A method for taming black soldier fly larvae to withstand high and low temperatures

Abstract

The present invention belongs to the technical field of insect domestication, and specifically relates to a domestication method for black soldier fly larvae to resist high / low temperature. The method comprises: S1, using black soldier fly larvae raised at room temperature and developing health as domestication materials; S2, performing extreme temperature domestication treatment on the larvae described in step S1: the domestication temperature is 12°C to 16°C for 30d, or 40°C for 14d-20d; S3, directional domestication: the larvae that survived after the treatment of step S2 are screened and raised under room temperature until the adults reproduce and lay eggs, and the first generation of seed worms is obtained after the eggs are hatched, and the seed worms are repeated steps S1 and S2 again, and continuously domesticated. The method is simple and easy to operate, and it is easy to carry out large-scale operation. The black soldier flies are domesticated to form a new strain of black soldier fly larvae that is cold-resistant / heat-resistant. Compared with the original strain, the larvae weight gain, development speed and survival rate are significantly improved, and the needs of producing and treating organic waste in cold / hot areas or after temperature fluctuations and producing a large amount of insect protein are met.

Description

Technical Field

[0001] The invention belongs to the technical field of insect domestication, and particularly relates to a high / low temperature resistant domestication method for black soldier fly larvae. Background Art

[0002] The scientific name of the black soldier fly (Hermitia illucens L.) is Hermitia illucens, which belongs to the genus Hermitia of the family Schizophora in the order Diptera. The black soldier fly has a wide range of diets, and its feeding period is mainly in the larval stage. The black soldier fly larvae feed on organic waste (animal carcasses, feces, kitchen waste), etc. The black soldier fly is well-known worldwide for its high efficiency in converting organic waste. It can convert organic waste into high-quality insect protein. At present, the international community mainly uses black soldier flies to treat organic waste. The black soldier fly larvae obtained after conversion are rich in protein, with a content of up to 42%. These insect proteins can be added to livestock and poultry feed to replace protein sources such as fish meal. Black soldier fly larvae have been used to produce animal feed and are a high-quality protein.

[0003] Black soldier flies are a new type of insect for breeding in recent years. Although black soldier flies have strong resistance to adversity, unsuitable environmental conditions will seriously affect their development and survival. Currently, there are no varieties of black soldier flies that are bred for extreme temperature environments. The varieties currently used are all domesticated from wild populations, including the Guangzhou strain domesticated by Shenzhen Biosource Company, the Wuhan strain domesticated by Huazhong Agricultural University, and the Henan strain domesticated by Natural Creation. However, these varieties have not been selected for heat-resistant / cold-resistant varieties.

[0004] When black soldier flies are farmed on a large scale, due to the high breeding density, according to the habits of black soldier flies, the larvae like to burrow into the feed, especially in the hot summer, which is more likely to cause the feed temperature to rise. The larvae cannot escape in time, which will cause a large number of black soldier fly larvae to die due to heat intolerance. When breeding in winter, or in some areas with a large temperature difference between day and night, low temperatures will cause some larvae to suffer from cold shock, that is, the larvae stop developing. Moreover, with the fluctuation of temperature, the overall feeding rate of black soldier fly larvae is low, and the feed conversion rate decreases, making it difficult to ensure the weight gain of the larvae, thereby failing to meet the output of a large amount of protein. At the same time, black soldier fly larvae may also have a stress response due to extreme temperature fluctuations, resulting in individual death. Black soldier fly larvae have poor ability to regulate body temperature. Their body temperature basically depends on the temperature conditions of the surrounding environment. The temperature regulating devices generally used in the breeding environment control system require large energy consumption, which increases the breeding cost. Therefore, domesticating and breeding black soldier fly larvae that are resistant to high and low temperatures, so that they can still maintain good growth performance after temperature fluctuations, has become a technical breakthrough in the black soldier fly breeding industry. At present, only Jia Fang et al. have published methods for breeding black soldier flies for different feeds in my country, and no research has been carried out on breeding new varieties of black soldier fly larvae for breeding under extreme temperatures. Summary of the invention

