Method for breeding trichogramma by using wild coriaria sinica to culture castor silkworms

Abstract

The invention provides a method for breeding trichogramma by breeding castor silkworms through wild coriaria sinica. The method comprises the steps that 1, the castor silkworms are bred; 1.1, preparation of Chinese coriaria leaves; 1.2, castor silkworms are fed, and larva excrement and sand are collected; 1.3, preparing an excrement water extracting solution and a soaking solution; 1.4, castor silkworm eggs are taken, treated with a fecal sand water soaking solution and aired to serve as host eggs for standby application; 2, the host eggs are taken for trichogramma inoculation, parasitic eggs are obtained and cultured, and filial generation trichogramma is obtained; and 2.2, expanding propagation of trichogramma to proliferate the trichogramma population. The invention aims to establish a novel breeding technology chain of coriaria sinica leaf-castor silkworm-trichogramma, firstly, coriaria sinica resource with large quantity and low cost is effectively utilized, the breeding cost of castor silkworm is reduced, and then various trichogramma can be bred on a large scale; secondly, toxic substances contained in coriaria sinica are effectively utilized, the disease resistance of castor silkworms is enhanced, host eggs are disinfected, high-quality host eggs are provided for subsequent trichogramma breeding, and then the breeding quality of various trichogramma is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biological control of agricultural pests, and in particular belongs to a method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry. Background Art

[0002] Trichogrammatids are a type of egg parasitic natural enemy. Their reproduction requires natural eggs or artificial eggs as hosts, with natural eggs being the main source at present. Obtaining natural eggs requires collecting a large number of host insects, which are usually obtained through artificial breeding. Since most host insects are herbivorous insects, the natural enemy insect industry generally forms a three-level breeding relationship of "plant feed-host insect-parasitic wasp".

[0003] Castor silkworms are native to India. In the 1940s and 1950s, my country introduced and bred them many times. Since then, the castor silkworm industry has experienced several rises and falls, and is currently in a new round of prosperity. The main problems restricting its development are the lack of downstream export channels and low market demand, which leads to poor enthusiasm of breeders and low attention at the policy level. Specific reasons include low efficiency in cocoon processing, few sales channels for silkworm pupae, and sericulture often requires supporting castor planting. If castor planting is poor, it may indirectly cause silkworm diseases, leading to economic problems such as low yield and high cost.

[0004] Existing research and applications have shown that in addition to feeding on castor leaves, castor silkworms can also be fed with leaves from plants such as cassava, ailanthus, mulberry, kenaf, smilax glabra, camphor, crane tree, Chinese tallow tree, and sunflower.

[0005] Among them, Coriaria is a plant of the genus Coriaria in the family Coriariaceae. It is produced in Yunnan, Guizhou, Sichuan, Hubei, Shaanxi, Gansu, Tibet and other provinces in China, and is also distributed in India, Nepal and other countries. It grows in shrubs at an altitude of 400-3200 meters. It has strong adaptability and is not strict with soil conditions. It is classified as least concern in the "Red List of Endangered Species of the World Conservation Union". The whole plant of Coriaria is poisonous. In addition to its ecological functions such as soil and water conservation, it lacks large-scale application channels. Due to the lack of consumption, Coriaria resources have accumulated relatively high reserves. In earlier reports, it was estimated that the area of ​​Coriaria in the country is more than 800,000 hectares, and it is widely distributed in the wild in various distribution areas in my country.

[0006] Toxic substances are the main obstacle to the resource utilization of Coriaria. Although there are a few research reports on the use of Coriaria toxic substances in pharmaceutical development and pesticide development, more reports focus on the rescue and treatment of poisoning in humans and animals. Its components belong to lactones. The broad sense of "Coriaria toxins" mainly includes four compounds with proprietary names, namely Coriaria toxins (compounds), hydroxycoriaria toxins, Coriaria tin and Coriaria nin. To avoid confusion, "Coriaria toxic substances" are used in this application to refer to the above four toxins. Related studies have shown that Coriaria toxic substances are neurotoxic agents, which produce muscle excitement, respiratory hyperexcitement, vasoconstriction, activation of cardiac inhibition centers, etc. in humans and animals, thereby causing symptoms such as convulsions, coma, convulsions, and epilepsy; contact with insects causes stress expression of the esterase enzyme system, and an inhibitory effect is produced in the later stage. After the toxic substances invade the insect body, the sticky insect can show a series of symptoms such as excitement, vomiting midgut fluid, paralysis, coma, and death. It has also been reported that after bees collect Coriaria flowers, Coriaria toxic substances can be transmitted along the honey, posing a threat to food safety. On the other hand, the toxic substances of Coriaria officinalis also have antibacterial activity.

