Artificial feed for larvae of spodoptera frugiperda as well as preparation method and application of artificial feed

Abstract

The invention relates to the technical field of feed, in particular to artificial feed for spodoptera frugiperda larvae as well as a preparation method and application of the artificial feed. The feed is prepared from the following raw materials in dosage: 110 to 130 grams of soybean meal, 110 to 130 grams of wheat bran powder, 40 to 55 grams of high-sugar-resistant yeast, 15 to 35 grams of casein, 20 to 30 grams of agar, 1 to 4 grams of potassium sorbate, 1 to 4 grams of methylparaben, 500 to 700 microliters of wheat germ oil, 0.1 to 0.4 gram of ferric citrate pentahydrate, 0.1 to 0.4 gram of microcrystalline cellulose, 5 to 15 grams of ascorbic acid, 0.8 to 3 grams of compound vitamin, 1 to 3 milliliters of formaldehyde, 2 to 5 milliliters of acetic acid and 1200 to 1400 milliliters of sterile purified water. The dosages of the raw materials are kept in the proportion, and the total amount of the feed can be increased or decreased according to the same proportion. The feed has the advantages of stable feeding quality, high application value and the like.

Description

Technical Field

[0001] This invention relates to the field of feed technology, and in particular to an artificial feed for fall armyworm larvae, its preparation method, and its application. Background Technology

[0002] The fall armyworm (Spodoptera furgiperda), belonging to the family Noctuidae in the order Lepidoptera, is listed by the Food and Agriculture Organization of the United Nations (FAO) as a major migratory pest requiring global early warning. It feeds on plants such as corn, cotton, sorghum, and rice, and its host population includes as many as 353 species from 76 families, causing severe crop yield reductions, especially on corn, where it can reduce yields by an average of 20-40%, with severely infested orchards experiencing yield reductions of over 70%, resulting in direct economic losses. Native to tropical and subtropical regions of the Americas, the fall armyworm's wide host range, high reproductive capacity, long migration distances, and difficulty in control have led to its rapid inclusion in the list of key pests and diseases for control since its first discovery in Yunnan Province, my country, in January 2019. In 2020, it was listed at the top of the "List of Class A Crop Pests and Diseases," and since January 2023, it has been included in the list of key managed invasive alien species. Furthermore, it continues to be a key pest and disease target in the 2021-2025 Technical Program for the Prevention and Control of Major Crop Pests and Diseases.

[0003] In recent years, with the continuous expansion of the suitable habitat of the fall armyworm in my country and the rapid development of pesticide resistance in the field, the damage caused by the fall armyworm has continued to intensify, posing a serious threat to agricultural production. To effectively control this major pest, in-depth scientific research is needed on its physiological ecology, toxicological mechanisms, and control technologies. All of this research relies on a stable, uniform, and large-scale supply of experimental insect sources under laboratory conditions. Currently, the main method for indoor breeding of the fall armyworm relies on live feeding using its natural host plants (such as corn seedlings). However, this traditional plant-based breeding model has many limitations in practical application. First, it requires a large amount of artificial climate chamber space and resources for plant cultivation, resulting in a long cycle, high costs, and a difficult-to-maintain stable and continuous insect source supply due to the influence of plant growth conditions. Second, the breeding process requires frequent replacement of fresh plants to meet the larval feeding needs, making operation and management cumbersome and consuming a lot of manpower and resources. Furthermore, this pest has the habit of burrowing into the soil to pupate during the prepupal stage. In potted breeding systems, the collection of pupae is extremely difficult, not only inefficient but also prone to causing mechanical damage to the insects. Furthermore, the nutritional composition of plant-based feeds naturally fluctuates, leading to uneven development of larvae and directly affecting the reliability and reproducibility of experimental data. Additionally, fall armyworm larvae exhibit significant self-mutilation when density is too high or feed is insufficient, further limiting the realization of high-density, large-scale rearing under traditional plant-based feeding methods.

[0004] Therefore, there is an urgent need to provide an artificial feed that is low in cost, easy to operate, nutritionally stable, and can meet the needs of large-scale rearing of fall armyworm larvae. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an artificial feed for fall armyworm larvae, its preparation method, and its application, in order to solve the problem of high difficulty in large-scale breeding of fall armyworm larvae in the prior art.

[0006] To achieve the above and other related objectives, the present invention is obtained through the following technical solution.

[0007] The first aspect of this invention is to provide an artificial feed for fall armyworm larvae, the feed comprising the following ingredients in the following amounts: 110-130g soybean flour, 110-130g wheat bran flour, 40-55g high-sugar-tolerant yeast, 15-35g casein, 20-30g agar, 1-4g potassium sorbate, 1-4g methylparaben, 500-700μL wheat germ oil, 0.1-0.4g ferric citrate pentahydrate, 0.1-0.4g microcrystalline cellulose, 5-15g ascorbic acid, 0.8-3g compound vitamins, 1-3mL formaldehyde, 2-5mL acetic acid, and 1200-1400mL sterile purified water; the amounts of each ingredient are maintained in the above proportions, and the total amount of the feed can be increased or decreased proportionally according to the above proportions.

