An artificial breeding method for Torymus nagoyensis

Abstract

The present invention relates to the technical field of biological control of agricultural and forestry pests, and particularly to an artificial breeding method for Torymus nagoyensis. The method comprises the following steps: using tussah eggs as hosts for wasp inoculation, using a fructose aqueous solution as a sugar source, and inoculating female wasps of Torymus nagoyensis at the age of 3 days with reproductive memory and having mated for two times of wasp inoculation treatment; cultivating the tussah eggs parasitized by Torymus nagoyensis collected from the two times of wasp inoculation treatment to obtain the Torymus nagoyensis. Based on reproductive memory and combined with the biological characteristics of Torymus nagoyensis, the present invention determines the influencing factors such as the optimal age of female wasps for wasp inoculation, the inoculation ratio and time of Torymus nagoyensis, avoiding the phenomena of low parasitism rate or over-parasitism caused by improper parasitism ratio or time, thereby improving the parasitism rate and emergence rate of Torymus nagoyensis.

Description

Technical Field

[0001] The invention relates to the technical field of biological control of agricultural and forestry pests, and in particular to an artificial breeding method of a short-stalked and long-tailed gnawing wasp. Background Art

[0002] In recent years, factors such as global warming, frequent extreme weather, and the reduction of natural forests and the increase of artificial forests have provided favorable conditions for the occurrence and harm of forest pests. At present, the prevention and control of forest pests is still mainly based on chemical control, but due to the long-term and large-scale use of chemical pesticides, pests will develop resistance, leading to the rampant pests, and will also kill a large number of natural enemy insects, other beneficial organisms and non-major pests, seriously destroying the balance and biodiversity of forest ecosystems. In addition, due to the extremely long larval stage of some forest pests and their extremely hidden occurrence, the control effect of using chemical pesticides is not ideal. Therefore, it is extremely important to use biological control technology to control the occurrence and harm of forest pests, and the use of parasitic natural enemies to carry out pest control is one of the important means to achieve biological control of agricultural and forestry pests. For a long time, researchers at home and abroad have never stopped the development and application of parasitic natural enemy resources of agricultural and forestry pests, but due to the failure to find suitable intermediate breeding hosts and scientific breeding technology, they have not been widely promoted and applied. It can be seen that artificial breeding technology is the key technology to achieve large-scale promotion and application of parasitic natural enemies.

[0003] The genus Aprostocetus is the largest genus in the subfamily Tetrastichinae and is widely distributed around the world. Parasitic wasps of the genus Aprostocetus are very important natural enemy resources for agricultural and forestry pests. They have a wide range of hosts, mainly including Lepidoptera, Coleoptera, Diptera, Hymenoptera, Hemiptera, and Orthoptera. Many species of parasitic wasps in this genus have been successfully applied to biological control of pests. Aprostocetus is an egg-stage parasitic wasp of the genus Aprostocetus. It can control a variety of pests such as Caligula japonica Moore, Dendrolimus spp., and Lebeda nobilis Walker. It is a new potential superior parasitic wasp for controlling agricultural and forestry pests and has good development and application prospects. At present, there are no relevant research reports on the artificial breeding technology of the short-stalked long-tailed gnawing wasp, which greatly limits its promotion and application. Therefore, it is urgent to develop a large-scale breeding technology for the short-stalked long-tailed gnawing wasp to lay the foundation for its effective use in the biological control of agricultural and forestry pests.

[0004] Learning behavior is a behavior that animals acquire on the basis of genetic factors, under the action of environmental factors, through life experience and learning. Compared with innate behavior, learning behavior is not innate. It enables animals to continuously acquire new behavior patterns in the subsequent life process, and this behavior will change with the change of factors such as the environment. The learning behaviors of insects mainly include the following:

