A rearing method of corn earworm larvae fed with switchgrass

Abstract

The present application relates to the technical field of insect feeding, in particular to a feeding method for feeding Spodoptera exigua larvae with switchgrass. The method comprises the following steps: placing 2nd instar larvae in a culture container, placing one larva in each culture container, putting 1-4 pieces of switchgrass leaf segments into the culture container every day, sealing the gap between the upper cover and the lower bottom of the culture container and leaving a ventilation opening, putting 2-4 pieces of switchgrass leaf segments into the culture container every day when the larvae grow to 3rd instar-4th instar, keeping the gap between the upper cover and the lower bottom of the culture container, putting 2-5 pieces of switchgrass leaf segments into the culture container every day when the larvae grow to 5th instar-6th instar, keeping the gap between the upper cover and the lower bottom of the culture container, and feeding the larvae until they pupate. The present application feeds Spodoptera exigua larvae individually, feeds the larvae with a specific amount of switchgrass leaf segments at different instars and controls the contact amount with air, thereby providing highly suitable food and optimal nutrition and feeding environment for the larvae and improving the survival rate of the larvae.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insect feeding, in particular to a feeding method for feeding Spodoptera frugiperda larvae with switchgrass. BACKGROUND

[0002] Spodoptera frugiperda is a major migratory pest originating from the tropics and subtropics of the Americas. In December 2018, Spodoptera frugiperda first invaded China, and in less than a year, it has spread to 26 provinces, cities and districts in China's major corn producing areas. It has become an important pest in China's agriculture and poses a significant threat to China's food security. It was listed in the "List of Class I Crop Diseases and Pests" in 2020 and ranked first. With the national attention on the prevention and control of Spodoptera frugiperda, researchers have conducted a large number of basic and application researches on Spodoptera frugiperda. Insect feeding and population maintenance are the basis and key of entomological research, and how to simply and well feed Spodoptera frugiperda is of great significance to its basic research and comprehensive prevention and control.

[0003] Although the artificial feeding technology of Spodoptera frugiperda is relatively mature, there are still some differences in physiological and biochemical indicators such as intestinal microorganisms, detoxification gene expression, and larval body color between S. frugiperda feeding on artificial feed and S. frugiperda feeding on plants. Therefore, it is necessary to find a plant with high fitness and easy to grow as the feed of S. frugiperda. S. frugiperda is an omnivorous pest with a wide range of host plants, including more than 80 species of plants such as corn, rice, cotton, sorghum, alfalfa, barley, wheat, oats, millet, peanut, soybean, tobacco, tomato, potato, and onion. A large number of indoor studies have shown that S. frugiperda (corn strain) can complete the larval stage on corn, rice, wheat, and sorghum. However, S. frugiperda has stronger tropism to corn and higher fitness when feeding on corn leaves than on other crops. Therefore, in terms of tropism and fitness, corn leaves are the best plant material for indoor rearing and population maintenance of S. frugiperda. However, there are three difficulties in using corn leaves as the rearing material for S. frugiperda: 1. S. frugiperda enters the voracious stage at the 4th instar and later, requiring a large amount of leaves for feeding. If all the 4-6 leaf stage corn leaves are cut off for feeding S. frugiperda, the corn plants will be hindered in growth and even die due to reduced photosynthesis. If only the old leaves of corn are cut off for feeding S. frugiperda, a large number of corn plants need to be planted in the same batch to meet the supply of leaves. 2. S. frugiperda rearing and population maintenance require continuous rearing of multiple generations or rearing of different batches at the same time. Therefore, to meet the needs of S. frugiperda rearing, a large number of corn plants need to be planted in multiple batches, which will consume more manpower and resources. 3. S. frugiperda and corn have regular life histories. If the life history matching is not considered before S. frugiperda rearing and corn planting, it will result in no leaves for S. frugiperda to eat or waste of corn leaves. In Chinese patent CN114766435A, grain seedlings are used to feed S. frugiperda larvae, but the survival rate of S. frugiperda larvae is low due to the low fitness of S. frugiperda feeding on wheat, barley, and rye. In Chinese patent CN111758672B, corn shoots are used to feed S. frugiperda larval populations, but this feeding method has the defects of difficulty in supplying plant materials and self-cannibalism in group feeding, resulting in a low survival rate of S. frugiperda larvae. SUMMARY

[0004] In view of the problems of difficulty in supplying plant materials and low survival rate of S. frugiperda larvae in the prior art, the present application provides a rearing method for feeding S. frugiperda larvae with switchgrass.

