CN105123624A - Method for controlling pomacea canaliculata by utilizing medicinal whitmania pigra - Google Patents

Abstract

The invention discloses a method for preventing and controlling the apple snails with medicinal wide-bodied leeches. The medicinal wide-bodied leech is used as the object, and the life of the leech that likes to suck the juice of snails, river mussels, and river clams molluscs as food is used. Habits, carried out the snail and leech co-culture hunting test, the body weight growth experiment of the wide-bodied golden leech and the contrast experiment of the difference in predation by the wide-bodied golden leech on male and female apple snails; It shows that the predation amount of leeches wide-bodied fluctuates between 0 and 0.4, indicating that there is no sex difference in the predation of leeches wide-bodied on apple snails; , there will be the phenomenon of apple snails biting leech corpses, but at the same time, under this environment, the cumulative predation amount of medicinal leeches on apple snails is the largest, which shows that medicinal leeches have a certain effect on apple snails. Prevention and control effect.

Description

A method of preventing and controlling apple snails with medicinal wide-bodied leeches

technical field

The invention relates to a method for killing adult apple snails, in particular to a method for preventing and controlling apple snails by medicinal wide-body golden leeches.

Background technique

Apple snails, also known as big bottle snails and apple snails, are amphibious freshwater shellfish molluscs. They belong to molluscs, gastropods, mesogastropods, bottle snails, and bottle snails. They belong to tropical and subtropical species; they are native to southern China. In the Amazon River Basin of America, apple snails were gradually introduced to Japan, the Philippines, Vietnam, Thailand and other countries as a food after the 1980s; Widely cultivated in Guangdong, and quickly spread to Guangxi, Fujian, Hainan, Zhejiang, Shanghai, Jiangsu and other places. Later, the apple snail was abandoned in the field because of its poor taste. Due to blind introduction and poor management, the apple snail is currently in China. Disasters broke out in many southern provinces, and became a vicious aquatic animal that endangers rice and other aquatic plants in China and other Asian countries. It is known as the "rice killer"; Many clusters inhabit shallow water areas, or adsorb on the stems and leaves of aquatic plants; they are suitable for growth at a water temperature of 25-32°C, and the growth will decrease significantly when the water temperature exceeds 35°C. The highest critical water temperature for survival is 45°C, and the lowest critical water temperature is 5°C. ℃; Apple snails are omnivorous snails that mainly feed on plants. They have a wide range of food habits. They mainly eat aquatic crops such as rice, wild rice stems, and duckweed. , can survive in moist soil for 6 to 8 months, and once the water layer is restored in the field, it can move around and eat and cause damage; Overwinter at the base of aquatic crops or at a depth of 2 to 3 cm below the soil surface of paddy fields, or at the edge of fields and ditches; egg masses are often produced on the surface of planting strips or dry objects 10 to 15 cm above the water surface, such as rice, wild rice, stone masonry Ditch walls, field ridges, weeds, etc.; one female snail can produce and hatch more than 325,000 young snails in one year, and the fertility is very strong. Snails and snail eggs, but their main food is higher plants and some dry land vegetables.

With the increase of the invasion time of apple snails in my country, coupled with the warming of the global climate, the continuous enhancement of ecological adaptability of apple snails and the introduction of artificial intelligence, the endangered areas will gradually migrate and expand to northern my country; apple snails are suitable for the vast areas of my country Habitat hazards, the area of the hazard area accounts for about 60%, which poses a serious threat to my country's rice production and ecological security; at the same time, due to changes in the agricultural planting structure in recent years, the types of apple snails that harm crops are also increasing. In addition to harming rice, Apple snails also attack twig fruit, water chestnut, sweet potato, arrowroot, milk vetch and aquatic vegetables in damp habitats. In recent years, apple snails are more common and have attracted widespread attention.

At present, there are many ways to control apple snails, such as: winter rice field trimming, scientific water management, manual removal of egg masses, release of ducks to eat snails, etc., but due to factors such as the stability of the effect, the choice of implementation timing, the acquisition of materials, and the cost , most of them are not suitable for large-scale use. Drug control is one of the measures for the control of apple snails. The agents used are basically chemical agents. In addition to causing a certain degree of pollution to the environment, there are also problems such as high prices; the chemicals sprayed on the surface of vegetables will affect the consumption of vegetables. Its residues are likely to endanger the ecological environment, and apple snails in some areas have developed resistance to chemical pesticides, making control more difficult and costly.