[0005] 1. Habituation and sensitization: The behavioral response value of insects to repeatedly presented stimuli gradually decreases. For example, after pollinating insects visit unremunerated flowers multiple times, they become less sensitive to the flower signal, reducing the flower-visiting efficiency and behavioral preference. 2. Associative learning: Insects learn through the consequences of their own behaviors. For example, when bees collect nectar in the flower cluster, if a certain type of flower has more nectar, they will be more inclined to visit this type of flower next time. 3. Learning and memory: One is that after insects experience learning, their memory will go through a consolidation stage, thus better guiding future behaviors. For example, after bees are trained multiple times, they can remember the relationship between flowers of a specific color or shape and nectar, and find the target more efficiently in subsequent foraging. The other is that if insects do not contact relevant stimuli for a long time, their memory will gradually fade; if they encounter new and more valuable stimuli, they will also update their memory. 4. Social learning: One is information transmission. Among social insects, information can be transmitted between individuals. For example, ants communicate through their antennae and release pheromones to transmit information such as food location and danger, and new members can quickly learn important survival information through this. The other is imitation behavior. Insects will imitate the behaviors of their peers. For example, young bees will observe the dance movements of older bees and learn information such as the location and distance of the nectar source. 5. Foraging learning: One is food selection learning. Insects can identify and select food based on color, shape, smell, etc., and can also learn to distinguish foods of different qualities and nutritional components. For example, the larvae of the cabbage white butterfly prefer cruciferous plants because they can recognize chemical signals such as glucosinolates. The other is foraging path learning. Insects can remember and optimize their foraging paths. For example, when ants are looking for food, they will leave pheromone marks on the path, and other ants can follow this path to find food and adjust the path according to the change of the food source. So far, there is no research report on the effect of reproductive learning (i.e., reproductive memory) on the reproduction of insects, nor is there a research report on improving the breeding efficiency of natural enemy insects based on reproductive memory. Summary of the Invention

[0006] The purpose of the present invention is to provide an artificial breeding method for Torymus nagoyensis to solve the problems existing in the above-mentioned prior art. The present invention provides an artificial breeding method for Torymus nagoyensis, which is obtained based on reproductive memory and the biological characteristics of Torymus nagoyensis. Using this method, a large number of Torymus nagoyensis can be obtained, and it also has the advantage of simple operation.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides an artificial breeding method for Torymus beneficus, comprising the following steps:

[0009] Using Chinese oak silkworm eggs as the host for introducing the wasps, and a fructose aqueous solution as the sugar source, introducing female Torymus beneficus at the age of 3 days with reproductive memory and having mated for breeding; after 24 hours of introducing the wasps, removing the Chinese oak silkworm eggs parasitized by Torymus beneficus;

[0010] On the second day, introducing new Chinese oak silkworm eggs, and after 24 hours of introducing the wasps, removing the Chinese oak silkworm eggs parasitized by Torymus beneficus;

[0011] Culturing the Chinese oak silkworm eggs parasitized by Torymus beneficus collected twice to obtain the Torymus beneficus.

[0012] Further preferably, the concentration of fructose in the fructose water is 20 wt.%.

[0013] Preferably, the female Torymus beneficus at the age of 3 days with reproductive memory and having mated is obtained through the following steps:

[0014] Using a fructose aqueous solution as the sugar source, mating female and male Torymus beneficus, and introducing Chinese oak silkworm eggs on the second day, and culturing for a total of 3 days to obtain the female Torymus beneficus at the age of 3 days with reproductive memory and having mated.

[0015] Preferably, the female Torymus beneficus is the newly emerged female Torymus beneficus of the second generation bred with the eggs of Actias selene as the host.

[0016] Preferably, the Chinese oak silkworm eggs are removed 6 hours after being introduced.

[0017] Preferably, the quantity ratio of the female Torymus beneficus to the male Torymus beneficus is (2 - 3):1.

[0018] Preferably, the condition parameters for breeding are: temperature 24 °C, relative humidity 70%, light time 14L, and dark time 10 h.

[0019] Preferably, the ratio of the female Torymus beneficus to the Chinese oak silkworm eggs for introducing the wasps is 3 heads:20 grains.

[0020] Preferably, the condition parameters for breeding are: temperature 24 °C, relative humidity 70%, light time 14L, and dark time 10 h.

[0021] Further preferably, the concentration of fructose in the fructose water is 20 wt.%.

[0022] Preferably, the culturing comprises the following steps:

[0023] Lay the tussah silkworm eggs parasitized by the Torymus beneficus flat and cover them with gauze; 8 hours after parasitization, turn them over once every 24 hours until the Torymus beneficus emerges.

[0024] Preferably, the cultivation condition parameters are: temperature 24°C, relative humidity 70%, light time 14L and dark time 10h.

[0025] More preferably, the laying thickness of the tussah silkworm eggs parasitized by the Torymus beneficus does not exceed 1 cm.

[0026] The present invention discloses the following technical effects:

[0027] Based on the learning behavior of organisms, the present invention has pioneered a new method globally that provides reproductive memory for natural enemies through reproductive learning, thereby improving the breeding efficiency of natural enemies. This method is of great significance for the efficient breeding of natural enemy insects in China and even the world.