[0007] Although there are reports that mulberry leaves can be used to feed castor silkworms, compared with breeding with castor leaves, there are problems such as 2-4 days longer age, uneven development, smaller silkworm bodies, slower activity, and slightly lower egg production. The reasons for this have not been reported.

[0008] In summary, there is currently no established "Coriaria-Castor Silkworm-Trichogrammatus" breeding technology. On the one hand, a large number of Coriaria resources are idle. On the other hand, due to the lack or high cost of host eggs, many Trichogrammatus species with application value are difficult to achieve large-scale application. Summary of the invention

[0009] The purpose of the present invention is to propose a method for breeding trichogrammatids by breeding ricin silkworms using wild corium mulberry, and to build a new breeding technology chain of "corium mulberry leaves-castor silkworms-trichogrammatids". First, the corium mulberry resources with large quantity and low cost are effectively utilized to reduce the breeding cost of castor silkworms, thereby enabling large-scale breeding of various trichogrammatids; second, the toxic substances contained in the corium mulberry resources are effectively utilized to enhance the disease resistance of castor silkworms and disinfect host eggs, thereby providing high-quality host eggs for subsequent bee breeding, thereby improving the breeding quality of various trichogrammatids.

[0010] The purpose of the present invention can be achieved through the following technical solutions:

[0011] A method for breeding trichogrammatids by using wild Coriaria mulberry to cultivate ricinus silkworms comprises the following steps:

[0012] Step 1, breeding castor silkworms;

[0013] Step 1.1, preparation of Coriaria leaves: collecting fresh Coriaria leaves;

[0014] Step 1.2, feeding the castor silkworms: preparing castor silkworm eggs, and after the castor silkworm eggs are hatched into castor silkworm larvae, providing the castor silkworm larvae with fresh Coriolus mulberry leaves, and collecting the feces and sand of the castor silkworm larvae;

[0015] Step 1.3, preparation of fecal sand water extract; adding clean water to the collected fecal sand, adding 300 to 600 ml of clean water to every 100 g of fecal sand, stirring thoroughly, soaking and filtering to obtain a fecal sand water extract; when using, adding 100 to 200 ml of clean water to dilute every 100 ml of fecal sand water extract to obtain a fecal sand water soaking solution;

[0016] Step 1.4, host egg preparation; after the larvae of the castor silkworm in step 1.2 pupate and emerge as adults, perform laparotomy on the female castor silkworm adults to obtain eggs, and obtain castor silkworm eggs; take the castor silkworm eggs, wash them, immerse them in a dung sand water soaking liquid, soak them for at least 10 minutes and no more than 1 hour, take them out, dry them, and use them as host eggs for later use;

[0017] Step 2, breeding trichogrammatids;

[0018] Step 2.1, breeding of trichogrammatids; taking prepared host eggs to inoculate trichogrammatids, obtaining host eggs parasitized by trichogrammatids, wherein the host eggs parasitized by trichogrammatids are called parasitized eggs, and culturing the parasitized eggs to obtain offspring trichogrammatids;

[0019] Step 2.2, propagation of trichogrammatids: taking offspring trichogrammatids and repeating the trichogrammatid breeding process of step 2.1 to carry out propagation generation by generation, so as to increase the trichogrammatid population.

[0020] The optimization scheme of the present invention also includes step 3, preparing a trichogrammatid product; when the trichogrammatid develops to the late pupal stage in step 2.1, the parasitic eggs are refrigerated at 4° C. as the trichogrammatid product and transported to a release environment.

[0021] Optimization scheme, in step 1.1 of the present invention, the method for collecting fresh Coriaria leaves is specifically: the Coriaria growth area is divided and collected in batches, and when collecting, fresh and tender side branches that have grown for 30-45 days are cut close to the roots of the Coriaria, and mature side branches that have grown for more than 45 days are cut close to the roots of the Coriaria, and the cut fresh and tender side branches and mature side branches are preserved and stored separately.

[0022] Further, in the step 1.2, the young leaves on the fresh and tender side branches described in step 1.1 are used to feed the castor silkworm eggs until the third instar larvae are hatched, and the old leaves on the mature side branches described in step 1.1 are used to feed the castor silkworm fourth instar larvae until the larvae pupate, and the upper limit of the percentage of the mass of the old leaves fed to the total mass of the mulberry leaves fed is 80%.