[0005] In view of the shortcomings of the prior art, the primary purpose of the present invention is to provide a method for taming black soldier fly larvae to resist high / low temperatures. The heat and cold resistance of the black soldier fly larvae obtained by this method are significantly enhanced, and new high / low temperature resistant strains can be obtained, which still show good growth and development performance after temperature fluctuations.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A method for taming black soldier fly larvae to resist high / low temperatures comprises the following steps:

[0008] S1, using black soldier fly larvae raised at room temperature and developing healthily as domestication materials;

[0009] S2. Extreme temperature acclimation treatment: the acclimation conditions are raising the fish at a low temperature of 12℃ to 16℃ for 30 days, or raising them at a high temperature of 40℃ for 14-20 days;

[0010] S3, directed domestication, the larvae that survived the treatment in step S2 are screened and raised at room temperature until they become adults and lay eggs. After the eggs are hatched, the first generation of breeding worms are obtained. Steps S1 and S2 are repeated for the breeding worms for continuous domestication.

[0011] Preferably, the black soldier fly larvae described in step S1 are larvae 5 days after hatching from eggs.

[0012] Preferably, the humidity range during feeding in step S2 is 70%-80%.

[0013] Preferably, the breeding density during the acclimation treatment in step S2 is 0.51 per cm 3 The feed density is 900-1000 larvae / kg. While ensuring the activity area of ​​the larvae, it is also necessary to ensure excess feed supply.

[0014] Preferably, the specific method for obtaining the first generation of breeding worms in step S3 is as follows: the larvae that survived the treatment in step S2 are eliminated by weight at a ratio of 50% for weak larvae, and then raised under room temperature until pupation, and the feed and pupae are sieved with a mesh sieve, and the pupae that cannot fall through the mesh sieve with a mesh size of 6 or more are collected, and the pupae are raised at room temperature until they emerge and reproduce and lay eggs, and the first generation of breeding worms are obtained after the eggs hatch.

[0015] In the actual breeding process of the present invention, some larvae will experience cold shock under low temperature, that is, the larvae stop developing. Then these larvae are weak larvae. The weak larvae can be distinguished very clearly. Their weight hardly increases after entering the low temperature. At 30 days, their weight is still the initial weight or slightly increased. Therefore, the weight is used as an indicator to eliminate them at a ratio of 50% for screening.

[0016] Preferably, the continuous acclimation in step S3 is performed for n (n≥10) generations at a low temperature of 12°C to 16°C.

[0017] Preferably, the continuous acclimatization in step S3 is carried out for 4 generations at a high temperature of 40°C.

[0018] The second object of the present invention is to provide an application of the above method in improving the growth performance of black soldier fly larvae under extreme temperatures.

[0019] The breeding goal of the present invention is to allow the larvae to have better tolerance and growth performance at low / high temperatures, and at the same time, after a period of temperature fluctuations, they can show better growth and development effects.

[0020] Preferably, the improvement in growth performance includes at least the following aspects: (1) body weight, (2) feed conversion rate, and (3) survival rate.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) The continuous low-temperature acclimation of the present invention can prolong the growth period of black soldier fly larvae; it can be used to acclimate and raise cold-resistant strains of black soldier fly larvae, meeting the needs of normal production and treatment of organic waste and production of a large amount of insect protein in cold regions in winter;

[0023] (2) At the same time, continuous high-temperature acclimation will promote the development period of black soldier fly larvae, reduce the number of days required for larval development, and quickly pre-pupae; it can be used to acclimate and raise heat-resistant strains of black soldier fly larvae, meeting the needs of normal production and treatment of organic waste in hot areas in summer and producing a large amount of insect protein;

[0024] (3) Compared with the untrained original strain, the trained black soldier fly larvae significantly increased their weight, developed faster, had a higher feed conversion rate, and reduced mortality after a period of temperature fluctuations. This can meet the needs of large-scale breeding of black soldier fly larvae to produce insect protein without being affected by extreme weather and temperature fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the black soldier fly domestication process of the technical route of the present invention.

[0026] Figure 2 This is a picture of the appearance of the 10th generation larvae after 30 days of low temperature treatment at 16°C in Example 1 of the present invention. The left picture is the acclimated larvae, and the right picture is the original strain.

