An indoor rearing of chilo uclealis leales diet and a rearing method of chilo uclealis leales

Abstract

The present application relates to the technical field of breeding, in particular to an indoor breeding of the formula feed of the chemi-smithia brycei and the breeding method of the chemi-smithia brycei, the formula feed is added with the compound essential oil of eugenol, citral and cinnamic acid (mass ratio 0.8:0.5:0.3), the formula feed is low in mouldy rate and zero in formaldehyde residue. The breeding method comprises the following steps: directly feeding the fermented feed to the newly hatched larvae (without the transition of rice stems), feeding the low-density 3rd instar larvae in different pipes (10 larvae per dish), and replacing the feed only once in the whole process. The application of the present application completely eliminates the reproductive toxicity of chemical preservatives and is suitable for large-scale year-round breeding of standard insect sources.

Description

An artificially formulated feed for indoor rearing of the rice stem borer and a method for rearing the rice stem borer. Technical Field

[0001] This invention relates to the field of aquaculture technology, and in particular to an artificially formulated feed for indoor rearing of rice stem borers and a method for raising rice stem borers. Background Technology

[0002] The rice stem borer (Chilo suppressalis), also known as the rice stem borer, is a formidable enemy of rice. The larvae bore into the stems, causing the heart to wither. The rice stem borer has a tendency to migrate between plants, meaning a single larva can damage multiple rice plants, resulting in withered leaf sheaths and dead hearts. Currently, this insect exhibits significant resistance to pesticides. Research on integrated pest management focuses primarily on the development of novel biological pesticides and transgenic insect-resistant rice. However, the determination of pesticide resistance, the screening and testing of biological pesticides, the investigation of resistance mechanisms, and the development of transgenic insect-resistant rice all require large-scale testing of uniformly developed rice stem borer larvae. Currently, the rice stem borer is mainly fed natural feed (rice seedlings, water chestnuts) or semi-artificial feed.

[0003] A search revealed several publicly available patent applications related to rice stem borer feed and aquaculture. For example, Chinese patent CN201110385929.7 describes a method for preparing artificial feed for rice stem borers, whose main components are: rice straw powder, sucrose, ascorbic acid, rice bran oil, yeast powder, casein, agar, methylparaben, and sorbic acid. Patent CN200910080336.2 describes an artificial feed for rice stem borers, mainly composed of: soybean flour, yeast powder, casein, sucrose, fresh water chestnuts (or fresh rice stalks), agar, ascorbic acid (Vc), cholesterol, choline chloride, chlorhexidine gluconate, B-complex vitamins, sorbic acid, methylparaben, and formaldehyde. All of the rice stem borer feeds disclosed in these patents include preservatives (sorbic acid, formaldehyde, etc.) in their raw materials. It is evident that adding preservatives to artificial feed for rice stem borers is a long-standing technical necessity in the industry. The fundamental reason lies in the combined effects of the rice stem borer's growth habits, feed composition characteristics, and microbial environment. However, the introduction of preservatives also brings significant harms, including affecting the growth and development of larvae and impacting the reliability of research data.

[0004] Based on this, this application proposes an artificial feed formula for indoor rearing of rice stem borers and a method for rearing rice stem borers. Summary of the Invention

[0005] In view of the above, it is necessary to provide an artificial feed formula for indoor rearing of the rice stem borer and a method for raising the rice stem borer. The rice stem borer feed formula 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] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing an artificial feed formula for rice stem borer, the method comprising the following steps:

[0008] (1) Mixing: Mix rice stem powder, water chestnut powder, soybean powder, sucrose and water in a mass ratio of 2-3:5:1-2:1:10-15 and stir until homogeneous to obtain a mixed slurry;

[0009] (2) Anti-corrosion treatment: Heat the mixed slurry obtained in step (1), then add compound essential oil to the mixed slurry, stir and mix well to obtain anti-corrosion feed;

[0010] (3) Fixed storage: Add agar water to the preservative feed, mix well, cool and cut into pieces to obtain the feed, which can be stored at low temperature for later use.