The medicinal broad-bodied leech is an aquatic mollusk that can also live in wet areas near the shore. In taxonomy, it belongs to the phylum Annelids, class Hirudo, order Hirudo, Hirudidae, and Genus Aureum. Its body is slightly spindle-shaped, the abdomen is relatively flat, the overall body is relatively flat, the body is soft, and can be stretched at will. It also changes with the amount of food eaten. The whole body is composed of multiple body segments, and there are multiple body rings on each body segment. The body length of adult leeches is generally about 6 cm to 20 cm, and the body length of the larger individual can reach about 30 cm when the body is fully extended, and the body width is generally between 1.3 cm and 2 cm. The back of the leeches usually appears dark. Green, with 5 longitudinal stripes composed of yellow and black stripes; the distribution pattern is one in the middle of the back and two on each side; in addition, there is a yellow longitudinal stripe at the lower end of the side of the leeches. The abdomen of the leech body is usually light yellow, with many dark green irregular spots in the middle. The front and rear ends of the leech body are the front sucker and the back sucker respectively, which have the functions of adsorption and movement. The broad-bodied golden leech is animal-eating and does not suck blood. It feeds on the juice of molluscs such as snails, mussels, and clams in water.

In the control of apple snails, the development and utilization of molluscicidal plant resources is an important part of biological molluscicidal work; so far, about 1,500 species of plants have been used for molluscicidal activity tests, and many plants have been found to have killing molluscs. snail activity; but this is only a small part of the control of apple snails, and there is still a lot of room for research on the ecological control mechanism between animals.

Contents of the invention

The object of the present invention is to provide a method for preventing and controlling apple snails by medicinal wide-bodied leeches.

The prevention and control method of this medicinal wide-body golden leech on apple snails:

Taking the medicinal leech as the object, taking advantage of its living habit of sucking the juice of snails, mussels, and clams molluscs as food, the snail-leech co-culture hunting experiment and the weight growth experiment of leeches were carried out Comparative experiment on predation difference between male and female apple snails by leech and broad-bodied leeches;

The research results show that the predation rate of the wide-bodied golden leeches on apple snails varies with the size of the apple snails, and its predation effect on small snails is better; 0.64g in the case of snails, the minimum value is -0.257g in the case of medium snails, and the weight change of leech is related to the amount of predation and the change of its own body shape;

The control experiment on the difference in predation of male and female apple snails by leeches wide-bodied showed that the predation amount of leech wide-bodied fluctuated between 0 and 0.4, indicating that there was no gender difference in the predation of leeches wide-bodied on apple snails; In the process of eating apple snails, leeches are more susceptible to external interference, and there are two wide-bodied leeches preying on the same apple snail at the same time; when the number of apple snails is large and the density is high, that is, greater than 3:1, there will Apple snails bite leech corpses, but at the same time, under this environment, the cumulative predation amount of medicinal leeches on apple snails is the largest, which shows that medicinal leeches have a certain control effect on apple snails .

The method of preventing and controlling apple snails by medicinal wide-bodied leech is specifically composed of the following steps:

1.1 Materials:

1.1.1 Wide-body golden leeches

Wide-body golden leeches are purchased from artificial farms. The age of the leeches is about one year. The individual body length is between 6 cm and 13 cm, and the weight is 5 grams to 12 grams. The leeches have no scars and are healthy individuals;

1.1.2 Apple snails

The snails used in the experiment were collected from the paddy fields, and the snails were all over 4 months old, with large individuals, and the shells were intact and healthy;

1.1.3 Instruments and equipment include:

Plastic basin with a diameter of 16cm, tweezers, filter paper, electronic balance, aquarium, plastic bucket, glass tank;

1.2 Experimental method:

1.2.1 Feeding of wide-bodied golden leeches:

In a glass tank of 100cm*50cm*50cm, put 5cm thick paddy field silt into it, dig a pit with a length of 50cm and a width of 30cm, fill it with water, plant suitable aquatic plants around it, put leeches in it, and Add shells, snails, and apple snails as feed;

