A method for extending the lifespan of ladybugs using alternative feeds

Abstract

The present invention relates to a method for extending the lifespan of ladybugs using an alternative feed. The method comprises feeding the ladybugs with natural prey for a first cycle, followed by feeding them with the alternative feed. The alternative feed comprises rice moth eggs, and the ladybugs are Japanese scimitar beetles. The first cycle is the time from newly hatched larvae to the second instar, or from newly hatched larvae to the first emergence of adults. The method uses rice moth eggs as an alternative feed to feed the scimitar beetles, thereby reducing the human and material resources required for large-scale production of ladybugs and extending their shelf life while ensuring the quality of their natural enemies.

Description

Technical Field

[0001] The invention belongs to the technical field of biological control, and in particular relates to a method for extending the lifespan of ladybugs by utilizing alternative feed. Background Art

[0002] Bemisia tabaci, a member of the Aleyrodidae family of the order Hemiptera, is a major pest with a worldwide distribution. It is a polyphagous pest that hosts over 600 plant species. Its nymphs and adults suck plant sap, secreting honeydew that causes sooty mold, turning leaves black and impairing photosynthesis. It can also transmit viruses and cause various plant diseases, causing significant economic losses to global agricultural production.

[0003] Currently, chemical control of Bemisia whitefly is primarily carried out, with effective pesticides including neonicotinoids, new amides, and pyrethroids. However, irrational use of insecticides has led to varying degrees of resistance in Bemisia whitefly to various insecticides. Two biotypes of Bemisia whitefly (B and Q) in southeastern China have been found to exhibit moderate to high levels of resistance to both neonicotinoids and moderate to high levels of resistance to α-cypermethrin.

[0004] Faced with the control difficulties brought about by the rapid increase in the pesticide resistance of whiteflies, biological pest control technologies such as "using insects to control insects" and "using bacteria to control insects" are effective means of controlling whiteflies.

[0005] The scimitar beetle, a member of the tribe Serangini, Coccinellidae, Coleoptera, is a specialized predator of whiteflies, including Bemisia tabaci, Aleurocanthus spiniferus, Dialeurodes citri, and Trialeurodes vaporariorum. It is highly effective in controlling whiteflies, with female adults and fourth-instar larvae consuming up to 723.7 and 814.1 eggs per day, respectively.

[0006] The Japanese ladybug, Serangium japonicum, is an important natural enemy of whitefly pests. It is widely distributed in southern my country and is only found in Japan. Its larvae and adults of all ages can feed on whiteflies of different insect stages, especially eggs. It has the advantages of a short reproduction cycle and a large egg production. It can effectively control the growth of the whitefly population in a short period of time and has great development and utilization value.

[0007] As a key group of predatory natural enemies, ladybugs have garnered significant research interest in developing their applications in biological control. While propagating prey on host plants has successfully enabled laboratory propagation of these predatory ladybugs, current propagation of horned ladybugs relies primarily on whitefly nymphs on host plants, requiring significant human and material resources. Therefore, large-scale production is essential for the practical application of predatory ladybugs in biological control. Traditional rearing methods that rely on natural prey require large quantities of both prey and host plants. Environmental factors such as temperature, photoperiod, and humidity also significantly impact prey propagation, making maintaining the continuity of the complex tertiary nutrient system a significant challenge. Large-scale propagation of predatory ladybugs using prey requires significant human and material resources, and high production costs have been a key bottleneck preventing widespread application of predatory ladybugs in agriculture and forestry. Therefore, large-scale propagation of natural enemies using low-cost feed is essential for the promotion and application of biological control. The market urgently needs new, efficient, and environmentally friendly biological control technologies to address the sustainable control of the resistant whitefly pest and provide technical support for the production of green food.

[0008] In the existing technology, researchers have focused their attention on other more easily obtained Lepidoptera eggs as alternative feeds. Feeding Lepidoptera eggs and other alternative feeds can support the development of ladybug larvae, but compared with larvae fed with natural prey, it usually leads to longer development time and lower survival rate of ladybugs.

