1℃, the relative humidity at 60%~80%, and no additional food was given within 72 hours.

[0023] The combined indoor toxicity test of *Pomacea canaliculata* involved preparing five different concentration gradients of the original drug and mixed drug using deionized water, based on the results of preliminary tests, with deionized water serving as a blank control. The prepared drug solutions were poured into open plastic containers. Healthy, uniformly sized *Pomacea canaliculata* snails collected from rice paddies and raised indoors for three days were divided into sample groups of 10 snails each, packaged in plastic mesh bags. Three bags of snails were placed in each treatment group and immersed in the drug solution. The solution depth was 2-3 cm above the snail bags. A deionized water control was also included. Each treatment was repeated three times. After immersion in the drug solution for 24, 48, and 72 hours, one bag was removed, washed with clean water, and dried. After a 72-hour recovery period, the number of dead and surviving snails was determined by tapping. The experimental conditions were controlled at a temperature of 25±1℃, relative humidity of 60%–80%, and a reasonable photoperiod.

[0024] Calculation method: The experimental data were analyzed using DPS statistical analysis software, and the LC of each agent was calculated based on the mortality data after 48 hours. 50 The molluscicidal activity of each agent was evaluated, and the co-toxicity coefficient (CTC value) of the mixture was calculated according to Sun Yunpei's method.

[0025] Actual Toxicity Index (ATI) = (LC50 of Standard Reagent / LC50 of Test Reagent) × 100 Theoretical Toxicity Index (TTI) = Toxicity Index of Agent A × Percentage of A in the Mixture + Toxicity Index of Agent B × Percentage of B in the Mixture Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of the mixture / Theoretical toxicity index (TTI) of the mixture] × 100 According to the NY / T1154.13-2008 standard for classifying combined effects: a co-toxicity coefficient (CTC) ≥120 indicates a synergistic effect; a co-toxicity coefficient (CTC) ≤80 indicates an antagonistic effect; and 80 < CTC <120 indicates an additive effect.

[0026] The experimental results are shown in Tables 1 and 2.

[0027] Table 1. Indoor combined toxicity test of calcium cyanamide and sodium rosinate against golden apple snail in rice.

[0028] Table 2. Indoor combined toxicity determination of calcium cyanamide and sodium rosinate against snails in vegetable fields.

[0029] Tables 1 and 2 show that when the mass ratio of calcium cyanamide to sodium rosinate in the composition is between 1:1 and 4:1, the co-toxicity coefficients against both golden apple snails and other snails are greater than 120, indicating that the composition exhibits a synergistic effect on the biological activity of both golden apple snails in rice and snails in dryland areas. In particular, when the mass ratio is between 2:1 and 4:1, the co-toxicity coefficients far exceed the synergistic threshold (CTC ≥ 120), demonstrating a significant synergistic effect. By fitting a Logistic toxicity model to the indoor toxicity data, the optimal value obtained using the intersection method of the indoor toxicity curves is found to be calcium cyanamide:sodium rosinate = 3:1. This ratio exhibits high stability in the dose-response relationship, and the synergistic effect of the two agents reaches an extremely high level, showing the best toxicity effect against mollusks. This ratio is suitable for optimizing the dosage of field application schemes. Its high CTC value may be due to the complementary effect of calcium cyanamide (strong alkaline dehydration + release of cyanamide to kill) and sodium rosinate (alkaline saponin rapidly dissolves the mucus layer of mollusks and disrupts the osmotic pressure of mollusks), or the permeability enhancement effect at the pharmacokinetic level. The specific mechanism needs to be further elucidated by molecular biology methods.

[0030] Example 2: Formulation examples and processing methods for preparing calcium cyanamide and sodium rosinate into granules, water-dispersible granules, wettable powders, and bait granules.

[0031] (1) Formulation and preparation method of 40% calcium cyanamide·sodium rosinate (active ingredient mass ratio 3:1) granules.