[0023] Furthermore, the step 1.2 also includes a larvae sampling step, specifically, starting from the 4th instar larvae, sampling the larvae at the end of each instar until the sampling is stopped after pupation; when the larvae are in normal life state, continue to feed them with the old leaves accounting for 80% of the total weight of the fresh mulberry leaves; when the larvae are in abnormal life state, reduce the old leaves by 20-40%; thereafter, continue to perform the larvae sampling step at the end of each instar, and determine whether to maintain or reduce the old leaves according to the sampling results of the larvae life state.

[0024] Optimization scheme, in step 1.3 of the present invention, the feces and sand collected are the feces and sand produced by the larvae from the 4th instar larvae to before pupation.

[0025] Furthermore, in step 1.3, the collected fecal sand is cleaned and air-dried, and then stored in a cool place for future use.

[0026] Optimization scheme, in step 2.1 of the present invention, the bee-inoculating environment of the host eggs is: inoculating bees for 24 to 48 hours under the conditions of temperature 26±1°C, relative air humidity 90±3%, and photoperiod 14L:10D, and then removing the bee species to obtain parasitic eggs; the culture environment of the parasitic eggs is: temperature 26±1°C, relative air humidity 90±3%, and development in a photoperiod 14L:10D environment to obtain offspring trichogrammatids.

[0027] Furthermore, in step 2.1, during the culture process, a number of parasitic eggs are taken every 48 hours to monitor the 24-hour O2 consumption and CO2 production. Based on the status of O2 consumption and CO2 production within 24 hours, it is determined whether there is respiratory abnormality. Based on the sampling monitoring results, when respiratory abnormality occurs, the parasitic eggs in large-scale production are appropriately evacuated, the stacking thickness of the eggs is reduced, and ventilation and heat dissipation are enhanced.

[0028] Optimization scheme, the trichogrammatids of the present invention include but are not limited to trichogrammatids of sticky insects, trichogrammatids of corn borers, trichogrammatids of short tubes, trichogrammatids of pine caterpillars and trichogrammatids of yellow stem borers.

[0029] The present invention has the following outstanding substantive features and remarkable progress:

[0030] 1. The present invention solves the problem of idle resource development and utilization by building a new breeding technology chain of "coriaria leaves-castor silkworm-trichogrammatus", including (1) coriaria resources are difficult to be used in large quantities due to the toxic substances they contain, (2) castor silkworms are subject to cost, disease and other problems, and resource development and utilization are intermittent, (3) various trichogrammatus are limited by the lack of artificial hosts and cannot be used on a large scale, etc.; on the other hand, it breaks through the bottleneck of existing technologies and obtains high-quality insect products, including enhancing the disease resistance of castor silkworms by regulating the content of toxic substances caused by eating coriaria within a reasonable range, providing high-quality host eggs for subsequent bee breeding; at the same time, using castor silkworm larvae feces to disinfect host eggs, replacing the side effects of traditional chemical disinfection methods on parasitic bees, inhibiting the growth of microorganisms, and providing more host signal substances for host eggs, which helps to stimulate parasitic bees to lay eggs, protect the original biological and physiological state of host eggs, and avoid the introduction of chemical substances that have a negative impact on parasitic bees, so as to not only enable various trichogrammatus to be bred on a large scale, but also improve the breeding quality.

[0031] 2. The present invention further provides users with parasitic eggs when the trichogrammatid develops to the pupal stage as a product. The life of the trichogrammatid in the pupal stage is the most stable and is less affected by external interference, which can effectively ensure the vitality of the trichogrammatid during transportation. At the same time, cold chain transportation is used to keep the parasitic eggs in a relatively low temperature environment during transportation, effectively prolonging the pupal state of the trichogrammatid on the parasitic eggs to prevent them from emerging into bees during transportation.

[0032] 3. The present invention further uses the tender leaves and old leaves of fresh Coriaria leaves to feed the larvae of castor silkworms, and the Coriaria leaves are collected in a simple and effective manner. Reasonable pruning and rotation collection methods can promote the growth of new branches of Coriaria mulberry and ensure the sustainability of resources. The wrong collection method will not only cause Coriaria mulberry to switch from vegetative growth to reproductive growth, but also produce a large number of toxic fruits. Excessive felling may also lead to resource depletion and damage the ecological environment. And further, by regulating the proportion of old leaves, timely intervention in the amount of toxins ingested by the larvae is achieved, which can achieve the purpose of making full use of Coriaria mulberry leaves on the one hand, and can ensure that the castor silkworms can normally complete their development on a population scale on the other hand.