[0005] Purus frumentum, also known as Mexican corn grass. A large number of studies have reported that Spodoptera frugiperda can cause great harm to field crops, but there are few reports on the harm to big bluestem. Secondly, big bluestem is mainly used in animal husbandry rather than traditional food crops, so pest control experts do not know this plant, let alone its characteristics, so there is no research on the application of big bluestem to Spodoptera frugiperda feeding.

[0006] Big bluestem has strong regenerative ability, and can be cut 7-8 times a year. It also has strong tillering ability, with 30-60 branches per cluster. Under high water and fertilizer conditions, each 667 square meter (1 mu) produces 5-10 tons of stems and leaves. At the same time, big bluestem is rich in nutrients, with a crude protein content of 13.68%, a crude fiber content of 22.73%, and a lysine content of 0.42%. Therefore, we hypothesize that corn can be replaced by big bluestem, a close relative of corn, to feed Spodoptera frugiperda and other agricultural pests that feed on corn leaves. At the same time, relying on the strong regenerative and tillering ability of big bluestem, the shortcomings of weak corn leaf supply can be made up for, and the number and frequency of host plant planting can be reduced.

[0007] To achieve the above technical purpose, the present application provides a feeding method for Spodoptera frugiperda larvae, comprising the following steps: placing the first-2 instar larvae in a culture container, placing 1 larva in each culture container, putting 1-4 pieces of big bluestem leaf segments into the culture container every day, and sealing the gap between the upper cover and the lower bottom of the culture container and leaving a ventilation hole; when growing to the 3rd-4th instar, putting 2-4 pieces of big bluestem leaf segments into the culture container every day and keeping the gap between the upper cover and the lower bottom of the culture container; when growing to the 5th-6th instar, putting 2-5 pieces of big bluestem leaf segments into the culture container every day and keeping the gap between the upper cover and the lower bottom of the culture container, until the larvae pupate.

[0008] Further, the culture container is lined with filter paper wetted with water; preferably, the culture container is a culture dish; more preferably, the diameter of the culture dish is 8-10 cm, and the height is 0.8-1.2 cm.

[0009] Further, during the feeding process of the first-2 instar larvae, 1-2 pieces of big bluestem leaf segments are put into the culture container every day; and / or, when growing to the 3rd-4th instar, 2-3 pieces of big bluestem leaf segments are put into the culture container every day; and / or, when growing to the 5th-6th instar, 4-5 pieces of big bluestem leaf segments are put into the culture container every day.

[0010] Further, the feces and big bluestem residues are removed before adding the big bluestem leaf segments.

[0011] Further, the temperature for feeding is 26-30 DEG C, the humidity is 55-65%, the light period is 15.5-16.5 hours of light and 7.5-8.5 hours of darkness; and / or, the width of the air vent is the same as the width of the gap between the upper cover and the lower bottom, and the length is 1 / 10-3 / 10 of the total length of the upper cover edge.

[0012] Further, a conventional sealing tape or sealing film can be used for sealing, and the most part of the gap between the upper cover and the lower bottom of the culture container is wrapped and sealed, and an air vent is left.

[0013] Further, the cross-sectional shape of the air vent is arc-shaped.

[0014] Further, the giant reed leaf segments are obtained by cutting the leaves of the giant reed plants obtained by cutting the giant reed plants; preferably, the length of the giant reed leaf segments is 4-6 cm; preferably, the cutting position is selected from 0.8-1.2 cm below the tillering point, the tillering point and / or 0.8-1.2 cm above the tillering point; more preferably, the cutting position is 1 cm above the tillering point.

[0015] Further, the method for obtaining the giant reed leaves comprises the following steps: placing the giant reed seeds in a container with wet cotton for the first time; transplanting the giant reed seeds into a culture pot after the roots and sprouts grow, for the second time, until the height of the giant reed plants reaches 50-60 cm, and cutting.