In order to keep the water quality fresh, change the water every two days, pick out the snail shells that have been sucked, and put in enough feed again to ensure that the overall breeding environment is clean and the food source is sufficient;

1.2.2 Breeding of apple snails:

Put the snails in 4 aquariums, put 40-50 snails in each box, and stock them at a density of 30-35 snails/square meter. Add the filtered water obtained from tap water and let it stand in the sun for 48 hours. The water depth is 30-35cm, and Add an appropriate amount of feed, and the feed used in this experiment is various leafy vegetables of lettuce and spinach;

In order to keep the water quality fresh, change the water once a day, remove the excrement in the water, and feed a sufficient amount of feed every morning and evening;

1.2.3 Co-culture of snails and leeches Predation experiment of leeches on apple snails:

Select wide-bodied golden leeches and apple snails with a weight between 5.5g and 7.5g to co-culture in a plastic round pot with a diameter of 16cm, and set up four treatments, namely:

(1) Spread 2 cm of paddy field mud on the bottom of the pot, and the water depth on the mud surface is 1 cm. Put a wide-body golden leech and a golden apple snail in the pot, and the mud is 1v1;

(2) Pour 2cm deep filtered water into the pot, place a wide-body golden leech and a golden apple snail in the pot, water 1v1;

(3) Pour 2cm deep filtered water into the pot, place a wide body golden leech and five apple snails in the pot, water 1v5;

(4) Three wide-body golden leeches and ten apple snails were placed in the pot, and the water was 3v10;

Each treatment was repeated three times, and the predation situation of the leech leech in each treatment was recorded every day, and the experiment was seven days in total.

During the co-cultivation process, if apple snails or leeches were found to be dead, they would be supplemented. The proportion of leech in each control was kept constant. During the test, the indoor temperature was 25±2°C, and the water used was filtered water;

1.2.4 Body weight change experiment of apple snails of different ages and leeches co-cultured with leeches:

The apple snails are divided into three grades according to individual size: A, B, and C: A: 0.7g-5.0g, B: 5.0g-8.5g, C: 8.5g-above, and each grade randomly selects three apple snails and one wide The leeches were co-raised in a round pot with a diameter of 16 cm and a water depth of 2 cm. Each treatment was replicated four times, and the predation situation of the leeches was observed and recorded every day. After seven days, it was weighed and recorded, and again after fifteen days. Carry out weighing record; Before weighing, use filter paper to absorb the water on the surface of the leeches, and then weigh with an electronic balance:

During the co-cultivation process, if apple snails or leeches were found to be dead, they would be supplemented. The proportion of leech in each control was kept constant. During the test, the indoor temperature was 25±2°C, and the water used was filtered water;

1.2.5 Differential experiments on the predation of male and female apple snails by wide-bodied golden leeches:

Separate the male and female apple snails, and select two mature males and females and a wide-bodied golden leech to co-culture in a round pot with a diameter of 16cm and a depth of 2cm. The predation situation of male and female apple snails. During the test period, the indoor temperature was 25±2°C, and the water used was filtered water;

1.2.6 Standards for identification of life and death of apple snails:

Referring to the Santos method, take out the suspected dead snails in each treatment, and put them in dechlorinated water for observation, and those that cannot start sanitation activities within 24 hours are considered dead;

2 result analysis:

2.1 The predation situation of the snail and leeches on the golden snail:

Figure 1 shows the predation results of the wide-bodied golden leech on apple snails under the condition of co-culture of snails and leeches. It can be seen from the figure that under the four treatments of 1v1 in mud, 1v1, 1v5, and 3v10 in water, the highest cumulative average predation amount is 17.01 in the 3v10 treatment, the lowest average predation amount was 5 in the 1v1 snail treatment in the mud, and the cumulative predation amount of the 1v1 co-cultured in water was 6. When the size is large, the predation rate is relatively high. If there is a soil environment, apple snails will sneak into the soil to avoid predation by the wide-bodied golden leech, thus increasing the difficulty of predation by the wide-bodied golden leech;