[0008] A second aspect of this invention is to provide a method for preparing artificial feed for fall armyworm larvae, the method comprising the following steps:

[0009] (1) Mix soybean flour, wheat bran flour, high sugar tolerant yeast and casein evenly to obtain a blend;

[0010] (2) Preheat 1 / 3 to 1 / 2 of the sterile purified water, pour it into the blend obtained in step (1) before boiling, and heat until bubbling to obtain mixture one;

[0011] (3) Mix ferric citrate pentahydrate, microcrystalline cellulose, ascorbic acid, and complex vitamins evenly to obtain mixture two;

[0012] (4) Preheat potassium sorbate, methylparaben, and the remaining sterile purified water, then add agar and heat to boiling to obtain mixture three;

[0013] (5) Mix the mixture one obtained in step (2) and the mixture three obtained in step (4), cool to a temperature of <60°C, then add wheat germ oil and the mixture two obtained in step (3), mix evenly to obtain mixture four;

[0014] (6) Add formaldehyde and acetic acid to the mixture obtained in step (5), mix evenly, let stand to form, and obtain artificial feed for fall armyworm larvae.

[0015] A third aspect of the present invention is to provide the use of the artificial feed for fall armyworm larvae as described above in the preparation of products for feeding fall armyworm larvae.

[0016] The fourth aspect of this invention is to provide a method for raising fall armyworm larvae, using artificial feed for fall armyworm larvae as described above.

[0017] As described above, the artificial feed for fall armyworm larvae, its preparation method, and its application, according to the present invention, have the following beneficial effects:

[0018] 1) The artificial feed for fall armyworm larvae of this invention can realize continuous multi-generation indoor cultivation, which solves the problems of high breeding and feeding costs, inconvenient collection of insects, and cumbersome breeding process. It overcomes the disadvantages of using corn and other plants to feed fall armyworm, which requires frequent plant replacement, is cumbersome, and occupies a lot of space.

[0019] 2) All the raw materials used in the feed formulation of this invention are commercially available, and the product quality is controllable and the composition and texture are uniform. The added ingredients, such as compound vitamins and wheat germ oil, not only reduce the risk of contamination of artificial feed, but also further improve the water retention and nutritional requirements of the feed, solving the problems of traditional artificial feed being easy to dry and spoil.

[0020] 3) The artificial feed prepared by this invention does not require frequent plant replacement when raising fall armyworm larvae, further reducing the use of labor. Its preparation process is simple and the quality of the prepared feed is stable, which is conducive to the establishment of indoor strains of fall armyworm. The raised larvae are suitable for research experiments in different directions such as physiology, biochemistry, genetics, and toxicology. Attached Figure Description

[0021] Figure 1 The diagram shows the effect of artificial feed and corn leaf feeding on the weight of 6th instar fall armyworm larvae in Embodiment 1 of the present invention.

[0022] Figure 2 The diagram shown is a schematic diagram of the artificial feed prepared according to Example 1 of the present invention. Detailed Implementation

[0023] To make the inventive objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. Those skilled in the art can easily understand other advantages and effects of this invention from the content disclosed in this specification.

[0024] Unless otherwise defined, 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. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] When using “including,” “having,” and “contains” as described herein, the intention is to cover non-exclusive inclusion, unless an explicit qualifying term such as “only,” “consisting of,” etc., is used, in which case another component may be added.

[0026] In this invention, the terms "preferredly," "more preferably," "better," and "even better" refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of the invention. That is, in this invention, "preferredly," "more preferably," "better," and "even better" are merely descriptions of more effective implementations or examples, but do not constitute a limitation on the scope of protection of the invention.

[0027] In this invention, terms such as "further," "even more," and "particularly" are used for descriptive purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0028] In this invention, "at least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two layers, three layers, etc., unless otherwise explicitly specified. In the description of this invention, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0029] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0030] Unless otherwise specified, all steps of this invention may be performed sequentially or randomly. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0031] Unless otherwise stated, a singular term may include a plural term and should not be understood as having a quantity of one.

[0032] In this invention, "above" or "below" both include the number itself. For example, "below 1" includes 1.

[0033] In this invention, room temperature refers to 15~30℃, including but not limited to 18~26℃.

[0034] In the experimental observations and data recordings of this invention, the determination and treatment of each developmental stage of the fall armyworm followed the following standards and methods:

[0035] The identification of larvae at each instar and prepupae is mainly based on the comprehensive changes in their body length, body surface pattern characteristics, and head morphology. In the rearing system and data records of this invention, the term "larval stage" encompasses the entire stage from the initial hatching of the first instar larva to the end of the prepupae stage, specifically including larvae at each instar from 1st to 6th instar and the subsequent prepupae stage. The prepupae stage is a transitional phase in the transformation of larvae into pupae; its appearance still retains the basic larval form and has not yet undergone the comprehensive morphological transformation characteristic of the pupal stage.

[0036] Specifically, the term "pupal stage" refers to the period from the completion of pupation and the possession of a complete pupal shell to the emergence of the adult insect, excluding the preceding prepupal stage.

[0037] Regarding weighing measurements, the insects are not weighed during the prepupal stage. The main reason is that the insects in the prepupal stage are extremely fragile; any movement or touch can easily disrupt their normal metamorphosis process, leading to a significantly increased pupation failure rate. Furthermore, during this stage, the insects prepare for pupation, and their body length and weight undergo a physiological shortening and decrease. Weight data from this period cannot represent the nutrient accumulation level during the feeding and growth stages. Therefore, data collection for growth indicators such as weight is completed during the active feeding larval instars and the stable pupal stage.

[0038] This invention, through its unique formula and physical morphology design, significantly reduces the self-mutilation rate of larvae in group rearing while ensuring normal development, and improves the quality of late-stage larvae and pupae, thus overcoming the core obstacle to the large-scale laboratory rearing of this pest.