[0028] Based on reproductive memory and combined with the biological characteristics of the Torymus beneficus, the present invention has determined the influencing factors such as the optimal maternal wasp age, parasitization ratio, and time for the Torymus beneficus to receive wasps, avoiding the phenomenon of low parasitization rate or over-parasitization caused by improper parasitization ratio or time, thereby improving the parasitization rate and emergence rate of the Torymus beneficus.

[0029] During the breeding process of the present invention, the Torymus beneficus is fed with a fructose aqueous solution, which can significantly increase the egg load of female wasps compared with honey before, thereby improving the parasitization ability of the Torymus beneficus.

[0030] The operation method of the reproductive memory of the parasitic wasp can be operated by ordinary people by learning the method of the present invention. The breeding hosts used are extremely easy to obtain, and the breeding device can be reused. The artificial breeding method provided by the present invention has the advantages of simple operation and low cost, can be continuously reproduced indoors throughout the year, and has a high parasitization rate and emergence rate of the Torymus beneficus, and can obtain Torymus beneficus products in batches, which has a positive significance for using the Torymus beneficus to carry out biological control of agricultural and forestry pests. Detailed implementation manners

[0031] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be regarded as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0032] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0033] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0034] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the description of the present invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.

[0035] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0036] Tetrastichus sp. with short stalks and long tails was disclosed in the literature "Biological Characteristics of Tetrastichus sp. with Short Stalks and Long Tails", and it is promised to be distributed externally for 20 years.

[0037] Example 1

[0038] An artificial breeding method of Tetrastichus sp. with short stalks and long tails based on reproductive memory, the main steps are as follows:

[0039] (1) Obtaining the parental generation of Tetrastichus sp. with short stalks and long tails having reproductive memory

[0040] The newly emerged female and male Tetrastichus planipennisi from the second generation bred from the eggs of the original host (Dictyoploca japonica eggs) were placed in a plastic beehive (cylindrical, diameter: 9.0 cm, height: 14.0 cm) at a quantity ratio of (2 - 3):1 for mating. They were reared in the plastic beehive for 3 days and fed with a fructose aqueous solution (concentration: 20 wt.%). On the second day, host Antheraea pernyi eggs were provided at a ratio of 10 wasps:1 egg for 6 hours to allow them to acquire reproductive memory. The rearing conditions were a temperature of 24 °C, a relative humidity of 70%, and a photoperiod of 14L:10D, that is, the light time was 14 hours and the dark time was 10 hours.

[0041] (2) Mass rearing of Tetrastichus planipennisi

[0042] The 3-day-old mated female Tetrastichus planipennisi with reproductive memory and host Antheraea pernyi eggs were introduced into a plastic breeding beehive (cylindrical, diameter: 9.0 cm, height: 14.0 cm). After 24 hours of introducing the wasps, the host Antheraea pernyi eggs were removed and collected. Then the female wasps were fed with a fructose aqueous solution (concentration: 20 wt.%). One day later, Antheraea pernyi eggs were introduced again. After 24 hours of introducing the wasps, the host Antheraea pernyi eggs were collected. The upper 1 / 3 of the plastic beehive was coated with a fructose aqueous solution for the parasitic wasps to feed on. The female Tetrastichus planipennisi and host Antheraea pernyi eggs were introduced at a ratio of 3 wasps:20 eggs. The conditions for introducing the wasps were a temperature of 24 °C, a relative humidity of 70%, and a photoperiod of 14L:10D, that is, the light time was 14 hours and the dark time was 10 hours.

[0043] (3) Rearing of the offspring wasps of Tetrastichus planipennisi

[0044] The host Antheraea pernyi eggs collected from the two introductions of the wasps were laid flat in a plastic square box (length × width × height: 25 cm × 25 cm × 3.5 cm) (the laying thickness did not exceed 1 cm). The box mouth was covered with a 100-mesh gauze and placed in an insect rearing room for cultivation (temperature 24 °C, relative humidity 70%, photoperiod 14L:10D (light time 14 hours, dark time 10 hours)). Starting from the 8th day after parasitism, the host eggs were turned over every 24 hours. The parasitic wasps emerged from the host eggs 21 - 23 days after parasitism to obtain Tetrastichus planipennisi.