In the process of co-cultivation, the predation time of the wide-bodied golden snails on apple snails varies with the size of the apple snails. The time for absorbing smaller individuals is shorter, and the time for larger individuals is longer. For apple snails of 5.0g to 8.5g, Leeches feed once every 1.5 hours. For apple snails weighing more than 8.5g, leeches feed once every 3 hours. According to experimental observations, leeches with wide bodies are easily disturbed by external interference and stop predation during the process of sucking apple snails. There are two wide The phenomenon that the golden leeches preyed on the same apple snail at the same time, under the 1v5 and 3v10 treatments, the wide-bodied golden leech died, and there were wounds on the body, suspected to be bitten by the golden apple snail; 2.2 The weight of the wide-bodied golden leech on 15 days Growth experiment:

The increase in body weight of the leeches is closely related to the number of apple snails they prey on. During the co-cultivation process, it is found that the dead apple snails or the leech will be supplemented, and the proportion of leech in each control is kept unchanged; the experimental results are shown in the figure 2. Within 15 days, the body weight of leeches with wide bodies has the largest change of 0.64g when they prey on small snails, and the smallest value is -0.257g when they prey on medium snails; the body shape of leeches with wide bodies is also related to body weight , when the body is plump and firm, the body weight is heavy, and when the body is shriveled and soft, the body weight is light; the results show that there are differences in the predation rate of the wide-bodied golden leech depending on the individual size of the apple snail. Smaller individuals are easier to prey on;

2.3 Differential control experiments on predation of male and female apple snails by wide-bodied golden leeches:

Figure 3 is a picture of the predation of male and female apple snails by the wide-bodied golden leeches. The 15-day experiment shows that comparing the number of wide-bodied golden leeches preying on the apple snails in each treatment, the cumulative number of predating female snails is 12, and the cumulative number of predating male snails is 12. The number is 7, and the amount of predation on female snails is significantly higher than that of male snails.

Beneficial effects of the invention:

The materials used are aquatic molluscs, which have incomparable advantages over chemical drugs: rich sources, low cost, and zero pollution to the environment.

The present invention has carried out the screening test of the snail-killing drug, and it is found that the medicinal leeches have a certain prevention and control mechanism on the apple snails; Some snails are more efficient; they will stop predation if they are disturbed by the outside during the feeding process.

The research on killing snails by using leech leeches can not only broaden the road of apple snail control in my country, but also effectively reduce the environmental pollution caused by chemical molluscicides. It has a broad application prospect and provides basic data for the further use of abundant plant resources for apple snail control research, as well as materials for the synthesis of biomimetic drugs.

(1) Materials Medicinal leech is an aquatic mollusc in South China, and it is easy to obtain.

(2) The treatment method is easy to operate, does not require complicated procedures, and is convenient to operate in the field.

(3) It is beneficial to control the invasive animal apple snail, and opens up a new way for the resource utilization of plants, which has great reference value for the research of invasion ecology and biological invasion control technology.

(4) The labor intensity is low, the application range is wide, and the work efficiency is high.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 Predation of apple snails under different treatments.

Fig. 2 Body weight change chart of 15 days when snails and leeches were co-raised with wide-bodied golden leech.

Fig. 3 Predation of different genders of apple snails by leeches broad-bodied.

Detailed ways

Example:

The prevention and control method of this medicinal wide-body golden leech on apple snails:

Taking the medicinal leech as the object, taking advantage of its living habit of sucking the juice of snails, mussels, and clams molluscs as food, the snail-leech co-culture hunting experiment and the weight growth experiment of leeches were carried out Comparative experiment on predation difference between male and female apple snails by leech and broad-bodied leeches;

The research results show that the predation rate of the wide-bodied golden leeches on apple snails varies with the size of the apple snails, and its predation effect on small snails is better; 0.64g in the case of snails, the minimum value is -0.257g in the case of medium snails, and the weight change of leech is related to the amount of predation and the change of its own body shape;

The control experiment on the difference in predation of male and female apple snails by leeches wide-bodied showed that the predation amount of leech wide-bodied fluctuated between 0 and 0.4, indicating that there was no gender difference in the predation of leeches wide-bodied on apple snails; In the process of eating apple snails, leeches are more susceptible to external interference, and there are two wide-bodied leeches preying on the same apple snail at the same time; when the number of apple snails is large and the density is high, that is, greater than 3:1, there will Apple snails bite leech corpses, but at the same time, under this environment, the cumulative predation amount of medicinal leeches on apple snails is the largest, which shows that medicinal leeches have a certain control effect on apple snails .