[0011] Furthermore, before mixing the rice stem powder in step (1), the rice stem powder is pretreated by adding 1% H2SO4 and then sterilized.

[0012] Furthermore, the compound 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 compound essential oil added is 2.6‰ of the mass of the mixture. Eugenol, citral, and cinnamic acid are purchased commercially.

[0013] Furthermore, in step (2), the mixture is first heated to 60°C and then the compound 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, and the amount of agar water added accounts for 3% of the mass of the preservative feed.

[0015] This application also provides an artificial feed formulation for rice stem borers prepared using the method described above.

[0016] This application also provides a method for feeding rice stem borers with artificial feed formulated using the method described above.

[0017] This application also provides a method for raising rice stem borers, the method comprising raising rice stem borers using the feed described above, specifically including the following steps:

[0018] (1) Rearing of newly hatched larvae: Place feed (5cm*2cm*0.5cm block feed) in a sterile culture dish, and inoculate 15 newly hatched larvae into each dish. Rear at 25℃ and 85% humidity; (no rice stem transition period required);

[0019] (2) Larval separation: 3rd instar larvae were separated into new culture dishes, with 10 larvae per dish;

[0020] (3) Pupation management: During the prepupal stage, the insects are moved into the emergence cages and rice seedlings are placed in the cages for the adults to lay eggs.

[0021] (4) Adult reproduction: Feed with 10% honey water and replace the rice seedlings that lay eggs daily.

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

[0023] During the research on rice pests, the applicant discovered that the larvae of the rice stem borer have unique growth habits, including slow feeding, which makes the feed easily exposed to a humid and hot environment, causing mold growth. In addition, the larvae like to burrow into the feed to feed, and the residue of saliva and excrement accelerates internal mold growth. Therefore, preservation of rice stem borer feed is a necessary measure. Conventional methods use preservatives (formaldehyde, parabens, sorbic acid, etc.), which not only affect the growth of larvae but also affect the reliability of research data.

[0024] Based on this, this application first pulverizes rice stems and then acid-treats them. This process can remove some lignin and break down the lignin barrier, increase the porosity of rice stem powder, and increase the content of soluble sugars. After larvae feed on the powder, it can promote the proliferation of beneficial bacteria in their intestines.

[0025] Next, the applicant mixed rice stem meal, water chestnut meal, soybean meal, and sucrose as the main feed ingredients. The fiber in rice stem meal and the protein in soybean meal formed an ideal carbon-nitrogen ratio to meet the nutritional needs of larvae. The palatability of water chestnut meal and the palatability of sucrose significantly improved feed utilization. While ensuring a high survival rate and development rate of larvae, it also had low cost and sustainability.

[0026] Furthermore, the mixed slurry is heated to 60°C before the addition of compound essential oils. This 60°C pretreatment of the mixed slurry is the golden point in the preservation process, as it maximizes the preservation of the essential oil's activity and inhibits the colonization of bacteria after sterilization. The added essential oil is prepared by mixing eugenol, citral, and cinnamic acid in a mass ratio of 0.8:0.5:0.3, completely replacing toxic preservatives such as formaldehyde and parabens, eliminating reproductive toxicity (such as ovarian atrophy and decreased egg production). Its components can be decomposed by intestinal enzymes in larvae without metabolic burden. This ratio (0.8:0.5:0.3) achieves maximum preservation efficacy through a three-level combined antibacterial mechanism of "membrane disruption (eugenol disrupts the integrity of microbial cell membranes) - energy inhibition (citral inhibits energy metabolism) - spore inactivation (cinnamic acid blocks fungal spore germination)," while also considering both improved palatability and zero toxicity, providing an irreplaceable preservation solution for the pollution-free breeding of rice stem borers.

