An indoor artificial breeding method for rice stem borers

Abstract

This application discloses an indoor artificial rearing method for the rice stem borer, belonging to the field of insect rearing technology. This method addresses the problems of drowning in young larvae and frequent disease outbreaks in older larvae caused by homogeneous rearing across all generations. It constructs a constant-temperature environment and prepares granular dry feed for young larvae and slightly dehydrated flake feed for older larvae based on differences in larval mouthparts. A heterogeneous three-dimensional rearing device is used. In the young larvae stage, a slow-release substrate at the bottom maintains a vertical humidity gradient, and layered feeding prevents mechanical damage to the larvae. In the older larvae stage, substrate-free bare-bottom rearing and full-volume replacement feeding are employed. Timely removal of filamentous netting blocks the breeding environment for soft rot. Furthermore, the method combines pupation induction with corrugated paper induction and non-contact moisturizing, humidification during the adult dark period to delay gelatinous hardening, and overall substrate replacement during the light period to achieve damage-free egg mass harvesting. This application, through precise age-based management, significantly improves the survival rate and population propagation efficiency of the rice stem borer across all generations.

Description

Technical Field

[0001] This application relates to the field of insect breeding technology, specifically a method for indoor artificial breeding of rice stem borers. Background Technology

[0002] The rice stem borer (Chilo suppressalis) is a significant boring pest in rice production, widely distributed across rice-growing areas, causing severe yield losses. Establishing standardized indoor populations is necessary for research in agricultural entomology, pesticide resistance screening, sex pheromone development, and the evaluation of insect resistance in transgenic rice. Obtaining sufficient numbers of test insects with consistent growth and development, and in good physiological condition, through artificial rearing techniques is fundamental for conducting these researches and a prerequisite for integrated pest management strategies.

[0003] Currently, indoor rearing of the rice stem borer mainly relies on artificial feed technology. Conventional artificial feed formulations typically include soybean meal, yeast powder, vitamins, sugars, and agar as a coagulant. The general rearing process involves pouring the prepared hot feed into containers such as glass bottles, finger tubes, or plastic boxes, allowing it to cool and solidify naturally into a gel, and then directly inoculating egg masses in the black-head stage or newly hatched larvae. To meet the larval growth's moisture requirements and prevent the feed from drying out and hardening too quickly, a high ambient humidity is usually maintained during rearing, or a high proportion of water is added during feed preparation to maintain the feed's suitable softness for larvae to consume.

[0004] However, in existing breeding techniques, the contradiction between feed moisture content and the survival rate of young larvae remains difficult to reconcile. Newly hatched larvae are extremely small and highly sensitive to humidity in their microenvironment, and their bodies are easily covered by liquids. Conventional artificial feeds, due to their high moisture content, often have a free water film on their surface or condensation forming in closed containers. This makes it easy for newly hatched larvae to suffocate when attempting to burrow and feed, or to starve to death because they are unable to move due to being stuck to the feed surface. If the feed moisture content is simply reduced to prevent suffocation, the feed hardens, making it difficult for newly hatched larvae, whose mouthparts have not yet hardened, to burrow into the feed, leading to dehydration and death due to prolonged exposure to a dry feed surface. This one-dimensional humidity management approach cannot simultaneously meet the dual requirements of keeping the feed moist and the feed surface dry, making it extremely difficult to establish artificial populations in the early larval stages, resulting in a persistently high mortality rate. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this application provides an indoor artificial breeding method for rice stem borers, which solves the problem of low survival rates caused by the uniformity of feeding and management across all generations in existing indoor artificial breeding methods for rice stem borers.

[0006] To achieve the above objectives, this application provides the following technical solution: an indoor artificial breeding method for rice stem borers, comprising the steps of environment construction, feed preparation, hatching and colonization, management of young larvae, management of older larvae, management of pupation, and management of adult insects.

[0007] In the environmental construction step, constant temperature, humidity, and photoperiod parameters are set in an artificial climate chamber or intelligent incubator. The temperature setting follows the effective accumulated temperature law for insect development, and the developmental period of each stage of the rice stem borer is controlled by the constant temperature environment to ensure the consistency of population development progress and provide a time reference for subsequent large-scale artificial operations.

[0008] In the feed preparation process, the artificial feed undergoes differentiated dehydration treatment based on the larval stages of the rice stem borer. Specifically, for 1st-3rd instar larvae, a deep dehydration standard is applied, using multiple physical pressing to absorb water, preparing the artificial feed into loose, granular dry feed with a diameter of 1-3 mm that does not stick together and does not deform or collapse when piled up; for 3rd-6th instar larvae, a surface dehydration standard is applied, using a single physical pressing to absorb water, removing condensed water from the cut surface while retaining internal bound water, preparing the artificial feed into sheet-like, slightly dehydrated feed with a matte surface and maintaining flexibility.

[0009] In the hatching and colonization process, the rice stem borer egg masses are placed in a humid environment for incubation. Once a clear black chitinous head shell of the embryo is visible through the eggshell (blackhead stage), the egg masses, along with the attached substrate, are transferred to a heterogeneous three-dimensional rearing device. During transfer, the egg masses are spread flat on the surface of a layer of granular dry feed, and the hygroscopic attraction of newly hatched larvae is used to induce them to actively burrow into the gaps between the feed to colonize.

[0010] In the management of early-stage larvae, a heterogeneous three-dimensional rearing device is used to maintain a vertical humidity gradient. The bottom of this device is laid with a sterilized slow-release moisture substrate, covered by a physical isolation net, and topped with stacked granular dry feed. Moisture permeates through the isolation net into the feed layer, creating a microenvironment that is moist at the bottom and dry at the top. During this stage, a layered feeding operation is performed, with new feed added daily on top of the old feed. The old feed and excrement at the bottom are not cleaned; the compacted old feed layer serves as a secondary moisture-retaining medium. When the ambient humidity is insufficient, a misting spray is used to replenish moisture to the sealing material, avoiding direct water spraying onto the feed layer.

[0011] In the management of older larvae, once the larvae reach the early third instar, they are transferred to high-rigidity, universal rearing containers. A substrate-free, bare-bottom rearing method is adopted, utilizing the large ventilation windows at the top of the container and metal mesh to maintain moderate humidity and accelerate fecal drying. At this stage, a full-volume replacement feeding operation is implemented, with all uneaten feed, feces, and filamentous mesh expelled by the larvae cleaned daily, and flake-shaped, slightly dehydrated feed introduced. If diseased or pest-infested larvae are found, they are immediately isolated, and all tools that have come into contact with them are disinfected.

[0012] In the pupation management process, corrugated paper with apertures matching the width of mature larvae is placed as a pupation induction medium. The mature larvae's tendency to seek narrow spaces for dorsal contact induces pupation. After collecting the pupae, a non-contact moisturizing method is used, utilizing moisture from the bottom to maintain humidity and preventing direct contact between the pupae and liquid water. Simultaneously, high and low temperature interventions are used to regulate the pupal development rate, achieving synchronized emergence of males and females.

[0013] In the adult management process, newly emerged adults are placed in a semi-enclosed mating chamber at a specific sex ratio for synchronous pairing. Before entering the dark period, the ambient humidity is increased by spraying to delay the hardening of the gelatinous substance secreted by the females. During the light period, periodic harvesting is performed to completely replace the oviposition substrate with attached egg masses, preventing disturbance to the adults.

