CN110892896A

CN110892896A - Formula of low-toxicity compound pesticide molluscicide

Info

Publication number: CN110892896A
Application number: CN201911173840.7A
Authority: CN
Inventors: 蒋继宏; 杨绪勤; 陈让让; 鞠秀云; 王军娟; 周降生; 曹小迎
Original assignee: Jiangsu Normal University
Current assignee: Jiangsu Normal University
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2020-03-20

Abstract

The invention relates to a molluscicide which is prepared by mixing an extract of safflower creeping oxalis and metaldehyde as main reagents to obtain the most suitable proportion for killing ampullaria gigas through compounding and combination. The molluscicide has extremely strong lethal effect on mollusks such as ampullaria gigas and the like, the raw material of the safflower creeping oxalis is easy to obtain, the extraction and purification technology of the safflower creeping oxalis extract is mature, and the production cost is basically equal to the selling price of 6 percent metaldehyde granular preparation (about 2Kg per mu) which is circulated in the market. The invention reduces the concentration of metaldehyde, reduces the chemical pesticide residue and ensures the development of green agriculture.

Description

Formula of low-toxicity compound pesticide molluscicide

The technical field is as follows:

the invention belongs to the field of biochemistry, and particularly relates to a biological pesticide formed by compounding metaldehyde and a safflower creeping oxalis extract, which is used as a molluscacide for preventing and treating ampullaria gigas disasters.

Background art:

safflower creeping oxalis (academic name:Oxalis corymbosaDC.) is a perennial upright herb of the genus Oxalidaceae of the family Oxalidaceae. No overground stem, underground globular bulb, scale membranous substance, brown color and basal leaf growth; leaf stalk hair; the lobule is flat and round and inverted heart-shaped, the top end is concave, the two side corners are round, the back surface is light green, the leaf supporting is long and round, the top is narrow and pointed, the total pedicel is basal, the two-branch cymbidium inflorescence, the pedicel, the bract and the sepal are all hairy; sepals are in the shape of needles, petals are in the shape of inverted hearts, the sepals are in the light purple to purple, and filaments are long and soft; the flower column is rusted, long and soft, and blossoms and fruits in 3-12 months. In the tropical areas of south America originally, China is introduced as ornamental plants in the north of the Yangtze river, and the southern areas are wild and distributed in the north of Hebei, Shaanxi, east China, south China, Sichuan, Yunnan and the like. Living in low-altitude mountainous regions, roadside, wasteland or paddy fields. Its bulb is easy to separate, so it can be quickly propagated, and is often used as field weed. The functional indications are as follows: clearing away heat and toxic material, removing blood stasis, relieving swelling, and regulating menstruation. Can be used for treating pyelonephritis, dysentery, watery diarrhea, pharyngitis, toothache, stranguria with turbid urine, menoxenia, and leucorrhea; it is used externally to treat venomous snake bite, traumatic injury, carbuncle, sore, burn and scald. Meanwhile, the plant extract has the effect of killing ampullaria gigas, and the literature is published in the ecological environment science report.

Metaldehyde is named as Mida, Anhuluoshu, Wormwood spark, Meita, Anhuling and Snail, and is named as Metaldehyde which is light blue in appearance, softened when meeting water, has special fragrance and strong attraction. When the snail is attracted by attractant and eaten or contacts with medicine, the acetylcholinesterase in the snail body is released in a large quantity, special mucus in the snail body is damaged, the snail body is quickly dehydrated, nerve paralysis is caused, the mucus is secreted, and the snail body, slug and the like are poisoned and killed in a short time due to the loss of a large quantity of body fluid and the damage of cells. However, metaldehyde is also a toxic chemical and can have adverse effects on the human body if contacted for a long time. The 6% granule is a molluscicide with strong selectivity and is more popular in the market.