The method of preventing and controlling apple snails by medicinal wide-bodied leech is specifically composed of the following steps:

1.1 Materials:

1.1.1 Wide-body golden leeches

Wide-body golden leeches are purchased from artificial farms. The age of the leeches is about one year. The individual body length is between 6 cm and 13 cm, and the weight is 5 grams to 12 grams. The leeches have no scars and are healthy individuals;

1.1.2 Apple snails

The snails used in the experiment were collected from the paddy fields, and the snails were all over 4 months old, with large individuals, and the shells were intact and healthy;

1.1.3 Instruments and equipment include:

Plastic basin with a diameter of 16cm, tweezers, filter paper, electronic balance, aquarium, plastic bucket, glass tank;

1.2 Experimental method:

1.2.1 Feeding of wide-bodied golden leeches:

In a glass tank of 100cm*50cm*50cm, put 5cm thick paddy field silt into it, dig a pit with a length of 50cm and a width of 30cm, fill it with water, plant suitable aquatic plants around it, put leeches in it, and Add shells, snails, and apple snails as feed;

In order to keep the water quality fresh, change the water every two days, pick out the snail shells that have been sucked, and put in enough feed again to ensure that the overall breeding environment is clean and the food source is sufficient;

1.2.2 Breeding of apple snails:

Put the snails in 4 aquariums, put 40-50 snails in each box, and stock them at a density of 30-35 snails/square meter. Add the filtered water obtained from tap water and let it stand in the sun for 48 hours. The water depth is 30-35cm, and Add an appropriate amount of feed, and the feed used in this experiment is various leafy vegetables of lettuce and spinach;

In order to keep the water quality fresh, change the water once a day, remove the excrement in the water, and feed a sufficient amount of feed every morning and evening;

1.2.3 Co-culture of snails and leeches Predation experiment of leeches on apple snails:

Select wide-bodied golden leeches and apple snails with a weight between 5.5g and 7.5g to co-culture in a plastic round pot with a diameter of 16cm, and set up four treatments, namely:

(1) Spread 2 cm of paddy field mud on the bottom of the pot, and the water depth on the mud surface is 1 cm. Put a wide body golden leech and a golden apple snail in the pot, mud 1v1, that is, the treatment of a golden apple snail and a leech in an environment with paddy field mud;

(2) Pour 2cm deep filtered water into the pot, place a wide body golden leech and a golden apple snail in the pot, water 1v1; treatment of a leech and 5 golden apple snails full of water;

(3) Pour 2cm deep filtered water into the pot, place a wide body golden leech and five apple snails in the pot, water 1v5;

(4) Three wide-body golden leeches and ten apple snails were placed in the pot, and the water was 3v10;

Each treatment was repeated three times, and the predation situation of the leech leech in each treatment was recorded every day, and the experiment was seven days in total.

During the co-cultivation process, if the apple snails or leeches were found to be dead, they would be supplemented. The proportion of leeches in each control was kept constant. During the test period, the indoor temperature was 25±2°C, and the water used was filtered water;

1.2.4 Body weight change experiment of apple snails of different ages and leeches co-cultured with leeches:

The apple snails are divided into three grades according to individual size: A, B, and C: A: 0.7g-5.0g, B: 5.0g-8.5g, C: 8.5g-above, and each grade randomly selects three apple snails and one wide The leeches were co-raised in a round pot with a diameter of 16 cm and a water depth of 2 cm. Each treatment was replicated four times, and the predation situation of the leeches was observed and recorded every day. After seven days, it was weighed and recorded, and again after fifteen days. Carry out weighing record; Before weighing, use filter paper to absorb the water on the surface of the leeches, and then weigh with an electronic balance;

During the co-cultivation process, if apple snails or leeches were found to be dead, they would be supplemented. The proportion of leech in each control was kept constant. During the test, the indoor temperature was 25±2°C, and the water used was filtered water;