[0033] 4. The present invention further conducts random inspections on the life status of castor silkworm larvae as a basis for regulating the proportion of old leaves, thereby effectively guiding and regulating the proportion of old leaves, avoiding poisoning of feeder insects, and efficiently, reliably and scientifically guiding the large-scale propagation and cultivation of castor silkworms.

[0034] 5. The present invention further utilizes the biological learning ability of the larvae of the castor silkworm. The larvae are fed with young leaves and old leaves according to their age. First, the larvae are prevented from eating old leaves too early, which is not conducive to their growth. Second, the utilization rate of the Coriaria mulberry is improved by feeding the old leaves to the older larvae. Third, the dung sand after the older larvae are fed with old leaves contains a higher content of toxic Coriaria mulberry, which is very beneficial to the subsequent disinfection of host eggs.

[0035] 6. An important manifestation of poisoning by toxic substances in Coriolus serrata is abnormal respiratory activity. Therefore, the present invention further monitors the respiratory metabolism of trichogrammatid larvae by sampling to achieve real-time monitoring of large-scale bee breeding development. In addition, since trichogrammatids are endoparasitic bees and develop in host eggs without going out to feed, this monitoring method will not interfere with the sampled bees, and non-destructive and non-interference monitoring can be achieved. The present invention adjusts the stacking thickness of parasitic eggs in real time according to the respiratory monitoring results, evacuates the egg particles, and then adjusts the temperature of the egg development microenvironment to avoid heat accumulation affecting the quality of bee products, thereby providing a basis for the management of parasitic eggs bred on a large scale.

[0036] 7. The method of the present invention is complete, scientific and efficient. The toxic substances of Coriaria mulberry are regulated under conditions that are harmless to the development of ricinus silkworms and trichogrammatids. It not only utilizes idle wild Coriaria mulberry resources, improves ricinus silkworm breeding, and reduces costs, but also obtains additional benefits, such as obtaining ricinus silkworm feces with antibacterial effects; the mechanical properties of ricinus silkworm eggs are improved, which is beneficial to the mechanization and automation of trichogrammatid products. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The test results of Example 4 on the metabolic recovery ability of castor silkworm larvae. DETAILED DESCRIPTION

[0038] The present invention will be further described below.

[0039] Example 1

[0040] A method for breeding trichogrammatids by using wild Coriaria mulberry to cultivate ricinus silkworms comprises the following steps:

[0041] Step 1, breeding castor silkworms;

[0042] Step 1.1, preparation of Coriolus alba leaves; collect fresh Coriolus alba leaves.

[0043] (1) Select a suitable location to set up a base based on the survey of Coriolus chinensis resources.

[0044] (2) Collection method: The growing area of ​​Coriaria mulberry is divided and collected in batches. Fresh and tender side branches that have grown for 30-45 days are cut close to the roots to feed the 3rd instar larvae of the ricinus silkworm after hatching eggs; mature side branches that have grown for more than 45 days are cut close to the roots to feed the 4th instar larvae of the ricinus silkworm until the larvae pupate. After collection, use perforated films to keep them fresh indoors for later use.

[0045] Table 1 The basis for harvesting a single Coriaria sinensis tree by zoning

[0046] Time (day) Length of fresh and tender lateral branches (cm) 10 3.4 20 11.2 30 22.7 40 35.2 50 41.5 60 45.6

[0047] Step 1.2, feeding castor silkworms: preparing castor silkworm eggs, and after the castor silkworm eggs are hatched into castor silkworm larvae, providing fresh Coriolus japonica leaves for the castor silkworm larvae, and collecting the feces and sand of the castor silkworm larvae.

[0048] Specifically, the young leaves on the fresh side branches described in step 1.1 are used to feed the castor silkworm eggs until they are hatched and the third-instar larvae are fed; the old leaves on the mature side branches described in step 1.1 are used to feed the castor silkworm larvae until the larvae pupate, and the upper limit of the percentage of the weight of the old leaves fed to the total weight of the Coriaria japonica leaves fed is 80%.

[0049] Step 1.3, preparation of fecal sand water extract; add clean water to the collected fecal sand, add 300 to 600 ml of clean water for every 100 g of fecal sand, stir thoroughly, soak and filter to obtain the fecal sand water extract; when using, add 100 to 200 ml of clean water to dilute every 100 ml of fecal sand water extract to obtain the fecal sand water soaking solution.