[0014] This application provides a method for indoor artificial breeding of rice stem borers. It has the following beneficial effects:

[0015] 1. This application prepares granular dry feed based on the mouthparts and habits of young larvae, and constructs a vertical humidity gradient with a wet bottom and dry top using a heterogeneous three-dimensional breeding device. The slow-release substrate at the bottom penetrates through the isolation net to the feed layer, creating a breathable and humid microenvironment between the granular dry feed. This solves the problem of newly hatched larvae suffocating or sticking together and dying due to being covered by a water film on the surface of the feed. At the same time, the superimposed feeding strategy maintains the freshness of the feed and the stability of the microenvironment without disturbing the larvae at the bottom.

[0016] 2. This application utilizes a substrate-free bare-bottom rearing model and full-volume replacement feeding during the advanced larval stage. Daily thorough cleaning of leftover feed, feces, and filamentous webs expelled by larvae disrupts the high-humidity and organic matter accumulation environment that fosters bacterial soft rot and stunted growth. Simultaneously, the use of dehydrated flake feed on the surface satisfies the physiological needs of advanced larvae for bound water while accelerating fecal drying through the dry feed surface and ventilation environment, thus blocking the horizontal spread and accumulation of pathogens within the rearing container.

[0017] 3. This application induces pupation by placing corrugated paper with an aperture matching the width of mature larvae, and avoids fungal infection of the pupae by using a non-contact moisturizing method. Combined with the synchronization regulation of emergence and the humidification operation before the dark period, the hardening speed of the gel secreted by the female insect is slowed down, ensuring that the egg mass adheres firmly to the rice leaves. With the harvesting method of replacing the oviposition substrate during the photoperiod, the egg mass is collected efficiently without disturbing the adults, which significantly improves the population propagation efficiency and offspring quality. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall process of this application. Detailed Implementation

[0019] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Example: Please see the appendix Figure 1 This application provides an indoor artificial breeding method for the rice stem borer. To ensure the effectiveness of the indoor artificial breeding method, it is necessary to construct an artificial climate environment with constant and controllable parameters. The establishment of the breeding environment involves the coordinated control of three elements: temperature, humidity, and photoperiod, to simulate a suitable ecological niche for the growth and development of the rice stem borer. Specifically, it includes the following steps: S101. Setting and controlling temperature parameters: In the artificial climate chamber or intelligent incubator, the ambient temperature is maintained at 27±1℃ through a temperature control unit. The temperature control unit uses a PID temperature controller in conjunction with heating and cooling units, and the temperature sensor is placed in the middle layer of the breeding rack to ensure that the collected temperature data represents the average level of the breeding area and avoids excessive local temperature differences.

[0021] The setting of 27℃ follows the principle of effective accumulated temperature for insect development. The functional relationship between the development rate V of the rice stem borer and the ambient temperature T satisfies:

[0022] In the formula: Defined as the developmental rate, it is numerically equal to the reciprocal of the developmental duration N (i.e., V=1 / N). The ambient temperature is set to 27°C in this embodiment; The developmental initiation temperature represents the minimum temperature threshold at which the rice stem borer begins its growth and development. The effective accumulated temperature constant represents the total amount of heat required to complete a specific stage of growth and development.

[0023] Under this constant temperature of 27℃, the developmental duration of each stage of the rice stem borer showed a high degree of uniformity: egg stage 5 to 6 days; larval stage 21 to 25 days (including 3-4 days for the 1st instar, 3-4 days for the 2nd instar, 4-5 days for each of the 3rd to 5th instars, and 3-4 days for the 6th instar); pupal stage 5 to 6 days; adult lifespan 6 to 7 days. This stable developmental duration provided a time benchmark for subsequent batch operations based on the number of days.

[0024] S102. Setting and controlling humidity parameters: The ambient relative humidity (RH) is maintained at 75±5% via a humidity control module. This module utilizes an ultrasonic humidifier or a high-pressure micro-mist system and is linked to a humidity sensor. The humidity sensor must be placed away from the humidifier's spray nozzle to prevent inaccurate readings caused by direct contact of water mist with the probe.

[0025] A humidity level of 75% can maintain the moisture balance of the rice stem borer larvae's body wall, preventing young larvae from rapidly losing water and dying due to their large surface area. At the same time, this humidity level meets the water absorption requirements for egg mass hatching and softens the pupal skin to aid in adult emergence. If the humidity is below 70%, the eggs are prone to drying out; if the humidity is above 80%, fungal diseases are likely to break out in the feed and on the larvae.

[0026] S103. The setting and adjustment of the optical period parameter are achieved through: The lighting control system is set to a light cycle of 16L:8D, meaning it provides 16 hours of light and 8 hours of darkness daily. The system uses an LED cold light source array with a spectral range covering the visible light spectrum, and the light intensity is controlled between 500-1000 lux.

[0027] The rice stem borer is a facultative diapause insect, and short-day light is the main signal for inducing diapause. A long-day light environment of 16 hours can effectively block the transmission of diapause signals, force the population to develop continuously, and ensure a continuous supply of the next generation of insects.

[0028] S104. Larval morphological monitoring based on environmental parameters: Under the temperature, humidity, and light conditions set in S101 to S103 above, the larvae of the rice stem borer at each instar exhibit specific morphological characteristics. These characteristics serve as verification indicators for the developmental stages mentioned in S101, and as judgment criteria for subsequent boxing operations. First instar larvae: head capsule width less than 0.8 mm, body length 1-2 mm, newly hatched head is dark brown, body is pale yellow, and there are no longitudinal lines on the back; Second instar larvae: head capsule width 0.8-0.9 mm, body length 2-4 mm, body color grayish-yellow, with 5 indistinct light brown longitudinal lines on the back; 3rd instar larvae: head capsule width 0.9-1.2mm, body length 4-5mm, body color yellowish-brown, 5 clear longitudinal lines on the back, the outermost longitudinal line passes through the spiracles; 4th to 5th instar larvae: the head capsule width increases to 1.3-1.6 mm, the body length is 10-20 mm, the longitudinal lines are dark brown, the body wall is hardened, and the abdominal prolegs are well developed; 6th instar larva (mature): Head capsule width 1.6-2.0 mm, body length 20-30 mm, large body shape, blurred and disappeared longitudinal line on the back, abdomen appears white and wrinkled. When the larvae are monitored to reach the morphological characteristics of the 6th instar, it is determined that they have entered the prepupal stage, and pupation isolation should be performed immediately.

[0029] Based on the temperature, humidity, and light parameters set in S101 to S103, the full-generation development process of the rice stem borer in the artificial breeding system exhibits regularity. This embodiment determines the specific time points for artificial intervention by monitoring biological morphological characteristics. The physiological time for the rice stem borer to complete a full generation is 37 to 44 days, and the timing and morphological characteristics of each developmental stage are as follows: S105, Timing of the Entire Generation Developmental Cycle: Under constant temperature and humidity conditions, the developmental progress of the rice stem borer population remains synchronized. The standardized developmental cycle is divided into the embryonic development period, the larval growth preference period, the mature larval prepupal stage, and the adult reproductive period. The morphological characteristics at the beginning and end of each stage determine the timing of larval reception, separation, isolation, and pairing operations.

[0030] S106. Embryonic development period and timing of worm inoculation: The egg stage lasts for 5 to 6 days. The day of egg laying is taken as day 0. From day 1 to day 3, the egg mass appears milky white. On day 4, the color of the eggs darkens to a grayish color. On day 5, black spots appear inside the eggs, which means that they have entered the black head stage, indicating that the larvae's head shell has hardened and the embryo has matured.

[0031] When more than 80% of the eggs in the egg mass show the blackhead characteristic, the inoculation standard is considered met. At this time, the rice leaves containing the egg mass should be transferred to the larval rearing container. The humidity environment set by S102 can maintain the permeability of the egg membrane, promoting the concentrated hatching of egg masses from the same batch within 24 hours and avoiding age differences among larvae in the same rearing box.