[0032] The granule carrier can be one or more of bentonite, diatomaceous earth, kaolin, montmorillonite, talc, etc.; the binder can be one or more of starch, dextrin, carboxymethyl (ethyl) cellulose, chitin; the dispersant can be one or more of polycarboxylate, lignin sulfonate, sodium naphthalene sulfonate formaldehyde condensate surfactant. Example formulation: 30% calcium cyanamide, 10% sodium rosinate, 8% sodium naphthalene sulfonate formaldehyde condensate dispersant, 2.0% sodium carboxymethyl cellulose binder, 0.5% borax (pH stabilizer), 40% diatomaceous earth carrier, bentonite to 100%. The manufacturing process can employ dry granulation, specifically mixing the active ingredients, additives, and carrier, pulverizing them using an ultrafine pulverizer, then granulating, shaping, drying, sieving, and inspecting to obtain the final product. Granulation can be achieved using one of the following methods: fluidized bed granulation, extrusion granulation, rotary granulation, or stamping granulation, with extrusion granulation being preferred. Product quality control is as follows: particle size is 2.0~4.0mm, moisture content is controlled below 1.5%, flowability is required to be ≥95% passing through a 5mm sieve, there is basically no dust, thermal storage stability is (54±2)℃ for 14 days, and the decomposition rate of effective ingredients is ≤5%.

[0033] (2) Formulation and preparation method of 50% calcium cyanamide·sodium rosinate (active ingredient mass ratio 4:1) water dispersible granules.

[0034] For water-dispersible granules, those skilled in the art are familiar with using appropriate additives to complete this invention. The dispersant can be one or more of carboxylate polymers, lignin sulfonates, sodium naphthalene sulfonate condensates, and alkyl naphthalene sulfonate condensates; the wetting agent can be one or more of dispersing powder BX, alkyl sulfates, alkyl sulfonates, and naphthalene sulfonates; the disintegrant can be one or more of ammonium sulfate, urea, potassium sulfate, sodium citrate, and glucose; the binder can be one or more of starch, polyvinyl alcohol, and carboxymethyl (ethyl) cellulose; the filler can be one or more of diatomaceous earth, kaolin, silica, light calcium carbonate, talc, and attapulgite. Example formulation: Calcium cyanamide 40%, sodium rosinate 10%, potassium sulfate 9.2%, borax (pH stabilizer) 0.8%, wetting agent alkyl naphthalene sulfonate 1.5%, dispersant carboxylate polymer 3.5%, condensed naphthalene sulfonate 3.0%, binder sodium carboxymethyl cellulose 2.0%, kaolin to make up 100%. The preparation process employs dry granulation, specifically involving mixing the active ingredients, additives, and fillers, pulverizing them using an ultrafine pulverizer, and then proceeding with plastic granulation, shaping, drying, sieving, and inspection to obtain the final product. Granulation can be achieved using one of three methods: fluidized bed granulation, extrusion granulation, or rotary granulation, with fluidized bed granulation being preferred. Product quality control requires uniform granules with minimal dust, no visible foreign impurities or hard lumps, a moisture content below 2.5%, a disintegration time of less than 2 minutes, wettability ≤100s (complete wetting), dispersibility ≥80% (after 1 minute of mechanical stirring), suspension rate ≥75%, flowability ≥95% (passing through a 5mm sieve), thermal storage stability at (54±2)℃ for 14 days, and an active ingredient decomposition rate ≤5%.

[0035] (3) Formulation and preparation method of 40% calcium cyanamide·sodium rosinate (active ingredient mass ratio 3:1) wettable powder.

