A method for killing golden apple snails using a combination of Peganum harmala and Phytolacca candida

Abstract

The present invention relates to a method for killing golden apple snails by using a composition of Peganum harmala and Phytolacca verticalis, comprising the following steps: S1, selecting specific plant tissues: selecting specific plant tissues of Peganum harmala and Phytolacca verticalis and air-drying or drying them for standby use; S2, crushing treatment: uniformly crushing the plant dry tissue in step S1 and then sieving; S3, preparing a composition: reasonably preparing the two plant dry powders in step S2 according to a certain proportion to form a dry powder composition; S4, placing according to snail density: according to the actual number of golden apple snails in the water body, the dry powder composition in step S3 is directly placed in the water body according to different snail-material ratios to effectively kill them. The method of the present invention is simple to operate, has little environmental pollution, and is relatively safe for non-target organisms; using a mixed dry powder of pure natural herbal plant crushed tissues, it can effectively improve the killing and inhibition effect on golden apple snails, avoid the generation of drug resistance, and reduce the cost of prevention and control.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural prevention and control, and particularly relates to a method for killing golden apple snails by utilizing a combination of Peganum harmala and Phytolacca verticalis. Background Art

[0002] The golden apple snail (Pomacea canaliculata) is an amphibious freshwater snail native to South America. It belongs to the family Pomacea, and is also known as the big bottle snail and apple snail. It has a 40-year history of invasion in my country and was identified as one of the first 16 most harmful alien species to invade China in 2003. It has strong resistance to adversity, a variegated diet, a large appetite, and strong reproductive capacity. It has caused serious damage to aquatic crops such as rice seedlings, water chestnuts, and wild rice stems, as well as the diversity of agricultural ecosystems. In addition, the golden apple snail is also an important intermediate host of the zoonotic parasite Angiostrongylus cantonensis, posing a potential threat to human health.

[0003] Phytolacca americana Linn. belongs to the genus Phytolacca Linn. of the family Phytolaccaceae and is a perennial herb. There are four species of Phytolacca in my country, among which Phytolacca americana is an alien invasive species with the widest distribution and abundant resources. It is mainly produced in Henan, Hubei, Anhui, Shaanxi and other places. Studies have shown that Phytolacca contains a variety of active substances such as polyphenols, Phytolacca polysaccharides, saponins, terpenes, flavonoids, and Phytolacca toxins, and the content of saponins in the roots is the highest. The extract Phytolacca americana saponins obtained from the dry powder of Phytolacca can kill 95.6% of the snails in 24 hours at 28°C and 125mg / L.

[0004] Plants of the genus Peganum L. are widely distributed in the arid desert areas of Northwest and North my country, and belong to the perennial herbaceous plant of the family Zytgophyllaceae. There are three species of this genus in my country: Peganum harmala L., P. nigellastrum, and P. multisectum L., among which Peganum harmala L. and P. multisectum L. are the most widely distributed and have large resources, with an annual output of more than 100 million kg in Gansu Province alone. Studies have shown that the whole plant of Peganum harmala L. contains alkaloids, flavonoids, steroids, anthraquinones and other components, among which alkaloids are the most numerous, and the order of content is seeds>roots>stems>leaves. It has a wide range of biological activities such as insecticide, acaricide, nematicide, antibacterial, antiviral, and stomach poison, contact killing, antifeedant and other modes of action. Previous studies have found that after soaking in 20g / L to 40g / L crude water extract of Salicornia herba for 24 hours, the mortality rate of Golden Apple Snails reached 73.8% to 100%.

[0005] At present, my country mainly relies on chemical agents such as niclosamide and molluscicide to control golden apple snails. Their large-scale and irregular use causes water environmental pollution, deterioration of water quality ecology and death of non-target organisms, and is also easy to induce drug resistance in golden apple snails. On the contrary, the use of plant-based pesticides to control golden apple snails has the characteristics of ecological protection and biosafety. The combined use of multiple plant molluscicides can greatly improve the snail-killing effect and reduce the dosage of each plant molluscicide. In view of this, the present invention selects two herbal plants with snail-killing activity, and their tissue dry powders are combined in a certain proportion and placed in the water to kill golden apple snails. The method of the present invention provides a new idea for the creation and development of green and efficient plant-based molluscicides. Summary of the invention

[0006] In order to solve the problems existing in the background technology, the present invention provides a method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca vertebrata. The method can effectively prevent the development of drug resistance of Pomacea canaliculata while killing the snails, reduce the risk of toxicity to non-target organisms, and reduce water pollution.

[0007] To achieve the above purpose, the technical solution adopted in the present invention is as follows:

[0008] A method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca erecta, comprising the following steps:

[0009] S1. Selecting specific plant tissues: selecting specific plant tissues of Peganum harmala and Phytolacca serrata, and air-drying or drying them for later use;

[0010] S2, crushing treatment: the plant stem tissue in step S1 is evenly crushed and then sieved;

[0011] S3, preparing a composition: preparing the two plant dry powders in step S2 in a reasonable proportion to form a dry powder composition;

[0012] S4. Release according to snail density: according to the actual number of Pomacea canaliculata snails in the water body and different snail-to-material ratios, the dry powder composition in step S3 is directly released into the water body to effectively kill the snails.