[0032] S107. Basis for segmented management during the larval development period: The larval stage lasts a total of 21 to 25 days and is managed in two sub-stages based on the larvae's different requirements for water and space: Phase 1 (1st to 3rd instar): Lasts 7 to 9 days. Newly hatched larvae are attracted to moisture and need a heterogeneous, three-dimensional humidity environment to establish themselves. As they grow, the larvae's body color changes from pale yellow to yellowish-brown. Phase 1 is considered complete when the larvae reach a length of 4-5 mm and show 5 clear brown longitudinal lines on their backs. This morphological indicator of "body length + longitudinal lines" is the direct basis for separating and diluting the larvae into smaller containers. At this point, the larvae need to be transferred to larger containers for low-density rearing.

[0033] The second stage (4th to 6th instars): lasts 14 to 16 days. Larvae increase their food intake, requiring daily supplementation. By the end of the 6th instar, larvae cease feeding, their body length shortens from an extended state, and the abdominal segments change color from yellowish-brown to milky white and become wrinkled, indicating they have entered the prepupal stage. The characteristic of "cessation of feeding + body wrinkling and whitening" is the trigger for pupation isolation; mature larvae must be immediately removed from the colony to prevent cannibalism.

[0034] S108, Operational Nodes During Metamorphosis and Reproductive Stages: The pupal stage lasts 5 to 6 days.

[0035] In the early stages of pupation, the pupa is pale yellow and soft, then hardens and turns reddish-brown. 24 hours before emergence, the pupal compound eyes turn black, black markings appear on the wing buds, and the overall body color turns dark brown.

[0036] The detection of pupae turning dark brown is a signal to initiate a transfer process; the pupae should be placed in an adult mating cage to await emergence. The adult stage lasts 6 to 7 days, with mating completed within 24 hours of emergence. A 7-day period is used as the cutoff time for adult reproductive management; after the 7th day, egg production declines, and the collected egg masses are used to initiate the next round of embryonic development. To address the biological characteristics of young larvae (1st-3rd instar) who are prone to dehydration and have a boring habit, this embodiment constructs a heterogeneous three-dimensional breeding device through a vertically layered physical structure. The device establishes a humidity gradient at the microscale to balance the high-humidity environment required by the larvae with the feed's mold prevention needs. The construction and preparation process of the device is as follows: S201, Pretreatment of transparent aquaculture containers: Use a transparent plastic petri dish with a diameter of 90mm and a height of 15-20mm or a square plastic box with a similar bottom area as the substrate.

[0037] The transparent material allows for direct observation of larval activity and feed consumption inside, avoiding environmental disturbance from opening the lid. Before use, the inner walls and lid of the plastic petri dish must be sterilized. This is done by wiping the surface with 75% alcohol, allowing the alcohol to evaporate, and then irradiating with ultraviolet light for 30 minutes. This sterilization process aims to kill fungal spores and mite eggs adhering to the container surface, blocking the initial source of infection for microsporidiosis or muscardine disease.

[0038] S202, Preparation and laying of the bottom layer moisture-release matrix: Lay a slow-release moisture substrate at the bottom of the plastic petri dish.

[0039] The substrate is a sponge layer or agar gel layer that has been sterilized by high-pressure steam.

[0040] When selecting a sponge layer, soak the sponge in sterile water, squeeze out the gravity water, retain the absorbed water, and lay the moistened sponge on the bottom of the dish, with a thickness controlled at 5-8mm. The porous structure of the sponge uses capillary action to lock in moisture and provides high humidity to the upper layer through natural evaporation.

[0041] When using agar gel, prepare an agar aqueous solution with a concentration of 1.5%-2.0%, boil it until completely dissolved, pour it into the bottom of the dish, and let it cool and solidify into a gel with a thickness of 5-8 mm. Compared with sponges, agar gel has a more stable water retention rate, and its dense surface makes it less likely to become a breeding ground for miscellaneous bacteria.

[0042] S203, Selection and Configuration of Mid-Layer Physical Isolation Net: A physical barrier net is placed over the moisture-release matrix.

[0043] The isolation netting is made of nylon mesh or perforated plastic sheet. The size of the netting must be strictly matched to the inner diameter of the container, and the edges must fit tightly against the inner wall of the container without gaps. The mesh size is set at 0.1-0.2mm, corresponding to an industrial standard screen size of 80 to 100 mesh. The physical barrier of 80 to 100 mesh is less than the 0.25mm width of the head shell of a first-instar larva, effectively preventing the larvae from burrowing downwards into the slow-release moisture substrate and drowning; at the same time, the mesh allows water vapor molecules from the bottom layer to diffuse vertically to the upper feeding area.

[0044] S204, Stacking construction of the upper feed area: Artificial feed that has undergone physical dehydration is laid on top of the physical isolation net.

[0045] After removing free water by pressing with multiple layers of absorbent paper, the feed is crushed into irregular particles with a diameter of 1-3 mm. These crushed feed particles are then evenly spread on the surface of the isolation mesh to a thickness of 3-5 mm. The irregular stacking of the granular feed creates numerous micropores, which, combined with moisture permeating from the bottom layer, form high-humidity tunnels within the feed layer. This stacking structure induces young larvae to feed through the gaps in the feed, preventing them from being exposed to the dry surface air. Simultaneously, the gaps between the particles ensure air circulation on the feed surface, inhibiting the growth of mold mycelia.

[0046] S205, Breathable and escape-proof sealing design: After the internal structure of the device is constructed, cover the top of the container with medical gauze or cotton fiber cloth and secure it to the outer wall of the container with rubber bands. The mesh size of the sealing material must be less than 80 mesh to prevent newly hatched larvae from crawling out and escaping. The medical gauze seal prevents external bacteria from falling in, while maintaining gas exchange between the inside and outside of the device and preventing the accumulation of carbon dioxide produced by metabolism at the bottom of the container.

[0047] As the larvae develop to the third instar, their mandibles harden, acquiring chewing and destructive abilities as well as the ability to escape. This embodiment uses a modified high-hardness plastic container as a general rearing device for older larvae. The device construction steps are as follows: S206, Selection of high-hardness transparent containers: Transparent plastic boxes made of polypropylene (PP) or polycarbonate (PC) are used as the main breeding material.

[0048] The transparent plastic box has a wall thickness greater than 0.5mm. Utilizing the hardness and smooth surface of PP or PC materials, it prevents larvae older than the 3rd instar from escaping by gnawing on the feeding container wall or climbing the inner wall. A square, wide-mouthed bottle with a volume of 500-1000ml is recommended; the wide mouth design facilitates the later addition of large pieces of feed and the cleaning of feces.

[0049] S207. The opening of large-area ventilation windows: A ventilation window was mechanically cut into the central area of ​​the transparent plastic lid.

[0050] The ventilation window area should be set to occupy 50%-70% of the total area of ​​the lid. A border at least 1.5cm wide should be retained around the lid edge to maintain the overall structural rigidity and prevent deformation leading to seal failure during frequent opening and closing. Large ventilation windows allow for the rapid removal of high heat and carbon dioxide generated by the metabolism of older larvae, preventing excessively high internal temperature and humidity levels that could cause larvae suffocation or bacterial soft rot outbreaks.

[0051] S208, Material selection for anti-chewing mesh: Metal mesh, cut to a size slightly larger than the ventilation window, is used as the breathable medium.

[0052] The metal mesh is made of 304 stainless steel. The high hardness of stainless steel can effectively prevent mechanical damage to the mandibles of older larvae.