[0027] Figure 3 This is a graph showing the growth performance test results of the 10th generation larvae of Example 1 of the present invention, A, B: body weight, C: dry matter conversion rate, D: survival rate, E: body length and width of successive larvae, and F: growth and development curve; the control group is the original strain that has not been selected.

[0028] Figure 4 This is a picture of the appearance of the 10th generation larvae after 12° C. low-temperature treatment for 30 days in Example 2 of the present invention. The left picture is the acclimated larvae, and the right picture is the original strain.

[0029] Figure 5 This is a graph showing the growth performance test results of the 10th generation larvae of Example 2 of the present invention, A: body weight, B: dry matter conversion rate, C: survival rate, D: body length and width of successive generation larvae, and E: growth and development curve.

[0030] Figure 6 This is a graph showing the growth performance test results of the fourth generation larvae of Example 3 of the present invention, A: body weight, B: dry matter conversion rate, C: survival rate, D: weight comparison of successive generation larvae, and E: growth and development curve.

[0031] Figure 7 This is a graph showing the effect of continuous 16°C low temperature acclimation on the developmental period of the 10th generation larvae in Example 1 of the present invention.

[0032] Figure 8 This is a graph showing the effect of continuous 12°C low temperature acclimation on the developmental period of the 10th generation larvae in Example 2 of the present invention.

[0033] Fig. 9 This is a graph showing the effect of continuous 40°C high temperature acclimation on the developmental period of the fourth generation larvae in Example 3 of the present invention. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments, but the scope of the present invention is not limited. It should be understood that, for those of ordinary skill in the art, improvements or changes can be made according to the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present invention.

[0035] Unless otherwise specified, the experimental methods used in the examples of the present invention are all conventional methods; the materials, reagents, etc. used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0036] Example 1

[0037] A method for taming black soldier fly larvae to resist low temperature comprises the following steps:

[0038] (1) Collect 5g of black soldier fly eggs laid on the same day (the difference in egg-laying time should not exceed 24h), place the eggs in a plastic box with a length of 12cm, a width of 8cm and a height of 10cm, cover it with a nylon mesh, and place the plastic box in a constant temperature incubator for incubation. The incubation temperature is 30℃ and the environmental humidity is maintained at about 70% to 75%. Record the time after the larvae hatch, and then add them to artificial feed (wheat bran, alfalfa and corn flour, mixed in a ratio of 5:3:2). Continue to place them in a constant temperature incubator when the feed humidity is about 70%. When the larvae grow to 5 days old, select healthy larvae;

[0039] (2) Select healthy 5-day-old larvae as breeding larvae, and the larvae breeding density is 0.51 / cm 3 , the feed stocking density was 1000 / kg, ensuring an excess of feed (dry weight), and the fish were placed in a low-temperature constant-temperature incubator (RH80%, photoperiod 14L:10D) to ensure sufficient feed, and were raised at 16°C for 30 days;

[0040] (3) Directed domestication: After being raised at 16°C for 30 days in step (2), the surviving larvae are eliminated according to the weight ratio of 50%, and then transferred to room temperature for further rearing until pupation. The feed and pupae are sieved using sieves of different mesh sizes, and the pupae that cannot fall through the 8-mesh sieve are collected. After the selected pupae emerge, the adults are collected and waited for them to mate and lay eggs under natural light conditions. After the eggs hatch, the first generation of breeding worms are obtained; the first generation of breeding worms are repeatedly operated according to the above methods (1) and (2), and the breeding is continued for 10 generations.

[0041] To test the effect of domestication, the 10th generation of breeding was tested.

[0042] Detection method:

[0043] 1. Larval weight gain: For each repeated test, 100 5-day-old black soldier fly larvae were selected (the breeding group and the control group should select healthy 5-day-old black soldier fly larvae with the same weight), 10 were selected and recorded in wet weight m0, and they were fed with feed until half of the prepupae appeared, and then feeding was stopped. Then 10 larvae were randomly selected, weighed and recorded in wet weight m1, and three repeated tests were performed to obtain the average. The weight gain calculation formula is as follows:

[0044] Larval weight gain = m1-m0;

[0045] Wherein, m1: total wet weight of larvae when half of the prepupae appear;

[0046] m0: total wet weight of 5-day-old larvae.