[0009] Ding Xueling et al. studied the effects of two alternative prey items on the growth, development, and fecundity of Japanese horned ladybirds. Using Bemisia tabaci eggs as a control, they investigated the effects of Mediterranean mealybug eggs and rice moth eggs on the growth, development, and fecundity of Japanese horned ladybirds. The results showed that when the Japanese horned ladybirds were fed rice moth eggs throughout their lifespan from larvae to adulthood, the survival rate was 17.16%, their developmental period was significantly prolonged, and the lifespan of females was significantly shortened. However, when the Japanese horned ladybirds were fed Mediterranean mealybug eggs, the survival rate was 77.82%, and the lifespan of females was significantly prolonged. Mediterranean mealybug eggs can serve as an alternative prey item for ladybird larval rearing. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a method for extending the lifespan of ladybugs by using alternative feeds. The eggs of the rice moth are used as an alternative feed for the cut-horned ladybugs and are fed alternately with natural prey, thereby extending the lifespan of the ladybugs, solving the problems of large-scale breeding and long-term storage of cut-horned ladybugs, realizing the industrialization of cut-horned ladybugs, and providing theoretical and technical support for the biological control of whitefly pests.

[0011] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0012] A method for extending the lifespan of ladybugs by using alternative feeds. The method comprises feeding the ladybugs with natural prey for a first cycle and then feeding them with the alternative feed. The alternative feed is rice moth eggs and the ladybugs are Japanese swordtail beetles. The first cycle is the time from the newly hatched larvae to the second instar or the time from the newly hatched larvae to the first emergence of adults.

[0013] Preferably, the first period is the time from the newly hatched larvae of the ladybug to the second instar.

[0014] Preferably, the first period is the time from when the ladybug larvae are newly hatched to when they first emerge as adults.

[0015] More preferably, the ladybugs are fed with rice moth eggs for a second cycle and then fed with natural prey.

[0016] More preferably, the second period is less than or equal to 50 days, preferably 30-50 days.

[0017] Preferably, the rice moth eggs are fresh rice moth eggs that are inactivated with ultraviolet light.

[0018] Preferably, the natural prey is Bemisia tabaci nymphs.

[0019] Preferably, the breeding temperature of ladybugs is 20°C-30°C.

[0020] Preferably, the rearing photoperiod L:D of ladybugs is 12-14:10-12.

[0021] Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art:

[0022] 1. The present invention confirms the feasibility of using rice moth eggs as an alternative feed for the cutworm, solving the technical bottleneck problem of large-scale breeding of the cutworm;

[0023] 2. The present invention analyzes and studies the effect of feeding rice moth eggs on the lifespan of ladybugs, and for the first time proposes to use alternative feeds to replace low-temperature storage to extend the shelf life, while solving the problems of transportation conditions and food. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a graph showing the lifespan of the horned ladybugs fed different food combinations during the juvenile and adult stages of Example 1, wherein: Figure 1a This is the lifespan analysis chart of female ladybugs. Figure 1b This is a chart analyzing the lifespan of male ladybirds;

[0025] Figure 2 This is a graph analyzing the hatching rate of the eggs of the cutworm beetle fed different food combinations during the juvenile-adult stage of Example 1;

[0026] Figure 3 This is a graph analyzing the survival rates of the generations of the horned ladybugs fed different food combinations during the juvenile and adult stages of Example 1;

[0027] Figure 4 This is an analysis chart of the developmental history of generations of the Cercis horned ladybug fed with different food combinations during the juvenile and adult stages of Example 1;

[0028] Figure 5 This is a graph analyzing the predation of the fourth-instar larvae of the first generation of Coccinella hornediformis fed with different food combinations during the juvenile-adult stage in Example 1 on the fourth-instar nymphs of Bemisia tabaci;

[0029] Figure 6 This is a graph showing the lifespan of female Coccinella serrata that were fed with oryzae moth eggs for different periods of time and then fed with Bemisia tabaci in Example 2;

[0030] Figure 7 This is a graph showing the generational survival rate of Coccinella officinalis when fed with rice moth eggs for different periods of time and then fed with Bemisia tabaci in Example 2;

[0031] Figure 8 This is an analysis of the developmental stages of the first generation of Coccinella hornediflora after feeding on rice moth eggs for different periods of time and then feeding on Bemisia tabaci in Example 2;

[0032] Figure 9 This is an analysis chart of the daily predation of the fourth-instar larvae of the first generation of Coccinella hornediformis on the fourth-instar nymphs of Bemisia tabaci after feeding on the oryzae moth eggs of Example 2 for different periods of time and then feeding on Bemisia tabaci;

[0033] Figure 10 A picture of Japanese ladybirds feeding on rice moth eggs;

[0034] Figure 11 A photo of an adult Japanese cutlass beetle feeding on a whitefly larva. DETAILED DESCRIPTION

[0035] To make the technical solutions and beneficial effects of the present invention more clearly understood, the following is a detailed description of the present invention by combining the accompanying drawings and listing specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0036] The applicant found in the study that using rice moth eggs as an alternative feed for large-scale breeding of cuttlefish can effectively prolong the lifespan of ladybugs.