[0045] Example 2 Optimization of the breeding conditions of Tetrastichus planipennisi

[0046] The optimization of the breeding conditions of Tetrastichus planipennisi was mainly verified through the following test examples, as follows:

[0047] Test example 1 Optimization of sugar source to increase the lifespan of Tetrastichus planipennisi

[0048] (1). Test method

[0049] Collect newly emerged, healthy, active, and uniform-sized short-stalked long-tailed gnawing bees, and introduce 10 bees into each finger-shaped tube (2.5cm×12cm) (the female bees and the male bees were observed to mate before being used in the experiment, that is, the parasitic bees used in the experiment were all mated). Feed the short-stalked long-tailed gnawing bees with fructose aqueous solution or honey water. Put the cotton balls dipped in different glycogens at the mouth of the test tube for the short-stalked long-tailed gnawing bees to eat. Replace the cotton balls every 24 hours, and observe and record the survival of the short-stalked long-tailed gnawing bees. The experiment used clear water as the control group, and observed 50 female and male bees for each treatment.

[0050] (2) Results and analysis

[0051] The effects on the life span of adults of the short-stalked long-tailed gnawing bee are shown in Table 1. As can be seen from Table 1, the life span of female bees of the short-stalked long-tailed gnawing bee is significantly longer than that of male bees. Compared with the control group, feeding glycogen can significantly increase the life span of female and male bees of the short-stalked long-tailed gnawing bee, but the effect of fructose aqueous solution is significantly better than the previously reported honey.

[0052] Table 1 Effect of glycogen on the life span of adults of Microhylidae brevirostris

[0053] Concentration Female wasps (days) Male wasps (days) Honey water 20wt.% 47 28 Fructose aqueous solution 20wt.% 48 30 CK - 3 2

[0054] Test Example 2: Test for selecting the best female bee age

[0055] (1) Test methods

[0056] The short-stalked long-tailed gnawing bees that had just emerged (<30 minutes) were collected, and the time of completion of emergence was recorded. Glycogen (a fructose aqueous solution with a concentration of 20wt.%) was provided to the parasitic bees for feeding every day, but no host eggs were provided. The parasitic bees within 24 hours after emergence were defined as 0-day-old parasitic bees, and the same was true for parasitic bees of other ages. The steps are as follows:

[0057] The second generation of newly emerged female and male short-stalked long-tailed gnawing wasps bred from the original host eggs (Ginkgo silk moth eggs) were placed in a beekeeping plastic jar (cylindrical, diameter: 9.0 cm, height: 14.0 cm) in a ratio of 2:1 for mating. They were raised in the beekeeping plastic jar for 3 days and fed with fructose aqueous solution (concentration of 20wt.%). On the second day, they were provided with tussah eggs in a ratio of 1 head:10 eggs for 6 hours to allow them to acquire reproductive memory.

[0058] One female wasp of Torymus beneficus at different ages (with reproductive memory and fully mated) was introduced into a plastic breeding pot containing 20 fresh host tussah eggs, and glycogen (an aqueous fructose solution with a concentration of 20 wt.%) was provided at the same time. After parasitism for 24 h, the wasps were removed. The conditions for introducing the wasps were a temperature of 24 °C, a relative humidity of 70%, and a photoperiod of 14L:10D, that is, the illumination time was 14 h and the dark time was 10 h. 30 female wasps of Torymus beneficus at each age were selected for the experiment to ensure that the female wasps at each selected age were of uniform size, avoiding experimental errors caused by differences in individual size. The parasitism effects of female wasps aged 0 - 10 days were measured in the experiment. The number of parasitized eggs of parasitoid wasps at each age was investigated 8 days after parasitism, and the emergence rate was counted after the parasitoid wasps emerged.

[0059] (2), Results and Analysis

[0060] By comparing the data in Table 2, it was found that the parasitism effect of female wasps of Torymus beneficus at 0 days old was the least satisfactory. The overall number of parasitized host tussah eggs by female wasps at each age showed a trend of first increasing and then decreasing. Among them, the parasitism effect of female wasps at 3 days old was the best, and they had a relatively high emergence rate. Thus, it can be seen that female wasps at 3 days old are more suitable for mass rearing of Torymus beneficus.

[0061] Table 2 Parasitism numbers and emergence rates of female wasps of Torymus beneficus at different ages

[0062] Day age of female Anastatus albicans Number of parasitized eggs (grains) Emergence rate (%) 0-day-old 0.17 95 1-day-old 2.70 96 2-day-old 4.43 96 3-day-old 7.03 98 4-day-old 6.80 98 5-day-old 6.33 97 6-day-old 6.20 97 7-day-old 6.43 96 8-day-old 5.83 97 9-day-old 5.90 95 10-day-old 5.83 95

[0063] Experimental Example 3 Comparison of parasitism effects of Torymus beneficus on host tussah eggs and original host eggs (screening of superior host eggs)

[0064] (1), Experimental Method

[0065] Female and male wasps of Torymus beneficus that newly emerged in the second generation bred from original host eggs (Dictyoploca japonica eggs) were placed in a plastic beekeeping pot (cylindrical, diameter: 9.0 cm, height: 14.0 cm) according to a quantity ratio of 2:1 for mating. They were reared in the plastic beekeeping pot for 3 days and fed an aqueous fructose solution (with a concentration of 20 wt.%). On the second day, tussah eggs were provided according to a wasp - egg ratio of 1 head:10 grains for 6 h to allow them to acquire reproductive memory.