The ampullaria gigas are also named as thamnaeus and apple snails, and are introduced into Taiwan in 20 th century and Taiwan in 1981 by Brazilian nationality. After 1984, ampullaria gigas have been widely cultivated in the Guangdong. Due to over-cultivation, plus bad taste, it is released to the field. The ampullaria gigas has strong environment-adaptive viability and can propagate quickly, and can live through winter naturally in many areas and two generations occur in the year. The ampullaria gigas is an oviparous animal with male and female variant, in vivo fertilization and in vitro development. The breeding season of the ampullaria gigas is 3-11 months per year, wherein 5-8 months are the breeding season, and the water temperature is suitable to be 18-30 ℃. And (3) oviposition can be carried out for multiple times through one-time fertilization, oviposition starts after 3-5 days after mating, and female snails lay eggs on pond walls, wooden piles and stems and leaves of aquatic plants 15-40 cm away from the water surface at night. Oval, pink, and an oval diameter of about 2 mm. The eggs are mutually adhered into blocks, 200-1000 eggs can be laid one by one, 20-40 eggs can be laid in one year, and the egg laying amount is 3-5 ten thousand eggs. The adult is bigger, the ampullaria gigas is bigger, each ampullaria gigas can reach 100-150 g, and the largest ampullaria gigas can reach more than 250 g. It is called giant river snail. The fertility is extremely strong, and the potential hazard is huge. Thus rapidly spreading to rivers, lakes and fields; the food intake is large, the variety of food is large, the growth of grain crops, vegetables and aquatic crops can be damaged, and the food becomes harmful animals in places such as Guangdong, Guangxi, Fujian, Yunnan, Zhejiang, Shanghai, Jiangsu and the like. In the area of south of Yangtze river, the ampullaria gigas can live through the winter naturally and two generations occur in the year. In Guangxi Luzhai county and other places, the occurrence density of the ampullaria gigas in the rice field is as high as 16.95/square meter; the damage rate of the rice plants is generally 7% -15% and can reach 64%. The ampullaria gigas not only harm rice, but also harm vegetables and other aquatic crops, and the ampullaria gigas also harm various aquatic plants such as narcissus, orchid and the like, and become a big harm in water areas in south China. In addition, the ampullaria gigas is an intermediate host of parasitic diseases which are commonly suffered by people and livestock, and is very easy to bring health problems to surrounding residents. It is estimated that the water areas (ponds, lakes, paddy fields, etc.) harmed by China in provinces and cities in south China are not less than 10 ten thousand hectares. At present, chemical pesticides are mainly used for preventing and treating mollusks, about 50 kinds of mollusks mainly comprise 6% metaldehyde, shell snail killer, 6% mineral granules, 45% fentin acetate, 45% Bailuidi and the like, and the organic molluscicides have a certain prevention effect on ampullaria gigas, but have strong stimulation effect on human skin, some organic molluscicides even cause teratogenesis and carcinogenesis, have high toxicity on aquatic organisms, damage to ecological balance in the nature to a certain extent, and have high prevention and treatment cost, so the molluscicides have great limitation in practical application.

The current situation of the rise and development of biological pesticides and the research of biological control and the use of chemical pesticides is inseparable. The biopesticide has the advantages of easy degradation in natural environment, strong targeting property, no damage to ecological environment, micro toxicity or no toxicity and the like, and is the first choice for developing biopesticide. In order to ensure stable grain yield and prevent and treat plant diseases and insect pests, farmers want to spray a large amount of chemical pesticides in the field. Not only the ecological environment is destroyed, but also the fertility of the land is influenced, the production cost of the crops is increased, and the burden of farmers is caused. China is a vast agricultural country with broad farmers, the cultivated land area in China is 14.3 hundred million acres, and the rice planting area is stabilized at 4.5 hundred million acres. This provides a solid foundation for the development of biological pesticides in China. In european countries, the success of synthesizing or modifying plant-derived active substances as lead structures depends on two major advantages, namely, full automation of compound synthesis and automation of high-throughput screening technology. In China, a system for independently creating new pesticides is not really formed at present. Has wide market prospect. The reduction of chemical fertilizer and pesticide is an effective measure which must be implemented in developing China.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

The invention content is as follows:

the invention aims to provide a formula of a low-toxicity compound pesticide molluscicide, thereby overcoming the defects in the prior art.