[0037] The present invention discloses a method for extending the lifespan of ladybugs by utilizing alternative feeds. The method comprises the following steps: feeding the ladybugs with natural prey for a first cycle and then feeding them with the alternative feeds. The alternative feeds are rice moth eggs, and the ladybugs are Japanese swordtail beetles. The first cycle is the time from newly hatched larvae to the second instar or the time from newly hatched larvae to the first emergence of adults.

[0038] In certain embodiments, the first period is the period from newly hatched larvae to the second instar of the ladybug.

[0039] In certain embodiments, the first period is the time from when a ladybug larvae first hatches to when it first emerges as an adult.

[0040] In certain embodiments, the ladybugs are fed with rice moth eggs for a second cycle and then switched to natural prey.

[0041] In some embodiments, the second period is less than or equal to 50 days, preferably 30-50 days, and more specifically 30 days, 40 days, or 50 days.

[0042] In certain embodiments, the rice moth eggs are fresh rice moth eggs that are inactivated using ultraviolet light.

[0043] In certain embodiments, the natural prey is Bemisia tabaci nymphs.

[0044] In certain embodiments, the ladybugs are reared at a temperature of 20°C-30°C, preferably 22-28°C, and more preferably 26±2°C.

[0045] In certain embodiments, the rearing photoperiod L:D of the ladybugs is 12-14:10-12, preferably 13-14:10-11, and more preferably 14:10.

[0046] Unless otherwise specified, the methods and conditions described in the literature are generally based on the conventional techniques and conditions described in the literature, or on the conditions recommended by the manufacturer. All materials used are commercially available products unless otherwise specified.

[0047] The research materials used in the examples are as follows:

[0048] Test plants: cotton Gossypium spp.: variety Lumianyan No. 32.

[0049] Test insects:

[0050] Bemisia tabaci: a laboratory population maintained using cotton seedlings as hosts.

[0051] Japanese horned ladybird: a laboratory population maintained by subculture on Bemisia tabaci nymphs on cotton seedlings.

[0052] Rice moth eggs were purchased from Guangzhou Yuefeng Biological Control Technology Co., Ltd. The rice moth was artificially reared according to the method of Yang Liwen et al. (2014). Specifically, the larvae were reared indoors (temperature: 25℃-28℃, humidity: 60%-80%) using a feed of corn flour: soybean flour: wheat bran in a ratio of 7:2:1 by weight. The larvae were reared in 455 mm × 325 mm × 40 mm insect boxes. After the larvae emerged, the adults were collected in 100 mm × 50 mm mesh bags to lay eggs. Fresh rice moth eggs were collected every day and inactivated with ultraviolet light for testing.

[0053] Insect rearing room conditions: temperature 26±2℃, photoperiod L:D: 14:10.

[0054] Instrument consumables:

[0055] Intelligent artificial climate incubator (RXZ-436E-LED): Ningbo Jiangnan Instrument Factory, insect stereoscope (Stemi508): Zeiss.

[0056] Insect cage: 60cm×60cm×60cm, Petri dish: φ=60mm, h=10mm, finger-shaped tube: φ=8mm, h=30mm, cotton wool, fine soft brush, tweezers, scissors, tray, etc.

[0057] Data processing: Excel 2010 and SPSS 22.0 software were used for data processing and analysis.

[0058] Example 1

[0059] Newly hatched larvae of the cutthroat beetle were collected and fed Bemisia tabaci nymphs to obtain newly emerged adults. These newly emerged adults were divided into two groups and fed Bemisia tabaci nymphs (control group) and rice moth eggs (WR group). Within each group, the sexes were matched and individual pairs of adults were placed in petri dishes for further rearing. Newly hatched larvae of the cutthroat beetle were collected and fed Bemisia tabaci nymphs until the second instar, followed by rice moth eggs until pupation. These newly emerged adults were divided into two groups and fed Bemisia tabaci nymphs (RW group) and rice moth eggs (RR group). Within each group, the sexes were matched and individual pairs of adults were placed in petri dishes for further rearing. Cutthroat beetles fed Bemisia tabaci nymphs at all stages served as controls to compare the effects of feeding on rice moth eggs at different stages on the lifespan of cutthroat beetles. Diet was changed daily, and survival of cutthroat beetles was recorded. Ten replicates were set up for each treatment.