[0039] The first aspect of this invention is to provide an artificial feed for fall armyworm larvae, the feed comprising the following ingredients in the following amounts: 110-130g soybean flour, 110-130g wheat bran flour, 40-55g high-sugar-tolerant yeast, 15-35g casein, 20-30g agar, 1-4g potassium sorbate, 1-4g methylparaben, 500-700μL wheat germ oil, 0.1-0.4g ferric citrate pentahydrate, 0.1-0.4g microcrystalline cellulose, 5-15g ascorbic acid, 0.8-3g compound vitamins, 1-3mL formaldehyde, 2-5mL acetic acid, and 1200-1400mL sterile purified water; the amounts of each ingredient are maintained in the above proportions, and the total amount of the feed can be increased or decreased proportionally according to the above proportions.

[0040] The combined effects of the ingredients in the artificial feed formulation of this invention, wherein:

[0041] 1) Soybean meal: One of the main ingredients in artificial feed for lepidopteran larvae. It is rich in proteins such as soybean protein and abundant unsaturated fatty acids, which can improve lipid metabolism and promote the absorption of fat-soluble vitamins.

[0042] 2) Wheat bran powder: It has the characteristics of wheat bran dietary fiber polyphenol complex, and is rich in wheat bran protein, wheat bran phenolic substances and phytic acid. While providing nutrition, it can improve intestinal metabolism, participate in regulating immunity, and enhance the absorption of various nutrients by insects.

[0043] 3) High sugar tolerant yeast: Compared with ordinary yeast, high sugar tolerant yeast can better maintain its vitality in a high osmotic pressure environment. At the same time, yeast contains rich B vitamins, minerals, β-glucan and mannan oligosaccharides, and its addition is beneficial to activate the insect immune system and improve feed utilization efficiency.

[0044] 4) Casein: It is mainly derived from purified protein in milk. It is rich in essential amino acids and phosphorus. It is digested slowly and can provide a continuous and stable supply of amino acids. At the same time, casein has good emulsifying properties, which can help feed bind water better and stabilize its structure, preventing separation or excessive softening.

[0045] 5) Agar: Agar powder dissolves in boiling water and forms a solid gel after cooling. It remains stable at room temperature after formation and will not collapse or liquefy due to insect feeding or damage. Therefore, it ensures that the substances contained in the feed formula are suspended or dissolved in the agar gel, avoiding nutrient separation and locking in moisture to prevent the feed from drying out quickly.

[0046] 6) Potassium sorbate and methylparaben: Both of these compounds play the role of core preservatives in insect feed formulations, but they target different bacterial groups and have different effective pH ranges. Under complex feeding conditions, the combined use of the two can achieve synergistic effects, broaden the antibacterial spectrum and their optimal effective pH range.

[0047] 7) Wheat germ oil: Wheat germ oil is a multifunctional oil additive with high nutritional value. It is rich in linoleic acid (especially an essential fatty acid that is crucial for lepidopteran insects) and vitamin E (which is crucial for the reproductive health of insects). It can improve the pupation rate, emergence rate and offspring vitality and improve feed palatability.

[0048] 8) Ferric citrate pentahydrate: Iron is an essential trace element for insects. As an organic iron source, ferric citrate is more easily absorbed and utilized by insects than inorganic iron. Compared to ferric citrate, ferric citrate pentahydrate is the most common stable form of ferric citrate on the market. As a highly efficient and safe iron supplement, it is mainly used to optimize insect nutrition, promote growth and development, and prevent problems such as stunted growth, low reproductive capacity and low immunity in fall armyworm larvae caused by iron deficiency. At the same time, ferric citrate pentahydrate is also one of the important trace element additives in industrial insect farming.

[0049] 9) Microcrystalline cellulose: Microcrystalline cellulose plays a unique role as a physical structure modifier and inert filler in feed. It does not provide nutrition, but it increases the roughness of the feed, improves the flowability of local feed, dilutes excessively high concentrations of protein and oil, makes the internal structure of the feed more uniform when it clumps, and makes the feed clumps better adaptable to the boring nature of fall armyworm larvae.

[0050] 10) Ascorbic acid and multivitamins: Ascorbic acid, also known as vitamin C, together with the multivitamins mentioned in this invention, are a number of essential vitamins that most insects cannot synthesize and must obtain from their food. Deficiency can lead to stunted growth, developmental deformities, or a significant decrease in reproductive capacity in insects. The synergistic effect of multiple multivitamins ensures the normal progress of the fall armyworm's complete life cycle.

[0051] 11) Formaldehyde and acetic acid: Although formaldehyde and acetic acid do not provide nutrition or metabolic assistance in the feed formulation for fall armyworm, as a highly efficient and powerful sterilizing agent and feed acidifier, they can directly inhibit microbial contamination and further extend the "shelf life" of the feed during the feeding process. At the same time, the volatile odor (sour smell) of acetic acid also has a certain repellent effect on some small pests, which can prevent some small pests from contaminating the feed when it is left to cool after being opened.

[0052] In terms of nutritional supply, soybean meal, wheat bran meal, and casein provide abundant protein, combining rapid and slow-release amino acid supply, laying the foundation for the continuous growth of larvae, especially the nutritional accumulation during the critical energy storage period. This balanced and continuous nitrogen supply, together with the essential fatty acids (such as linoleic acid) and vitamin E abundant in wheat germ oil for lepidopteran insects, ensures the quality of late-stage larval development and pupae. High-sugar tolerant yeast exhibits good activity under high osmotic pressure conditions. Its combined use with ascorbic acid, multivitamins, and ferric citrate pentahydrate provides a variety of abundant essential vitamins and minerals, which helps activate the insect's immune system, improve feed utilization efficiency, and ensure that the nutritional needs of fall armyworm larvae at different instars and developmental stages are fully met.