In order to achieve the purpose, the invention provides a molluscicide which is prepared by mixing the extract of the safflower creeping oxalis extract and metaldehyde as main reagents to obtain the most suitable proportion for killing ampullaria gigas through compounding and combination. The molluscicide has extremely strong lethal effect on mollusks such as ampullaria gigas and the like, the raw material of the safflower creeping oxalis is easy to obtain, the extraction and purification technology of the safflower creeping oxalis extract is mature, and the production cost is basically equal to the selling price of 6 percent metaldehyde granular preparation (about 2Kg per mu) which is circulated in the market. The invention reduces the concentration of metaldehyde, reduces the chemical pesticide residue and ensures the development of green agriculture.

The combination ratios of the present invention will be provided below:

the invention relates to a compound biological pesticide capable of effectively killing ampullaria gigas, which can replace 6% metaldehyde granular preparation circulating in the market, and the pesticide comprises the following components in percentage by weight: 5% of metaldehyde, 12% -18% of safflower creeping oxalis extract, 8% of gypsum powder, 1% of attractant and 68% -74% of flour, and the total weight is added to 100%.

The effective proportion of metaldehyde and safflower oxalis extract in the invention is: 5: 12-18;

in the invention, considering the cost, the optimal proportion of metaldehyde and the extract of the safflower creeping oxalis is as follows: 5: 12;

the invention also discloses a compound biopesticide capable of effectively killing ampullaria gigas, which can replace 6% metaldehyde granular preparation circulating in the market, and the biopesticide comprises the following components in percentage by weight: 4 percent of metaldehyde powder, 24 to 36 percent of safflower creeping oxalis extract, 8 percent of gypsum powder, 1 percent of attractant and 51 to 63 percent of flour are supplemented to 100 percent.

The effective proportion of metaldehyde and safflower oxalis extract in the invention is: 4: 24-36;

in the invention, considering the cost, the optimal proportion of metaldehyde and the extract of the safflower creeping oxalis is as follows: 4: 24;

the third invention is a compound biological pesticide capable of effectively killing ampullaria gigas, which can replace 6% metaldehyde granular preparation circulating in the market, and the biological pesticide comprises the following components in percentage by weight: 3 percent of metaldehyde powder, 36 to 54 percent of safflower creeping oxalis extract, 8 percent of gypsum powder, 1 percent of attractant and 34 to 52 percent of flour are supplemented to 100 percent.

The effective proportion of metaldehyde and safflower oxalis extract in the invention is: 4: 36-54;

in the invention, considering the cost, the optimal proportion of metaldehyde and the extract of the safflower creeping oxalis is as follows: 4: 36;

the first invention, the second invention and the third invention are mainly prepared into wettable preparations, and the specific processing method comprises the following steps: weighing metaldehyde powder, herba Oxalidis Corniculatae extract powder and filler (Gypsum Fibrosum powder, attractant, and flour) according to required proportion, and stirring in a stirring kettle.

Compared with the prior art, the invention has the following beneficial effects:

the compound biopesticide has the advantages of strong pesticide effect, low price, environmental pollution reduction, green preference of people, purchase order of healthy food and huge industrialization prospect. Compared with the negative effect of the chemical pesticide molluscicide in many countries, the low-toxicity compound biological pesticide has good development prospect and has wide popularization value and significance.

The specific implementation mode is as follows:

the following detailed description of specific embodiments of the invention is provided, but it should be understood that the scope of the invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

The experimental method comprises the following steps:

the invention adopts a method for testing toxicity in a laboratory, which comprises the following steps:

the amount of the required experimental material was calculated and weighed and dissolved in 2L of dechlorinated water. The experiments were repeated 3 times per treatment set up with the dechlorinated water as a control. Selecting 25-30 adult ampullaria gigas individuals with 5-7 revolutions, placing the adult ampullaria gigas individuals in an experimental container, adding vegetables such as water spinach and Chinese cabbage as food of the ampullaria gigas, changing the food every two days to keep the freshness of the ampullaria gigas food, and simultaneously covering a layer of gauze or net to prevent the ampullaria gigas from escaping. The temperature stability of the experimental region is strictly maintained so as to prevent the ampullaria gigas from being influenced by the large change of the early and late temperatures. And (5) observing the situation of the ampullaria gigas on time, and recording the death number of the ampullaria gigas. All the above steps ensure the accuracy of the experimental result.