1.2.5 Differential experiments on the predation of male and female apple snails by wide-bodied golden leeches:

Separate the male and female apple snails, and select two mature males and females and a wide-bodied golden leech to co-culture in a round pot with a diameter of 16cm and a depth of 2cm. The predation situation of male and female apple snails. During the test period, the indoor temperature was 25±2°C, and the water used was filtered water;

1.2.6 Standards for identification of life and death of apple snails:

Referring to the Santos method, take out the suspected dead snails in each treatment, and put them in dechlorinated water for observation, and those that cannot start sanitation activities within 24 hours are considered dead;

2 result analysis:

2.1 The predation situation of the snail and leeches on the golden snail:

Figure 1 shows the predation results of the wide-bodied golden leech on apple snails under the condition of co-culture of snails and leeches. It can be seen from the figure that under the four treatments of 1v1 in mud, 1v1, 1v5, and 3v10 in water, the highest cumulative average predation amount is 17.01 in the 3v10 treatment, the lowest average predation amount was 5 in the 1v1 snail treatment in the mud, and the cumulative predation amount of the 1v1 co-cultured in water was 6. When the size is large, the predation rate is relatively high. If there is a soil environment, apple snails will sneak into the soil to avoid predation by the wide-bodied golden leech, thus increasing the difficulty of predation by the wide-bodied golden leech;

In the process of co-cultivation, the predation time of the wide-bodied golden snails on apple snails varies with the size of the apple snails. The time for absorbing smaller individuals is shorter, and the time for larger individuals is longer. For apple snails of 5.0g to 8.5g, Leeches feed once every 1.5 hours. For apple snails weighing more than 8.5g, leeches feed once every 3 hours. According to experimental observations, leeches with wide bodies are easily disturbed by external interference and stop predation during the process of sucking apple snails. There are two wide The phenomenon that the golden leech preys on the same apple snail at the same time, under the 1v5 and 3v10 treatments, there is a phenomenon of death of the wide-body golden leech, and there are wounds on the body, which is suspected to be bitten by the apple snail;

2.2 Experiment on weight gain of wide-body golden leeches for 15 days:

The increase in body weight of the leeches is closely related to the number of apple snails they prey on. During the co-cultivation process, it was found that the dead apple snails or leeches would be supplemented, and the proportion of leech in each control was kept unchanged; the experimental results are shown in the figure 2. Within 15 days, the body weight of leeches with wide body changed 0.64g when they preyed on small snails, and the minimum value was -0.257g when they preyed on medium snails. , when the body is plump and firm, the body weight is heavy, and when the body is shriveled and soft, the body weight is light; the results show that there are differences in the predation rate of the wide-bodied golden leeches depending on the individual size of the apple snail. Smaller individuals are easier to prey on;

2.3 Differential control experiments on predation of male and female apple snails by wide-bodied golden leeches:

Figure 3 is a picture of the predation of male and female apple snails by the wide-bodied leeches. The 15-day experiment shows that the number of predation by the wide-bodied leech preying on the apple snails in each treatment is 12. The number is 7, and the amount of predation on female snails is significantly higher than that of male snails.

Claims (2)

1. medicinal eurysome golden thread leech is to a preventing control method for Pomacea canaliculata, it is characterized in that:

Adopt medicinal eurysome golden thread leech as object, utilize its happiness draw river snail, freshwater mussel, the molluscan juice of Corbicula fluminea be food life habit, carried out spiral shell leech altogether support catch and kill test, eurysome golden thread leech body weight gain situation experiment and eurysome golden thread leech to Pomacea canaliculata male and female individuality predation contrast difference test;

Result of study draws: eurysome golden thread leech is to the ingestion rate of Pomacea canaliculata, and different with the difference of Pomacea canaliculata Individual Size, it preys on little spiral shell better effects if; Eurysome golden thread leech is in 15 days, and body weight change maximum is the 0.64g in the little spiral shell situation of predation, and minimum of a value is the-0.257g in middle spiral shell situation, and leech body weight change changes relevant with predatory number and self figure simultaneously;

The difference control experiment of eurysome golden thread leech to the predation of Pomacea canaliculata male and female individuality shows: eurysome golden thread leech predatory number difference fluctuates between 0 ~ 0.4, shows the other difference of the predation nonexistence of eurysome golden thread leech to Pomacea canaliculata; Eurysome golden thread leech, sucking in Pomacea canaliculata process, is comparatively vulnerable to external interference, and there is the phenomenon that two eurysome golden thread leech prey on same Pomacea canaliculata simultaneously; More in Pomacea canaliculata quantity, density is larger, when being namely greater than 3: 1, Pomacea canaliculata can be there is and sting drinking water leech postmortem phenomena, but simultaneously, in such circumstances, the accumulative predatory number of medicinal eurysome golden thread leech to Pomacea canaliculata is maximum, shows that medicinal eurysome golden thread leech exists certain control effect to Pomacea canaliculata thus.