[0036] For wettable powders, the following additives can be used: dispersants such as one or more of polycarboxylates, lignin sulfonates, and alkyl naphthalene sulfonates; wetting agents such as one or more of alkyl sulfates, alkyl sulfonates, and naphthalene sulfonates; and fillers such as one or more of ammonium sulfate, urea, sucrose, glucose, diatomaceous earth, kaolin, silica, light calcium carbonate, montmorillonite, talc, attapulgite, and clay. Example formulation: 30% calcium cyanamide, 10% sodium rosinate, 0.8% borax (pH stabilizer), 3% dispersant alkylphenol polyoxyethylene ether formaldehyde condensate sulfonate, 1% sodium naphthalene sulfonate formaldehyde condensate, 1% wetting agent calcium dodecylbenzene sulfonate, 1% separating agent BX, 3% filler silica, and kaolin to bring the total to 100%. Preparation process: After uniformly mixing the above raw and auxiliary materials in a twin-screw mixer, the mixture is pulverized by an ultrafine pulverizer or an air jet mill to control the particle size to less than 325 mesh (wet sieving method). The mixture is then uniformly mixed again in another twin-screw mixer. After passing inspection, a wettable powder is obtained. Product quality control requires a uniform, loose powder appearance, free of visible lumps and odor; a fineness ≥98% passing through a 325 mesh sieve (44μm); a wetting time ≤80s; a suspension rate ≥80%; thermal storage stability at (54±2)℃ for 14 days; and an effective ingredient decomposition rate ≤5%.

[0037] (4) 20% calcium cyanamide·sodium rosinate (active ingredient mass ratio 3:1) bait formulation and preparation method.

[0038] Common bait formulations include active ingredients, bait base such as wheat bran, yeast powder, corn flour, alfalfa meal, soybean meal, corn germ meal, rapeseed meal, rice bran, concentrated molasses fermentation liquid, white sugar, fructose syrup, glucose, sucrose, and honey (one or more), attractants such as ethanol, beer, yeast flour (one or more), humectants such as glycerin, sorbitol, and propylene glycol (one or more), binders such as carrageenan, gelatin, agar, and xanthan gum (one or more), preservatives such as potassium sorbate, sodium benzoate, and lactic acid + sodium lactate (one or more), and antioxidants such as sodium ascorbate and 2,6-di-tert-butyl-p-cresol (one or more). Example formulation: Calcium cyanamide 15%, sodium rosinate 5%, borax (pH stabilizer) 0.5%, bait base 25% wheat bran 20%, corn flour 20%, alfalfa meal 10%, corn germ meal 10%, concentrated molasses fermentation liquid 9.5%, attractant active yeast flour 5%, binder gelatin 0.6%, preservative sodium benzoate 0.3%, antioxidant sodium ascorbate 0.1%. The preparation process uses a rolling coating method. First, the powdered bait base and binder are mixed evenly, then extruded into granules using an extruder. After drying, the granules are rolled in a mixed solution of concentrated molasses fermentation liquid, humectant, and preservative, allowing for layered adsorption of the effective components, borax stabilizer, molasses, and attractant. Finally, the mixture is dried at low temperature until the moisture content is ≤5%, yielding the granular bait. In terms of product quality control, the appearance is uniform in color, the particle size is 2~4mm, the mildew resistance level is 28℃, RH 85%, no visible mildew spots after 14d, the thermal storage stability is (54±2)℃ for 14d, and the decomposition rate of the active ingredient is ≤5%.

[0039] Example 3: Preliminary Indoor Efficacy Test The 40% calcium cyanamide·sodium rosinate (active ingredient mass ratio 3:1) granules, 50% calcium cyanamide·sodium rosinate (active ingredient mass ratio 4:1) water-dispersible granules, 40% calcium cyanamide·sodium rosinate (active ingredient mass ratio 3:1) wettable powder, and 20% calcium cyanamide·sodium rosinate (active ingredient mass ratio 3:1) bait formulations prepared in Example 2 of this invention were used to treat wild slugs, basal snails, gray basal snails, and golden apple snails indoors to test their efficacy. 6g of each of the combined formulations was sprinkled into 70×70×70cm rearing cages enclosed with mesh. Ten healthy mollusks of the same size were placed in each cage, with three replicates. Water was sprayed into the cages regularly, and a certain amount of cabbage leaves were fed to maintain a humid living environment and a reasonable light cycle. The reactions of the mollusks were observed daily, and mortality rates were checked at 3, 5, 7, and 9 days after administration. The efficacy was corrected after 3 days. Statistical analysis showed that the four compositions prepared in Example 2 all achieved efficacy of over 90% against wild slugs, homomorph snails, gray snails, and golden apple snails within 3-5 days, and over 98% within 5-9 days.