[0013] Furthermore, the plant tissue in step S1 is seeds, roots, stems, leaves of Peganum harmala, roots, stems, leaves, and berries of Phytolacca americana; the excess moisture is removed by natural air drying at room temperature or by drying in an electric blast drying oven at 60° C. for 24 hours.

[0014] Furthermore, in step S2, the plant dry tissue in step S1 is evenly crushed by a plant sample crusher, and a dry powder is obtained by passing the crushed tissue through a 40-60 mesh sieve, and the particle size of the dry powder is 0.25 mm to 0.45 mm.

[0015] Furthermore, the preparation method of the dry powder composition in step S3 is as follows: the dry powder in step S2 is uniformly mixed according to 35% to 45% by weight of Peganum harmala and 65% to 55% by weight of Pyrola bicolor.

[0016] Furthermore, the water body in step S4 is a stationary water body for rice or wild rice cultivation, and the water depth is ≤1 meter; the screw-to-material ratio is based on pieces / m 2 :g / m 2 The ratio is (2-4):1; the density of golden apple snails in the water is less than 100 / m 2 If the density is too high, they should be caught manually and then released.

[0017] Preferably, according to the distribution characteristics of their biologically active substances, Peganum harmala seeds and Phytolacca americana root tissues with higher alkaloid and saponin contents are selected to achieve better killing effects.

[0018] Preferably, the plant tissue in S1 is air-dried and dried, then evenly crushed with a small grinder and passed through a 50-mesh sieve. The dry powder of this particle size not only has a high solubility in water, but also has a good killing effect on Pomacea canaliculata snails.

[0019] Preferably, the dry powder in S2 is formulated into a dry powder composition according to 40% by weight of Salicornia herba and 60% by weight of Phytolacca americana to improve the comprehensive killing effect on Pomacea canaliculata snails.

[0020] Preferably, based on the number of golden apple snails in the still water, the density is more than 100 / m 2 After artificial fishing, the dry powder composition is added according to the screw-to-feed ratio of 3:1.

[0021] Specifically, the application amount of the dry powder composition is shown to be in the range of 10 to 50 g / m 2 , too much dosage may affect the growth and development of algae and fish in the water; too little dosage will have no killing effect, and the golden apple snail can rely on the body's self-repair and detoxification mechanism to survive. After the powder is added, part of it floats on the water surface and part of it sinks to the bottom of the water, both of which have a poisonous effect on the golden apple snail. The water body for release should be a still water body (water depth ≤ 1 meter) where rice fields or wild rice plants are planted to reduce dry powder loss and improve the killing effect.

[0022] The present invention has the following beneficial effects: (1) Phytolacca americana is a common invasive plant in my country, and its resources are easy to obtain. The development and utilization of the plant for biological control can achieve the purpose of treating harm with harm, turning harm into benefit, and turning waste into treasure; (2) The method of the present invention is simple to operate, has little pollution to the environment, and is relatively safe to non-target organisms; (3) The present invention adopts a mixed dry powder of crushed tissues of pure natural herbal plants, which can effectively improve the killing and inhibition effects on golden apple snails, avoid the generation of drug resistance, and reduce the cost of control; (4) The composition prepared by the present invention can effectively control and kill the invasive animal golden apple snail. DETAILED DESCRIPTION

[0023] Unless otherwise specified, the components described in the present invention are all purchased by those skilled in the art.

[0024] Example 1

[0025] The method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca erecta in this embodiment comprises the following steps: 2 Place 100 adult Pomacea canaliculata snails (7±0.5g) or 100 young Pomacea canaliculata snails (1±0.2g) in a plastic basin, add 1.0-2.0L dechlorinated tap water (25-30℃) to just submerge the snails, and cover with a transparent plastic film with holes to prevent the Pomacea canaliculata snails from escaping. Select seeds of Peganum harmala and root tissues of Phytolacca verticalis to air-dry, dry them in a constant temperature blast drying oven at 60℃ for 24h, use a small grinder to evenly grind them, and pass through a 50-mesh sieve. Prepare a dry powder composition by mixing 40% weight of Peganum harmala + 60% weight of Phytolacca verticalis with the ground powder, put 50g in the above plastic basin, and count the number of dead and live snails 24, 48 and 72h after application. Death is judged by no activity and no reaction to acupuncture. For individuals with closed shells all the time, you can choose to wash off the surface drugs and place them in clean water. If they cannot open their shells within 24h, they are determined to be dead. Three plastic basins were set up for both adult and juvenile snails in parallel, according to the formula: The mortality rate was calculated and the results are shown in Table 1.