[0016] Further, the temperature for the first time or the second time is 26-30 DEG C, the humidity is 55-65%, the light period is 15-17 hours of light and 7-9 hours of darkness.

[0017] Further, during the second time, water is poured every 2-3 days, and compound fertilizer is applied every 6-8 days.

[0018] The application further provides a feeding method of the adult Spodoptera frugiperda, after the larvae obtained by the above feeding method pupate, the pupae hatch into adults, the female adults and the male adults are paired and placed in a feeding device for feeding; preferably, the feeding device is an adult feeding device or a fresh-keeping bag; more preferably, the feeding space of a single pair of adults is greater than or equal to 0.003 m 2 .

[0019] Further, the adults are supplemented with nutrients and water by honey water.

[0020] Further, the content of honey in the honey water is 14-16%.

[0021] The technical scheme of the application has the following beneficial effects:

[0022] (1) The application provides a feeding method for Spodoptera frugiperda larvae, which comprises the following steps: placing first-instar to second-instar larvae in culture containers, placing one larva in each culture container, putting 1-4 pieces of leaf segments of big bluestem into the culture containers every day, and sealing the gap between the upper cover and the lower bottom of the culture container and leaving a ventilation opening; when the larvae grow to the third-instar to the fourth-instar, putting 2-4 pieces of leaf segments of big bluestem into the culture containers every day and keeping the gap between the upper cover and the lower bottom of the culture container; when the larvae grow to the fifth-instar to the sixth-instar, putting 2-5 pieces of leaf segments of big bluestem into the culture containers every day and keeping the gap between the upper cover and the lower bottom of the culture container, until the larvae pupate. The larvae of Spodoptera frugiperda are fed individually and fed with specific leaf segments of big bluestem, the problem of difficulty in supplying plant materials is solved, the larvae are supplied with highly suitable food, and the phenomenon of self-cannibalism is avoided; in different instars, the amount of leaf segments of big bluestem and the amount of contact with air are controlled, the larvae are given the best nutrition and feeding environment, and thus the survival rate of the larvae is improved.

[0023] (2) The application provides a feeding method for Spodoptera frugiperda larvae, in the feeding process of first-instar to second-instar larvae, 1-2 pieces of leaf segments of big bluestem are put into the culture containers every day; when the larvae grow to the third-instar to the fourth-instar, 2-3 pieces of leaf segments of big bluestem are put into the culture containers every day, the nutrition required by the larvae for growth is met, the waste of food is reduced, and the feeding cost is reduced. When the larvae grow to the fifth-instar to the sixth-instar, 4-5 pieces of leaf segments of big bluestem are put into the culture containers every day, and the pupa weight is further improved.

[0024] (3) The application provides a feeding method for Spodoptera frugiperda larvae, in the process of planting big bluestem plants, old leaves and new leaves can be cut at the same time, compared with conventional crops such as corn and wheat, more leaves can be provided at the same time; different tillers of the big bluestem plants can be cut in batches to meet the nutritional needs of different batches of Spodoptera frugiperda.

[0025] (4) The application provides a feeding method for Spodoptera frugiperda adults, a preservative bag is selected as a feeding device, after the adults lay eggs, the eggs can continue to hatch into larvae in the preservative bag, other containers do not need to be replaced, compared with the adult feeding device, the feeding device is simpler and more convenient, and a large amount of space is saved. DETAILED DESCRIPTION

[0026] The following examples are provided to better further understand the application, and do not limit the content and protection scope of the application, and do not constitute a limitation on the content and protection scope of the application, and any person under the inspiration of the application or the combination of the application with other prior art features falls within the protection scope of the application.

[0027] The specific experimental steps or conditions not mentioned in the examples can be carried out according to the conventional experimental steps or conditions described in the literature in the art. The reagents or instruments used are not specified by the manufacturer, but are conventional reagent products that can be obtained commercially.

[0028] The Spodoptera frugiperda population was maintained by the Institute of Plant Protection, Jiangxi Academy of Agricultural Sciences.

[0029] Corn, Gannanke Tian No. 8.

[0030] Big bluestem, variety: Mustang Mexico corn grass.