[0053] The mesh size of the metal mesh is controlled between 60 and 80 meshes. The mesh diameter of 60 to 80 meshes can prevent third-instar larvae (with a head width of about 1 mm) from crawling out, and can also ensure gas exchange between the inside and outside of the container by utilizing the principle of air convection.

[0054] S209, Hot-melt embedded fixing process: Non-toxic ethylene-vinyl acetate copolymer (EVA) hot melt adhesive was used as the fixing medium.

[0055] Apply molten hot melt adhesive evenly to the edge of the ventilation window to form a continuous strip. Before the adhesive solidifies, lay stainless steel mesh flat and press it firmly onto the strip.

[0056] Utilizing the fluid filling properties of hot melt adhesive, the adhesive penetrates the mesh of the mesh and fuses with the surface of the plastic lid. After cooling and solidification, it forms an integrated embedded structure of "plastic-adhesive-metal mesh." This structure seals the microscopic gaps between the mesh and the plastic lid, blocking the escape route of larvae. The box is ready for use after the hot melt adhesive odor has dissipated.

[0057] After adult emergence, insects need to fly, court, mate, and lay eggs, thus requiring specific spatial volume and environmental humidity. This embodiment constructs a semi-enclosed, high-humidity mating and egg-laying device. The construction steps are as follows: Selection of S210, semi-enclosed transparent mating chamber: A transparent polypropylene (PP) plastic storage box with a volume of 40L to 60L was selected as the main body of the mating chamber. The height of the box was set at more than 30cm, and the vertical height space of more than 30cm met the spiral ascent habit of adult rice stem borers during nocturnal courtship flights and mating. The transparent box walls allow the light period signal set by the external S103 to be transmitted into the box. The light signal regulates the diurnal rhythm of the adults and induces the adults to mate in concentrated periods during the dark period.

[0058] S211, Opening of a micro-ventilation operation window: An operating window should be made on the top of the lid or side wall of the plastic storage box, with the window area set at 10%-15% of the total surface area of ​​the box. This small opening (10%-15%) differs from the large ventilation during the larval stage; its purpose is to create a semi-enclosed space, maintaining a relative humidity above 80% inside the box. This high humidity environment prevents the laid egg masses from drying out and softens the gelatinous substance secreted by adults during egg laying, facilitating egg attachment. The window should be covered with nylon mesh with an 80-100 mesh opening, and sealed and secured along the edges using strong fabric tape or hot melt adhesive. The nylon mesh prevents adults from escaping and also serves as a limited gas exchange channel, preventing excessive condensation buildup inside the box due to plant transpiration.

[0059] S212, Preparation of rice oviposition substrate unit: Individual rice planting cups were prepared as oviposition substrates.

[0060] Select fresh rice plants that are in the tillering stage and 15-20cm tall, and transplant them into disposable plastic cups. Fill the cups with water-retaining soil or hydroponic nutrient solution.

[0061] Completely seal the mouth of the plastic cup with plastic wrap or sealing film, leaving only a small hole in the center for the rice stem to protrude. This sealing process isolates the cup from the soil or nutrient solution, preventing female adults from laying eggs in soil crevices or on the inside of the cup wall, thus preventing them from being collected. It also prevents adults from falling into the nutrient solution and drowning. Place 2-3 prepared rice planting cups at the bottom of the mating chamber. The volatile substances released by the rice leaves during the tillering stage will induce females to concentrate on laying eggs on the leaf surface.

[0062] S213. Installation of anti-drowning nutrition supply unit: Place a 60mm diameter petri dish at the bottom of the mating chamber.

[0063] Line a petri dish with defatted cotton balls or absorbent sponges, and pour in a prepared 1% honey solution. The volume should be controlled so that the cotton balls are saturated but not overflowing. The cotton balls or sponges act as absorbent carriers for the liquid nutrients, providing a foothold for the adult insects and preventing them from drowning due to surface tension during feeding. The 1% honey solution also provides carbohydrates for the adult insects' flight and reproductive system development.

[0064] The moisture content of artificial feed is a key parameter affecting the survival rate of rice stem borers in indoor rearing. Conventional artificial feeds have a high moisture content after preparation, and direct use can lead to larvae adhering to their bodies and drowning, or the outbreak of mold. This embodiment implements a graded physical dehydration treatment based on the differences in mouthpart structure and moisture tolerance at different larval stages. The specific implementation steps are as follows: S301. Feed coagulation and slicing: Pour the prepared hot liquid artificial feed into a flat-bottomed container.

[0065] Flat-bottomed containers must be pre-sterilized with ultraviolet light. Allow the feed to cool until it reaches room temperature and solidifies into a non-flowing gel. Remove the solidified feed block and slice it into thin slices using an alcohol-sterilized scalpel or slicer. The slice thickness should be 2-4 mm. This 2-4 mm thickness is designed to shorten the path of moisture migration from the center of the feed to the surface, ensuring that subsequent water absorption effectively reduces the water activity within the feed.

[0066] S302, Multiple water absorption, desiccation, and granulation of feed for young larvae: To address the characteristics of 1st-3rd instar larvae—their small size, susceptibility to being encased in water and their need to bore into the earth—the feed slices prepared in step S301 undergo multiple dehydration treatments. Multiple layers of clean, dry absorbent paper (such as industrial wiping paper or toilet paper) are prepared. The feed slices are laid flat on the absorbent paper, leaving gaps between them. Three to five layers of absorbent paper are then placed on top of the feed slices, and pressure is applied vertically downwards with the palm of the hand. This process of "covering absorbent paper - pressing - replacing with dry absorbent paper" is repeated 3 to 4 times. The dehydration endpoint is determined when there is no obvious wetness on the surface of the absorbent paper after pressing, and the feed slices change from soft and sticky to firm and no longer sticky. The dehydrated feed slices are then placed in a mortar or crushed using tweezers to prepare irregular particles with a diameter of 1-3 mm. The dehydrated and crushed granular feed particles are dry and do not stick together. Combined with the physical isolation net in step S204, this creates breathable porous spaces for young larvae to bore into.

[0067] S303, Surface dehydration and shape preservation of feed for older larvae: To address the characteristics of 3rd-6th instar larvae—large appetite, strong resistance, and well-developed mandibles—the feed slices prepared in step S301 undergo surface dehydration treatment. The feed slices are laid flat on absorbent paper, covered with 1-2 layers of absorbent paper. Only one light pressing operation is performed. The judgment criterion is: the condensed water droplets seeping from the cut surface of the feed are absorbed, but the bound water inside the feed is retained, and the feed slices maintain overall flexibility. The treated feed retains a complete sheet structure and is not pulverized. The complete sheet structure is suitable for the cutting and grasping feeding habits of 3rd instar and older larvae. In the daily management of step S305, the sheet residue is easy to remove whole with tweezers, preventing debris from remaining in the container and causing secondary mold growth.

[0068] Based on the biological differences in water requirements at different developmental stages of larvae, this embodiment establishes differentiated feed dehydration standards. These differentiated dehydration standards establish physical morphological indicators for the two feeds by controlling the number of physical pressing operations.

[0069] S304, Deep dehydration standards for feed for young larvae (1st-3rd instar): Feed for young larvae must meet the physical standards of deep dehydration and loose granulation.