[0053] In maintaining the physical form and microenvironmental stability of feed, the gel network formed by agar constitutes the basic framework of the feed, effectively locking in moisture and carrying other components. The emulsifying properties of casein help to evenly disperse oils, while the addition of microcrystalline cellulose works synergistically with the agar network to finely regulate the mechanical strength within the gel. This allows the feed blocks to maintain their shape and resist rapid drying and disintegration, while also possessing a texture suitable for larvae to bore into and feed on. It may also have a synergistic effect with wheat germ oil in improving feed palatability, jointly promoting feeding and reducing self-mutilation behavior caused by nutritional inadequacy or competition. This stable physical structure provides a physical guarantee for the even distribution and continuous release of nutrients, while also reducing difficulties for larvae to feed or environmental pollution caused by poor feed physical properties.

[0054] In constructing a multi-layered preservation and maintenance system, the combined use of potassium sorbate and methylparaben produces a synergistic effect and broadens the antibacterial spectrum, thus extending the overall shelf life of the feed. Formaldehyde and acetic acid used in the processing reduce the microbial load at the source. This integrated preservation system ensures that the feed is not easily spoiled during the feeding cycle, directly supporting the feed formulation's core advantage of "extended replacement frequency," which reduces labor costs.

[0055] This invention achieves significant superiority over natural host plants in key performance indicators by matching and synergistically enhancing the nutritional, structural, and preservative functions of each component. This results in artificial feed as a whole system, greatly reducing the self-mutilation rate in group rearing and simultaneously improving feed preservation and larval development quality.

[0056] In some embodiments of the present invention, the feed comprises the following ingredients in the following amounts: 110-115g soybean flour, 110-115g wheat bran flour, 40-45g high-sugar-tolerant yeast, 15-20g casein, 20-30g agar, 1-2g potassium sorbate, 1-2g methylparaben, 500-550μL wheat germ oil, 0.1-0.2g ferric citrate pentahydrate, 0.1-0.2g microcrystalline cellulose, 5-10g ascorbic acid, 0.8-1.5g compound vitamins, 1-2mL formaldehyde, 2-3mL acetic acid, and 1200-1300mL sterile purified water; the amounts of each ingredient are maintained in the above proportions, and the total amount of the feed can be increased or decreased proportionally according to the above proportions.

[0057] In some embodiments of the present invention, the feed comprises the following ingredients in the following amounts: 115-120g soybean flour, 115-120g wheat bran flour, 45-50g high-sugar-tolerant yeast, 20-25g casein, 20-25g agar, 2-4g potassium sorbate, 2-4g methylparaben, 550-600μL wheat germ oil, 0.2-0.4g ferric citrate pentahydrate, 0.2-0.4g microcrystalline cellulose, 10-12g ascorbic acid, 1.5-2.5g compound vitamins, 2-3mL formaldehyde, 3-5mL acetic acid, and 1300-1350mL sterile purified water; the amounts of each ingredient are maintained in the above proportions, and the total amount of the feed can be increased or decreased proportionally according to the above proportions.

[0058] In some embodiments of the present invention, the feed comprises the following ingredients in the following amounts: 120-130g soybean flour, 120-130g wheat bran flour, 50-55g high-sugar-tolerant yeast, 25-35g casein, 25-30g agar, 1-4g potassium sorbate, 1-4g methylparaben, 600-700μL wheat germ oil, 0.1-0.4g ferric citrate pentahydrate, 0.1-0.4g microcrystalline cellulose, 12-15g ascorbic acid, 2.5-3g compound vitamins, 1-3mL formaldehyde, 2-5mL acetic acid, and 1350-1400mL sterile purified water; the amounts of each ingredient are maintained in the above proportions, and the total amount of the feed can be increased or decreased proportionally according to the above proportions.

[0059] In some embodiments of the present invention, the feed comprises the following ingredients in the following amounts: 120g soybean flour, 120g wheat bran flour, 48g high-sugar-tolerant yeast, 24g casein, 24g agar, 2.4g potassium sorbate, 2.4g methylparaben, 600μL wheat germ oil, 0.25g ferric citrate pentahydrate, 0.25g microcrystalline cellulose, 9.6g ascorbic acid, 1.2g compound vitamins, 2mL formaldehyde, 4mL acetic acid, and 1200-1400mL sterile purified water; the amounts of each ingredient are maintained in the above proportions, and the total amount of the feed can be increased or decreased proportionally according to the above proportions.

[0060] In some embodiments of the present invention, the compound vitamin comprises the following components in parts by weight: 2-3 parts niacin, 2-3 parts calcium pantothenate, 1-2 parts riboflavin, 0.3-1 part thiamine, 0.3-1 part pyridoxine hydrochloride, 0.01-0.06 parts biotin, 0.01-0.06 parts vitamin B12, 0.2-0.8 parts folic acid, and 400-600 parts sucrose.

[0061] In some embodiments of the present invention, the compound vitamin comprises the following components in parts by weight: niacin 2-2.5 parts, calcium pantothenate 2-2.5 parts, riboflavin 1-1.5 parts, thiamine 0.3-0.6 parts, pyridoxine hydrochloride 0.3-0.6 parts, biotin 0.01-0.03 parts, vitamin B12 0.01-0.03 parts, folic acid 0.2-0.5 parts, and sucrose 400-500 parts.

[0062] In some embodiments of the present invention, the compound vitamin comprises the following components in parts by weight: niacin 2.5-3 parts, calcium pantothenate 2.5-3 parts, riboflavin 1.5-2 parts, thiamine 0.6-1 part, pyridoxine hydrochloride 0.6-1 part, biotin 0.03-0.06 parts, vitamin B12 0.03-0.06 parts, folic acid 0.5-0.8 parts, and sucrose 500-600 parts.