[0060] Eggs from the four treatments were collected and checked twice daily for hatching. After hatching, newly hatched larvae were transferred to finger-shaped tubes using a soft brush and housed individually. The tubes were sealed with absorbent cotton balls. Leaves containing whitefly nymphs were replaced daily until the larvae pupated. The hatching rate, generational developmental duration, and generational survival rate of the first generation of whiteflies fed on rice moth eggs at different stages were observed and recorded. Thirty eggs were observed for each treatment, with three replicates.

[0061] Clean cotton seedlings were placed in insect cages and inoculated with adult whiteflies for 24 hours. Afterward, the adult whiteflies were removed. Eggs laid by adult whiteflies on the cotton leaves were allowed to hatch into nymphs, which then developed to the fourth instar. Second-generation larvae from the four treatments were fed with nymphs until the nymphs reached the fourth instar. A single larva was starved for 12 hours in a Petri dish, then placed on a cotton leaf containing 100 fourth-instar whiteflies. After 24 hours, the number of remaining whitefly nymphs in each dish was checked. Ten replicates were used for each treatment.

[0062] Result Analysis

[0063] 1. Effects of feeding on rice moth eggs on the lifespan of female Coccinella serrata

[0064] The lifespan of the larval-adult ladybirds fed different diet combinations is shown in Figure 1 (the bars in the figure are mean values, the error bars are standard errors, and the same letters indicate no significant differences at the 0.05 level (Tukey method)). The lifespan of female ladybirds fed on rice moth eggs was significantly affected (F 3,36 =8.29, P < 0.001). The lifespan of females in the RW group was 97.60 days, which was not significantly different from the 100.80 days of females in the control group. The lifespans of females in the WR and RR groups were 128.10 and 122.7 days, respectively, with no significant difference. However, the lifespans of females in the WR and RR groups were significantly longer than those in the control group. The lifespan of males of the cutthroat ladybird feeding on rice moth eggs was not significantly different from that in the control group.

[0065] The results showed that feeding on rice moth eggs during the larval stage had no significant effect on the lifespan of female Coccinella serrata; feeding on rice moth eggs during the adult stage significantly increased the lifespan of female Coccinella serrata.

[0066] 2. Effects of feeding on rice moth eggs on the development, survival, and predation ability of the first generation of Coccinella serrata

[0067] The hatching rate of the eggs of the cutworm beetle with different food combinations during the juvenile to adult stage is shown in the attached Figure 2 (The bars in the figure are mean values, the error bars are standard errors, and the same letters indicate no significant difference at the 0.05 level (Tukey method)). The survival rates of the first and second generations of the horned ladybugs fed different food combinations during the juvenile and adult stages are shown in the attached figure. Figure 3 (The bars in the figure are mean values, the error bars are standard errors, and the same letters indicate no significant difference at the 0.05 level (Tukey method).) The hatching rate and generational survival rate of the eggs laid by the females of the larval or adult stage of the cutworm feeding on the rice moth eggs were not significantly different from those of the control group (F 3,8 =3.83, P=0.057; F 3,8 =4.00, P=0.052).

[0068] The developmental history of the first generation of the horned ladybug fed with different food combinations during the juvenile and adult stages is shown in the attached figure. Figure 4 (The bars in the figure are mean values, the error bars are standard errors, and the same letters indicate no significant difference at the 0.05 level (Tukey method).) The amount of prey that the fourth-instar larvae of the first generation of the horned ladybird fed different food combinations on the fourth-instar nymphs of the whitefly is shown in the attached figure. Figure 5 (The bars in the figure are mean values, the error bars are standard errors, and the same letters indicate no significant difference at the 0.05 level (Tukey method).) There were no significant differences in the developmental duration of the first generation and the amount of prey preyed on the fourth instar nymphs of Bemisia tabaci by the fourth instar larvae of the first generation in the treatment group compared with the control group (F 3,8 =2.57, P=0.127; F 3,8=21.80, P=0.651).

