Artificial formula feed for indoor breeding of chilo suppressalis and breeding method of chilo suppressalis

Abstract

The invention relates to the technical field of breeding, in particular to an artificial formula feed for indoor breeding of chilo suppressalis and a breeding method of the chilo suppressalis, eugenol, citral and cinnamic acid compound essential oil (the mass ratio is 0.8: 0.5: 0.3) are added, and low feed mildew rate and zero formaldehyde residue are achieved. The breeding method comprises the steps that newly hatched larvae are directly fed with fermented feed (rice stem transition is not needed), 3-year-old larvae are divided into tubes with low density (10 larvae / dish), and the feed is only replaced once in the whole process. By applying the technology, the reproductive toxicity of chemical preservatives is thoroughly relieved, and the method is suitable for large-scale annual feeding of standardized insect sources.

Description

Technical field

[0001] The invention relates to the technical field of breeding, and in particular to an artificial formula feed for indoor breeding of striped stem borers and a breeding method for the striped stem borers. [Background Technology]

[0002] The rice stem borer (Chilo suppressalis), commonly known as the heart borer, heart borer, or stalk borer, is a formidable enemy of rice. Its larvae bore into the stems, causing heart decay. The stem borer also has a habit of rotating from one plant to another, with a single larva capable of infesting multiple rice plants, causing leaf sheath and heart decay. Currently, the insect is highly resistant to pesticides, and research on integrated control measures is primarily focused on the development of new biopesticides and transgenic insect-resistant rice. The determination of pesticide resistance, the screening and determination of biopesticides, the mechanisms of resistance, and the development of transgenic insect-resistant rice all require large, uniformly developed populations of stem borer larvae. Currently, stem borers are primarily reared on natural feeds (rice seedlings and wild rice) or semi-artificial feeds.

[0003] A search revealed several patent applications related to Chilo suppressalis feed and farming. For example, Chinese patent CN201110385929.7 describes a method for preparing an artificial feed for Chilo suppressalis, the main ingredients of which are rice straw powder, sucrose, ascorbic acid, rice oil, yeast powder, casein, agar, methyl parahydroxybenzoate, and sorbic acid. Patent CN200910080336.2 describes an artificial feed for Chilo suppressalis, which is primarily formulated with the following ingredients: soybean powder, yeast powder, casein, sucrose, fresh wild rice stem (which can be substituted with fresh water chestnuts or fresh rice stems), agar, ascorbic acid (Vc), cholesterol, choline chloride, Wilbur's salt, vitamin B complex, sorbic acid, methyl parahydroxybenzoate, and formaldehyde. The Chilo suppressalis feeds disclosed in these patents all contain preservatives (sorbic acid, formaldehyde, etc.). It can be seen that adding preservatives to the artificial feed of the Chilo suppressalis is a long-standing technical need in the industry. The fundamental reason is that it is the result of the combined effects of the growth habits of the Chilo suppressalis, the characteristics of the feed ingredients and the microbial environment. However, the introduction of preservatives also brings significant hazards, including affecting the growth and development of the larvae and affecting the reliability of research data.

[0004] Based on this, the present application proposes an artificial formula feed for indoor rearing of Chilo suppressalis and a method for rearing Chilo suppressalis. [Summary of the invention]

[0005] In view of the above, it is necessary to provide an artificial formula feed for indoor rearing of striped stem borers and a method for rearing striped stem borers. The formula feed for striped stem borers has low cost, simple preparation process, completely eliminates the reproductive toxicity of chemical preservatives, and is suitable for large-scale year-round production of standardized insect sources.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing an artificial feed for Chilo suppressalis, comprising the following steps:

[0008] (1) Mixing: Rice stem powder, wild rice stem powder, soybean powder, sucrose and water are mixed in a mass ratio of 2-3:5:1-2:1:10-15, and stirred to obtain a mixed slurry;

[0009] (2) Antiseptic treatment: heating the mixed pulp obtained in step (1), then adding the composite essential oil to the mixed pulp, stirring and mixing, and obtaining an antiseptic feed;

[0010] (3) Storage by shaping: Add agar water to the antiseptic feed, mix well, cool and cut into pieces, and then obtain the feed, refrigerate at low temperature and set aside.

[0011] Furthermore, the rice stem powder is treated as follows before mixing in step (1): 1% H2SO4 is added to the rice stem powder for pretreatment, and then sterilized.

[0012] Furthermore, the composite essential oil in step (2) is prepared by mixing eugenol, citral and cinnamic acid in a mass ratio of 0.8:0.5:0.3, and the amount of the composite essential oil added is 2.6‰ of the mass of the mixed slurry. Eugenol, citral and cinnamic acid are purchased from the market.