[0047] 2. Dry matter conversion rate: Three groups of repeated tests were conducted to obtain the average value. In each repeated test, 100 5-day-old black soldier fly larvae were selected (the 5-day-old black soldier fly larvae of the breeding group and the control group should be healthy and of the same weight), and the feed was fed. The feed was added in multiple times, and the total dry weight of each feed added was recorded m2. When half of the prepupae appeared, the feeding was stopped, and the remaining material was dried at 60°C for 36 hours and weighed m4. The conversion rate formula is as follows:

[0048] Conversion rate = (m2-m4) / m4

[0049] Where, m2: total dry weight of added feed;

[0050] m4: Total dry weight of remaining residue.

[0051] 3. Survival rate: For each repeated test, 100 5-day-old black soldier fly larvae were selected (the 5-day-old black soldier fly larvae of the breeding group and the control group should be healthy and of the same weight), and the larvae were fed until half of the prepupae appeared. The number of surviving larvae was recorded, and the mean value was calculated by performing three repeated tests. The survival rate formula is as follows:

[0052] Survival rate = (number of survivors / 100)*100%.

[0053] 4. Larval growth curve: Carry out three sets of repeated experiments to find the mean value. In each repeated experiment, 10 larvae were randomly selected and weighed, and the changes in larval weight were recorded, and a growth curve was prepared.

[0054] 5. Time until half of the larvae prepupae: For each repeated test, 100 5-day-old black soldier fly larvae were selected (the 5-day-old black soldier fly larvae of the breeding group and the control group should be healthy and of the same weight), and they were fed until half of the prepupae appeared. The time required for development was recorded, and the average value was calculated by performing three repeated tests.

[0055] 6. Reproductive capacity: For each repeated test, 100 5-day-old black soldier fly larvae were selected (the 5-day-old black soldier fly larvae of the breeding group and the control group should be healthy and of the same weight). After temperature treatment, the black soldier fly larvae were raised until pupation. After the pupae emerged, the adults were collected and waited for them to mate and lay eggs under natural light conditions. The number of eggs laid by each of the 5 random female insects in each group was recorded and the mean was calculated.

[0056] Larvae phenotype Figure 2 As shown. After 30 days of low temperature treatment at 16℃, the total weight of ten larvae in the 16℃ breeding group (tenth generation) was 1.157g ( Figure 3A, 3B), the total weight of ten larvae in the control group (unselected source strain) was 0.442g. The weight gain of the selected group was 0.715g higher than that of the control group, and the relative weight gain rate [(weight gain of the selected group - weight gain of the control group) / total weight of the control group] increased by 161.76%. The weight growth rate of the tenth generation of selected breeding after 30 days of low temperature treatment was significantly higher than that of the control group.

[0057] like Figure 7 As shown in the figure, the half-prepupal time of larvae shows that when treated at 16℃ for 30 days, the growth and development of larvae is significantly slow. After ten generations of breeding, the half-prepupal time of larvae in the breeding group is 45.6 days, and that in the unbred control group is 43.6 days, which is 2 days higher than that in the control group. This indicates that continuous low-temperature acclimation will prolong the growth period of black soldier flies.

[0058] After 30 days of low temperature treatment, the larvae had not reached half of the prepupae and were still in the growth stage. In order to further study the effect of temperature fluctuation on the larvae, since the black soldier flies had the best conversion rate of feed when they were half prepupae, they were kept at normal temperature until half of them pupated. The dry matter conversion rate of the 16℃ breeding group (tenth generation) was 59.9% ( Figure 3 C), the dry matter conversion rate of the control group was 53.86%, and the dry matter conversion rate of the breeding group was 6.04% higher than that of the control group. It can be seen that the 16℃ breeding group (tenth generation) can show better feed processing ability than the control group after temperature fluctuation. When half of the pupae were restored to normal temperature, the survival rate of the 16℃ breeding group (tenth generation) was 88.33% ( Figure 3 D), the survival rate of the control group was 76%, and the survival rate of the breeding group was significantly higher than that of the control group. Figure 3 E, 3F), the length and width of the T16 breeding group G7-G10 generations are compared, and the body length also shows a trend of increasing generation by generation. From the curve chart, it can be seen that the growth and development speed increases with each generation, and the development speed of the 16℃ breeding group (tenth generation) is also significantly higher than that of the control group. Continue to raise them until all pupates, collect adults after the pupae emerge, and wait for them to mate and lay eggs under natural light conditions. After the statistics of the number of eggs laid, the breeding group has better reproductive capacity than the control group.