[0063] In some embodiments of the present invention, the compound vitamin comprises the following components in parts by weight: 2-3 parts niacin, 2-3 parts calcium pantothenate, 1 part riboflavin, 0.5 parts thiamine, 0.5 parts pyridoxine hydrochloride, 0.04 parts biotin, 0.04 parts vitamin B12, 0.5 parts folic acid, and 500 parts sucrose.

[0064] Multivitamins can be prepared in advance according to the required proportions, then ground in a mortar until there are no obvious large particles. After mixing evenly with a pestle, place in a dry, water-free, sealed box and store at room temperature away from light for no more than one month.

[0065] In some embodiments of the present invention, the feed is a solid feed block formed by an agar gel network. Under standard feeding conditions (26°C, 50% humidity), it remains intact and shows no liquefaction after 3 days, thus meeting the requirements for low-frequency feed changes.

[0066] In some embodiments of the present invention, after the feed is prepared and placed into a feed box, it is left to cool completely at room temperature and then stored in a refrigerator at 4°C for no more than half a month.

[0067] A second aspect of this invention is to provide a method for preparing artificial feed for fall armyworm larvae, the method comprising the following steps:

[0068] (1) Mix soybean flour, wheat bran flour, high sugar tolerant yeast and casein evenly to obtain a blend;

[0069] (2) Preheat 1 / 3 to 1 / 2 of the sterile purified water, pour it into the blend obtained in step (1) before boiling, and heat until bubbling to obtain mixture one;

[0070] (3) Mix ferric citrate pentahydrate, microcrystalline cellulose, ascorbic acid, and complex vitamins evenly to obtain mixture two;

[0071] (4) Preheat potassium sorbate, methylparaben, and the remaining sterile purified water, then add agar and heat to boiling to obtain mixture three;

[0072] (5) Mix the mixture one obtained in step (2) and the mixture three obtained in step (4), cool to a temperature of <60°C, then add wheat germ oil and the mixture two obtained in step (3), mix evenly to obtain mixture four;

[0073] (6) Add formaldehyde and acetic acid to the mixture obtained in step (5), mix evenly, let stand to form, and obtain artificial feed for fall armyworm larvae.

[0074] In some embodiments of the present invention, the preheating temperature in step (2) is 30-45°C and the preheating time is 1-3 min; the heating temperature in step (2) is 90-100°C and the heating time is 5-8 min.

[0075] In some embodiments of the present invention, the preheating temperature in step (4) is 45-60°C and the preheating time is 1-5 min; the heating temperature in step (4) is 95-100°C and the heating time is 8-12 min.

[0076] A third aspect of the present invention is to provide the use of the artificial feed for fall armyworm larvae as described above in the preparation of products for feeding fall armyworm larvae.

[0077] The fourth aspect of this invention is to provide a method for raising fall armyworm larvae, using artificial feed for fall armyworm larvae as described above.

[0078] In some embodiments of the present invention, the rearing conditions are as follows: temperature: 25-28°C; for example, 25-27°C, 27-28°C; humidity: 40-60%; for example, 40-50%, 50-60%; photoperiod: (15-18)L:(6-9)D, i.e., 15-18 hours of light: 6-9 hours of darkness. For example, 15L:9D, 16L:8D, 18L:6D.

[0079] In this invention, there are no special restrictions on the source of fall armyworm egg masses, which can be obtained through conventional commercial means or prepared by the manufacturer under laboratory conditions according to methods known in the art.

[0080] Specifically, healthy male and female adults after emergence are placed in a 120-mesh rearing cage at a ratio of approximately 1.5:1 to prevent escape and create mating conditions. Simultaneously, the adults are fed a 10% (by weight / volume) honey solution to supplement their nutrition. To collect egg masses, a moist, smooth plastic film is attached to the inner walls of the rearing cage for the female to lay eggs. This smooth plastic film is replaced every 1-2 days depending on the number of eggs laid by the female. During collection, the plastic film containing the egg masses is removed from the rearing cage, cut off, and transferred to a suitable hatching container (such as a small rearing box). Under suitable temperature and humidity conditions, the newly hatched larvae will hatch.

[0081] The present invention will be further illustrated by the following examples, but these examples do not limit the scope of the invention.

[0082] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are conventional products that can be purchased commercially. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, equipment, and materials similar to or equivalent to those described, used, and materials in the embodiments of this invention may be used to implement this invention.

[0083] The manufacturer of the high-sugar-tolerant yeast of this invention is Angel Yeast Co., Ltd.

[0084] Example

[0085] Example 1

[0086] This embodiment provides an artificial feed for fall armyworm larvae, comprising the following ingredients: 120g soybean flour, 120g wheat bran flour, 48g high-sugar-tolerant yeast, 24g casein, 24g agar, 2.4g potassium sorbate, 2.4g methylparaben, 600μL wheat germ oil, 0.25g ferric citrate pentahydrate, 0.25g microcrystalline cellulose, 9.6g ascorbic acid, 1.2g compound vitamins, 2mL formaldehyde, 4mL acetic acid, and 1200mL sterile purified water. The compound vitamins comprise the following components in parts by weight: 2 parts niacin, 2 parts calcium pantothenate, 1 part riboflavin, 0.5 parts thiamine, 0.5 parts pyridoxine hydrochloride, 0.04 parts biotin, 0.04 parts vitamin B12, 0.5 parts folic acid, and 500 parts sucrose.