[0013] Furthermore, in step (2), the mixed slurry is first heated to 60° C. and then the composite essential oil is added.

[0014] Furthermore, the agar water in step (3) is obtained by pre-dissolving agar in water and boiling it to dissolve it. The amount of the agar water added is 3% of the mass of the preservative feed.

[0015] The present application also provides an artificial formula feed for Chilo suppressalis prepared by the above method.

[0016] The present application also provides a method for raising Chilo suppressalis using the artificial Chilo suppressalis formula feed prepared by the above method.

[0017] The present application also provides a method for raising the Chilo suppressalis, which comprises raising the Chilo suppressalis using the feed described above, and specifically comprises the following steps:

[0018] (1) Rearing newly hatched larvae: Place feed (5 cm*2 cm*0.5 cm block feed) in sterile culture dishes, seed each dish with 15 newly hatched larvae, and rear them at 25°C and 85% humidity (no rice stalk transition period is required);

[0019] (2) Larvae distribution: 3rd instar larvae are divided into new culture dishes, with 10 larvae per dish;

[0020] (3) Pupation management: During the pre-pupal stage, the insects are collectively moved into the emergence cage, and rice seedlings are placed in the cage for the adults to lay eggs;

[0021] (4) Adult reproduction: Feed the insects with 10% honey water and replace the rice seedlings for egg laying every day.

[0022] The present invention has at least the following beneficial effects:

[0023] During their research on rice pests, the applicant discovered that the larvae of the Chilo suppressalis (Striped Rice Borer) have unique growth habits. These include slow feeding, which makes the feed susceptible to exposure to hot and humid environments, causing it to mold. Furthermore, the larvae prefer to burrow into the feed to feed, leaving saliva and feces that accelerate internal mold. Therefore, preserving the feed for Chilo suppressalis is essential. Conventional methods use preservatives (such as formaldehyde, parabens, and sorbic acid), which not only affect the growth of the larvae but also undermine the reliability of the research data.

[0024] Based on this, the present application firstly crushes the rice stems and then treats them with acid. Firstly, this can remove some lignin and remove the lignin barrier. Secondly, it can increase the porosity of the rice stem powder. Thirdly, it can increase the content of soluble sugars. After the larvae eat it, it can promote the proliferation of probiotics in their intestines.

[0025] Next, the applicant mixed rice stem powder, wild rice stem powder, soybean meal, and sucrose as the main ingredients of the feed. The fiber of the rice stem powder and the protein of the soybean meal formed an ideal carbon-nitrogen ratio to meet the nutritional needs of the larvae. The food appeal of the wild rice stem powder and the palatability of the sucrose significantly improved the feed utilization rate, while ensuring a high survival rate and development rate of the larvae, while also being low-cost and sustainable.

[0026] In addition, the mixed pulp is heated to 60°C before adding the compound essential oil. The 60°C mixed pulp pretreatment is the golden node of the antiseptic process. Firstly, it can maximize the retention of the activity of the essential oil and inhibit the colonization of miscellaneous bacteria after sterilization. The added essential oil is made by mixing eugenol, citral and cinnamic acid in a mass ratio of 0.8:0.5:0.3, which completely replaces toxic preservatives such as formaldehyde and parabens, eliminates reproductive toxicity (such as ovarian atrophy and decreased egg production), and its components can be decomposed by larval intestinal enzymes without metabolic burden. This ratio (0.8:0.5:0.3) maximizes the antiseptic effect through the three-level combined antibacterial mechanism of "membrane destruction (eugenol destroys the integrity of microbial cell membranes) - energy inhibition (citral inhibits energy metabolism) - spore inactivation (cinnamic acid blocks fungal spore germination)", while taking into account the promotion of feeding attraction and safety and zero toxicity, providing an irreplaceable antiseptic solution for pollution-free breeding of Chilo suppressalis.

[0027] Finally, this application uses an agar aqueous solution to add to the feed and then set it at low temperature, which does not require complex extrusion and granulation equipment and reduces the ingredients. In addition, the gel treatment forms a porous grid structure after solidification, which perfectly simulates the internal channels of rice stems, induces larval boring behavior, and improves feeding efficiency. The gel network can also bind nutrients such as sugars and amino acids, slow down the dissolution rate of nutrients, and extend the effective period of a single feeding. At the same time, the dense gel structure can block the migration path of microorganisms and further inhibit deep mildew.