[0031] In the previous study, the planting and mowing methods of big bluestem plants were studied. The seeds of big bluestem were evenly spread on the bottom of a plastic bowl containing wet cotton, and then transferred to an artificial climate chamber. The climate chamber conditions were as follows: temperature 28±1℃, humidity 60±5%, light cycle 16 hours of light and 8 hours of darkness. After 3 days of planting, the big bluestem seeds germinated and were transplanted into culture pots. The culture pots were then transferred to a plant culture room (temperature 28±2℃, humidity 60±5%, light cycle 16 hours of light and 8 hours of darkness). Water was poured every 3 days and compound fertilizer was applied every 7 days. When the height of the big bluestem plants reached 50-60 cm, mowing began. The plants were divided into 3 batches and mowed at 1 cm below the tillering point, at the tillering point, and 1 cm above the tillering point, respectively. The height of the mowed big bluestem plants was counted every day. When the height of the big bluestem plants grew to 50-60 cm again, mowing was repeated, and the above mowing method was repeated multiple times.

[0032] By mowing at 1 cm below the tillering point, at the tillering point, and 1 cm above the tillering point, respectively, big bluestem plants at different mowing positions all have strong regenerative ability, with growth rates of 3.21 cm / day, 3.11 cm / day, and 3.74 cm / day, respectively. When mowing at 1 cm above the tillering point, the big bluestem plants can grow to the height before mowing in 10 days and produce 2-3 tillers. Under the condition of sufficient fertilizer supply, big bluestem can be repeatedly mowed more than 4 times, and the growth rate remains above 3.5 cm / day. Therefore, multiple mowing of big bluestem at 1 cm above the tillering point can be selected, and the mowed big bluestem leaves can be cut into 5 cm long leaf segments for feeding Spodoptera frugiperda.

[0033] The feeding environment of the following examples and comparative examples was as follows: temperature 28±2℃, humidity 60±5%, light cycle 16 hours of light and 8 hours of darkness.

[0034] Example 1

[0035] The present example provides a method for feeding Spodoptera frugiperda larvae and adults, comprising the following steps:

[0036] S1, larva feeding: filter paper (diameter 9 cm) was laid in a culture dish (diameter 9 cm, height 1 cm) and moistened with distilled water, covered, and 50 were prepared for standby. After the eggs of the Spodoptera exigua (Hübner) adults in Jiangxi Academy of Agricultural Sciences were hatched, 50 first instar larvae were placed in the culture dish, and 1 piece of big reed leaf segment (5 cm) was placed in the culture dish at the first instar-2 instar stage, 2 pieces were placed when the larvae reached the 3-4 instar stage, and 4 pieces were placed when the larvae were 5-6 instar. According to the characteristics of the low-age larvae of Spodoptera exigua (Hübner) that like wet and the older ones that like dry, at the first instar-2 instar stage, the gap between the cover and the culture dish was sealed with sealing film and a breathable port (the width of the breathable port was the same as the width of the gap between the upper cover and the lower bottom, and the length was 1 / 10 of the total length of the upper cover edge), keeping the air permeable while reducing water loss; when the larvae reached the 3 instar and above, the sealing film was removed to speed up the water loss. The leaf residues were cleaned up and fresh wet leaf segments were added every day, and if the water content of the filter paper was too high (clear water could be observed), the filter paper was replaced. The number of larvae and each instar stage was recorded every day.

[0037] S2, pupa feeding: 2 groups of wet cotton were placed in the holes and the gap between the holes of a 12-hole plate for standby. After the larvae pupated, the pupae were placed in the 12-hole plate, respectively, and recorded as the first day. On the second day, the pupae were weighed.

[0038] S3, adult feeding: after the pupae emerged into adults, 3 female adults and 3 male adults were placed in each fresh-keeping bag (40 cm*30 cm), and 1 group of honey water (honey content 15%) wet cotton ball was placed in each bag, and the fresh-keeping bag was filled with air, and the opening was sealed with an elastic band. The number of surviving female and male adults and the number of eggs were recorded every day until all the adults died.