[0059] Example 2

[0060] A method for taming black soldier fly larvae to resist low temperature comprises the following steps:

[0061] (1) Collect 5g of black soldier fly eggs laid on the same day (the difference in egg-laying time should not exceed 24h), place the eggs in a plastic box with a length of 12cm, a width of 8cm and a height of 10cm, cover it with a nylon mesh, and place the plastic box in a constant temperature incubator for incubation. The incubation temperature is 30℃ and the environmental humidity is maintained at about 70% to 75%. Record the time after the larvae hatch, and then add them to artificial feed (wheat bran, alfalfa and corn flour, mixed in a ratio of 5:3:2). Continue to place them in a constant temperature incubator when the feed humidity is about 70%. When the larvae grow to 5 days old, select healthy larvae;

[0062] (2) Select healthy 5-day-old larvae as breeding larvae, and the larvae breeding density is 0.51 / cm 3 , the feed breeding density is 1000 / kg, ensuring excessive feed, and the fish are placed in a low-temperature constant temperature incubator (RH80%, photoperiod 14L:10D) to ensure sufficient feed, and raised at 12℃ for 30 days;

[0063] (3) Directed domestication: After being raised at 12°C for 30 days in step (2), the surviving larvae are eliminated according to the weight ratio of 50%, and then transferred to room temperature for further rearing until pupation. The feed and pupae are sieved using sieves of different mesh sizes, and the pupae that cannot fall through the 6-mesh sieve are collected. After the selected pupae emerge, the adults are collected and waited for them to mate and lay eggs under natural light conditions. After the eggs hatch, the first generation of breeding worms are obtained; the first generation of breeding worms are repeatedly operated according to the above methods (1) and (2), and the breeding is continued for 10 generations.

[0064] The acclimation effect was tested on the 10th generation of breeding, and the growth performance test method was the same as in Example 1.

[0065] The larvae's appearance after acclimation is Figure 4 As shown. After 30 days of low temperature treatment at 12℃, the total weight of ten larvae in the 12℃ breeding group (tenth generation) was 0.6475g ( Figure 5 A), the total weight of ten larvae in the control group (unselected source strain) was 0.37g. The weight gain of the selected group was 0.2775g higher than that of the control group, and the relative weight gain rate was increased by 75%. The weight growth rate of the tenth generation of selected low temperature treatment for 30 days was significantly higher than that of the control group.

[0066] like Figure 8 As shown in the figure, the half-prepupal time of the larvae showed that when treated at 12℃ for 30 days, the growth and development of the larvae was significantly slowed down. After ten generations of breeding, the half-prepupal time of the larvae in the breeding group was 44.33 days, and that in the unselected control group was 41.33 days. The breeding group was 3 days higher than the control group, indicating that continuous low-temperature acclimation would prolong the growth period of black soldier flies.

[0067] After 30 days of low temperature treatment, the larvae had not reached half of the prepupae and were still in the growth stage. In order to further study the effect of temperature fluctuation on the larvae, since the black soldier flies had the best conversion rate of feed when they were half prepupae, they were kept at normal temperature until half of them pupated. The dry matter conversion rate of the 12℃ breeding group (tenth generation) was 63.22% ( Figure 5 B), the dry matter conversion rate of the control group was 59.81%. The dry matter conversion rate of the breeding group was 3.41% higher than that of the control group. Survival rate: When half of the pupae were pupated at normal temperature, the survival rate of the 12℃ breeding group (ten generations) was 69.33% ( Figure 5 C), the survival rate of the control group was 58%, and the survival rate of the breeding group was significantly higher than that of the control group. Figure 5 D, 5E), T12 (G10) breeding group G6-G10 body length and width: G10 generation has the longest body length, and it shows an increasing trend from generation to generation. T12 breeding group G6-G10 development curve: G10 generation has the fastest development speed, and it shows an increasing trend from generation to generation. The development speed of the breeding group (tenth generation) under 12℃ is significantly higher than that of the control group. Continue to raise until all pupates, collect adults after the pupae emerge, wait for them to mate and lay eggs under natural light conditions, and after statistics on the number of eggs laid, the breeding group has better reproductive capacity than the control group.