2. a kind of medicinal eurysome golden thread leech according to claim 1 is to the preventing control method of Pomacea canaliculata, it is characterized in that: be specifically made up of following steps:

1.1 materials:

1.1.1 eurysome golden thread leech

Eurysome golden thread leech is bought in propagating field artificially, is about 1 year age of leech, individual body length between 6 centimetres ~ 13 centimetres, weight 5 grams ~ 12 grams, leech body, without scar, is the individuality of health;

1.1.2 Pomacea canaliculata

Testing spiral shell used picks up from paddy field, and spiral shell is 4 monthly ages more than, individual large, and spiral shell shell is intact, be the individuality of health;

1.1.3 instrument and equipment comprises:

The plastic basin of diameter 16cm, tweezers, filter paper, electronic balance, aquarium, Plastic Drum, glass jar;

1.2 experimental techniques:

1.2.1 the raising of eurysome golden thread leech:

In the glass jar of 100cm*50cm*50cm, load the paddy field mud of 5 cm thicks, dig the hole of a wide 30cm of long 50cm betwixt, fill water, enter applicable water plants in surrounding kind, leech is thrown in wherein, and put into shell, river snail, Pomacea canaliculata as feed;

For keeping water quality pure and fresh, within two days, changing a water, choosing and sucked spiral shell shell, and again throw in enough feeds, ensure the clean of overall breeding environment and food source sufficient;

1.2.2 the raising of Pomacea canaliculata:

One-tenth spiral shell is placed in 4 aquariums, and every case is put 40 ~ 50 and is become spiral shell, and breeding density is 30 ~ 35/square metre, add running water exposure in sunshine and leave standstill the filtered water that 48h obtains, the depth of water 30 ~ 35cm, and add appropriate feed, this tests feed used is romaine lettuce, the various leafy vegetable of water spinach;

For keeping water quality pure and fresh, changing a water every day, removing excreta in water, enough feeds of sooner or later throwing something and feeding every day;

1.2.3 spiral shell leech altogether support leech the predation of Pomacea canaliculata is tested:

Select the eurysome golden thread leech of weight between 5.5g ~ 7.5g and Pomacea canaliculata to support in diameter to be altogether in the plastics circle basin of 16cm, to arrange four kinds of process, be respectively:

(1) spread 2cm rice field mud at the bottom of basin, mud face depth of water 1cm, place an eurysome golden thread leech and a Pomacea canaliculata in basin, mud 1v1;

(2) pour the dark filtered water of 2cm in basin into, place an eurysome golden thread leech and a Pomacea canaliculata in basin, water 1v1;

(3) pour the dark filtered water of 2cm in basin into, place an eurysome golden thread leech and five Pomacea canaliculatas in basin, water 1v5;

(4) three eurysome golden thread leech and ten Pomacea canaliculatas are placed in basin, water 3v10;

Each process three repetition, every day entry manage everywhere in eurysome golden thread leech predation situation, altogether test seven days,

Support in process altogether and be found Pomacea canaliculata or eurysome golden thread leech death all can fill into, keep the spiral shell leech constant rate in each contrast, duration of test indoor temperature is 25 ± 2 DEG C, and water used is filtered water;

1.2.4 all ages and classes Pomacea canaliculata and eurysome golden thread leech altogether support leech body weight change test:

Pomacea canaliculata is divided into A, B, C Three Estate by Individual Size: A:0.7g-5.0g, B:5.0g-8.5g, more than C:8.5g-, each grade Pomacea canaliculata Stochastic choice three is only supported in the round basin of diameter 16cm, depth of water 2cm with an eurysome golden thread leech altogether, each process four repetition, observe every day and record eurysome golden thread leech predation situation, once weigh and record after seven days, after 15 days, again carry out weighing record; After first leech surface moisture being drawn with filter paper before weighing, then weigh with electronic balance;