[0039] Example 2

[0040] The present embodiment provides a feeding method for Spodoptera exigua larvae and adults, and the specific parameters and steps are consistent with those of Example 1, and the only difference is that in the S1 step of the present embodiment, 2 fresh and wet big reed leaf segments are placed in the culture dish every day from the first instar larva to the pupation of the larva.

[0041] Example 3

[0042] The present embodiment provides a feeding method for Spodoptera exigua larvae and adults, and the specific parameters and steps are consistent with those of Example 1, and the only difference is that in the S1 step of the present embodiment, 4 fresh and wet big reed leaf segments are placed in the culture dish every day from the first instar larva to the pupation of the larva.

[0043] Example 4

[0044] The embodiment provides a feeding method for Spodoptera frugiperda larvae and adults, specific parameters and steps are consistent with those of example 1, and the only difference is that the S3 step of the embodiment is that after the pupae are hatched into adults, 5 female adults and 5 male adults are placed in each adult feeding device (specification: 60cm*60cm*60cm, manufacturer: Huayu Kepu Experimental Instrument Store), a glass bottle, a preservative bag and a culture dish are placed in the adult feeding device, a cotton block soaked with honey water (honey content is 15%) is placed in the culture dish (air in the feeding device is easy to flow, the cotton block is arranged to reduce water loss), a leaf segment of switchgrass is wrapped with the preservative bag and inserted into the glass bottle containing water, 140-160 fine holes are punched on the preservative bag, and the female adults are attracted to lay eggs on the outer surface of the preservative bag through the smell of the switchgrass. The number of female adults and male adults and the number of eggs are recorded every day until the adults all die.

[0045] Comparative example 1

[0046] The comparative example provides a feeding method for Spodoptera frugiperda larvae and adults, specific parameters and steps are consistent with those of example 1, and the only difference is that the "switchgrass leaf segment" is replaced by "elephant grass leaf".

[0047] Comparative example 2

[0048] The comparative example provides a feeding method for Spodoptera frugiperda larvae and adults, specific parameters and steps are consistent with those of example 1, and the only difference is that the "switchgrass leaf segment" is replaced by "elephant grass leaf".

[0049] Comparative example 3

[0050] The comparative example provides a feeding method for Spodoptera frugiperda larvae and adults, specific parameters and steps are consistent with those of example 1, and the only difference is that the "switchgrass leaf segment" is replaced by "elephant grass leaf".

[0051] Comparative example 4

[0052] The comparative example provides a feeding method for Spodoptera frugiperda larvae and adults, specific parameters and steps are consistent with those of example 1, and the only difference is that in the S1 step of the comparative example, a gap between the cover and the culture dish is kept from the initial stage of the larvae to before the larvae pupate.

[0053] Comparative example 5

[0054] The comparative example provides a feeding method for Spodoptera frugiperda larvae and adults, specific parameters and steps are consistent with those of example 1, and the only difference is that in the S1 step of the comparative example, a gap between the cover and the culture dish is kept from the initial stage of the larvae to before the larvae pupate.

[0055] Comparative Example 6

[0056] This comparative example provides a feeding method for Spodoptera frugiperda larvae and adults, the specific parameters and steps of which are consistent with those of Example 1, except that in the S1 step of this comparative example, 50 first instar larvae are placed in one culture dish for every 2 larvae.

[0057] Comparative Example 7

[0058] This comparative example provides a feeding method for Spodoptera frugiperda larvae and adults, the specific parameters and steps of which are consistent with those of Example 1, except that in the S1 step of this comparative example, a total of 17 culture dishes are used, 3 larvae are placed in each of 16 culture dishes, and 2 larvae are placed in the other culture dish, for a total of 50 first instar larvae.

[0059] Experimental Example 1

[0060] The data during the feeding of Spodoptera frugiperda in Example 1 and Comparative Examples 1-3 were statistically analyzed, and the larval survival rate, larval duration (the time from hatching to pupation, i.e., the time from first instar to pupation), average pupal weight, and average single female egg production were calculated. The results are shown in Table 1. The length of the larval duration is related to the food. As can be seen from the table, the larval duration of Example 1 is lower than that of Comparative Examples 1-3, but compared with Comparative Examples 1-3, the larval survival rate, pupal weight, and single female egg production of Example 1 are all better. Therefore, under the condition that other feeding conditions remain the same, the growth and reproduction indicators of Spodoptera frugiperda larvae feeding on switchgrass leaf segments are better and significantly higher than those of Spodoptera frugiperda larvae feeding on Eupatorium adenophorum leaf, Setaria viridis leaf, and Miscanthus xunidus leaf.