[0070] Under this standard, the free water content of the feed is reduced, and the artificial feed slices, after being processed in step S302, exhibit independent, non-sticky, and non-agglomerated granules. The specific technical indicators for determining whether the differentiated dehydration standard is met are: Tactile indicators: When artificial feed pellets are gently rubbed and crushed between the fingers, the surface of the fingers does not feel wet, and there is no powdery or paste-like residue on the surface of the fingers after the pellets fall. Morphological indicators: The diameter of the crushed artificial feed pellets is distributed in the range of 1-3mm. When the pellets are piled up, air-permeable interconnected pores are naturally formed between the pellets, and the bottom pellets do not deform or collapse. Absorbent paper residue index: No visible water stains were observed on the surface of the dry absorbent paper after the final pressing operation.

[0071] The technical purpose of deep dehydration standards is to inhibit the germination of mold spores by reducing the surface humidity of the feed. Combined with the bottom water-retaining substrate and isolation mesh structure in step S204, the dried artificial feed pellets absorb moisture from the bottom environment, creating a dynamic moisture balance. This dry feed pellet environment, combined with a high-humidity environment, is specifically designed for young larvae whose bodies are highly hydrophilic and easily drowned by a water film.

[0072] S305, Surface dehydration standard for feed for older larvae (3rd-6th instar): The feed for older larvae must meet the physical standard of being dry on the surface and moist on the inside.

[0073] Under this standard, only condensate or exudate adhering to the cut surface of artificial feed due to surface tension is removed, while the bound water inside the feed matrix is ​​retained. The specific technical indicators for determining whether the differentiated dehydration standard is met are: Appearance indicators: The surface of the artificial feed slices has no reflective water film and presents a matte appearance; Structural indicators: Artificial feed slices maintain a complete geometric shape (2-4mm thick slices). When the feed slices are bent with tweezers, they undergo elastic deformation without breaking, indicating that they contain bound water. Compression index: When the cross-section of the artificial feed slices is squeezed with force using tweezers, a small amount of moisture can be seen seeping out, but no liquid flows when it is laid flat naturally.

[0074] The technical purpose of surface dehydration standards is to ensure that the mandibles of larvae older than the third instar are fully hardened, enabling them to cut fibers and directly absorb water from their food. Retaining internal moisture meets the metabolic needs of older larvae during their voracious feeding period, preventing developmental delays caused by excessively dry feed; and drying the surface reduces the risk of mold growth on the contact surface between artificial feed and containers.

[0075] S306, Adaptation of dehydration standards to mouthpart development: Two differentiated dehydration standards established a correlation between feed physical properties and the developmental stage of the mouthparts of the rice stem borer: Pelleted dry feed (for 1st to 3rd instars): It is suitable for the tiny chewing mouthparts and burrowing habits, and uses the gaps between the pellets for larvae to burrow into and feed, avoiding contact between the larvae's body surface and a large area of ​​wet feed. Flake wet feed (for 3-6 year olds): It is adapted to the well-developed chewing palate and supports the feeding pattern of grasping-cutting-swallowing.

[0076] The differentiated dehydration described in the instruction manual refers to the process of switching from the S304 standard to the S305 standard within the same breeding cycle, based on different time points in the larval growth.

[0077] The hatching rate of eggs is directly limited by environmental humidity and the degree of pathogen contamination. This embodiment divides the egg mass hatching process into a moisture-retaining stage and a transfer and colonization stage, with the specific implementation steps as follows: S307. Egg mass collection and surface disinfection: Cut rice leaves with attached rice stem borer egg masses from the adult oviposition cages. Use ophthalmic scissors to trim the rice leaves to a distance of 1-2 cm from the egg masses. Trimming excess leaf area prevents the rice leaves from becoming too large and coming into contact with the moistened filter paper in step S308, avoiding a siphon effect that could cause water accumulation on the leaves. To prevent vertical transmission of the pathogen, use a soft-bristled brush dipped in 75% medical alcohol to gently brush the surface of the egg masses and both sides of the rice leaves. After brushing, place the rice leaves on a sterile laminar flow hood to air dry naturally. Continue subsequent operations only after the alcohol has completely evaporated and there is no liquid residue on the leaf surface to prevent residual alcohol from seeping into the eggshells and killing the embryos.

[0078] S308, Establishment of an in vitro moisturizing incubation environment: Prepare a clean petri dish with a diameter of 90 mm.

[0079] Place 1-2 layers of qualitative filter paper at the bottom of the petri dish. Add sterile distilled water droplets to the filter paper, adding enough to completely wet the filter paper but without any water flowing out when the petri dish is tilted. The wet filter paper acts as a localized high humidity source, maintaining the relative humidity inside the dish close to saturation.

[0080] Lay the surface-sterilized rice leaves flat on moistened filter paper, keeping the egg mass facing upwards. Ensure the rice leaves do not overlap to prevent mold growth in overlapping areas due to poor ventilation. Cover the culture dish and place it in a constant temperature environment at 27°C in the dark. During this moist incubation stage, the egg mass does not come into contact with artificial feed and relies solely on the nutrients within the egg for development. The moisture provided by the moist filter paper prevents the eggs from drying out.

[0081] S309. Embryo Development Monitoring and Transfer Window Determination: Observe the color change of the egg mass daily.

[0082] At 27℃, the egg mass undergoes a milky white stage, a grayish stage, and finally enters the blackhead stage. During the blackhead stage, a clear black chitinous head shell (black spot) is visible through the eggshell, and the embryo exhibits wriggling motion within the egg. The appearance of the blackhead stage indicates that the larvae will hatch within 24-48 hours, which is the optimal window for transfer operations. If transfer is performed before the egg mass turns black, the rice leaves will become damp and moldy on the surface of the artificial feed; if transfer is delayed until a large number of larvae have hatched, the newly hatched larvae are highly susceptible to death from mechanical contact. Therefore, accurately capturing the blackhead stage is crucial for successful transfer.

[0083] S310. Colonization and transfer of blackhead stage egg masses and subsequent cleaning: After monitoring that the egg masses have entered the blackhead stage, rice leaves containing the egg masses are picked up with tweezers and transferred to the heterogeneous three-dimensional aquaculture device constructed in steps S201-S205. The rice leaves are laid flat on the surface of the granular dry feed layer laid in step S204, with the egg masses facing upwards. At this time, the water-retaining substrate at the bottom of the device provides humidity to the granular feed layer through the isolation net, maintaining a moist microenvironment on the leaves. After the newly hatched larvae emerge from their shells, driven by the odor of the artificial feed and their own hygroscopic tendency, they actively crawl away from the rice leaves and burrow into the gaps between the loose granular feed below to establish nests. After the egg masses have completely hatched and turned into white empty shells (usually 2-3 days after transfer), the discarded rice leaves and egg shells should be removed from the device promptly with tweezers. Timely removal of discarded leaves prevents the decay of organic matter and the growth of mold, avoiding contamination of the feed layer below.

[0084] The core of managing early larval stages (1st-3rd instar) lies in maintaining a balanced microenvironmental humidity and minimizing damage to the larvae from manual or mechanical handling. This embodiment employs a management method combining heterogeneous three-dimensional moisture retention with layered feeding. The specific implementation steps are as follows: S311. Standardized control of insect inoculation density: Based on the bottom area of ​​the culture container (approximately 63.5 cm²) 2 The larval density should be controlled at 50 to 60 larvae per container. A density range of 50 to 60 larvae balances the population's thermal effect and spatial competition: if the density is below 30 larvae, the larval population is too small and it is difficult to maintain the stability of the local microclimate between feed particles through collective respiration; if the density is above 80 larvae, as the second instar larvae increase their food intake, they are prone to biting injuries due to competition for burrowing space.

[0085] After the initial inoculation is complete, wait for the egg masses to fully hatch and count the number of active larvae. If the number exceeds the set range, use a soft brush to remove the excess larvae; if the number is insufficient, add larvae from the same batch to ensure a uniform larval population density in each container.