[0066] Female wasps of Torymus beneficus at 3 days old with uniform size and fully mated were selected. Each female wasp was introduced into a test tube containing 20 host eggs (tussah eggs or Dictyoploca japonica eggs) for parasitism for 24 h. After parasitism for 24 h, the wasps were removed. After the parasitoid wasps emerged, the parasitism number, the number of wasps emerging from a single egg, the developmental duration, the emergence rate, and the sex ratio were investigated; meanwhile, the fecundity was investigated. In this experimental example, the investigation of fecundity started from the initial emergence of female wasps until death, and the host eggs were replaced once a day to record the reproduction of the parasitoid wasps.

[0067] (2) Results and Analysis

[0068] The results of the investigation on the parasitism effect are shown in Table 3. The results indicate that the number of Trichogrammatoidea bactrae Nagaraja parasitizing the host Antheraea pernyi eggs is significantly higher than that of the original host eggs (Actias selene eggs). Moreover, the number of wasps emerging from a single egg, the female ratio, and the fecundity are all significantly higher than those of the original host eggs. Additionally, the developmental duration is short and the emergence rate is high. Generally speaking, the host Antheraea pernyi eggs are suitable hosts for the large-scale propagation of Trichogrammatoidea bactrae Nagaraja.

[0069] Table 3 Comparison of the parasitism effects of Trichogrammatoidea bactrae Nagaraja on host Antheraea pernyi eggs and original host eggs

[0070]

[0071] Experimental Example 4 Influence of Reproductive Behavior Learning or Reproductive Memory Acquisition on the Propagation of Trichogrammatoidea bactrae Nagaraja

[0072] (1) Experimental Method

[0073] This experiment was divided into treatments with reproductive learning (reproductive memory) (A and B) and treatments without reproductive learning (reproductive memory) (C and D). For each treatment, Trichogrammatoidea bactrae Nagaraja with uniform individual sizes were selected. The specific details of each treatment are as follows:

[0074] Treatment A with reproductive learning (reproductive memory): Female and male Trichogrammatoidea bactrae Nagaraja newly emerged from the second generation bred from the original host eggs (Actias selene eggs) were placed in a beekeeping plastic jar (cylindrical, diameter: 9.0 cm, height: 14.0 cm) at a quantity ratio of 2:1 for mating. They were raised in the beekeeping plastic jar for 3 days and fed with a fructose aqueous solution (concentration: 20 wt.%). Starting from the 1st day of age, host Antheraea pernyi eggs were provided for 6 hours every day, with a wasp - egg ratio of 1 wasp:10 eggs. On the 2nd day of age, host Antheraea pernyi eggs were also provided for 6 hours to allow them to form reproductive memory;

[0075] Treatment B with reproductive learning (reproductive memory): Female and male Trichogrammatoidea bactrae Nagaraja newly emerged from the second generation bred from the original host eggs (Actias selene eggs) were placed in a beekeeping plastic jar (cylindrical, diameter: 9.0 cm, height: 14.0 cm) at a quantity ratio of 2:1 for mating. They were raised in the beekeeping plastic jar for 3 days and fed with a fructose aqueous solution (concentration: 20 wt.%). Starting from the 2nd day of age, host Antheraea pernyi eggs were provided for 6 hours every day, with a wasp - egg ratio of 1 wasp:10 eggs, to allow them to form reproductive memory;

[0076] Treatment C without reproductive learning (reproductive memory): It was the same as Treatment A with reproductive learning (reproductive memory), except that host Antheraea pernyi eggs were not provided in this treatment to prevent them from forming reproductive memory;

[0077] Treatment D without reproductive learning (reproductive memory): It is the same as Treatment B with reproductive learning (reproductive memory), except that this treatment does not provide host Antheraea pernyi eggs to induce reproductive memory.

[0078] Put 3-day-old female wasps in Treatments A - D into test tubes with host Antheraea pernyi eggs. Among them, 20 host Antheraea pernyi eggs were introduced for each female wasp. After 24 hours of wasp introduction, the wasps were removed. Eight days after parasitism, the number of parasitized eggs of the parasitic wasps was investigated.