[0068] Example 3

[0069] A method for taming black soldier fly larvae to resist high temperatures comprises the following steps:

[0070] (1) Collect 5g of black soldier fly eggs laid on the same day (the difference in egg-laying time should not exceed 24h), place the eggs in a plastic box with a length of 12cm, a width of 8cm and a height of 10cm, cover it with a nylon mesh, and place the plastic box in a constant temperature incubator for incubation. The incubation temperature is 30℃ and the environmental humidity is maintained at about 70% to 75%. Record the time after the larvae hatch, and then add them to artificial feed (wheat bran, alfalfa and corn flour, mixed in a ratio of 5:3:2). Continue to place them in a constant temperature incubator when the feed humidity is about 70%. When the larvae grow to 5 days old, select healthy larvae;

[0071] (2) Select healthy 5-day-old larvae as breeding larvae, and the larvae breeding density is 0.51 / cm 3 , the feed breeding density is 1000 / kg, ensuring excessive feed, and the fish are placed in a low-temperature constant temperature incubator (RH80%, photoperiod 14L:10D) to ensure sufficient feed, and raised at a high temperature of 40℃ for 20 days;

[0072] (3) Directed domestication: After being raised at 40°C for 20 days in step (2), the surviving larvae are eliminated according to the weight ratio of 50%, and then transferred to room temperature for further rearing until pupation. The feed and pupae are sieved using sieves of different mesh sizes, and the pupae that cannot fall through the 8-mesh sieve are collected. After the selected pupae emerge, the adults are collected and waited for them to mate and lay eggs under natural light conditions. After the eggs hatch, the first generation of breeding worms are obtained; the first generation of breeding worms are repeatedly operated according to the above methods (1) and (2), and the breeding is continued for 10 generations.

[0073] The acclimation effect was tested on the 4th and 10th generation larvae. The growth performance test method was the same as in Example 1.

[0074] like Fig. 9 As shown in the figure, when treated at 40℃ for 14 days, half of the larvae had already pre-pupae. After ten generations of selection, the pre-pupae time of half of the larvae in the selection group was 14.6 days, and that of the control group without selection was 15.6 days, which was 1 day lower than that of the control group. This indicates that continuous high-temperature domestication will shorten the growth period of black soldier fly larvae.

[0075] After 14 days of high temperature treatment at 40℃, the total weight of ten larvae in the 40℃ breeding group (fourth generation) was 2.589g ( Figure 6 A), the total weight of ten larvae in the control group (unselected source strain) was 2.077g. The weight gain of the selected group was 0.512g higher than that of the control group, and the relative weight gain rate was increased by 24.65%. The dry matter conversion rate of the 40℃ selected group (fourth generation) was 61.34% ( Figure 6 B), the dry matter conversion rate of the control group was 48.73%. The dry matter conversion rate of the breeding group was 12.61% higher than that of the control group. Survival rate ( Figure 6 C): When half of the larvae pupated at normal temperature, the survival rate of the 40℃ breeding group (four generations) was 89.33%, and the survival rate of the control group was 85%. The survival rate of the breeding group was slightly higher than that of the control group, but after ten generations of breeding, the larvae can have a higher weight gain while ensuring the survival rate. From the maximum weight chart ( Figure 6 D), the fourth generation also showed the most advantageous high temperature tolerance. It can be seen from the growth curve ( Figure 6 E), the breeding group (fourth generation) developed significantly faster at 40°C than the control group. The insects were kept until all pupated, and the adults were collected after the pupae emerged. They were then placed under natural light and waited for them to mate and lay eggs. The number of eggs laid was statistically analyzed, and the breeding group had better reproductive capacity than the control group.