[0086] S312. Maintaining the dynamic balance of the three-dimensional microenvironment: A heterogeneous three-dimensional aquaculture device is used to maintain a vertical humidity gradient during the 1-3 year age period. The bottom water-retaining substrate continuously conducts water vapor upwards, and the water vapor passes through the 80-100 mesh isolation net to enter the upper feeding area.

[0087] In a vertical humidity gradient environment, the bottom granular artificial feed absorbs moisture and regains moisture, with a relative humidity of nearly 90%, which meets the physiological needs of first-instar larvae to absorb water through their skin and prevent water loss from their spiracles; the surface granular artificial feed is in direct contact with the air, with a relative humidity of around 75%, keeping it relatively dry.

[0088] By utilizing the hygrotaxis and negative phototaxis of newly hatched rice stem borer larvae, the larvae are induced to actively burrow into the gaps between the moist feed particles at the bottom to feed and inhabit. The structure of a moist bottom and a dry top prevents the larvae from dehydrating, while the dry surface layer blocks the germination of fungal spores.

[0089] S313, Stacked feeding operation: During the rearing cycle of 1st to 3rd instar larvae, a cumulative feeding operation is carried out, with only increases and no decreases.

[0090] Replenish the container with deeply dehydrated pelleted artificial feed daily at set times. The amount fed should be enough to cover the surface of the previous day's leftover feed in a thin layer (approximately 1-2 g / plate). The newly added dry pelleted feed covers the old feed, forming a new surface dry barrier.

[0091] Avoid cleaning the old feed or feces at the bottom of the container during this stage. Since 1st and 2nd instar larvae often hide deep within feed debris, cleaning can easily result in the discarding of healthy larvae. As new feed is continuously added, the old feed layer and larval excrement at the bottom are gradually compacted, transforming into a secondary water-retaining medium that helps the bottom water-retaining substrate maintain the humidity of the microenvironment.

[0092] S314. Abnormal Status Monitoring and Environmental Intervention: Observe the condensation on the container walls and lid surface daily.

[0093] If water droplets larger than 2mm in diameter appear on the container wall or water drips from the lid, it indicates poor internal ventilation. The number of gauze layers used for sealing should be reduced or the bottom humidification should be stopped.

[0094] If you find a large number of larvae crawling out of the feed layer and restless on the container wall, or if their bodies are shriveled, it indicates that the bottom layer is not moist enough. In this case, use a misting nozzle to spray a small amount of sterile water onto the gauze-sealed surface to compensate by increasing the ambient humidity and avoiding direct water spray on the feed layer, which could cause the feed to become muddy.

[0095] Monitor for mold growth. If white or green mycelial spots are found in the feed layer, immediately remove the moldy area along with the surrounding feed using tweezers.

[0096] During the later larval stages (3rd-6th instar), larvae grow and develop rapidly, consuming large amounts of food and excreting large quantities, making them susceptible to disease outbreaks due to environmental degradation. This example employs a management method combining low-density grouping with full-volume replacement feeding. The specific implementation steps are as follows: S315, Age Transfer and Dilution: When the young larvae reach a body length of 4-5 mm and show 5 clear brown longitudinal lines on their backs, they are considered to have entered the early stage of the 3rd instar, and the transfer box operation is performed.

[0097] Prepare the high-rigidity universal rearing container constructed in steps S206-S209. Using a soft brush or wide-mouthed tweezers, remove the 3rd instar larvae from their original rearing containers and transfer them to the high-rigidity universal rearing container. During the transfer, perform density dilution, adjusting the rearing density to 40-50 larvae per 100 cm² of base area. Lowering the density reduces biting injuries among larvae due to competition for food space, while also reducing the accumulation of metabolic heat per unit volume, preventing localized high temperatures from inducing stunted growth.

[0098] S316. Full-volume replacement feeding operation: During the rearing period of 3rd to 6th instar larvae, the feeding method is to clean them first and then feed them.

[0099] Before feeding each day, open the container lid and use tweezers to thoroughly remove any leftover food, fecal particles, and filamentous webs expelled by the larvae from the previous day. Removing the filamentous webs prevents fecal accumulation and moisture absorption. Remove any dead or weak individuals. After cleaning, add the surface-dehydrated flake feed treated to S305 standards. Adjust the feeding amount dynamically according to the larvae's age, ensuring a slight surplus for the next day (typically 5-8g per 50 larvae per day). The intact flake feed structure suits the feeding habits of older larvae, reducing debris shedding, keeping the bottom of the container clean and dry, and preventing bacterial soft rot.

[0100] S317, Environmental control for bare-bottom rearing without substrate: Older larvae mainly maintain their body fluid balance by consuming artificial feed containing bound water, and no longer rely on osmotic water absorption from the environment.

[0101] For older larvae, the bottom of the rearing container is not lined with moisturizing sponges or agar; a bare-bottom rearing method without substrate is used. A 60-80 mesh stainless steel mesh on top of the container, combined with the substrate-free environment, maintains the relative humidity inside the container at 60%-70%. Lower humidity accelerates the drying process of the large amounts of feces excreted by older larvae, and dried feces are unfavorable for pathogen growth. In extremely dry weather with relative humidity below 50%, a small amount of sterile water mist is sprayed onto the mesh surface to regulate humidity, preventing water from condensing directly at the bottom of the container and forming water accumulation.

[0102] S318. Escape prevention and bite detection: Check the sealing of the high-hardness general-purpose feeding container daily and observe whether there are signs of chewing or loosening at the hot melt adhesive fixation points in step S209.

[0103] Fifth and sixth instar larvae have strong mandibles and a strong bite. If scratches are found on the inner wall of the plastic container or the mesh is damaged, replace the container immediately. Minimize the time the lid is open during operation to prevent active older larvae from crawling out along the container wall and escaping.

[0104] S319. Disease prevention measures: During routine cleaning, monitor the larvae's body color and behavior.

[0105] If the larvae are found to have turned black, become limp (suspected soft rot), or have black spots or stiffness on their surface (suspected stiffness disease), immediately implement isolation procedures.

[0106] Use specialized tweezers to remove the diseased larvae and their entire container from the rearing room. Tweezers that have come into contact with the diseased larvae must be immediately immersed in 75% alcohol or flame-sterilized to prevent cross-contamination of pathogens to other healthy containers. For the remaining outwardly healthy larvae in the diseased container, replace them with a new container and isolate them for 24 hours. Continue rearing only after confirming the absence of symptoms. The original diseased container and waste should be autoclaved or incinerated to prevent horizontal transmission of the pathogen.

[0107] The mature larval stage is the crucial transition period for the rice stem borer from vegetative to reproductive growth. Mature larvae are sluggish and have weak defenses, making them vulnerable to attacks from more active larvae of the same species. This embodiment employs a management method combining induced pupation and physical isolation. The specific implementation steps are as follows: S320, the application and parameter matching of the pupation induction medium: When the larvae in the container have grown to the 5th or 6th instar and some individuals have begun to stop feeding, pupation induction medium is introduced into a high-hardness general-purpose rearing container.

[0108] The pupation induction medium is dry, mold-free corrugated cardboard. The cardboard should be B-flute or C-flute, with the wavy pore diameter controlled at 3.5-4.5 mm. This pore diameter is slightly larger than the body width of mature larvae, satisfying their biological instinct to seek narrow spaces for dorsal contact (tactile attraction). The corrugated cardboard is cut into strips 2-3 cm wide and placed vertically or at an angle along the edge of the container. Mature larvae actively leave the artificial feed layer, burrow into the pores of the corrugated cardboard, and spin cocoons. The corrugated cardboard structure provides the larvae with physical support and a light-protected environment.