[0061] Table 1 data results

[0062]

[0063] Note: a, b, c, the same letter means no significant difference, and different letters mean significant difference.

[0064] Experimental Example 2

[0065] The data during the rearing of Spodoptera frugiperda in Examples 1-3 and Comparative Examples 4-5 were statistically analyzed, and the larval survival rate and pupal weight average were calculated, and the results are shown in Table 2. In summary, the results of Examples 1-3 are better. Compared with Example 1, Comparative Example 4 did not use a sealing film in the early stage, resulting in too fast water loss, and some larvae did not eat, resulting in a decrease in survival rate; Comparative Example 5 used a sealing film throughout the larval period, and the water accumulated in the later stage, the filter paper was wet, resulting in the death of some old larvae or the difficulty of pupation, and the survival rate decreased; in Example 2, the leaf segments were less in the later stage, which did not affect the survival rate of the larvae; in Example 3, 4 leaf segments were added all the time, although the survival rate and pupal weight were less affected, but the 1-4 instar larvae had small feeding amount, resulting in waste of leaf segments.

[0066] Table 2 data results

[0067]

[0068] Note: a, b, the same letter means no significant difference, different letters mean significant difference.

[0069] Experimental Example 3

[0070] The data during the rearing of Spodoptera frugiperda in Examples 1 and 4 were statistically analyzed, and the single female egg production, male longevity, female longevity and average space occupied by a pair were calculated.

[0071] The air-filled preservation bag was sealed with an elastic band, and then the air-filled preservation bag was squeezed to obtain a cube close to the side length of 25 cm. The size of 25 cm was used to estimate the average space occupied by a pair of Spodoptera frugiperda in the preservation bag. Average space occupied by a pair = volume of rearing device / number of pairs of Spodoptera frugiperda.

[0072] The results are shown in Table 3 below. Compared with Example 4, the single female egg production index of Example 1 is higher. Secondly, the average space occupied by a pair of adults in Example 1 is only 11.6% of that in Example 4, and the structure of the preservation bag in Example 1 is simple, the operation is convenient, the material price is low, all eggs are produced on the inner wall of the preservation bag, which is beneficial to collection, the operation of Example 4 is difficult, and expensive adult rearing device is needed, and eggs are not only produced on the outer wall of the preservation bag, but also possibly produced on the adult rearing device. The preservation bag used in Example 1 has multiple functions such as container, support, moisture retention and egg laying pad, while the preservation bag used in Example 4 only has the function of egg laying pad.

[0073] Table 3 data results

[0074]

[0075] Note: a, the same letter means no significant difference, different letters mean significant difference.

[0076] Experimental Example 4

[0077] The data of the rearing process of the corn earworm in Example 1 and Comparative Examples 6-7 were statistically analyzed, and the larval survival rate and the average pupal weight were calculated, and the results are shown in Table 4. The total larval survival rate of Example 1 was higher than that of Comparative Examples 6-7. Since the corn earworm cannibalizes, the survival rates of the 4th to 6th instar larvae and the total larval survival rate in Comparative Examples 6-7 rapidly decreased, and the total larval survival rate was less than 60%. Since the corn earworm can feed on the same species to obtain nutrition, the pupal weights of Comparative Examples 6-7 were greater than that of Example 1, but there was no significant difference.

[0078] Table 4 Data Results

[0079]

[0080] Note: a, the same letter means no significant difference, and different letters mean significant difference.