[0050] Step 1.4, host egg preparation; after the ricinus silkworm larvae in step 1.2 pupate and emerge as adults, perform laparotomy on the female ricinus silkworm adults to obtain eggs, thereby obtaining ricinus silkworm eggs; after washing the ricinus silkworm eggs, immerse them in a dung sand water soaking liquid, soak for at least 10 minutes and no more than 1 hour, take them out, dry them, and use them as host eggs for later use.

[0051] Step 2: Breed trichogrammatids.

[0052] Step 2.1, breeding of trichogrammatids; taking prepared host eggs for inoculation with trichogrammatids, the inoculation environment of the host eggs is: inoculating bees for 24 to 48 hours under the conditions of temperature 26±1°C, relative air humidity 90±3%, and photoperiod 14L:10D, and then removing the bee species to obtain host eggs parasitized by trichogrammatids, the host eggs parasitized by trichogrammatids are called parasitic eggs, and the parasitic eggs are cultured, and the culture environment of the parasitic eggs is: temperature 26±1°C, relative air humidity 90±3%, and photoperiod 14L:10D environment to develop, and obtain offspring trichogrammatids.

[0053] Step 2.2, propagation of trichogrammatids: taking offspring trichogrammatids and repeating the trichogrammatid breeding process of step 2.1 to carry out propagation generation by generation, so as to increase the trichogrammatid population.

[0054] Table 2 The detection results of the proliferation quality of the trichogrammatid population obtained in step 2 of this method

[0055] Trichogramma myxomycetes Trichogramma dendrolimus Trichogramma vulgaris Parasitism rate (%) 78.6 90.7 87.1 Eclosion rate (%) 63.3 86.6 81.9 Number of hatched bees / eggs 70.6 55.1 50.3 Remaining bee numbers / eggs 2.23 0.96 1.25

[0056] Usually, only one trichogrammatid can be produced from an egg of the rice moth at a time, and the reproductive efficiency of each generation is very low. One host egg can produce one parasitic wasp, and the cultivation cost of the host egg and the parasitic wasp is correspondingly higher than that of the castor silkworm egg. As can be seen from the above Table 2, one castor silkworm egg can obtain 50-70 parasitic wasps, and the castor silkworm egg rarely has residual parasitic wasps that have not emerged, indicating that the single castor silkworm egg of the present invention shows an excellent peak output, effectively reducing the cultivation cost of the host egg and the parasitic wasp, reducing the large-scale breeding cost of the trichogrammatid and improving the breeding efficiency.

[0057] After the Trichogrammatid population has multiplied to a certain number, a portion of the Trichogrammatid adults can be directly taken and released into the release environment as Trichogrammatid products.

[0058] The cold chain transportation method of step 3 can also be used to release the parasitic eggs to the release environment. Step 3 specifically includes: preparing trichogrammatid products; when the trichogrammatids in step 2.1 develop to the late pupal stage, refrigerate the parasitic eggs as trichogrammatid products at 4°C and transport them to the release environment.

[0059] The above method builds a new breeding technology chain with "corium leaves-castor silkworm-trichogrammatus", feeds castor silkworms with corium leaves, and then the castor silkworms lay eggs as host eggs for the trichogrammatus, and at the same time, the feces and sand of the castor silkworm larvae are used for disinfection and strengthening of the host eggs, so that the trichogrammatus, including but not limited to the sticky insect trichogrammatus, corn borer trichogrammatus, short-tube trichogrammatus, pine caterpillar trichogrammatus and yellow stem borer trichogrammatus, can be bred on a large scale, and at the same time solves the problem of development and utilization of wild corium resources.

[0060] Furthermore, step 1.2 of this embodiment also includes a larvae sampling step, specifically starting from the 4th instar larvae, sampling the larvae at the end of each instar until the sampling is stopped after pupation; when the larvae are in normal life state, continue to feed them with the old leaves accounting for 80% of the total mass of the fresh mulberry leaves; when the larvae are in abnormal life state, reduce the old leaves by 20-40%; thereafter, continue to perform the larvae sampling step at the end of each instar, and determine whether to maintain or reduce the old leaves according to the sampling results of the larvae life state.