[0076] Comparative Example 1

[0077] Compared with Example 3, the difference is that the humidity is RH85%. The results show that at a high temperature of 40°C, the black soldier flies cannot molt due to excessive humidity and die in large numbers.

[0078] Comparative Example 2

[0079] Compared with Example 3, the difference is that the breeding density of domesticated black soldier fly larvae is 2000 / kg. The results show that the larvae escaped due to the high density, and the remaining larvae could not grow up due to insufficient feed and died due to long-term exposure to high temperature.

[0080] In summary, continuous low-temperature acclimation will prolong the growth period of black soldier fly larvae, significantly increase the weight gain of black soldier fly larvae in cold environments, greatly improve the cold resistance of the insect body, increase the survival rate of black soldier fly larvae, and increase the growth and development rate of black soldier fly larvae in cold environments; the study shows that the low-temperature acclimation method is feasible, can significantly improve the cold resistance of black soldier fly larvae, and directed acclimation from generation to generation can obtain its low-temperature and cold-resistant strain.

[0081] Continuous high-temperature acclimation will shorten the growth period of black soldier fly larvae, not only significantly increase the weight of black soldier fly larvae in a hot environment, greatly improve the heat resistance of the insect body, increase the survival rate of black soldier fly larvae, but also increase the weight growth rate of black soldier fly larvae in a hot environment; the high-temperature acclimation method is feasible, can significantly improve the heat resistance of black soldier fly larvae, and can be directed acclimated generation by generation, and the optimal high-temperature heat-resistant strain can be obtained in the fourth generation.

[0082] Even better, the domesticated black soldier fly larvae showed better feed handling ability than the control group after temperature fluctuations from high or low temperature back to normal temperature, while improving the larval survival rate and reproductive capacity.

[0083] Obviously, the specific implementation scheme described above is only a further detailed description of the purpose, technical scheme and beneficial effects of the present invention. It should be understood that the above is only a specific example of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for taming black soldier fly larvae to resist high / low temperatures, characterized in that: The following steps are involved: S1, using black soldier fly larvae raised at room temperature and developing healthily as domestication materials; S2, subjecting the larvae described in step S1 to extreme temperature acclimation treatment: raising them at a low temperature acclimation temperature of 12°C to 16°C for 30 days, or raising them at a high temperature acclimation temperature of 40°C for 14 days to 20 days; S3, directed domestication, taking the larvae that survived the treatment in step S2, screening them and raising them at room temperature until they become adults and lay eggs, and after the eggs are hatched, the first generation of seed worms are obtained, and the seed worms are repeatedly subjected to steps S1 and S2 for continuous domestication; The humidity during the feeding in step S2 is 70%-80%; the breeding density during the acclimation treatment is 0.51 / cm 3 , the feed density is 900~1000 / kg.

2. The method for acclimating black soldier fly larvae to high / low temperature resistance according to claim 1, characterized in that: The black soldier fly larvae in step S1 are larvae that are five days old after hatching from eggs.

3. The method for acclimating black soldier fly larvae to high / low temperature resistance according to claim 1, characterized in that: The specific method for obtaining the first generation of breeding worms in step S3 is as follows: the larvae that survive the treatment in step S2 are eliminated at a ratio of 50% by weight and then raised under room temperature until pupation, the feed and the pupae are sieved with a mesh screen, the pupae that cannot fall through the mesh screen with a mesh size of 6 or more are collected, the pupae are raised at room temperature until they emerge and reproduce and lay eggs, and the first generation of breeding worms are obtained after the eggs hatch.

4. The method for acclimating black soldier fly larvae to high / low temperature resistance according to claim 1, characterized in that: The continuous domestication in step S3 is domestication at 12°C to 16°C for n generations, where n≥10.

5. The method for acclimating black soldier fly larvae to high / low temperature resistance according to claim 1, characterized in that: The continuous domestication in step S3 is domestication at 40° C. for 4 generations.

6. Application of the method according to any one of claims 1 to 5 in improving the growth performance of black soldier fly larvae under extreme temperatures, characterized in that: The growth performance includes at least the following aspects: (1) body weight, (2) feed conversion rate, and (3) survival rate.

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