[0040] Example 4 Field efficacy trial (1) Efficacy test of pesticides for controlling snails and slugs in cauliflower planting areas. The field efficacy test was conducted in accordance with the guidelines for field efficacy tests of pesticides (II) Part 69: Insecticides for the control of snails and slugs in dryland areas (GB / T 17980.69-2004). The test was conducted in an area of ​​a cauliflower planting base in a city in Hubei Province where snails and slugs were severely infested. The previous crop was cabbage, and the cauliflower variety was "Xueli 150 Days" loose cauliflower. The average row spacing was 65 cm and the average plant spacing was 55 cm. Local snails (mainly the common barnacle snail and the grey barnacle snail) and slugs (wild slugs) have two peak infestation periods in June-July and September-October. In November, as temperatures drop and food becomes scarce in the fields, snails and slugs begin to overwinter as adult and juvenile shellfish in soil crevices, crop roots, or on weeds. The experiment included six treatment zones, each replicated three times. Each plot was 12 m², enclosed by plastic film. The 40% calcium cyanamide·sodium rosinate granules and 20% calcium cyanamide·sodium rosinate bait granules prepared in Example 2 were used for pest control. The control group received ① 15% metaldehyde granules; ② 6% polyaldehyde·carbamate granules; ③ 2.4% ferric phosphate granules. All pesticides were applied directly and evenly between the rows of cauliflower plants. The blank control group received no pesticides. On the day of application, the weather was sunny with temperatures ranging from 23 to 31°C and relative humidity from 80% to 90%. Application was carried out around 6 PM. The number of surviving snails and slugs on both sides of cauliflower leaves in each experimental plot was recorded one day before application and on days 3, 7, and 14 after application, with each survey conducted after 7 PM. The safety of each pesticide treatment on cauliflower was also observed. The reduction rate and control effect on the two mollusks were calculated using the following formula. The results are shown in Tables 3 and 4.

[0041] Reduction rate (%) = [(Quantity before treatment - Number of survivors after treatment) / Quantity before treatment] × 100 Efficacy (%) = [(Reduction rate in the treated area - Reduction rate in the blank control area) / (100 - Reduction rate in the blank control area)] × 100 Table 3. Control efficacy of different pesticides against snails in vegetable growing bases.

[0042] Table 4. Control efficacy of different pesticides against slugs in vegetable growing areas.

[0043] Table 3 shows the field efficacy against snails. Three days after application, the 40% calcium cyanamide·sodium rosinate granules showed the highest snail control efficacy among all treatments, reaching 80.79%. This efficacy was not significantly different from that of the 15% metaldehyde granules and 20% calcium cyanamide·sodium rosinate bait treatments, but significantly higher than that of the 6% polyaldehyde·carbamate granules and 2.4% ferric phosphate granules. Seven days after application, the snail reduction rate reached its maximum in all treatment areas, with efficacy exceeding 86%. The 40% calcium cyanamide·sodium rosinate granules showed the highest efficacy, and there was no significant difference in efficacy among the five treatments. Fourteen days after application, the efficacy of all treatments decreased to varying degrees, but the efficacy of the 40% calcium cyanamide·sodium rosinate granules and 20% calcium cyanamide·sodium rosinate bait treatments remained at 88.65% and 87.78%, respectively, significantly higher than the other three treatments.