[0087] This embodiment provides a method for preparing artificial feed for fall armyworm larvae, including the following steps:

[0088] (1) Weigh 600mL of sterile purified water and preheat it in a pot for 1 minute to 35℃. Before boiling, pour in 120g of soybean powder, 120g of wheat bran powder, 48g of high sugar tolerant yeast, and 24g of casein and heat and stir continuously for 5 minutes to about 95℃. When the substrate starts to bubble, turn off the heat immediately to form mixture one.

[0089] (2) Weigh 0.25g of ferric citrate pentahydrate, 0.25g of microcrystalline cellulose, 9.6g of ascorbic acid, and 1.2g of compound vitamins, mix them evenly to form mixture two, and set aside for use;

[0090] (3) Weigh 600mL of sterile purified water into another pot, add 2.4g potassium sorbate and 2.4g methylparaben, stir and preheat for 3 min to 50℃ until there is no obvious solid, then add 24g agar, stir and heat for 10 min to 100℃, and turn off the heat after the substrate boils and turns white and is mixed evenly to form mixture three.

[0091] (4) Pour mixture 1 into mixture 3, stir evenly and cool to room temperature below 60°C, then add 600 μL of wheat germ oil and mixture 2 and mix evenly to obtain mixture 4;

[0092] (5) Add 2 mL of formaldehyde and 4 mL of acetic acid to the mixture obtained in step (4), mix well, pour into a feed box, let stand at room temperature for 1 h to shape, and obtain artificial feed for fall armyworm larvae. Figure 2 As shown.

[0093] Performance testing

[0094] 1. Storage Tolerance Test: The storage tolerance test steps for the artificial feed are as follows:

[0095] (1) Sample preparation: Cut the artificial feed to be tested into cubes of about 0.5cm×0.5cm×0.5cm; at the same time, cut the corn leaves into rectangular pieces of about 2cm in length as control samples.

[0096] (2) Grouping: The feed blocks and corn leaf blocks are placed in sterile petri dishes, with 15 samples placed in parallel in each petri dish to form a treatment group; each treatment group has at least three replicate petri dishes.

[0097] (3) Environmental control: After covering the above culture dishes, place them in an artificial climate environment with a temperature of 26±1℃, relative humidity of 50±10%, photoperiod of 16 hours, light: 8 hours, and darkness for static culture.

[0098] (4) Observation and recording: The drying time and deterioration time of each group of samples were observed and recorded regularly. The results are shown in Table 1. The "drying time" refers to the time when the sample becomes obviously hardened, curled or the weight loss rate reaches a stable state due to the evaporation of water. The "deterioration time" refers to the time when visible microbial colonies appear on the sample surface or when obvious putrefaction, liquefaction or other morphological deterioration occurs.

[0099] Before the experiment, the tweezers, scissors, and knives used were sterilized and placed in a clean bench to cool to room temperature before use.

[0100] Table 1. Comparison of deterioration and drying time between artificial feed and corn leaves.

[0101]

[0102] As can be seen from the data in Table 1, the artificial feed formulated in this invention exhibits a significantly longer deterioration and drying time compared to existing natural plant feeds, such as corn leaves, under the same environmental conditions. This characteristic allows for a significant reduction in the frequency of feed changes when raising fall armyworm larvae, thereby alleviating the labor burden caused by frequent operations. Furthermore, compared to plant-based feeding methods that require harvesting leaves only after sowing, seedling cultivation, and maturity, this feed does not require a long plant growth cycle and can be prepared or used on demand, effectively saving the time and space costs associated with traditional plant cultivation. This provides convenience for the large-scale, standardized indoor rearing of fall armyworms.

[0103] 2. Examples of artificial feed application for fall armyworm larvae

[0104] 2.1 The method for individually rearing the fall armyworm is as follows:

[0105] (1) Preparation of test insect sources: After the fall armyworm egg masses hatch, the newly hatched larvae are obtained as test insect sources;

[0106] (2) Experimental group setup: An artificial feed experimental group and a corn leaf control group were set up;

[0107] (3) Feeding procedures for the artificial feed experimental group:

[0108] (3.1) Feed preparation: Cut artificial feed into cubic feed blocks of 0.5cm × 0.5cm × 0.5cm;

[0109] (3.2) Placement and inoculation: Place one of the feed blocks into a sterilized feeding container and inoculate one newly hatched larva;

[0110] (3.3) Feeding and management: The containers were placed in a temperature of 26±1℃, relative humidity of 50±10%, and photoperiod of 16 hours light: 8 hours darkness for cultivation.

[0111] (3.4) Feed replacement and adjustment: Before the larvae develop to the 4th instar, the feed blocks should be replaced every 3 days; after the larvae develop to the 4th instar, the size of the feed blocks should be changed to 0.7cm × 0.7cm × 0.7cm, and the replacement frequency should be maintained at 3 days.

[0112] (4) Feeding procedures for the maize leaf control group:

[0113] (4.1) Feed preparation: Cut the corn leaves into rectangular pieces about 2cm long;

[0114] (4.2) Placement and inoculation: Place one leaf block as described above into a sterilized rearing container and inoculate one newly hatched larva;

[0115] (4.3) Feeding and management: Place the container under the same environmental conditions as in step (3.3) for cultivation;

[0116] (4.4) Feed replacement and adjustment: Before the larvae develop to the 4th instar, the leaf pieces should be replaced once a day; after the larvae develop to the 4th instar, the amount of leaf pieces in each container should be increased to 4 pieces, and the replacement frequency should be maintained at 4 times a day.

[0117] (5) Use tweezers to select the pupae from the artificial feed experimental group and the corn leaf control group, spread the pupae flat in the insect rearing cage with plastic film, and wait for the adults to emerge.

[0118] (6) Replication experiments: Each treatment group shall have no fewer than 30 replicate single-head feeding containers and conduct at least 3 independent biological replication experiments.