The judgment standard of ampullaria gigas death comprises 2 modes:

(1) the acromion snails do not extend out of tentacles or foot pads in clear water and do not sink when touching the ampullaria gigas floating up to the water surface.

(2) The operculum is not closed even if the operculum is touched when the operculum is completely opened to expose the parts such as the horn.

Laboratory conditions: all experiments in the research are in key laboratories of medicinal plant biotechnology in Jiangsu province. The experimental department has an engineering technical center, a large number of advanced reaction instruments and detection equipment, provides a good hardware foundation for scientific research, and has conditions for developing and killing ampullaria gigas indoor experiments.

First, experimental material

Biological material: the ampullaria gigas are provided by a culture room of Xuzhou Nuote company, 5-7 spiral ampullaria gigas with high activity are selected indoors, 1500 experiments in each round are reserved, and 3 experiments are repeated.

Experimental agents: the experimental medicament is safflower oxalis extract obtained by using an extraction and purification technology, 6% metaldehyde preparation provided by Xuzhou Nutt company and metaldehyde original drug.

Preparing safflower creeping oxalis extract: weighing 50g of safflower creeping oxalis, pouring stems and leaves, grinding, adding into a 1L stainless steel pot, adding 500m L distilled water, boiling on an electric furnace with strong fire, keeping boiling on slow fire for 2.5-3.0 h, filtering the solution with gauze, returning the plant powder residue into the pot, adding 500m L distilled water, boiling and extracting, repeating for 3 times, filtering the water solution obtained by boiling and extracting for 3 times, boiling and evaporating to dryness, cooling the extract, and placing in a refrigerator for later use.

Second, the experimental procedure

The method comprises the following steps:

grouping: preparing experimental tools, namely transparent plastic pots, which are divided into 8 groups, and numbering the groups in sequence as 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 30mg/L and 40mg/L of 6% metaldehyde preparation; 50 mg/L; blank without drug was used as control. 2L of dechlorinated water is poured into each group, 25-30 ampullaria gigas are added, vegetables such as water spinach and Chinese cabbage are added as food for the ampullaria gigas, the ampullaria gigas are placed on the net to prevent the ampullaria gigas from climbing out, the food is changed every 2 days, and 3 experiments are repeated.

Application of the medicine: accurately weighing 6% metaldehyde preparation with a balance, applying medicinal liquid corresponding to the number, and taking another group with 2L of dechlorinated water as blank control. In order to prevent errors in the application of the liquid medicine, the liquid medicine is applied in a low concentration to a high concentration (5 mg/L to 50 mg/L). When the types and the concentration of the medicines are changed, deionized water is used for repeatedly cleaning, and the method can effectively avoid cross contamination or errors caused by medicine residues and the like in an experiment.

And (3) observing and recording: the subjects were observed every 12 hours after administration for a week. The experimental observation is that firstly, ampullaria gigas with obvious openings and death are picked out, and for the ampullaria gigas with the shells closed tightly all the time, the ampullaria gigas can be placed in clear water after surface medicines are washed out, and whether the ampullaria gigas die or not is observed after a plurality of days or a tapping method is selected to determine the death and the death of the ampullaria gigas. And (5) recording the number of dead snails in time after observation, and recording a table.

The experimental results are as follows: 6% metaldehyde preparation 25mg/L, 30mg/L, 40 mg/L; 50mg/L, dead ampullaria gigas individuals appear within 12 hours after spraying, the death rate of the ampullaria gigas is more than 92% within 3-7 days, and the drug effect tends to be stable within 8-15 days; namely, 6% metaldehyde starts from 25mg/L, the drug effect is stronger, and the empty group ampullaria gigas are not killed; because the temperature change range is large in the early and late places of the experiment, repeated experiments show that the activity of the ampullaria gigas is influenced by the early and late low temperature, and the prevention and treatment effect of the pesticide application is reduced. The temperature difference is obviously related to the activity of ampullaria gigas^[5]。

The experimental process of the invention I comprises the following steps:

the method comprises the following steps:

after determining the minimum lethal dose of ampullaria gigas of the 6% metaldehyde preparation, carrying out a compounding experiment: metaldehyde and safflower oxalis extract are prepared into wettable preparations according to the proportion, and the invention is not limited in the scope of the invention.