[0044] The field efficacy against slugs is shown in Table 4. Three days after application, the 40% calcium cyanamide·sodium rosinate granules showed the highest slug control efficacy among all treatments, reaching 85.09%. This efficacy was not significantly different from the 15% metaldehyde granules treatment, but significantly higher than the other three treatments. Seven days after application, the slug reduction rates in the three treatment areas (40% calcium cyanamide·sodium rosinate granules, 20% calcium cyanamide·sodium rosinate bait, and 2.4% ferric phosphate granules) reached their highest levels, while the reduction rates in the other two treatments began to decline. The 40% calcium cyanamide·sodium rosinate granules and 20% calcium cyanamide·sodium rosinate bait showed significantly higher efficacy than the other three treatments. Fourteen days after application, the slug reduction rate and control efficacy of each treatment decreased to varying degrees. However, the control efficacy of the 40% calcium cyanamide·sodium rosinate granules and the 20% calcium cyanamide·sodium rosinate bait treatment remained at 88.92% and 83.71%, respectively, which were significantly higher than the other three treatments.

[0045] Overall, the experiment showed that the treatment of snails and slugs on cauliflower with 40% calcium cyanamide·sodium rosinate granules and 20% calcium cyanamide·sodium rosinate bait demonstrated good rapid and sustained effectiveness.

[0046] (2) Efficacy test of snail control in citrus orchards. The test site was a mature citrus orchard in a city in Hunan Province. The orchard was flat, and the planted variety was Yizhang navel orange. The plant spacing was 4m×2m. In recent years, snails (mainly the same type of barnacle snail) have been a serious problem. According to the preliminary survey, snails in this citrus orchard began to emerge from the soil in late March, and their numbers gradually increased thereafter. The number of snails showed two peaks during May-June and September-October, and the number of snails gradually decreased from November to February of the following year. Further observation revealed that snails in citrus orchards generally overwinter in the loose soil on the surface of citrus trees and under piles of weeds. Mating behavior of snails could be observed from May to September. The experiment consisted of five treatment zones, as follows: ① 40% calcium cyanamide·sodium rosinate (active ingredient mass ratio 3:1) wettable powder diluted 250 times; ② 80% metaldehyde wettable powder diluted 600 times; ③ 30% tea saponin aqueous solution diluted 250 times; ④ 70% molluscicide wettable powder diluted 1000 times; ⑤ control group, no treatment. The spray treatments covered the tree canopy and the ground within a 50cm radius of the citrus tree trunk. Each experimental zone consisted of six adjacent citrus trees, covering an area of ​​approximately 27m². 2 The experiment was conducted with three replicates. Five days prior to application, weeds in the experimental area were cleared. The experiment began in early June. Before application, the number of snails on the tree canopy and ground was surveyed and counted. In the control group, snails on the tree canopy were manually removed before application. Spraying was performed after 4 PM. The number of live snails on the tree canopy and ground was surveyed and counted on days 1, 3, 7, 14, and 21 after application, along with the inhibitory effect on snails climbing the trees. The effects of the pesticide on citrus trees, including any potential phytotoxicity, were also observed. The experimental results are shown in Table 5.

[0047] Reduction rate (%) = [(Quantity before treatment - Number of survivors after treatment) / Quantity before treatment] × 100 Efficacy (%) = [(Reduction rate in the treated area - Reduction rate in the blank control area) / (100 - Reduction rate in the blank control area)] × 100 Table 5. Control efficacy of different pesticides against snails in citrus orchards.