[0119] During the feeding process using the above method, the growth status of fall armyworm larvae in each group was observed and recorded. The results are shown in Tables 2-4 and 2-4. Figure 1 As shown.

[0120] Table 2. Effects of artificial feed and corn leaf feeding on the growth and development stages of fall armyworm.

[0121]

[0122] Table 3. Effects of artificial feed and corn leaf feeding on the body weight of fall armyworm at different developmental stages.

[0123]

[0124] The data in Tables 2 and 3 show that the average developmental period of fall armyworm larvae fed with the artificial feed provided by this invention did not show a statistically significant difference compared with the control group fed with corn leaves, indicating that the artificial feed can support the larvae to complete the normal growth and development process.

[0125] Regarding growth and development quality, the weight data of each larval stage showed that, starting from the 4th instar larval stage, the average weight of the larvae in the artificial feed group was slightly higher than that in the corn leaf control group. Especially in the 6th instar larval stage—the last critical stage of nutrient accumulation and energy storage before the larvae enter molting and metamorphosis—the weight of the larvae in the artificial feed group was significantly higher than that in the corn leaf control group.

[0126] In addition, compared with the corn leaf control, the artificial feed group showed the following trends in the subsequent developmental stages: the time required for larvae to pupate and the length of the pupal stage were slightly shortened, while the overall quality of the pupae was improved, reflecting the positive role of artificial feed in promoting nutrient reserves and development efficiency in the late larval stage.

[0127] Table 4. Effects of artificial feed and corn leaves on the survival rate, pupation rate, and emergence rate of fall armyworm larvae.

[0128]

[0129] Compared with the control group fed with corn leaves, feeding fall armyworms with the artificial feed and its preparation method provided by this invention yielded the following beneficial effects: the survival rate of larvae, pupation rate, and adult emergence rate were all effectively improved; at the same time, the time required for pupation and emergence was relatively shortened. This indicates that the artificial feed of this invention can provide fall armyworms with comprehensive and balanced nutritional support, ensuring their successful completion of the entire life cycle from larva to adult, and is more conducive to obtaining healthy, uniform, and efficient laboratory populations.

[0130] 2.2 The group rearing method for fall armyworm is as follows:

[0131] (1) Preparation of test insect sources: After the fall armyworm egg masses hatch, collect the newly hatched larvae as test insect sources;

[0132] (2) Experimental grouping: An artificial feed experimental group and a corn leaf control group were set up;

[0133] (3) Group rearing setup: 9cm sterile petri dishes were used as rearing containers. 30 newly hatched larvae were placed in each container and sealed with a sealing film after sealing the container.

[0134] (4) Feeding procedures for the artificial feed experimental group:

[0135] (4.1) Feeding: Place 5 artificial feed cubes with a size of 0.5cm × 0.5cm × 0.5cm into each petri dish;

[0136] (4.2) Breeding conditions: After covering the petri dish, place it in a temperature of 26±1℃, relative humidity of 50±10%, and photoperiod of 16 hours light: 8 hours darkness.

[0137] (4.3) Feeding and management: Before the larvae develop to the 4th instar, the feed should be changed every 3 days and the number of surviving larvae and the self-mutilation situation should be recorded; after the larvae develop to the 4th instar, the amount of feed in each culture dish should be increased to 9 pieces, and the frequency of changing and observing should be maintained every 3 days.

[0138] (5) Feeding procedures for the maize leaf control group:

[0139] (5.1) Feeding: Place 5 rectangular corn leaves, each about 6 cm long, into each petri dish;

[0140] (5.2) Feeding conditions: Same as in step (4.2);

[0141] (5.3) Feeding and management: Before the larvae develop to the 4th instar, the corn leaves are replaced once a day and the number of surviving larvae and the self-mutilation situation are recorded; after the larvae develop to the 4th instar, the number of leaves in each petri dish is increased to 12, and the frequency of replacement and observation is maintained daily.

[0142] (6) Observation index recording: When changing the feed each time, count the number of surviving larvae in each container and check the morphology of the dead larvae. Record the dead individuals with obvious bite or mutilation characteristics as deaths caused by self-mutilation, which are used to calculate the larval self-mutilation rate of each treatment group.

[0143] (7) Use tweezers to select the pupae from the artificial feed experimental group and the corn leaf control group, spread the pupae flat in the insect rearing cage with plastic film, and wait for the adults to emerge.

[0144] (8) Experimental replication: Each treatment group shall have no less than 30 replicate single-head feeding containers and no less than 3 independent biological replicates.

[0145] In an embodiment of the present invention, in order to accurately assess the cannibalistic behavior of fall armyworm larvae in group rearing, the larval growth process is systematically observed and recorded. The specific method is as follows:

[0146] Observations were conducted every 24 hours after the experiment. Upon discovery of dead larvae, a preliminary assessment was made based on their body morphology: if the larvae exhibited obvious signs of limb mutilation, large-scale body wall damage, or other signs of gnawing injuries, they were recorded as "suspected self-mutilation deaths." These individuals must be removed from the rearing container immediately after counting using sterile tools to prevent them from being further fed on and thus unidentifiable, or from decaying and interfering with the determination of the cause of death. If the larvae were intact but stiffened, or if their body surface features were intact (e.g., mold, intact but shriveled), they were recorded as deaths from other causes. The observation results are shown in Table 5. The "total number of surviving larvae at the start of each stage" mentioned in the table refers to the initial number of surviving larvae in the container at the beginning of each instar stage; for example, a total of 96 surviving larvae at the start of the 1st-2nd instar stage means that 96 larvae were surviving at the first observation in the early 1st instar stage.