Formula 1:

wettable preparation of 5% metaldehyde and 12% safflower creeping oxalis extract

The weight percentage of each component is as follows: 5% of metaldehyde, 12% of safflower oxalis extract, 8% of gypsum powder, 1% of attractant and 74% of flour, which are complemented to 100%, and fully stirred and mixed to prepare the 4% metaldehyde-12% safflower oxalis extract wettable preparation.

And (2) formula:

wettable preparation of 5% metaldehyde and 18% safflower creeping oxalis extract

The weight percentage of each component is as follows: 5% of metaldehyde, 18% of safflower oxalis extract, 8% of gypsum powder, 1% of attractant and 66% of flour, supplementing 100%, fully stirring and mixing them to obtain 4% of metaldehyde-15% of safflower oxalis extract wettable preparation.

Step two:

grouping: preparing experimental tools, namely transparent plastic pots, which are divided into 9 groups, and sequentially numbered 5% metaldehyde and 12% safflower oxalis extract wettable preparations 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 30mg/L and 40 mg/L; 50 mg/L; the serial number is 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 30mg/L, 40mg/L and 50mg/L of metaldehyde and 18% safflower oxalis extract wettable preparation; blank without drug was used as control. 2L of dechlorinated water is poured into each group, 25-30 ampullaria gigas are added, vegetables such as water spinach and Chinese cabbage are added as food for the ampullaria gigas, the ampullaria gigas are placed on the net to prevent the ampullaria gigas from climbing out, the food is changed every 2 days, and 3 experiments are repeated.

Application of the medicine: accurately weighing 5% metaldehyde-12% herba Oxalidis Corniculatae extract wettable preparation and 5% metaldehyde-18% herba Oxalidis Corniculatae extract wettable preparation with a balance, applying medicinal liquid corresponding to the numbers, and collecting another group with 2L of dechlorinated water as blank control. When the types and the concentration of the medicines are changed, deionized water is used for repeatedly cleaning, and the method can effectively avoid cross contamination or errors caused by medicine residues and the like in an experiment.

The experimental result shows that the concentration of the wettable preparation of 5% metaldehyde and 12% safflower oxalis extract is 25mg/L, 30mg/L and 40 mg/L; 50mg/L, 5% metaldehyde and 18% safflower oxalis extract wettable preparation concentration is 25mg/L, 30mg/L and 40 mg/L; the death rate of the ampullaria gigas reaches more than 93 percent within 3-7 days when the concentration is 50mg/L, and the effect is stable within 8-15 days. Therefore, the 5% metaldehyde and 12% safflower oxalis extract wettable preparation and the 5% metaldehyde and 18% safflower oxalis extract wettable preparation can replace 6% metaldehyde chemical pesticides which are popular in the market to prevent and control the harm of ampullaria gigas, the two biological pesticides compounded in proportion can achieve the effect of killing the ampullaria gigas in a shorter time, the 5% metaldehyde and 12% safflower oxalis extract wettable preparation are recommended to be used in consideration of the cost, the toxic action of metaldehyde to the environment can be reduced, and the killing effect of the ampullaria gigas is ensured at the same time.

The experimental process of the invention II comprises the following steps:

the method comprises the following steps:

Formula 1:

wettable preparation of 4% metaldehyde and 24% safflower creeping oxalis extract

The weight percentage of each component is as follows: metaldehyde 4%, safflower oxalis extract 24%, gypsum powder 8%, attractant 1% and flour 63%, adding to 100%, stirring thoroughly, and mixing to obtain 4% metaldehyde-12% safflower oxalis extract wettable preparation.