[0079] (2) Results and Analysis

[0080] As can be seen from Table 4, by comparing the parasitism quantities, it was found that the parasitism quantities of female Torymus beneficus with parasitism experience (Treatments A and B) were significantly higher than those of female wasps without parasitism experience (Treatments C and D), and the reproductive ability of Torymus beneficus that started learning at 2 days old was stronger.

[0081] Table 4 Influence of parasitism experience on the parasitism quantity of Torymus beneficus

[0082]

[0083] Experimental Example 5 Optimization of the Optimal Temperature for the Reproduction of Torymus beneficus under Reproductive Memory Conditions

[0084] (1) Experimental Method

[0085] A total of 5 constant temperature gradients were set for the temperature experiment, which were 16°C, 20°C, 24°C, 28°C, and 32°C respectively, with an error of ±1°C, a relative humidity of 70 ± 5%, and a photoperiod of 14L:10D. The steps are as follows:

[0086] Put female and male Torymus beneficus that newly emerged from the second generation bred from the original host eggs (Dictyoploca japonica eggs) into a plastic beekeeping jar (cylindrical, diameter: 9.0 cm, height: 14.0 cm) at a quantity ratio of 2:1 for mating. They were reared in the plastic beekeeping jar for 3 days and fed with a fructose aqueous solution (concentration: 20 wt.%). On the second day, Antheraea pernyi eggs were provided at a ratio of 1 wasp:10 eggs for 6 hours to allow them to obtain reproductive memory.

[0087] Put a 3-day-old female Torymus beneficus (with reproductive memory and fully mated) into a glass finger tube containing 20 host eggs. After 24 hours of parasitism, the female wasp was removed. When the offspring wasps of Torymus beneficus were about to emerge, the emergence of the parasitic wasps was observed every 12 hours, the emergence date was recorded, and the total number of wasps emerging from a single host egg, the number of female and male wasps, and the remaining wasps were counted. After all the parasitic wasps emerged, the unhatched host eggs were dissected to investigate whether they were parasitized or parasitized but did not emerge. There were 25 valid replicates for each temperature treatment.

[0088] (2) Results and Analysis

[0089] The results are shown in Table 5. During the implementation of the experiment, it was found that Tetrastichus howardi could only develop into mature larvae at 16°C, and then diapaused in the state of mature larvae. Under the condition of 32°C, although the offspring wasps could develop into the adult stage, the adult wasps could not break through the eggshell to emerge. By comparing the data in Table 2, it was found that the number of wasps emerging from a single egg and the development duration of the offspring wasps of Tetrastichus howardi gradually decreased with the increase of temperature. Appropriate high-temperature conditions would increase the number of female offspring wasps of Tetrastichus howardi. At 24°C, the number of wasps emerging from a single egg of the offspring wasps was relatively large, the female ratio was relatively high, the development duration was relatively short, and the number of remaining wasps was the least, and the emergence rate was the highest. Generally speaking, under the condition of reproductive memory, a temperature of 24°C was more suitable for the breeding of Tetrastichus howardi, rather than 25°C reported previously.

[0090] Table 5 Biological parameters of the offspring wasps of Tetrastichus howardi under different temperatures

[0091] Temperature / ℃ Number of wasps emerging from a single egg (heads) Female ratio (%) Number of remaining wasps (heads) Emergence rate (%) Developmental duration / days 16 — — — — — 20 7.2a 86c 0.6b 92b 32a 24 7.2a 87b 0.2c 97a 25b 28 6.7b 88a 1.2a 85c 22c 32 — — — 0d —

[0092] Experimental Example 6 Optimization of the Optimal Humidity for the Breeding of Tetrastichus howardi under the Condition of Reproductive Memory

[0093] (1) Experimental Method

[0094] A total of 4 constant humidity gradients were set in the experiment, which were 30%, 50%, 70% and 90% respectively, with an error of ±5%, a temperature of 24±1°C, and a photoperiod of 14L:10D.

[0095] Female and male wasps of Tetrastichus howardi newly emerged from the second generation bred from the original host eggs (Antheraea pernyi eggs) were placed in a plastic beekeeping jar (cylindrical, diameter: 9.0 cm, height: 14.0 cm) according to the quantity ratio of 2:1 for mating. They were reared in the plastic beekeeping jar for 3 days and fed with a fructose aqueous solution (concentration: 20 wt.%). On the second day, Antheraea pernyi eggs were provided according to the ratio of 1 wasp:10 eggs for 6 hours to allow them to obtain reproductive memory.