[0027] Finally, this application uses agar aqueous solution to add to the feed and then set it at low temperature, eliminating the need for complex extrusion granulation equipment and reducing the content. In addition, the gel treatment solidifies to form a porous mesh structure, which perfectly simulates the internal channels of rice stems, inducing larval boring behavior and improving feeding efficiency. The gel network can also bind nutrients such as sugars and amino acids, slowing down the rate of nutrient loss and extending 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 mold growth.

[0028] In summary, the artificial feed of this invention uses plant-based compound feed to replace chemical preservatives, achieving irreversible technical advantages of "detoxification, efficiency enhancement, and cost reduction," providing the only industrially feasible path for standardized breeding of rice stem borers, and has outstanding substantive significance. Detailed Implementation Methods

[0029] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Example 1: Feed Preparation

[0031] This embodiment provides a method for preparing artificial feed for rice stem borers, including the following steps:

[0032] (1) Mixing: The rice stem powder is pretreated as follows: 1% H2SO4 is added to the rice stem powder for pretreatment, and then sterilized; then the pretreated rice stem powder, water chestnut 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 compound essential oil: Eugenol, citral and cinnamic acid purchased from the market were homogenized and mixed in a mass ratio of 0.8:0.5:0.3 to obtain compound essential oil for later use;

[0034] (3) Anti-corrosion treatment: Heat the mixed slurry obtained in step (1) to 60°C, then add compound essential oil to the mixed slurry and stir to mix evenly to obtain anti-corrosion feed; the amount of compound essential oil added is 2.6‰ of the mass of the mixed slurry;

[0035] (4) Fixed 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 accounts for 3% of the mass of the preservative feed. Then mix it well and pour it into a stainless steel tray (2cm thick). Cool and solidify at 4°C for 2 hours. Cut it into 5cm×2cm×0.5cm blocks, vacuum package them, and store them at 4°C.

[0036] Example 2: Rearing of Rice Stem Borers

[0037] This embodiment provides a method for raising rice stem borers, using the feed described in Example 1, and specifically includes the following steps:

[0038] (1) Rearing of newly hatched larvae: Place feed (5cm*2cm*0.5cm block feed) in a sterile culture dish, and inoculate 15 newly hatched larvae into each dish. Rear at 25℃ and 85% humidity; (no rice stem transition period required);

[0039] (2) Larval separation: 3rd instar larvae were separated into new culture dishes, with 10 larvae per dish;

[0040] (3) Pupation management: During the prepupal stage, the insects are moved into the emergence cages and rice seedlings are placed in the cages for the adults to lay eggs.

[0041] (4) Adult reproduction: Feed with 10% honey water and replace the rice seedlings that lay eggs daily.

[0042] The above-mentioned breeding method only requires changing the feed once throughout the entire process and involves no contact with chemical preservatives.

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

[0044] This embodiment verifies the necessity of treating rice stem meal with dilute acid, and compares the larval weight gain and feed conversion ratio with dilute acid and other treatment methods, grouped as follows:

[0045] Group A: No rice stem powder pretreatment was performed;

[0046] Group B: Fermented feed pretreated with 1% H2SO4;

[0047] Group C: Fermented feed after 2% NaOH pretreatment.

[0048] The results are shown in Table 1:

[0049] Table 1 Comparison of larval weight gain and feed conversion ratio among groups

[0050]

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

[0052] As shown in Table 1, dilute acid pretreatment completely breaks down the lignin-cellulose complex structure by targeting and hydrolyzing hemicellulose. Through selective degradation of hemicellulose, the utilization rate of cellulose by larvae is effectively improved, and the cost is 40% lower than that of alkali treatment.