And (2) formula:

wettable preparation of 4% metaldehyde, 36% safflower creeping oxalis extract

The weight percentage of each component is as follows: 5% of metaldehyde, 36% of safflower oxalis extract, 8% of gypsum powder, 1% of attractant and 50% of flour, supplementing 100%, fully stirring and mixing to obtain 4% of metaldehyde and 36% of safflower oxalis extract wettable preparation.

Step two:

grouping: preparing experimental tools, namely transparent plastic pots, which are divided into 9 groups, wherein the numbers of the transparent plastic pots are 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 30mg/L and 40mg/L of the wettable preparation of the extract of the creeping oxalis, 4% metaldehyde and 24% safflower; 50 mg/L; the number is 4% metaldehyde, 36% safflower oxalis extract wettable preparation 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 30mg/L, 40mg/L, 50 mg/L; blank without drug was used as control. 2L of dechlorinated water is poured into each group, 25-30 ampullaria gigas are added, vegetables such as water spinach and Chinese cabbage are added as food for the ampullaria gigas, the ampullaria gigas are placed on the net to prevent the ampullaria gigas from climbing out, the food is changed every 2 days, and 3 experiments are repeated.

Application of the medicine: accurately weighing 4% metaldehyde-24% safflower oxalis extract wettable preparation and 4% metaldehyde-36% safflower oxalis extract wettable preparation by using a balance, applying medicinal liquid in corresponding numbers, and taking another group with 2L of dechlorinated water as blank control. When the types and the concentration of the medicines are changed, deionized water is used for repeatedly cleaning, and the method can effectively avoid cross contamination or errors caused by medicine residues and the like in an experiment.

The experimental result shows that the concentration of the wettable preparation of the formula of 4% metaldehyde and 24% safflower oxalis extract is 25mg/L, 30mg/L and 40 mg/L; the concentration of 50mg/L, 4% metaldehyde, 37% safflower oxalis extract wettable preparation is 25mg/L, 30mg/L, 40 mg/L; the death rate of the ampullaria gigas reaches more than 93 percent within 3-7 days when the concentration is 50mg/L, and the effect is stable within 8-15 days. Therefore, the wettable preparation containing 4% metaldehyde and 24% safflower oxalis extract and the wettable preparation containing 4% metaldehyde and 36% safflower oxalis extract can replace the 6% metaldehyde chemical pesticide which is popular in the market to prevent and control the harm of ampullaria gigas, the biological pesticide compounded by the two proportions can achieve the effect of killing the ampullaria gigas in a shorter time, the wettable preparation containing 4% metaldehyde and 24% safflower oxalis extract is recommended to be used in consideration of the cost, the toxic action of metaldehyde on the environment can be reduced, and the killing effect on the ampullaria gigas is ensured at the same time.

The experimental process of the invention III is as follows:

the method comprises the following steps:

Formula 1:

wettable preparation of 3% metaldehyde, 36% safflower creeping oxalis extract

The weight percentage of each component is as follows: metaldehyde 3%, safflower oxalis extract 36%, gypsum powder 8%, attractant 1% and flour 52% by weight, adding them to 100%, fully stirring and mixing so as to obtain 4% metaldehyde-12% safflower oxalis extract wettable preparation.

And (2) formula:

wettable preparation of 3% metaldehyde, 54% safflower creeping oxalis extract

The weight percentage of each component is as follows: metaldehyde 3%, safflower oxalis extract 54%, gypsum powder 8%, attractant 1% and flour 34% which supplement 100% are fully stirred and mixed to obtain the wettable preparation of metaldehyde 3% and safflower oxalis extract 54%.

Step two:

grouping: preparing experimental tools, namely transparent plastic pots, which are divided into 9 groups, wherein the numbers of the transparent plastic pots are respectively 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 30mg/L and 40mg/L of the wettable preparation of the extract of the creeping oxalis, which is 3% metaldehyde and 36% safflower; 50 mg/L; the number of the wettable preparation is 5mg/L, 10mg/L, 15mg/L, 20mg/L, 25mg/L, 30mg/L, 40mg/L and 50mg/L of 3% metaldehyde and 54% safflower oxalis extract; blank without drug was used as control. 2L of dechlorinated water is poured into each group, 25-30 ampullaria gigas are added, vegetables such as water spinach and Chinese cabbage are added as food for the ampullaria gigas, the ampullaria gigas are placed on the net to prevent the ampullaria gigas from climbing out, the food is changed every 2 days, and 3 experiments are repeated.