[0096] One 3-day-old female wasp of Tetrastichus howardi that had mated sufficiently and had reproductive memory was introduced into a glass finger tube containing 20 host eggs. After parasitism for 24 hours, the female wasp was removed. When the offspring wasps of Tetrastichus howardi were about to emerge, the emergence of the parasitoid wasps was observed every 12 hours, the emergence date was recorded, and the total number of wasps emerging from a single host egg, the number of female and male wasps, and the number of remaining wasps were counted. After all the parasitoid wasps emerged, the unemerged host eggs were dissected to investigate whether they were parasitized or parasitized but not emerged. There were 25 valid replicates for each humidity treatment.

[0097] (2) Results and Analysis

[0098] By comparing the data in Table 6, it was found that under the condition of a temperature of 24 °C, the number of emerged wasps from a single egg of *Aprostocetus prolixus* gradually decreased with the increase in humidity. Both high humidity and low humidity increased the female ratio of this parasitoid wasp. When the relative humidity was 30%, the number of remaining wasps of *Aprostocetus prolixus* was significantly higher than that of the other three humidity treatments. Among them, when the relative humidity was 70%, the number of remaining wasps was the least. The emergence rate of the offspring wasps first increased and then decreased with the increase in humidity. Among them, the emergence rate was the highest at 70% humidity, reaching 97%. Humidity also had a significant impact on the development duration. Low humidity (RH 30% and RH 50%) increased the development duration of this parasitoid wasp. Generally speaking, under the condition of reproductive memory, 70% relative humidity is more suitable for the breeding of *Aprostocetus prolixus* rather than 75% reported previously.

[0099] Table 6 Biological parameters of the offspring wasps of *Aprostocetus prolixus* under different humidities

[0100] Humidity Number of wasps emerging from a single egg (heads) Female ratio (%) Number of remaining wasps (heads) Emergence rate (%) Developmental duration / days 30％ <![CDATA[8.9 a > <![CDATA[91 a > <![CDATA[1.2 a > <![CDATA[85 c > <![CDATA[25.7 a > 50％ <![CDATA[7.2 b > <![CDATA[85 c > <![CDATA[0.6 b > <![CDATA[92 b > <![CDATA[25.4 a > 70％ <![CDATA[7.2 b > <![CDATA[87 b > <![CDATA[0.2 c > <![CDATA[97 a > <![CDATA[24.7 b > 90％ <![CDATA[6.7 c > <![CDATA[91 a > <![CDATA[0.4 bc > <![CDATA[94 ab > <![CDATA[24.6 b >

[0101] Note: Different superscripts in each column represent significant differences.

[0102] Experimental Example 7 Comparison of the parasitism quantity and biological parameters of the offspring wasps of *Aprostocetus prolixus* under different wasp-host ratios and times under the condition of reproductive memory

[0103] (1) Experimental method

[0104] Collect newly emerged *Aprostocetus prolixus*, allow them to mate fully, and provide glycogen for the parasitoid wasps to feed on to endow the parasitoid wasps with reproductive memory. The steps are as follows: Place newly emerged female and male *Aprostocetus prolixus* bred from the second-generation eggs of the original host (eggs of *Actias selene*) in a plastic beehive (cylindrical, diameter: 9.0 cm, height: 14.0 cm) at a quantity ratio of 2:1 for mating. Raise them in the plastic beehive for 3 days and feed them with a fructose aqueous solution (concentration: 20 wt.%). On the second day, provide an appropriate amount of host *Antheraea pernyi* eggs at a wasp-egg ratio of 1 wasp:10 eggs for 6 hours to allow them to obtain reproductive memory.

[0105] After that, select 3-day-old female wasps (with reproductive memory) of uniform size for the experiment. Then, inoculate the wasps at ratios of *Aprostocetus prolixus* to host *Antheraea pernyi* eggs of 1 wasp:20 eggs, 2 wasps:20 eggs, 3 wasps:20 eggs, and 4 wasps:20 eggs respectively. Set 3 treatments for the inoculation time, which are 12 h, 24 h, and 48 h respectively. Each treatment has 30 valid replicates. Investigate the number of parasitized egg grains 8 days after the parasitism of *Aprostocetus prolixus*, and store the parasitized host eggs individually in single tubes. Investigate the emergence rate of each treatment after the emergence of the parasitoid wasps.