[0147] Table 5. Observation Record of Cannibalistic Behavior in Fall Armyworm Larvae during Group Rearing (Unit: larvae)

[0148]

[0149] Table 5 shows the number of self-cannibalistic larvae and the remaining number of larvae in the fall armyworm colony. As can be seen from Table 5, the fall armyworm begins to exhibit self-cannibalistic behavior from the second instar larvae, and this phenomenon persists throughout the entire larval development stage. Comparative analysis shows that the number of self-cannibalistic larvae in the experimental group fed the artificial feed provided by this invention was significantly lower than that in the control group fed corn leaves from the fourth instar onwards. Specifically, at the critical stage of the sixth instar larvae to pupation, the corn leaf control group had as many as 18 self-cannibalistic larvae, with only 5 remaining to enter the prepupal stage, while the artificial feed experimental group still had 41 larvae entering the prepupal stage at the same stage. This data proves that the artificial feed of this invention can effectively meet the nutritional needs of the larval population, significantly reducing competitive cannibalistic behavior caused by poor nutrition, insufficient feed, or unsuitable feed, thus providing key technical support for obtaining higher survival rates and more uniform population sources.

[0150] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An artificial feed for fall armyworm larvae, characterized in that, The feed comprises the following ingredients in the following proportions: 110-130g soybean flour, 110-130g wheat bran flour, 40-55g high-sugar-tolerant yeast, 15-35g casein, 20-30g agar, 1-4g potassium sorbate, 1-4g methylparaben, 500-700μL wheat germ oil, 0.1-0.4g ferric citrate pentahydrate, 0.1-0.4g microcrystalline cellulose, 5-15g ascorbic acid, 0.8-3g compound vitamins, 1-3mL formaldehyde, 2-5mL acetic acid, and 1200-1400mL sterile purified water. The proportions of each ingredient are maintained as described above, and the total amount of the feed can be increased or decreased proportionally.

2. The artificial feed for fall armyworm larvae according to claim 1, characterized in that: The feed comprises the following ingredients in the following proportions: 120g soybean flour, 120g wheat bran flour, 48g high-sugar-tolerant yeast, 24g casein, 24g agar, 2.4g potassium sorbate, 2.4g methylparaben, 600μL wheat germ oil, 0.25g ferric citrate pentahydrate, 0.25g microcrystalline cellulose, 9.6g ascorbic acid, 1.2g compound vitamins, 2mL formaldehyde, 4mL acetic acid, and 1200-1400mL sterile purified water. The proportions of each ingredient are maintained as described above, and the total amount of the feed can be increased or decreased proportionally.

3. The artificial feed for fall armyworm larvae according to claim 1, characterized in that: The compound vitamin comprises the following components in parts by weight: niacin 2-3 parts, calcium pantothenate 2-3 parts, riboflavin 1-2 parts, thiamine 0.3-1 part, pyridoxine hydrochloride 0.3-1 part, biotin 0.01-0.06 parts, vitamin B12 0.01-0.06 parts, folic acid 0.2-0.8 parts, and sucrose 400-600 parts.

4. The artificial feed for fall armyworm larvae according to claim 3, characterized in that: The compound vitamin comprises the following components in parts by weight: 2-3 parts niacin, 2-3 parts calcium pantothenate, 1 part riboflavin, 0.5 parts thiamine, 0.5 parts pyridoxine hydrochloride, 0.04 parts biotin, 0.04 parts vitamin B12, 0.5 parts folic acid, and 500 parts sucrose.

5. The artificial feed for fall armyworm larvae according to any one of claims 1-4, characterized in that: The feed is a solid feed block formed by an agar gel network.

6. A method for preparing artificial feed for fall armyworm larvae as described in any one of claims 1-5, characterized in that: The preparation method includes the following steps: (1) Mix soybean flour, wheat bran flour, high sugar tolerant yeast and casein evenly to obtain a blend; (2) Preheat 1 / 3 to 1 / 2 of the sterile purified water, pour it into the blend obtained in step (1) before boiling, and heat until bubbling to obtain mixture one; (3) Mix ferric citrate pentahydrate, microcrystalline cellulose, ascorbic acid, and complex vitamins evenly to obtain mixture two; (4) Preheat potassium sorbate, methylparaben, and the remaining sterile purified water, then add agar and heat to boiling to obtain mixture three; (5) Mix the mixture one obtained in step (2) and the mixture three obtained in step (4), cool to a temperature of <60°C, then add wheat germ oil and the mixture two obtained in step (3), mix evenly to obtain mixture four; (6) Add formaldehyde and acetic acid to the mixture obtained in step (5), mix evenly, let stand to form, and obtain artificial feed for fall armyworm larvae.

7. The preparation method according to claim 6, characterized in that: It also includes one or more of the following features: 21) The preheating temperature in step (2) is 30-45℃, and the preheating time is 1-3 min; 22) The heating temperature in step (2) is 90-100℃, and the heating time is 5-8 min; 41) The preheating temperature in step (4) is 45-60℃, and the preheating time is 1-5 min; 42) The heating temperature in step (4) is 95-100℃ and the heating time is 8-12 min.

8. The use of the artificial feed for fall armyworm larvae as described in any one of claims 1-5 in the preparation of products for feeding fall armyworm larvae.

9. A method for rearing fall armyworm larvae, characterized in that: The fall armyworm larvae were fed with artificial feed as described in any one of claims 1-5.

10. The feeding method according to claim 9, characterized in that: The conditions for rearing are: temperature: 25-28℃; humidity: 40-60%; photoperiod: (15-18)L: (6-9)D.

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