[0061] The method for determining whether the life state is normal is: take 50 larvae, first do a qualitative examination, observe the body surface state, and exclude obvious abnormalities such as bacterial disease (softening, black death), drug damage (twisting and reversing, spasm, swelling, and the appearance of body surface water), and white muscardine disease (whitening of the body surface); after the larvae pass the qualitative examination and have no above-mentioned body surface symptoms, further investigate the possibility of poisoning by eating Coriaria leaves. Place the larvae in a suitable container (adjusted according to the body length of larvae of different ages and the number of larvae to be inspected at one time, so that the larvae can crawl evenly in the recording area) and record for 20 minutes, and use behavioral analysis software to detect the crawling trajectory. According to the software trajectory tracking performance, it can be tested head by head or in batches. A trajectory distance <5cm (slowed down or not moving due to dullness or excitement tremor) is considered abnormal. If the proportion of abnormal worms exceeds 20%, it is considered that the life state of the sampled larvae is abnormal.

[0062] Tables 3 and 4 below show the crawling track lengths of the ricinus silkworm larvae when their behavior is abnormal, which also serve as the basis for considering a track distance < 5 cm as abnormal in this embodiment.

[0063] Table 3 Crawling distance of 3rd instar larvae when feed was provided

[0064]

[0065] Table 4 Changes in crawling distance of 4th instar larvae in different states over time when feed is provided

[0066]

[0067] This embodiment increases the step of random inspection of larvae to timely understand the vitality of castor silkworm larvae. Once the abnormal life state of the larvae is monitored, such as excitement or dullness, the amount of old leaves fed is reduced by 20-40% based on the existing feeding mass percentage. After reducing the intake of old leaves, the behavior of castor silkworm larvae can gradually return to normal. By performing random inspections at each age and adjusting the proportion of old leaves accordingly, timely intervention in the amount of toxins ingested by the larvae can be achieved. On the one hand, the purpose of making full use of the leaves of Coriolus mulberry is achieved, and on the other hand, the castor silkworm can be guaranteed to complete its development normally on a population scale.

[0068] Further, in step 1.3 of this embodiment, the feces and sand collected are feces and sand produced by the larvae from the 4th instar to before pupation. The collected feces and sand are further cleaned and air-dried, and then stored in a cool place for later use. For every 100g of air-dried feces and sand, 500 to 600ml of clean water is added to obtain a feces and sand water extract.

[0069] Furthermore, in step 2.1 of this embodiment, during the culture process of the parasitic eggs, a number of parasitic eggs are taken every 48 hours to monitor the 24-hour O2 consumption and CO2 production. According to the status of O2 consumption and CO2 production within 24 hours, it is determined whether there is respiratory abnormality. According to the sampling monitoring results, when respiratory abnormality occurs, the parasitic eggs in large-scale production are appropriately evacuated, the stacking thickness of the eggs is reduced, and ventilation and heat dissipation are enhanced.

[0070] Specifically, 100 parasitic eggs were taken and the insect respirometer was used to monitor the 24-hour O2 consumption and CO2 production. Under normal circumstances, the insect's O2 consumption and CO2 production were stable within 24 hours. Once the O2 consumption and CO2 production changed abnormally, it was determined that the trichogrammatid parasitizing the parasitic eggs had respiratory abnormalities. Since the stimulation of Coriolus sanguinea poison can lead to increased respiratory intensity, according to the sampling monitoring results, when respiratory abnormalities occur, the eggs in large-scale production will be appropriately evacuated, the thickness of the egg stacking will be reduced, and ventilation and heat dissipation will be strengthened.

[0071] Example 2

[0072] This example compares the egg disinfection modes, specifically, the three egg disinfection modes of using the feces sand water soaking solution of Example 1, 0.1% chlorhexidine aqueous solution and 30W ultraviolet light irradiation to treat and compare the castor silkworm eggs, and the specific steps are as follows:

[0073] 1. Host egg preparation. After the ricinus silkworm pupates and emerges, collect the female moths and perform laparotomy to obtain the eggs. After washing, divide the eggs into 4 groups: the first group is immersed in the ricinus silkworm feces sand water soaking solution, taken out after half an hour, and dried; the second group is immersed in 0.1% chlorhexidine aqueous solution for 10 minutes for disinfection, then taken out and dried; the third group is fully spread into a single layer of eggs, and then irradiated with a 30W ultraviolet lamp for 45 minutes; the fourth group is washed and dried directly as a blank control.

[0074] 2. Reproduction of Trichogrammatids. Take the prepared host eggs, inoculate them with bees at a ratio of 3:1 for 24 hours at (26±1)℃, relative air humidity (90±3)%, and a photoperiod of 14L:10D, then remove the bees and place the parasitized eggs in an environment with a temperature of (26±1)℃, relative air humidity (90±3)%, and a photoperiod of 14L:10D to develop, and obtain the offspring of Trichogrammatids. On the 5th day of development, sample the egg microbial infection rate.