[0069] The results showed that when the larvae or adults of the cutworms fed on the eggs of the rice moth and their offspring preyed on whiteflies, it would not affect the generation survival rate, developmental period and predation ability of whiteflies.

[0070] In summary, feeding rice moth eggs during larval stages had no significant effect on the reproductive capacity or biological characteristics of offspring of horned ladybirds that normally feed on whiteflies during adult stages. During large-scale propagation of horned ladybirds, feeding rice moth eggs to older larvae can reduce the labor and material costs of propagating whiteflies while ensuring the quantity and quality of reared adults.

[0071] Example 2

[0072] Newly hatched larvae of the horned ladybird (Schistos horned beetle) were collected and fed with Bemisia tabaci nymphs to produce newly emerged adults. Male and female adults were paired and placed in petri dishes. Freshly inactivated eggs of the larvae (Schistos oryzae) were added daily to the dishes. After 30, 40, 50, and 60 days, the cotton leaves infested with Bemisia tabaci nymphs were replaced daily. A control group was fed Bemisia tabaci nymphs throughout the treatment. Ladybird survival was recorded daily. Ten replicates were performed for each treatment.

[0073] Egg masses were collected from female cutthroat beetles during peak egg-laying periods in the treatment groups. Egg hatching was checked twice daily. After hatching, newly hatched larvae were transferred to finger-shaped tubes using a soft brush and individually housed. The tubes were sealed with absorbent cotton balls. Leaves containing whitefly nymphs were replaced daily until the larvae pupated. The hatching rate, generational developmental duration, and generational survival rate of the first-generation cutthroat beetles fed on rice moth eggs were observed and recorded. Thirty eggs were observed in each treatment group, with three replicates.

[0074] Clean cotton seedlings were placed in an insect cage and inoculated with adult whiteflies for 24 hours. The adult whiteflies were then removed by suction. Eggs laid by adult whiteflies on the cotton leaves were allowed to hatch into nymphs, which then developed to the fourth instar. The second-generation larvae from this treatment were then fed with nymphs until they reached the fourth instar. A single larva was starved for 12 hours in a Petri dish, after which it was placed on a cotton leaf containing 100 fourth-instar whiteflies. After 24 hours, the number of remaining whitefly nymphs in each dish was checked. Ten replicates were used for each treatment.

[0075] Result Analysis

[0076] 1. Effects of alternating feeding on rice moth eggs and whiteflies on the lifespan of the cutworm

[0077] The lifespan of female Coccinella serrata fed on oryzae moth eggs for different periods of time and then fed on Bemisia tabaci nymphs is shown in the attached figure. Figure 6(The bars in the figure are mean values, the error bars are standard errors, and different letters indicate significant differences at the 0.05 level (Tukey method).) The time when female horned ladybirds feed on rice moth eggs before switching to whiteflies has a significant effect on the lifespan of the ladybirds (F 4,45 =6.58, P < 0.001). Female C. serrata fed on 40, 50, and 60 days of rice moth eggs before switching to Bemisia tabaci was significantly longer-lived than the control (101.18 days). Female C. serrata fed on 30 days of rice moth eggs before switching to Bemisia tabaci nymphs had a lifespan of 111.78 days, which was not significantly different from the control or treatment groups. The time period during which male C. serrata fed on rice moth eggs before switching to Bemisia tabaci had no significant effect on their lifespan.

[0078] 2. Effects of alternating feeding with rice moth eggs and Bemisia tabaci on the development, survival, and predation ability of the first generation of Coccinella serrata

[0079] The survival rates of the generations of the cutworms fed with rice moth eggs for different periods of time and then fed with whitefly nymphs are shown in the attached figure. Figure 7 (The bars in the figure are mean values, the error bars are standard errors, and different letters on the bars indicate significant differences at the 0.05 level (Tukey method).) The time when female C. serrata feeds on rice moth eggs before switching to whiteflies has a significant effect on the survival rate of the first generation (F 4,10 =6.29, P=0.009). The generational survival rates of ladybugs fed with glutinous rice moth eggs for 30, 40, and 50 days and then fed with Bemisia tabaci nymphs were 82.22%, 81.11%, and 77.78%, respectively, which were not significantly different from the generational survival rate of 85.56% in the control group. The generational survival rate of ladybugs fed with glutinous rice moth eggs for 60 days and then fed with Bemisia tabaci nymphs was 68.89%, which was significantly lower than the generational survival rate of the control group, but not significantly different from the generational survival rate of the ladybugs fed with glutinous rice moth eggs for 50 days.