[0109] S321. Morphological identification and transfer of prepupal individuals: Inspect the rearing containers daily to identify mature larvae in the prepupae stage.

[0110] The morphological characteristics of prepupal individuals are as follows: the body shortens from a slender cylindrical shape to a spindle shape, the body segments contract significantly, the abdominal color changes from yellowish-brown to milky white or pale yellow, and they become unresponsive to external touch. Individuals exhibiting prepupal morphological characteristics, or those that have burrowed into corrugated cardboard and sealed themselves with silk, should be removed from the group rearing container using tweezers. Timely removal of prepupal individuals prevents active feeding larvae from biting resting prepupal individuals, thus preventing fluid loss or pathogen invasion due to epidermal damage.

[0111] S322. Collection, sex identification, and non-contact moisturizing of pupae: Transfer the removed pre-pupae or corrugated cardboard pieces containing pupae to individual molting boxes.

[0112] A moistened filter paper is placed at the bottom of the emergence box, and a dry nylon mesh or plastic pad is placed on top of the filter paper. The naked pupa or corrugated cardboard piece is placed on the nylon mesh or plastic pad, ensuring that the pupa does not directly contact the liquid water or the surface of the moistened filter paper. The water vapor evaporating from the moistened filter paper at the bottom maintains the relative humidity inside the emergence box at 85%-90%. This high humidity meets the pupa's respiratory and metabolic water requirements while preventing direct contact with a water film that could cause spiracular blockage or fungal infection.

[0113] Sexing was performed on the third day after pupation, when the pupal body hardened and turned reddish-brown. The identification was based on the characteristics of the genital opening at the end of the pupal abdomen: in male pupae, the genital opening was located on the 9th abdominal segment, with a longitudinal fissure in the center of the ventral surface and flat sides; in female pupae, the genital opening was located on the 8th and 9th abdominal segments, with a longitudinal fissure in the center of the ventral surface and semi-circular protrusions on both sides. Based on the identification results, male and female pupae were placed in separate emergence boxes.

[0114] S323, Temperature control synchronization of feathering progress: Monitor the developmental progress of pupae within the emergence box.

[0115] Six to seven days after pupation, the compound eyes and wing buds of the pupa are clearly visible. To ensure synchronized emergence of male and female adults, temperature intervention was applied to pupae with abnormal development. Pupae with prematurely blackened compound eyes (overly rapid development) were temporarily stored at 20-22℃ to slow their metabolic rate and delay emergence; pupae with lighter-colored compound eyes (delayed development) were maintained at 27-28℃. Through differential temperature control, the peak emergence period of male and female pupae in the same batch was concentrated within a 24-48 hour time window, providing a synchronized breeding stock for subsequent adult pairing.

[0116] Adult stage management is crucial for the propagation of the rice stem borer population and the acquisition of high-quality egg masses for the next generation. The goals of adult stage management are to increase the mating rate of adults and the number of eggs laid by a single female, while ensuring that the egg masses are not contaminated. This embodiment employs a management method combining synchronous pairing and periodic egg collection. The specific implementation steps are as follows: S324. Adult synchronous pairing and density control: Using the temperature-controlled synchronized pupae from step S323, pairing was completed within 24 hours after emergence.

[0117] Identified male and female adults were placed in semi-enclosed mating chambers at a sex ratio of 1:1.2. This 1:1.2 ratio (with slightly more males) compensates for the decline in sperm motility in males after multiple matings. Competition among males encourages females to fertilize quickly in the early stages of emergence, preventing the production of unfertilized eggs due to delayed mating. The density was controlled at 30-40 pairs of adults per 40-60L mating chamber. This density ensures sufficient space for courtship flight while increasing the frequency of physical contact between males and females within the limited space. Too high a density would cause frequent mechanical collisions during flight, interrupting the mating process; too low a density would result in insufficient sex pheromone concentration, leading to prolonged courtship positioning time.

[0118] S325. Environmental induction of mating behavior during the dark period: The photoperiod is maintained at 16L:8D. The mating behavior of the rice stem borer is diurnal and rhythm-dependent, with the mating peak concentrated within 2-4 hours after the start of the dark period.

[0119] One hour before the dark period begins, use a misting nozzle to spray sterile water mist onto the nylon mesh surface of the operating window, raising the relative humidity in the mating chamber to 85%-90%. This high humidity environment slows down the drying and hardening of the sticky cerum secreted by the female's accessory glands, ensuring that the laid egg masses have sufficient time to adhere firmly to the rice leaf surface. If the environment is too dry, the cerum quickly loses water and hardens, resulting in insufficient adhesion of the egg masses, causing them to fall off the leaves.

[0120] S326. Dynamic replenishment and mold prevention of nutrient solution: Check the nutrition supply unit daily. Every 24 hours, remove the cotton ball soaked in 1% honey water and replace it with a new cotton ball soaked in fresh honey water.

[0121] The high temperature and humidity in the mating chamber can cause the sugar water to ferment within 24 hours, producing ethanol or acidic substances. Adult insects that ingest the spoiled sugar water will experience abdominal swelling and death, or a decrease in egg production. Uneaten and dried cotton balls should not be reused with fresh solution; they must be discarded entirely to maintain the sterility of the nutrient source.

[0122] S327. Egg mass harvesting under photoperiod quiescence: Adults begin laying eggs on the second day after pairing, with the peak egg-laying period occurring from the third to the fifth day.

[0123] Perform periodic egg mass harvesting. Harvesting must be strictly limited to the photophase. Under light conditions, adult rice stem borers are in a dormant state, mostly residing on the undersides of rice leaves or in the corners of the container, and are not easily disturbed. The harvesting method uses whole-plant replacement. Open the mating chamber's operating window and gently remove the rice planting cup containing the egg mass as a whole, immediately placing a fresh, ready-made rice planting cup inside. Whole-plant replacement avoids the vibration caused by directly cutting leaves inside the mating chamber, preventing adults from being startled and escaping. The removed rice planting cup is placed on an external operating table, and leaves containing the egg mass are cut off with scissors for subsequent disinfection and hatching.

[0124] S328. Termination of reproductive cycle and group clearing: The breeding cycle ends on the 7th day after the adult emerges.

[0125] After the 7th day, the female insects' fat bodies are depleted, resulting in a significant decrease in egg production and hatching rate. On the 7th day, the mating chamber is cleaned. All remaining live adults and dead insects are removed, and the waste is either frozen or incinerated. The emptied mating chamber is then soaked and cleaned in a 0.5% sodium hypochlorite solution, and then placed in a ventilated area to air dry for 24 hours until the chlorine has completely evaporated before use for the next batch of adults to mate. Residual chlorine can corrode and poison the spiracles of the next batch of adults; therefore, complete evaporation must be ensured.

[0126] To verify the effectiveness of the breeding method proposed in this application, the following comparative experiment was conducted: Control group: The conventional high-moisture artificial feed described in the background art was used for uniform feeding throughout generations in a general glass bottle.

[0127] Experimental groups were set up: the differentiated dehydrated feed described in this embodiment was used, and the animals were grouped and reared according to their age using a heterogeneous three-dimensional aquaculture device and a high-hardness universal feeding container.

[0128] Two groups were inoculated with the same batch and number of black-headed rice stem borer egg masses (500 eggs in each group). They were cultured under identical environmental temperature, humidity, and photoperiod parameters. The drowning rate during the 1-3 instar period, the incidence of soft rot and stunted growth during the 3-6 instar period, and the final survival rate across all generations were recorded for both groups. Specific experimental data are shown in Table 1.