[0026] Example 2

[0027] The method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca erecta in this embodiment comprises the following steps: 2 Place 100 adult Pomacea canaliculata snails (7±0.5g) or 100 young Pomacea canaliculata snails (1±0.2g) in a plastic basin, add 1.0-2.0L dechlorinated tap water (25-30℃) to just submerge the snails, and cover with a transparent plastic film with holes to prevent the Pomacea canaliculata snails from escaping. Select the leaves of Peganum harmala and Phytolacca verticalis leaves to air-dry, dry them in a constant temperature blast drying oven at 60℃ for 24h, use a small grinder to evenly grind them, and pass through a 40-mesh sieve. Prepare the ground dry powder into a dry powder composition according to 45% weight of Peganum harmala + 55% weight of Phytolacca verticalis, put 25g in the above plastic basin, and count the number of dead and live snails 24, 48 and 72h after application. Death is judged by no activity and no reaction to acupuncture. For individuals with closed shells all the time, you can choose to wash off the surface drugs and place them in clean water. If they cannot open their shells within 24h, they are determined to be dead. Three plastic basins were set up for both adult and juvenile snails in parallel, according to the formula: The mortality rate was calculated and the results are shown in Table 1.

[0028] Comparative Example 1

[0029] The method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca erecta in this comparative example comprises the following steps: 2 Place 100 adult Pomacea apple snails (7±0.5g) or 100 juvenile snails (1±0.2g) in a plastic basin, add 1.0-2.0L of dechlorinated tap water (25-30℃) to just immerse the snails, and cover with a transparent plastic film with holes to prevent the snails from escaping. Use 5-10mg of 6% niclosamide preparation (niclosamide) to add to the above plastic basin, and count the number of dead and live snails 24, 48 and 72 hours after application. Death is determined by no activity and no reaction to acupuncture. For individuals that always keep their shells tightly closed, you can choose to wash off the surface drugs and place them in clean water. If they cannot open their shells and move within 24 hours, they are determined to be dead. Set up 3 plastic basins for both adult and juvenile snails for parallel replication, according to the formula: The mortality rate was calculated and the results are shown in Table 1.

[0030] Comparative Example 2

[0031] The method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca erecta in this comparative example comprises the following steps: 2 Place 100 adult Pomacea apple snails (7±0.5g) or 100 juvenile snails (1±0.2g) in a plastic basin, add 1.0-2.0L of dechlorinated tap water (25-30℃) to just submerge the snails, and cover with a transparent plastic film with holes to prevent the snails from escaping. Count the number of dead and live snails at 24, 48 and 72 hours. Death is determined by no activity and no reaction to acupuncture. For individuals that always keep their shells tightly closed, wash off the surface drugs and place them in clean water. If they cannot open their shells and move within 24 hours, they are determined to be dead. Set up 3 plastic basins for both adult and juvenile snails for parallel replication, according to the formula: The mortality rate was calculated, and if the mortality rate was > 10%, the experiment should be repeated. The results are shown in Table 1.

[0032] Table 1 Killing effect of different embodiments on Pomacea canaliculata

[0033]

[0034] Note: The data in the table are mean ± standard error. Different lowercase letters after the same column of data represent significant differences after ANOVA one-way analysis of variance and Turkey's multiple comparisons, p < 0.05.

[0035] As can be seen from the above table, the dry powder composition of Peganum harmala and Phytolacca verticalis tissues can effectively kill and control adult and juvenile Pomacea canaliculata snails, and the juvenile snails are more sensitive to the agents than the adult snails; the mortality rate of Pomacea canaliculata snails after treatment with the dry powder composition of Peganum harmala seeds and Phytolacca verticalis root system was not significantly different from that of chemical snailicides, while the dry powder composition of their leaves was second to none, indicating that the best snail-killing effect can be obtained in practical application according to Example 1.

Claims

1. A method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca erecta, characterized in that: The following steps are involved: S1. Selecting specific plant tissues: selecting specific plant tissues of Peganum harmala and Phytolacca serrata, and air-drying or drying them for later use; S2, crushing treatment: the plant stem tissue in step S1 is evenly crushed and then sieved; S3, preparing a composition: preparing the two plant dry powders in step S2 in a reasonable proportion to form a dry powder composition; S4, according to the density of snails: according to the actual number of golden apple snails in the water body, the dry powder composition in step S3 is directly placed in the water body according to different snail-to-material ratios to effectively kill them; the plant tissues in step S1 are seeds, roots, stems, and leaves of Peganum harmala, and roots, stems, leaves, and berries of Phytolacca americana; natural air drying at room temperature or electric blast drying oven at 60°C constant temperature for 24 hours is used to remove excess moisture; step S2 uses a plant sample grinder to evenly grind the plant dry tissues in step S1, and sieve through 40-60 meshes to obtain dry powder, and the dry powder particle size is 0.25mm-0.45mm; the preparation method of the dry powder composition in step S3 is as follows: the dry powder in step S2 is evenly mixed according to 35%-45% by weight of Peganum harmala and 65%-55% by weight of Phytolacca americana.

2. The method for killing Pomacea canaliculata using a combination of Peganum harmala and Phytolacca erecta according to claim 1, characterized in that: The water body in step S4 is a stationary water body for rice or wild rice cultivation, and the water depth is ≤1 meter; the screw-to-material ratio is based on pcs / m 2 :g / m 2 The ratio is (2-4):1; the density of golden apple snails in the water is less than 100 / m 2 If the density is too high, they should be caught manually and then released.

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