Application of the medicine: accurately weighing 3% metaldehyde-36% herba Oxalidis Corniculatae extract wettable preparation and 3% metaldehyde-54% herba Oxalidis Corniculatae extract wettable preparation by balance, applying medicinal liquid corresponding to the numbers, and collecting another group with 2L of dechlorinated water as blank control. When the types and the concentration of the medicines are changed, deionized water is used for repeatedly cleaning, and the method can effectively avoid cross contamination or errors caused by medicine residues and the like in an experiment.

The experimental result shows that the concentration of the wettable preparation of the formula of 3% metaldehyde-36% safflower oxalis extract is 25mg/L, 30mg/L and 40 mg/L; 50mg/L, 3% metaldehyde, 54% safflower oxalis extract wettable preparation concentration is 25mg/L, 30mg/L, 40 mg/L; the death rate of the ampullaria gigas reaches more than 93 percent within 3-7 days when the concentration is 50mg/L, and the effect is stable within 8-15 days. Therefore, the 3% metaldehyde-36% safflower oxalis extract wettable preparation and the 3% metaldehyde-54% safflower oxalis extract wettable preparation can both replace 6% metaldehyde chemical pesticides which are popular in the market to prevent and control the harm of ampullaria gigas, the two biological pesticides compounded in proportion can both play a role in killing ampullaria gigas in a shorter time, the cost is considered, the 3% metaldehyde-36% safflower oxalis extract wettable preparation is recommended to be used, the toxic action of metaldehyde to the environment can be reduced, and the killing effect of ampullaria gigas is ensured at the same time.

The invention takes the production cost into consideration: 5% metaldehyde-12% safflower oxalis extract wettable preparation, 4% metaldehyde-24% safflower oxalis extract wettable preparation and 3% metaldehyde-36% safflower oxalis extract wettable preparation can be preferably considered in future industrialization.

The invention is safe and convenient to use, the safflower creeping oxalis material for producing the compound molluscacide is easy to obtain, the production cost is lower than that of common chemical agents, the safflower creeping oxalis material is easy to be accepted by the masses of farmers when being put into the market, and the safflower creeping oxalis material is a special molluscacide which really achieves the purposes of preventing and treating the occurrence of ampullaria gigas disasters, protecting human beings and livestock and being environment-friendly.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

1. The formula of the low-toxicity compound pesticide molluscicide is characterized by comprising the following materials in percentage by weight: 5% of metaldehyde powder, 12% -18% of safflower oxalis extract, 8% of gypsum powder, 1% of attractant and 68% -74% of flour; wherein the effective proportion of metaldehyde and safflower oxalis extract is as follows: 5: 12-18.

2. The formula of the low-toxicity compound pesticide molluscicide is characterized in that: the material composition comprises the following materials in percentage by weight: 4% of metaldehyde powder, 24% -36% of safflower creeping oxalis extract, 8% of gypsum powder, 1% of attractant and 51% -63% of flour.

3. Wherein the effective proportion of metaldehyde and safflower oxalis extract is as follows: 4: 24-36.

4. The formula of the low-toxicity compound pesticide molluscicide is characterized in that: the material composition comprises the following materials in percentage by weight: 3% of metaldehyde powder, 36% -54% of safflower creeping oxalis extract, 8% of gypsum powder, 1% of attractant and 34% -52% of flour.

5. Wherein the effective proportion of metaldehyde and safflower oxalis extract is as follows: 3: 36-54.

6. A method for preparing the low-toxicity compound pesticide molluscicide as defined in claim 1, 2 or 3, which is characterized in that: weighing metaldehyde powder, safflower oxalis extract, gypsum powder, attractant and flour according to a preset weight ratio, and putting into a stirring kettle in sequence to be fully stirred and uniformly mixed.