[0129] Table 1. Comparison of survival rates of rice stem borer between the control and experimental groups.

[0130] Note: The final full-generation survival rate in the table includes samples that have pupated but not emerged, and the final full-generation survival rate is experimental data and is not calculated based on the 1-3 instar larval drowning rate and the 3-6 instar disease incidence rate.

[0131] The data in Table 1 show that, using the indoor artificial breeding method described in this application, the mortality rate of larvae in the 1st to 3rd instar larvae in the experimental group was significantly lower than that in the control group, and the incidence of diseases in the 3rd to 6th instar larvae was effectively controlled. These data confirm that the age-specific refined management and differentiated feed preparation method described in this application completely solves the technical problems of early-age drowning and frequent diseases in older larvae during conventional breeding, significantly improving the survival rate and population propagation efficiency of the rice stem borer across all generations.

[0132] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for indoor artificial breeding of rice stem borers, characterized in that, Includes the following steps: Environment construction steps: Set constant temperature, humidity and photoperiod parameters in an artificial climate chamber or intelligent incubator; Feed preparation steps: Prepare artificial feed, and according to the age differences of the rice stem borer larvae, perform differentiated dehydration treatment on the artificial feed to prepare granular dry feed suitable for young larvae and flake micro-dehydrated feed suitable for older larvae. Hatching and colonization steps: Place the rice stem borer egg mass in a humid environment for incubation. After it develops to the blackhead stage, transfer it along with the attached substrate to a heterogeneous three-dimensional aquaculture device and colonize it using granular dry feed. Management steps for young larvae: During the 1st to 3rd instar larval stage, use a heterogeneous three-dimensional breeding device to maintain a vertical humidity gradient and perform superimposed feeding operations. Management steps for older larvae: When the larvae develop to the early stage of the 3rd instar, transfer them to a high-hardness general-purpose rearing container and rear them in a bare-bottom environment without substrate, and perform full replacement feeding. Pupation management steps: Induce mature larvae to pupate by releasing pupation induction medium, collect the pupae and synchronize their emergence under temperature control; Adult management steps: After emergence, the adults are placed in a semi-enclosed mating chamber for synchronous pairing, and egg masses are collected periodically.

2. The method for indoor artificial breeding of rice stem borers according to claim 1, characterized in that, In the environmental setup step, the temperature is set to 27±1℃; the humidity is set to 75±5%RH; and the photoperiod is set to 16L:8D. In the hatching and colonization steps, the criteria for determining the blackhead stage are that the embryo's head is clearly visible through the eggshell, forming a black chitinous head shell, and the embryo is wriggling inside the egg; during transfer, the substrate carrying the egg mass is spread evenly on the surface of the granular dry feed layer, keeping the egg mass side facing upwards.

3. The method for indoor artificial breeding of rice stem borers according to claim 1, characterized in that, In the feed preparation steps, the differentiated dehydration treatment specifically includes: For 1st to 3rd instar larvae, implement the deep dehydration standard: physically press the artificial feed slices 3 to 4 times to absorb water until there are no obvious wet watermarks on the surface of the absorbent paper, and crush the feed into loose particles with a diameter of 1-3mm, which do not stick together and do not deform or collapse when piled up. For larvae in their 3rd to 6th instar, the surface dehydration standard is applied: the artificial feed slices are physically pressed once to absorb water, removing the condensed water droplets seeping from the cut surface but retaining the internal bound water, so that the surface of the feed slices is matte and can undergo elastic deformation without breaking when bent.

4. The method for indoor artificial breeding of rice stem borers according to claim 1, characterized in that, In the management step of young larvae, the heterogeneous three-dimensional culture device is constructed as follows: A sterilized slow-release moisture substrate is laid at the bottom of the transparent aquaculture container; A physical barrier mesh with a pore size of 80 to 100 mesh is covered on top of the water-release matrix, and the edge of the physical barrier mesh is tightly fitted to the inner wall of the container; The granular dry feed is stacked and laid on top of the physical isolation net to form a breathable porous space for larvae to bore into; The top of the container is sealed with a breathable material with a mesh size of less than 80 mesh.

5. The method for indoor artificial breeding of rice stem borers according to claim 4, characterized in that, In the management steps for young larvae, the superimposed feeding operation specifically includes: Add new granular dry feed to the container daily, covering the surface of the feed residue from the previous day to form a new surface dry barrier. Do not clean the old feed and excrement at the bottom, so that the old feed layer is compacted and transformed into a secondary water-retaining medium. When the larvae are found to be shriveled or there is no condensation on the container walls, use a misting nozzle to spray sterile water onto the surface of the breathable material seal, and avoid spraying water directly onto the feed layer.

6. The method for indoor artificial breeding of rice stem borers according to claim 1, characterized in that, In the management of older larvae, the high-hardness general-purpose rearing container is made of polypropylene or polycarbonate with a wall thickness greater than 0.5mm; the container lid has ventilation windows covering 50%-70% of the total area, and 60-80 mesh 304 stainless steel mesh is installed at the windows using a hot-melt embedded fixing process. The substrate-free bare bottom environment refers to a container where no slow-release moisture substrate is laid at the bottom, and the relative humidity inside the container is maintained at 60%-70% by using the ventilation window at the top of the container.

7. The method for indoor artificial breeding of rice stem borers according to claim 1, characterized in that, In the management steps for older larvae, the full replacement feeding operation specifically involves: before feeding each day, thoroughly cleaning and removing the leftover feed, fecal particles, and filamentous webs expelled by the larvae from the container from the previous day, and then adding the flake-shaped micro-dehydrated feed. If, during the cleaning process, larvae are found to have turned black, become limp, or have black spots on their surface, the diseased larvae and their containers should be immediately removed and isolated, and the tools that have come into contact with them should be disinfected.

8. The method for indoor artificial breeding of rice stem borers according to claim 1, characterized in that, In the pupation management step, the pupation induction medium is selected from corrugated paper sheets of B-flute or C-flute type, with a wavy pore diameter of 3.5-4.5 mm. After collecting the pupae, place them on a nylon mesh or plastic pad inside the emergence box. Maintain humidity by the water vapor evaporating from the bottom moist filter paper to ensure that the pupae do not come into direct contact with liquid water or the surface of the moist filter paper. During temperature-controlled synchronized eclosion, pupae with prematurely darkened compound eyes were temporarily stored in an environment of 20-22℃, while pupae with lighter-colored compound eyes were maintained in an environment of 27-28℃.

9. The method for indoor artificial breeding of rice stem borers according to claim 1, characterized in that, In the adult insect management step, the construction of the semi-enclosed mating chamber includes: An operating window, occupying 10%-15% of the total surface area, is opened in the enclosure and covered with 80-100 mesh nylon mesh. The prepared rice oviposition substrate is placed at the bottom of the box. The rice oviposition substrate is a rice plant in the tillering stage that has been transplanted into a cup and whose mouth is completely sealed with plastic wrap, leaving only the rice stems protruding. Place defatted cotton balls soaked in 1% honey water at the bottom of the box as a nutrient supply unit.

10. The method for indoor artificial breeding of rice stem borers according to claim 9, characterized in that, The adult insect management steps also include: One hour before entering the dark period, sterile water mist is sprayed onto the surface of the window screen of the semi-enclosed mating chamber to increase the relative humidity to 85%-90%. After entering the photoperiod, the periodic harvesting of egg masses is carried out. The operation window is opened, the rice egg-laying substrate with attached egg masses is removed as a whole, and replaced with fresh rice egg-laying substrate.

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