[0075] Table 5 Detection of parasitism rate of trichogrammatid (%)

[0076] Egg handling method Trichogramma myxomycetes Trichogramma dendrolimus Trichogramma vulgaris Manure sand flooding 78.6 90.7 87.1 New Cleanser disinfection 70.9 85.3 78.7 UV irradiation 74.4 87.8 79.2 blank 74.1 88.2 80.4

[0077] Table 6 Results of random inspection of parasitic egg infection microorganisms (%)

[0078] Egg handling method Trichogramma myxomycetes Trichogramma dendrolimus Trichogramma vulgaris Manure sand flooding 2.5 3.9 2.8 New Cleanser disinfection 2.3 4.1 3.2 UV irradiation 6.9 7.8 5.8 blank 11.9 14.3 12.2

[0079] The results show that there is a risk of microbial infection if the eggs are not disinfected. And as the scale of production expands, the amount of eggs used increases, and the eggs are stacked in large quantities, the infection is easier to spread, and the cost control risk increases accordingly. Ultraviolet irradiation disinfection has the problem of ineffective irradiation due to shielding, and the energy consumption is relatively high. There will still be microorganisms remaining in the unirradiated part. The larger the egg, the more serious the problem. Therefore, this method is often used on tiny eggs such as rice moth eggs (rice moth eggs can only parasitize 1-2 trichogrammatids, and castor silkworm eggs can parasitize 50-70 trichogrammatids); the chemical agent chlorhexidine is effective in disinfection, but it has an adverse effect on the parasitism rate. It may be that the residual smell of the agent hinders the parasitic bee from identifying the host eggs, or reduces the parasitic preference; this method uses the water extract of the dung of the castor silkworm that feeds on Coriolus leaves for disinfection. On the one hand, it utilizes the antibacterial effect of the residual Coriolus toxin, and on the other hand, it also provides the smell from the host insect, and strikes a balance between antibacterial and attracting parasitic bees.

[0080] Example 3

[0081] This example compares the mechanical strength of eggs, as follows:

[0082] 1. Host egg preparation: Feed the ricinus silkworms with Coriolus mulberry leaves and castor leaves respectively. After the ricinus silkworms have pupated and emerged from the shell, collect the female moths, cut open their abdomens to take out the eggs, and then wash and dry them.

[0083] 2. Egg pressure test. The eggs were placed under a particle strength tester to test their ultimate pressure when broken. The host egg pressure data were: 21.8N for the group fed with Coriaria sinensis and 20.6N for the group fed with Castor bean.

[0084] The results showed that the eggs of castor silkworms fed with Coriaria showed improved mechanical strength. Although the mechanism of this phenomenon remains to be studied, compared with thin, brittle and easily broken eggs, eggs with suitable mechanical strength are conducive to mechanized sorting and packaging, which can reduce the loss of raw materials and products caused by egg breakage during the production process, and thus facilitate cost control.

[0085] Example 4

[0086] This example tests the metabolic recovery ability of castor silkworm larvae, as follows:

[0087] 1. Induce poisoning. Take ricinus silkworm larvae and feed them exclusively with old Coriaria mulberry leaves from the third instar until the proportion of abnormal worms exceeds 20% in random inspections.

[0088] 2. Restore dynamics. After the experimental population is sampled and found to be abnormal, the proportion of old leaves is reduced to 50%, and the above population is continued to be fed, sampled daily, and the changes in the proportion of abnormal insects after the old leaves are reduced to 50% with the number of days of feeding are recorded, and a plot is made. Figure 1 .

[0089] The results showed that the toxin metabolism of poisoned insects is generally concentrated within 48 hours. After reducing the intake of old leaves, their behavior can gradually return to normal. By sampling each age and adjusting the proportion of old leaves, timely intervention in the amount of toxin intake by larvae can be achieved. On the one hand, it can achieve the purpose of making full use of the leaves of Coriolus mulberry, and on the other hand, it can ensure that the castor silkworm completes its development normally at the population scale.