[0106] (2) Results and analysis

[0107] By comparing the data in Table 7, it is found that for the Tetrastichus planipennisi with reproductive memory, the number of parasitized host eggs gradually increases with the extension of the parasitization time when the wasp-egg ratio is 1:20. When the parasitization ratios are 2 wasps:20 eggs, 3 wasps:20 eggs, and 4 wasps:20 eggs, the number of parasitized eggs first increases and then levels off with the extension of the parasitization time. Under the condition that the parasitization time is 12 h, the number of parasitized host eggs by Tetrastichus planipennisi gradually increases with the increase of the parasitization ratio. When the parasitization time is 24 h and 48 h, the number of parasitized eggs by this parasitoid wasp first increases and then levels off with the increase of the parasitization ratio. It can be seen from the table that when the parasitization ratio is 3 wasps:20 eggs and the parasitization time is 24 h, the number of parasitized eggs of Antheraea pernyi by Tetrastichus planipennisi reaches the highest value, and there is no significant change with the extension of the parasitization time or the increase of the parasitization ratio. The offspring wasps all have a relatively high emergence rate, and the highest emergence rate can reach 97%.

[0108] Generally speaking, under the condition of having reproductive memory, the most suitable parasitization ratio and time for Tetrastichus planipennisi when using Antheraea pernyi eggs as the breeding host are a parasitization ratio of 3 wasps:20 eggs and a parasitization time of 24 h, because under this condition, the parasitization effect of this parasitoid wasp is the best and it has the highest emergence rate.

[0109] Table 7 Parasitization quantity and emergence rate of Tetrastichus planipennisi under different parasitization ratios and times

[0110] Parameter Parasitism quantity (grains) Emergence rate (%) 1：20-12h 3 97 1：20-24h 7 97 1：20-48h 8 95 2：20-12h 7 97 2：20-24h 10 96 2：20-48h 11 93 3：20-12h 8 96 3：20-24h 15 97 3：20-48h 15 93 4：20-12h 9 95 4：20-24h 15 95 4：20-48h 15 92

[0111] The embodiments described above are only for describing the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solution of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. An artificial breeding method for Torymus beneficus Yang et You, characterized in that, It includes the following steps: Using Antheraea pernyi eggs as the host for wasp inoculation, using a 20 wt.% fructose aqueous solution as the sugar source, inoculating female wasps of Aprostocetus prolixus at 3 days old with reproductive memory and having mated for rearing; 24 hours after inoculating the wasps, removing the Antheraea pernyi eggs parasitized by Aprostocetus prolixus; On the second day, inoculating new Antheraea pernyi eggs, and 24 hours after inoculating the wasps, removing the Antheraea pernyi eggs parasitized by Aprostocetus prolixus; Cultivating the Antheraea pernyi eggs parasitized by Aprostocetus prolixus collected twice to obtain the Aprostocetus prolixus; The female wasps of Aprostocetus prolixus at 3 days old with reproductive memory and having mated are obtained through the following steps: Using a fructose aqueous solution as the sugar source, mating female wasps and male wasps of Aprostocetus prolixus, and inoculating Antheraea pernyi eggs on the second day, and rearing for a total of 3 days to obtain the female wasps of Aprostocetus prolixus at 3 days old with reproductive memory and having mated; The inoculation ratio of the female wasps of Aprostocetus prolixus to Antheraea pernyi eggs is 3 heads: 20 grains.

2. The artificial breeding method according to claim 1, wherein The female wasps of Aprostocetus prolixus are the newly emerged female wasps of the second generation reared with Dictyoploca japonica eggs as the host.

3. The artificial breeding method according to claim 1, wherein The Antheraea pernyi eggs are removed 6 hours after inoculation.

4. The artificial breeding method according to claim 1, characterized in that, The quantity ratio of the female wasps and male wasps of Aprostocetus prolixus is (2 - 3):

1.

5. The artificial breeding method according to claim 1, characterized in that, The condition parameters for rearing are: temperature 24 °C, relative humidity 70%, light time 14L, and dark time 10h.

6. The artificial breeding method according to claim 1, characterized in that, The condition parameters for rearing are: temperature 24 °C, relative humidity 70%, light time 14L, and dark time 10h.

7. The artificial breeding method according to claim 1, characterized in that The cultivation includes the following steps: Laying the Antheraea pernyi eggs parasitized by Aprostocetus prolixus flat and covering them with gauze; 8 hours after parasitization, turning them over once every 24 hours until the Aprostocetus prolixus emerges.

8. The artificial breeding method according to claim 1, characterized in that, The condition parameters for cultivation are: temperature 24 °C, relative humidity 70%, light time 14L, and dark time 10h.

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