[0081] Obviously, the above examples are merely examples for the purpose of clarity, and are not limitations on the embodiments. Based on the above description, other different forms of changes or variations can also be made by those of ordinary skill in the art. All embodiments do not need to be exhausted here, and obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for rearing Spodoptera frugiperda larvae, characterized by, The method comprises the following steps: The first-instar to second-instar larvae are placed in culture containers, one larva per culture container, 1-4 pieces of leaf segments of big bluestem are put into the culture containers every day, the gap between the upper cover and the lower bottom of the culture container is sealed and a ventilation hole is left, 2-4 pieces of leaf segments of big bluestem are put into the culture containers every day when the larvae grow to the third-instar to fourth-instar, the gap between the upper cover and the lower bottom of the culture container is kept, 2-5 pieces of leaf segments of big bluestem are put into the culture containers every day when the larvae grow to the fifth-instar to sixth-instar, and the gap between the upper cover and the lower bottom of the culture container is kept until the larvae pupate.

2. The rearing method of Spodoptera fugiperda larvae according to claim 1, characterized in that, The culture container is lined with filter paper wetted with water.

3. The rearing method of Spodoptera fugiperda larvae according to claim 2, characterized in that, The culture container is a culture dish.

4. The rearing method of Spodoptera fugiperda larvae according to claim 3, characterized in that, The diameter of the culture dish is 8-10 cm, and the height is 0.8-1.2 cm.

5. The rearing method of Spodoptera fugiperda larvae according to claim 1, characterized in that, During the feeding of the first-instar to second-instar larvae, 1-2 pieces of leaf segments of big bluestem are put into the culture containers every day, and / or when the larvae grow to the third-instar to fourth-instar, 2-3 pieces of leaf segments of big bluestem are put into the culture containers every day, and / or when the larvae grow to the fifth-instar to sixth-instar, 4-5 pieces of leaf segments of big bluestem are put into the culture containers every day.

6. The rearing method of Spodoptera fugiperda larvae according to any one of claims 1-5, characterized in that, The temperature for feeding is 26-30℃, the humidity is 55-65%, the light period is 15.5-16.5 hours of light and 7.5-8.5 hours of darkness, and / or the width of the ventilation hole is the same as the width of the gap between the upper cover and the lower bottom, and the length is 1 / 10-3 / 10 of the total length of the edge of the upper cover.

7. The rearing method of Spodoptera fugiperda larvae according to any one of claims 1-5, characterized in that, The leaf segments of big bluestem are obtained by cutting the big bluestem plants to obtain leaf blades, and then cutting the leaf blades.

8. The rearing method of Spodoptera fugiperda larvae according to claim 7, characterized in that, The length of the leaf segments of big bluestem is 4-6 cm.

9. The rearing method of Spodoptera fugiperda larvae according to claim 7, characterized in that, The cutting site is selected from 0.8-1.2 cm below the tillering point, the tillering point, and / or 0.8-1.2 cm above the tillering point.

10. The rearing method of Spodoptera fugiperda larvae according to claim 7, characterized in that, The cutting site is 1 cm above the tillering point.

11. The rearing method of Spodoptera fugiperda larvae according to claim 7, characterized in that, The method for obtaining the leaf blades of big bluestem comprises placing big bluestem seeds in a container with wet cotton for the first time of cultivation, transplanting the big bluestem seeds to a culture pot after the emergence of root sprouts for the second time of cultivation, and cutting the big bluestem plants when the height reaches 50-60 cm.

12. The rearing method of Spodoptera fugiperda larvae according to claim 11, characterized in that, The temperature for the first time of cultivation or the second time of cultivation is 26-30℃, the humidity is 55-65%, the light period is 15-17 hours of light and 7-9 hours of darkness.

13. The rearing method of Spodoptera fugiperda larvae according to claim 11, characterized in that, During the second time of cultivation, water is poured every 2-3 days, and compound fertilizer is applied every 6-8 days.

14. A method of rearing Spodoptera frugiperda adult moths, characterized by, After the larvae pupate, the pupae are fed to the adult insects, and the female adult insects and the male adult insects are paired and placed in a feeding device for feeding.

15. The rearing method of Spodoptera exigua adults according to claim 14, characterized in that, The feeding device is an adult insect feeding device or a fresh-keeping bag.

16. The rearing method of Spodoptera exigua adults according to claim 14, characterized in that, Single pair of adult insects per rearing space > 0.003 m 2 .

17. The method for rearing adult fall armyworms according to claim 14, characterized in that, The adult insects are supplemented with nutrients and water through honey water.

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