[0080] The developmental period of the first generation of the female Coccinella serrata before switching to feeding on Bemisia tabaci is shown in the attached figure. Figure 8 (The bars in the figure are mean values, the error bars are standard errors, and different letters on the bars indicate significant differences at the 0.05 level (Tukey method). The time when female horned ladybirds fed on rice moth eggs before switching to feeding on whiteflies is shown in the attached figure. The amount of prey that the fourth-instar larvae of the next generation fed on the fourth-instar nymphs of whiteflies was Figure 9 (The bars in the figure are mean values, the error bars are standard errors, and different letters on the bars indicate significant differences at the 0.05 level (Tukey method).) The time when female C. serrata fed on rice moth eggs before switching to feeding on whiteflies had no significant effect on the developmental duration of the first generation or the amount of predation by the fourth-instar larvae of the first generation on the fourth-instar nymphs of whiteflies (F 4,10 =1.22, P=0.363; F 4,45=2.21, P=0.929). The developmental duration of the first generation of offspring fed with oryza moth eggs for 30, 40, 50, and 60 days and then fed with Bemisia tabaci nymphs was 17.46, 17.50, 17.54, and 17.39 days, respectively, which was not significantly different from the developmental duration of the first generation of offspring in the control group (17.37 days). The predation rate of the fourth-instar offspring of offspring fed with oryza moth eggs for 30, 40, 50, and 60 days and then fed with Bemisia tabaci nymphs on fourth-instar Bemisia tabaci nymphs was 59.10, 61.20, 60.20, and 60.70, respectively, which was not significantly different from the predation rate of 59.10 on fourth-instar Bemisia tabaci nymphs by the fourth-instar offspring of the control group.

[0081] The results showed that the time that the cutworms fed on oryzae moth eggs before switching to whiteflies had no significant effect on the developmental duration of the first generation and the predation ability of whiteflies. However, as the feeding time of oryzae moth eggs was extended to 60 days, the survival rate of the next generation decreased significantly.

[0082] In summary, the lifespans of adult C. serrata (H. serrata) females fed with glutinous rice moth eggs for 30, 40, 50, and 60 days, followed by a diet of Bemisia tabaci (B. whitefly), were 117.78, 128.9, 125.8, and 122.00 days, respectively, all exceeding the lifespan of females in the control group (101.18 days). Alternating feeding with glutinous rice moth eggs and Bemisia tabaci nymphs had no significant effect on the biological characteristics of the first generation of C. serrata (H. serrata). The presence of glutinous rice moth eggs delays oviposition and maintains the lifespan of C. serrata (H. serrata) and can be used to extend the shelf life of C. serrata in large-scale production.

[0083] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations of the claims. Various modifications and variations may be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form additional embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments merely illustrate several implementations of the present invention and do not limit the scope of protection of the patent of this invention.

Claims

1. A method for extending the lifespan of ladybugs using alternative feeds, characterized in that: After the ladybugs are fed with natural prey for the first cycle, they are fed with an alternative feed, which is rice moth eggs. After the ladybugs are fed with rice moth eggs for the second cycle, they are fed with natural prey. The ladybugs are Japanese swordtail beetles, and the first cycle is the time from the newly hatched larvae to the newly emerged adults. The second cycle is less than or equal to 50 days.

2. The method for extending the lifespan of ladybugs using alternative feed according to claim 1, characterized in that: The rice moth eggs are fresh rice moth eggs that are inactivated by ultraviolet light.

3. The method for extending the lifespan of ladybugs using alternative feed according to claim 1, characterized in that: The natural prey is Bemisia tabaci nymphs.

4. The method for extending the lifespan of ladybugs using alternative feed according to claim 1, wherein: The breeding temperature of the ladybug is 20°C-30°C.

5. The method for extending the lifespan of ladybugs using alternative feed according to claim 1, characterized in that: The rearing photoperiod of the ladybug is L:D 12-14:10-12.

6. The method for extending the lifespan of ladybugs using alternative feed according to claim 1, characterized in that: The second cycle is 30-50 days.

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