[0048] Table 3 shows that after spraying, the control efficacy of all four pesticide treatments was above 76% at 7 days post-application, but the efficacy began to decline at 14 days. While the efficacy of 40% calcium cyanamide·sodium rosinate wettable powder also decreased, it still reached 57.26%. At 21 days post-application, the efficacy of all pesticides was poor. This indicates that the 40% calcium cyanamide·sodium rosinate wettable powder has significantly higher efficacy and persistence than the other three pesticides, and can be preferentially applied for field control of snails and slugs in orchards. Simultaneously, the inhibitory effects of each treatment on snail climbing were investigated. It was found that 7 days after application, all treatments showed significant inhibitory effects compared to the control group. However, after 14 days, only the 40% calcium cyanamide·sodium rosinate wettable powder showed significant inhibitory effects; the other treatments showed a significant number of snails climbing the trees and no significant inhibitory effect compared to the control. At 21 days, although a small number of snails climbed the trees with the 40% calcium cyanamide·sodium rosinate wettable powder, it still showed a significant inhibitory effect compared to the control. Regarding safety, observations of the citrus trees after spraying revealed no phytotoxicity symptoms or inhibition of normal growth in any of the tested treatments, indicating that the dosages of each treatment were safe.

[0049] (3) Efficacy test of controlling golden apple snail in paddy fields. The test site was located in an early rice field in a city in Hunan Province. The rice variety was Xiangzaoxian 32. The water depth in the paddy field was maintained at 3-4 cm, and the water retention time was until the last survey. There were 6 treatments in the experiment, including 2 blank controls, namely the snail-containing blank treatment (used to determine the control effect) and the non-snail-containing blank treatment (used to determine the seedling protection effect). The experiment used ① 50% calcium cyanamide·sodium rosinate (active ingredient mass ratio 4:1) water-dispersible granules at 1500 g ai / hm. 2 For other control treatments, the dosage of the agent used was the recommended dosage indicated on the product packaging, namely ② 70% molluscicide ethanolamine salt wettable powder, 630 g ai / hm. 2 ③ 30% tea saponin aqueous solution, 1500 g ai / hm 2 ④ 15% metaldehyde granules, 600 g ai / hm 2 ⑤ Blank control group with snails; ⑥ Blank control group without snails. Each plot had 3 replicates, for a total of 18 plots, each plot being 20 m². 2 Each treatment was arranged in a randomized block design, enclosed by 80 cm high netting and small embankments, with independent irrigation and drainage to prevent cross-contamination. Rice was planted in plots at 25 clumps per square meter, with 4 plants per clump. Snails were introduced one week after planting. Three days prior to the experiment, healthy adult golden apple snails of similar size (with a snail mouth diameter of 0.8–1.2 cm) were collected and pre-cultured in a natural environment for at least 48 hours. On the morning of the day of application, 10 snails / m² were collected. 2The pesticide was applied to the experimental plots. Wettable powder and aqueous solutions were diluted with water and sprayed evenly using a manual sprayer. Water-dispersible granules and pellets were directly applied to each plot. A water layer of 4-6 cm was maintained in the field during application and throughout the experiment. Ten 1.5m high bamboo strips were inserted into the field at the same time as application to collect egg masses on the bamboo strips. At 2 and 7 days after application, the number of live and dead snails in each plot was checked. At 14 days after application, all released snails were identified, and the number of live and dead snails was checked (if the number was less than the original number, it was counted as escape). The number of egg masses, the total number of rice plants and tillers in the entire plot were also checked. The safety to rice was investigated, and the length of the flag leaf and root system, and the number of tillers were observed. Two days after application, the safety to aquatic organisms, such as the mortality of small fish, was observed. The efficacy calculation method is as follows, and the experimental results are shown in Tables 6 and 7.

[0050] Mortality rate (%) = [Number of dead snails / (Number of released snails - Number of escaped snails)] × 100 Control efficacy (%) = [(mortality rate in the treated area - mortality rate in the blank control area) / (100 - mortality rate in the blank control area)] × 100 Egg mass reduction rate (%) = [(Number of egg masses in the blank control area - Number of egg masses in the drug-treated area) / Number of egg masses in the blank control area] × 100 Rice seedling loss rate (%) = [1 - (total number of seedlings in the pesticide-treated area / total number of seedlings at transplanting)] × 100 Seedling survival rate (%) = [(Number of tillers in the treatment zone - Number of tillers in the control zone / Number of tillers in the treatment zone)] × 100 Table 6. Effects of different molluscicides on the control of golden apple snails in rice paddies.