[0028] In summary, the artificial feed of the present invention replaces chemical preservatives with plant compounds, achieving the irreversible technical advantages of "detoxification, efficiency improvement and cost reduction", providing the only industrially feasible path for standardized breeding of Chilo suppressalis, and has outstanding substantive significance. [Specific implementation method]

[0029] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Example 1: Preparation of feed

[0031] This embodiment provides a method for preparing an artificial feed for Chilo suppressalis, comprising the following steps:

[0032] (1) Mixing: The rice stem powder is pre-treated as follows: 1% H2SO4 is added to the rice stem powder for pretreatment, and then sterilized; then the pre-treated rice stem powder, wild rice root powder, soybean powder, sucrose and water are mixed in a mass ratio of 2-3:5:1-2:1:10-15, and stirred to obtain a mixed slurry;

[0033] (2) Preparation of composite essential oil: Eugenol, citral and cinnamic acid purchased from the market were homogeneously mixed in a mass ratio of 0.8:0.5:0.3 to obtain composite essential oil for later use;

[0034] (3) Antiseptic treatment: heating the mixed pulp obtained in step (1) to 60° C., then adding the composite essential oil to the mixed pulp, stirring and mixing, to obtain an antiseptic feed; the amount of the composite essential oil added is 2.6‰ of the mass of the mixed pulp;

[0035] (4) Storage: Add agar water to the preservative feed. The agar water is obtained by pre-dissolving agar in water and boiling it. The amount of agar water added is 3% of the mass of the preservative feed. Then, mix well and pour it into a stainless steel tray (thickness 2 cm). Cool and solidify at 4°C for 2 hours, cut into 5 cm × 2 cm × 0.5 cm blocks, vacuum pack, and store at 4°C.

[0036] Example 2: Rearing of Chilo suppressalis

[0037] This embodiment provides a method for raising Chilo suppressalis, which uses the feed described in Example 1 for breeding, and specifically includes the following steps:

[0038] (1) Rearing newly hatched larvae: Place feed (5 cm*2 cm*0.5 cm block feed) in sterile culture dishes, seed each dish with 15 newly hatched larvae, and rear them at 25°C and 85% humidity (no rice stalk transition period is required);

[0039] (2) Larvae distribution: 3rd instar larvae are divided into new culture dishes, with 10 larvae per dish;

[0040] (3) Pupation management: During the pre-pupal stage, the insects are collectively moved into the emergence cage, and rice seedlings are placed in the cage for the adults to lay eggs;

[0041] (4) Adult reproduction: Feed the insects with 10% honey water and replace the rice seedlings for egg laying every day.

[0042] In the above breeding method, the feed is only changed once during the whole process and there is no contact with chemical preservatives.

[0043] Example 3: Verification of the significance of rice stem powder pretreatment

[0044] This example verifies the necessity of dilute acid treatment of rice stem powder. The weight gain and feed conversion rate of larvae treated with dilute acid and other treatments are compared, and the groups are as follows:

[0045] Group A: no rice stem powder pretreatment;

[0046] Group B: fermented feed after 1% H2SO4 pretreatment;

[0047] Group C: feed was fermented after pretreatment with 2% NaOH.

[0048] The results are shown in Table 1:

[0049] Table 1 Comparison of weight gain and feed conversion rate of larvae in each group

[0050]

[0051] Note: Different letters indicate significant differences (p<0.05).

[0052] According to the results in Table 1, the dilute acid pretreatment can effectively improve the utilization of cellulose by larvae by targeting the hydrolysis of hemicellulose and completely breaking the lignin-cellulose composite structure. The selective degradation of hemicellulose can also effectively improve the utilization of cellulose by larvae, and the cost is 40% lower than that of the alkaline treatment method.

[0053] Example 4: Verifying the significance of mixed slurry heating temperature

[0054] This example demonstrates the necessity of adding the composite essential oil after the mixed slurry temperature is heated to 60°C. The applicant has found through experiments that 60°C is a key process node for balancing component stability and dissolution efficiency. The design group verification is as follows:

[0055] Control group: essential oil was added at room temperature (25°C);

[0056] Experimental group 1: added at 60°C;

[0057] Experimental group 2: added at 70℃.

[0058] The essential oil residue rate, feed inhibition zone diameter and larval survival rate of the above groups were tested, as shown in Table 2:

[0059] Table 2 Comparison of the effects of different essential oil addition temperatures

[0060]

[0061]

[0062] According to the data in Table 2, adding essential oils when the mixture is heated to 60°C can maximize the retention of essential oil activity (loss rate <6%) and achieve the best antibacterial effect (inhibition zone 22.3 mm), which is significantly better than other temperature schemes.