Support in process altogether and be found Pomacea canaliculata or eurysome golden thread leech death all can fill into, keep the spiral shell leech constant rate in each contrast, duration of test indoor temperature is 25 ± 2 DEG C, and water used is filtered water;

1.2.5 eurysome golden thread leech is to the difference test of Pomacea canaliculata male and female individuality predation:

By male and female Pomacea canaliculata separately, and select two ripe male and female and an eurysome golden thread leech to support altogether in the round basin of diameter 16cm water, dark 2cm respectively, five repetitions are set, and every day observed and recorded eurysome golden thread leech to the predation situation of different sexes Pomacea canaliculata, duration of test indoor temperature is 25 ± 2 DEG C, and water used is filtered water;

1.2.6 Pomacea canaliculata standard of perfection anyway:

With reference to Santos method, take out the dead spiral shell of suspection in each process, put in a suitable place to breed respectively and observe in dechlorination water, what can not open operculum activity in 24h is death;

2 interpretations of result:

2.1 spiral shell leech support eurysome golden thread leech altogether to the predation situation of Pomacea canaliculata:

Figure 1 shows that spiral shell leech to support in situation eurysome golden thread leech altogether to the predation result of Pomacea canaliculata, from figure, 1v1 in mud, 1v1 in water, 1v5, under 3v10 these four process, the highest accumulative average predatory number is 17.01 in water in 3v10 process, minimum average predatory number is 5 in mud in the process of 1v1 spiral shell, it is 6 that the 1v1 process of supporting altogether in water adds up predatory number, show thus, eurysome golden thread leech is when Pomacea canaliculata density is larger, ingestion rate is relatively high, if there is earth environment, Pomacea canaliculata can slip in earth hides eurysome golden thread leech predation, thus increase the predation difficulty of eurysome golden thread leech,

Supporting in process altogether, eurysome golden thread leech is to the predation time of Pomacea canaliculata, different with the difference of Pomacea canaliculata Individual Size, absorb the less individual time shorter, the larger individual time is longer, and to the Pomacea canaliculata of 5.0g ~ 8.5g, leech takes food once in every 1.5 hours, to more than 8.5g Pomacea canaliculata, leech takes food once in every 3 hours; According to Germicidal efficacy, eurysome golden thread leech is being sucked in Pomacea canaliculata process, is easily subject to external interference thus stops predation; There is the phenomenon that two eurysome golden thread leech prey on same Pomacea canaliculata simultaneously simultaneously, under 1v5 and 3v10 processes, there are the eurysome golden thread leech phenomena of mortality, and body has wound, doubtfully stung food by Pomacea canaliculata;

2.2 eurysome golden thread leech 15 daily weight growth pattern experiments:

The body weight gain of eurysome golden thread leech, closely related with the quantity of its predation Pomacea canaliculata, support in process altogether and find that Pomacea canaliculata or eurysome golden thread leech death all can fill into, keep spiral shell leech constant rate in each contrast; Experimental result is shown in Fig. 2, eurysome golden thread leech in 15 days, body weight change maximum be the 0.64g in the little spiral shell situation of predation, minimum of a value is the-0.257g in predation in spiral shell situation; Eurysome golden thread leech figure and body weight are also relevant, and when figure becomes full strong state, body weight is heavier, and when figure becomes shrivelled softness, body weight is lighter; Result shows: the ingestion rate of Individual Size to eurysome golden thread leech of Pomacea canaliculata there are differences, and individual large predation is more difficult, and individual little predation is comparatively held;

2.3 eurysome golden thread leech are to the difference control experiment of Pomacea canaliculata male and female individuality predation:

Fig. 3 is the predation situation map of eurysome golden thread leech to male and female Pomacea canaliculata, shown by the experiment of 15 days, contrast each process eurysome golden thread leech predation Pomacea canaliculata quantity, its accumulated quantity preying on female spiral shell is 12, preying on male spiral shell accumulated quantity is 7, to female spiral shell predatory number apparently higher than male spiral shell.