Claims

1. A method for breeding trichogrammatids by using wild Coriaria mulberry to cultivate ricinus silkworms, characterized in that The following steps are included: Step 1, breeding castor silkworms; Step 1.1, preparation of Coriaria leaves: collecting fresh Coriaria leaves; Step 1.2, feeding the castor silkworms: preparing castor silkworm eggs, and after the castor silkworm eggs are hatched into castor silkworm larvae, providing the castor silkworm larvae with fresh Coriolus chinensis leaves, and collecting the feces and sand of the castor silkworm larvae; Step 1.3, preparation of fecal sand water extract; adding clean water to the collected fecal sand, adding 300 to 600 ml of clean water to every 100 g of fecal sand, stirring thoroughly, soaking and filtering to obtain a fecal sand water extract; when using, adding 100 to 200 ml of clean water to dilute every 100 ml of fecal sand water extract to obtain a fecal sand water soaking solution; Step 1.4, host egg preparation; after the larvae of the castor silkworm in step 1.2 pupate and emerge as adults, perform laparotomy on the female castor silkworm adults to obtain eggs, and obtain castor silkworm eggs; take the castor silkworm eggs, wash them, immerse them in a dung sand water soaking liquid, soak them for at least 10 minutes and no more than 1 hour, take them out, dry them, and use them as host eggs for later use; Step 2, breeding trichogrammatids; Step 2.1, breeding of trichogrammatids; taking prepared host eggs to inoculate trichogrammatids, obtaining host eggs parasitized by trichogrammatids, wherein the host eggs parasitized by trichogrammatids are called parasitized eggs, and culturing the parasitized eggs to obtain offspring trichogrammatids; Step 2.2, propagation of trichogrammatids: taking offspring trichogrammatids and repeating the trichogrammatid breeding process of step 2.1 to carry out propagation generation by generation, so as to increase the trichogrammatid population.

2. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 1, characterized in that: The method further comprises step 3 of preparing a trichogrammatid product; when the trichogrammatid in step 2.1 develops to the late pupal stage, the parasitic eggs are refrigerated at 4° C. as the trichogrammatid product and transported to a release environment.

3. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 1, characterized in that: In step 1.1, the method for collecting fresh Coriaria leaves is as follows: the Coriaria growing area is divided and collected in batches. When collecting, fresh and tender side branches that have grown for 30-45 days are cut close to the roots of the Coriaria, and mature side branches that have grown for more than 45 days are cut close to the roots of the Coriaria. The cut fresh and tender side branches and mature side branches are preserved and stored separately.

4. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 3, characterized in that: In step 1.2, the young leaves on the fresh and tender side branches described in step 1.1 are used to feed the castor silkworm eggs until they are hatched to the third instar larvae, and the old leaves on the mature side branches described in step 1.1 are used to feed the castor silkworm larvae until the larvae pupate, and the upper limit of the percentage of the mass of the old leaves fed to the total mass of the Coriaria officinalis leaves fed is 80%.

5. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 4, characterized in that: Step 1.2 also includes a larvae sampling step, specifically, starting from the 4th instar larvae, sampling the larvae at the end of each instar until the sampling is stopped after pupation; when the larvae are in normal life state, continue to feed with the old leaves accounting for 80% of the total weight of the fresh mulberry leaves; when the larvae are in abnormal life state, reduce the old leaves by 20-40%; thereafter, continue to perform the larvae sampling step at the end of each instar, and determine whether to maintain or reduce the old leaves according to the sampling results of the larvae life state.

6. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 1, characterized in that: In step 1.3, the feces and sand collected are feces and sand produced by the larvae from the 4th instar larvae to before pupation.

7. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 1 or 6, characterized in that: Step 1.3, remove impurities from the collected feces and sand, air-dry it, and store it in a cool place for later use.

8. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 1, characterized in that: In step 2.1, the host egg inoculation environment is: inoculation for 24 to 48 hours at a temperature of 26±1°C, a relative air humidity of 90±3%, and a photoperiod of 14L:10D, and then the bee species are removed to obtain parasitic eggs; the parasitic eggs are cultured in an environment of 26±1°C, a relative air humidity of 90±3%, and a photoperiod of 14L:10D to obtain offspring trichogrammatids.

9. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 1 or 8, characterized in that: In step 2.1, during the culture process, a number of parasitic eggs are taken every 48 hours to monitor the 24-hour O2 consumption and CO2 production. Based on the status of O2 consumption and CO2 production within 24 hours, it is determined whether there is respiratory abnormality. Based on the sampling monitoring results, when respiratory abnormality occurs, the parasitic eggs in large-scale production are appropriately evacuated to reduce the stacking thickness of the eggs and enhance ventilation and heat dissipation.

10. The method for breeding trichogrammatids by culturing ricinus silkworms using wild Coriaria mulberry according to claim 1, characterized in that: The trichogrammatids include but are not limited to trichogrammatids of armyworms, trichogrammatids of corn borers, trichogrammatids of short tubes, trichogrammatids of pine caterpillars and trichogrammatids of corn borers.

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