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

[0054] This embodiment demonstrates the necessity of heating the mixed slurry to 60°C before adding the compound essential oil. The applicant discovered through experiments that 60°C is a key process point for balancing component stability and dissolution efficiency. The design group verification is as follows:

[0055] Control group: Essential oils were added at room temperature (25℃);

[0056] Experimental group 1: Added at 60℃;

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

[0058] The essential oil residue rate, feed antibacterial 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 maximizes the preservation of essential oil activity (loss rate <6%) and achieves the best antibacterial effect (antibacterial zone 22.3mm), which is significantly better than other temperature schemes.

[0063] Example 5: Experiment to Verify the Effectiveness of Essential Oils

[0064] This embodiment demonstrates the irreplaceable nature of the compound essential oils in this application:

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

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

[0067] Group Eugenol: Citral: Cinnamic Acid Mold Deterioration Rate (7 days) Inhibition Zone Diameter (mm) 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 surface

[0068] Based on Table 3, the following conclusions can be drawn: when the ratio deviation is ±0.1, the mold rate is >8%, and the antibacterial effect is significantly reduced (p<0.01). This demonstrates the irreplaceable nature of the compound ratio of 0.8:0.5:0.3.

[0069] In addition, the applicant compared the preservation effects and feeding effects under different preservation systems, grouped as follows:

[0070] Group 1: Traditional preservative group, using formaldehyde and methylparaben as substitutes for essential oils; see Example 1 for feed preparation method.

[0071] Group 2: Single-component preservative, using only eugenol; feed preparation method is described in Example 1.

[0072] Group 3: Feed was prepared using the method described in Example 1;

[0073] Group 4: Control group, preservative-free (Example 1 feed with compound essential oil removed).

[0074] The above-mentioned feed was used to rear the rice stem borer, and the antiseptic efficacy and rearing effect of each group were tested. Rearing conditions: Insect source: newly hatched larvae of the rice stem borer (F1-F3 generations); Environment: 25℃, RH 85%, darkness; Testing period: 7 days (mold rate), larval to adult stage (biological indicators). The results are shown in Tables 4-5.

[0075] Table 4 Comparison of anti-corrosion efficacy among groups

[0076]

[0077] Table 5 Comparison of feeding effects (F3 generation mean)

[0078] Indicators 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 Number of eggs laid per female (eggs) 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 surface

[0079] Note: Different letters indicate significant differences (p<0.05); the number of eggs laid is the statistical value 5 days after emergence.

[0080] According to the results in Table 4-5, the mold rate of the compound essential oil was 2.8% (18.2% in the traditional group), and the inhibition zone was 22.3 mm (≤16.5 mm in 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, protect the health of the population, and improve the reliability of scientific research data, avoiding formaldehyde interference with the binding of Bt toxin to midgut receptors, etc.

[0081] The various embodiments of this invention are described in detail, but they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this invention, and these all fall within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A method for preparing an artificial feed formula for rice stem borer, characterized in that, The method includes the following steps: (1) Mixing: Mix rice stem powder, water chestnut powder, soybean powder, sucrose and water in a mass ratio of 2-3:5:1-2:1:10-15 and stir to homogenize to obtain a mixed slurry; (2) Preservative treatment: Heat the mixed slurry obtained in step (1), then add compound essential oil to the mixed slurry and stir to mix evenly to obtain preservative feed; (3) Shaping and storage: Add agar water to the preservative feed, mix evenly and then cool and cut into pieces to obtain the feed, which is then refrigerated at low temperature for later use; Before mixing in step (1), the rice stem powder is first treated as follows: 1% H2SO4 is added to the rice stem powder for pretreatment and then sterilized; The mixed slurry in step (2) is first heated to 60°C and then compound essential oil is added; The compound 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.

2. The method according to claim 1, characterized in that, In step (2), the amount of compound essential oil added is 2.6‰ of the mass of the mixed paste.

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

4. An artificial feed formulation for rice stem borer prepared using the method described in any one of claims 1-3.

5. A method for feeding rice stem borers with artificial feed formulated according to any one of claims 1-3.

6. A method for raising rice stem borers, characterized in that, The method includes raising rice stem borers using the feed described in claim 4.

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