[0051] Note: The initial population of golden apple snails in each area was 200 before the application of the pesticide.

[0052] Table 7. Effects of different molluscicides on egg mass control and seedling protection in rice paddies.

[0053] Note: The number of rice seedlings in each plot before applying the pesticide was 2000.

[0054] As shown in Tables 6 and 7, the efficacy of 50% calcium cyanamide·sodium rosinate (active ingredient mass ratio 4:1) water-dispersible granules at 1500 g ai / hm at 3, 7 and 14 days after application was [data missing]. 2 Treatment with 70% molluscicide ethanolamine salt wettable powder 630 g ai / hm 2 Both treatments showed good rapid and sustained effects, significantly better than 30% tea saponin aqueous solution at 1500 g ai / hm. 2 And 15% metaldehyde granules 600 g ai / hm 2Treatment. Fourteen days after application, 50% calcium cyanamide·sodium rosinate water-dispersible granules showed the best effect in inhibiting egg masses and protecting seedlings. Simultaneously, observation revealed no phytotoxicity to rice from any of the tested agents. However, three days after application, a small number of small fish died in the experimental plots for molluscicide ethanolamine salt and metaldehyde, indicating that molluscicides and metaldehyde are highly toxic to aquatic organisms. During production, these agents should be applied away from aquaculture areas and other water bodies, and their use in rice paddies with fish, shrimp, or crab co-culture is prohibited. Water from treated rice paddies must not be directly discharged into water bodies, and washing application equipment in ponds or other bodies of water is prohibited. Therefore, calcium cyanamide·sodium rosinate, as a screened, highly effective, low-toxicity, and low-residue novel environmentally friendly pesticide, has strong practical significance for the control of golden apple snails.

[0055] In summary, the combination of "calcium cyanamide + sodium rosinate" offers five major advantages: rapid effect, long-lasting effect, ovicidal effect, low toxicity, and soil improvement. It can fill the gap in mollusc control during low-temperature periods, in restricted (prohibited) farming areas, and in resistant regions. It can be used in rotation with metaldehyde and molluscicides to delay the treatment of regional resistance. It possesses good commercialization and promotion prospects.

Claims

1. A molluscicide composition containing calcium cyanamide and sodium pinoresinate, characterized in that, The composition contains a first active ingredient, calcium cyanamide, and a second active ingredient, sodium pinoresinate; wherein the mass ratio of calcium cyanamide to sodium pinoresinate is 4:1 to 2:1, and the total weight of the two active ingredients accounts for 20% to 60% of the total weight of the composition.

2. The molluscicide composition containing calcium cyanamide and sodium pinoresinate as described in claim 1, characterized in that, The mass ratio of calcium cyanamide to sodium rosinate is 3:

1.

3. The molluscicide composition containing calcium cyanamide and sodium pinoresinate as described in claim 2, characterized in that, The composition can be formulated into a dosage form acceptable for use in agricultural production.

4. The molluscicide composition containing calcium cyanamide and sodium pinoresinate as described in claim 3, characterized in that, The composition also contains adjuvants and / or fillers permitted in pesticide formulations.

5. The composition according to any one of claims 1-4 for controlling mollusks in crop production, characterized in that, The molluscs in question are harmful organisms belonging to the class Gastropoda.

6. The composition according to claim 5 for controlling mollusks in crop production, characterized in that, The crops mentioned are vegetables, rice, medicinal herbs, or fruit trees.

7. The composition according to claim 6 for controlling mollusks in crop production, characterized in that, The composition is applied by spreading, spraying, or baiting between crop rows, on water surfaces, on the ground, or in tree canopies.

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