[0063] Example 5: Essential oil effectiveness verification experiment

[0064] This example demonstrates the irreplaceability of the composite essential oil of this application:

[0065] First, the mold rate (7 days) and inhibition zone diameter of the feed were tested after adding essential oils to the feed at different proportions. The results are shown in Table 3:

[0066] Table 3 Antiseptic efficacy of essential oils in different proportions

[0067] Group Eugenol:Citral:Cinnamic acid Mildew rate (7 days) Diameter of inhibition zone (mm) The present invention group 0.8:0.5:0.3 2.8％ 22.3 Deviation Group 1 0.7:0.5:0.3 8.5％ 18.1 Deviation Group 2 0.8:0.4:0.3 11.2％ 16.7 Deviation Group 3 0.8:0.5:0.2 9.7％ 17.9

[0068] According to Table 3, the following conclusions can be drawn: when the ratio deviation is ±0.1, the mildew rate is greater than 8%, and the antibacterial effect is significantly reduced (p<0.01), which proves the irreplaceable nature of the compound ratio of 0.8:0.5:0.3.

[0069] In addition, the applicant also compared the antiseptic effect and feeding effect under different antiseptic systems, and grouped them as follows:

[0070] Group 1: Traditional preservation group, formaldehyde + methylparaben replaced essential oil, feed preparation method see Example 1;

[0071] Group 2: Single-ingredient preservation, using only eugenol, and the feed preparation method is as shown in Example 1;

[0072] Group 3: feed was prepared in the manner of Example 1;

[0073] Group 4: control group, without preservatives (feed of Example 1 without the compound essential oil).

[0074] The above-mentioned feed was used to feed Chilo suppressalis, and the antiseptic efficacy and feeding effect of each group were tested. The feeding conditions were as follows: the test insect source: newly hatched Chilo suppressalis larvae (F1-F3 generations); the environment was 25°C, 85% RH, and dark; the testing period was 7 days (mildew rate) and the entire process from larvae to adults (biological indicators). The results are shown in Tables 4-5:

[0075] Table 4 Comparison of anticorrosion efficacy of each group

[0076]

[0077] Table 5 Feeding effect comparison (F3 generation average)

[0078] index Group 1 Group 2 Group 3 Larval duration (days) 32.8±1.5a 30.1±1.4b 28.5±1.3c Pupation rate (%) 82.0±2.3b 85.3±1.8b 96.2±1.2a Egg production per female (grains) 80.7±9.1c 132±11b 189±15a Egg hatching rate (%) 91.5±1.4b 93.2±1.6b 96.8±0.9a Formaldehyde residue (ppm) 23.6 Not detected Not detected

[0079] Note: Different letters indicate significant differences (p<0.05); the egg production is the statistical value 5 days after hatching.

[0080] According to the results in Table 4-5, the mildew rate of the compound essential oil is 2.8% (18.2% for the traditional group), and the inhibition zone is 22.3 mm (≤16.5 mm for the single essential oil group); the compound essential oil of this application has high preservative efficacy. In addition, the compound essential oil group can achieve zero formaldehyde residue, eliminate reproductive toxicity, ensure population health, and improve the reliability of scientific research data, avoiding formaldehyde interference with the binding of Bt toxin to midgut receptors, etc.

[0081] While the descriptions of several embodiments of the present invention are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, and such modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing an artificial feed for Chilo suppressalis, characterized in that: The method comprises the following steps: (1) Mixing: Rice stem powder, wild rice stem powder, soybean powder, sucrose and water are mixed in a mass ratio of 2-3:5:1-2:1:10-15, and stirred to obtain a mixed slurry; (2) Antiseptic treatment: heating the mixed pulp obtained in step (1), then adding the composite essential oil to the mixed pulp, stirring and mixing, and obtaining an antiseptic feed; (3) Storage by shaping: Add agar water to the antiseptic feed, mix well, cool and cut into pieces, and then obtain the feed, refrigerate at low temperature and set aside.

2. The method according to claim 1, characterized in that In the step (1), the rice stem powder is first treated as follows before mixing: 1% H2SO4 is added to the rice stem powder for pretreatment, and then sterilized.

3. The method according to claim 1, characterized in that In the step (2), the mixed slurry is first heated to 60° C. and then the composite essential oil is added.

4. The method according to claim 1, wherein The composite essential oil in step (2) is prepared by mixing eugenol, citral and cinnamic acid in a mass ratio of 0.8:0.5:0.3, and the added amount of the composite essential oil is 2.6‰ of the mass of the mixed slurry.

5. The method according to claim 1, wherein The agar water in step (3) is obtained by pre-dissolving agar in water and boiling it to dissolve it. The amount of the agar water added accounts for 3% of the mass of the preservative feed.

6. An artificial formula feed for Chilo suppressalis prepared by the method according to any one of claims 1 to 5.

7. A method for raising Chilo suppressalis using the artificial Chilo suppressalis formula feed prepared by the method according to any one of claims 1 to 5.

8. A method for raising Chilo suppressalis, characterized in that: The method comprises cultivating the Chilo suppressalis using the feed according to claim 6.

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