Artificial breeding and island plant pollination method of hoverflies brachypoda

Abstract

The artificial breeding and island plant pollination method comprises the following steps: artificial breeding of aphids: broad bean seedlings are planted in an insect breeding cage to propagate black bean aphids, so that adults of the hoverflies can lay fly eggs, and larvae of the hoverflies can eat the fly eggs at the same time; feeding of hoverfly larvae: feeding the hoverfly larvae with black bean aphids in an insect breeding cage, and enabling the hoverfly larvae to develop into pupae after 6 days; collecting pupae of hoverflies with short thorn legs: harvesting broad bean seedlings with mature larvae of hoverflies, putting the broad bean seedlings into a plastic box with a gauze opening for continuous feeding, and putting the collected pupae of hoverflies into a culture dish until all the larvae in the plastic box pupate; and transporting and releasing the short-spur hoverflies, namely storing pupae of the hoverflies in a pupa card device at the temperature of 4 DEG C, transporting the pupae to an open sea island, and releasing the pupae. By the adoption of the method, scale breeding can be conducted on the species of the hoverfly brachypoda, and the hoverfly brachypoda can be transported to the island area and used for pollination of island plants.

Description

Technical Field

[0001] The present invention belongs to the technical field of insect breeding methods, and particularly relates to an artificial breeding method of Ischiodon scutellaris and a method for pollinating island plants. Background Art

[0002] Syrphidae is an important group of Diptera insects. The larval stage of Syrphidae is a predatory natural enemy of agricultural pests such as aphids and whiteflies, and the adults pollinate plants through flower-visiting activities, with both biological control and ecological service functions. Among them, Ischiodon scutellaris is a common species in the East Asian region, with characteristics such as strong reproductive ability and strong environmental adaptability, and plays a significant role in aphid population regulation and plant pollination in natural ecosystems.

[0003] Island ecosystems often face the problem of a lack of pollinating insects, resulting in limited reproduction of native plants (such as endangered endemic species). Ischiodon scutellaris has strong flight ability and a wide range of flower-visiting areas, and it has good tolerance to the harsh island environment (such as salt spray and intermittent drought). However, in the existing technology, there is no method for large-scale breeding of this species and transporting it to the islands, nor any research on its application in island pollination. Summary of the Invention

[0004] In order to overcome the deficiencies of the existing technology, the purpose of the present invention is to provide an artificial breeding method of Ischiodon scutellaris and a method for pollinating island plants, which can carry out large-scale breeding of Ischiodon scutellaris and transport it to island areas for pollinating island plants.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] An artificial breeding method of Ischiodon scutellaris and a method for pollinating island plants, including the following methods:

[0007] Artificial breeding of aphids: Plant broad bean seedlings in an insect rearing cage to propagate Aphis fabae for the adult Syrphidae to lay eggs and for the larval Syrphidae to feed on.

[0008] Rearing of Ischiodon scutellaris larvae: Rearing the larvae of Ischiodon scutellaris with Aphis fabae in an insect rearing cage. After 6 days of development, the larvae of Ischiodon scutellaris can develop from newly hatched larvae to pupae.

[0009] Collection of Ischiodon scutellaris pupae: Harvest the broad bean seedlings with mature larvae of Ischiodon scutellaris and place them in a plastic box with a screened opening for continued rearing. Put the collected pupae of Ischiodon scutellaris in a petri dish for preservation and record the date until all the larvae in the plastic box pupate.

[0010] Transportation and release of **Ischiodon scutellaris**: Keep the aphid fly pupae in a pupal card device at a temperature of 4°C, and then transport them to a remote offshore island for release.

[0011] Furthermore, during the artificial breeding process of **Aphis craccivora**, the following method is adopted: Plant broad beans in a rearing cage of 40 cm × 40 cm × 40 cm to propagate **Aphis craccivora**. The rearing cage is placed in an incubator with a temperature of 25 ± 1°C, a humidity of 50% - 70%, a photoperiod of 14L:10D, and a light intensity of 9000 Lux at the top of the cage; Use plant nursery soil as the substrate to plant broad beans. The nursery pots are plastic pots with a diameter of 10 cm - 12 cm. Soak the broad bean seeds in clean water for 24 hours and then disinfect them with chlorine dioxide disinfectant tablets to improve the emergence rate. Insert the black end of the broad bean downward into the soil by about half, and then cover it with about 1 cm of nursery soil layer. Plant 7 - 9 broad bean seeds in each nursery pot, and plant broad beans 3 times a week to continuously supply seedlings; When the broad bean seedlings grow to 3 cm - 5 cm, inoculate them with **Aphis craccivora**. Inoculate 20 - 30 adult aphids on each seedling. The adult aphids can lay eggs for the adult aphid flies 2 - 3 days after inoculation, and a large number of **Aphis craccivora** will be produced 6 ± 1 days after inoculation for the larval aphid flies to feed on.

[0012] Furthermore, during the rearing process of **Ischiodon scutellaris** larvae, the following method is adopted: Rearing the **Ischiodon scutellaris** larvae in a rearing cage of 40 cm × 40 cm × 40 cm. The rearing cage is placed in an incubator with a temperature of 25 ± 1°C, a humidity of 50% - 70%, a photoperiod of 14L:10D, and a light intensity of 9000 Lux at the top of the cage; Transfer the broad bean seedlings with **Ischiodon scutellaris** eggs in the adult breeding box to the larval rearing cage. After 2 days, the larvae hatch and start feeding on aphids. When it is observed that the aphids on the broad bean seedlings will be completely eaten 4 - 5 days later, cut the broad bean seedlings with **Ischiodon scutellaris** larvae from the roots and transfer them to new broad bean seedlings with aphids in the larval rearing cage. The **Ischiodon scutellaris** larvae will transfer to the new broad bean seedlings by themselves to feed on aphids; The **Ischiodon scutellaris** larvae can pupate after 6 ± 1 days of development, that is, develop from newly hatched larvae to pupae. Only one supplement of aphids is needed during the larval rearing period.

[0013] Furthermore, during the collection process of **Ischiodon scutellaris** pupae, the following method is adopted: When the mature larvae of the aphid fly start to excrete black feces, it indicates that the larvae of the aphid fly have completed development and are about to pupate. At this time, harvest the broad bean seedlings with mature larvae of the aphid fly and put them into a plastic box of 6.5 cm × 11.8 cm × 17.5 cm with a screen opening for continued rearing. Collect the aphid fly pupae every day and put them in a petri dish for preservation and record the date until all the larvae in the plastic box have pupated.

[0014] Further, the following methods are also included: Management of adult Ischiodon scutellaris: Create an environment suitable for the breeding and egg-laying of adult Ischiodon scutellaris in a breeding cage; Select multiple pairs of newly emerged adult Ischiodon scutellaris and put them into the breeding cage. After supplementing nutrition by feeding on pollen and honey water for 2 days, under the stimulation of strong light and ultraviolet light, male and female adult Ischiodon scutellaris fly and chase each other and mate; After the adult Ischiodon scutellaris mate, put broad bean seedlings with aphids into the breeding cage to induce adult Ischiodon scutellaris to lay eggs; Transfer the broad bean seedlings with Ischiodon scutellaris eggs into the larval cage every day for egg hatching and larval rearing, and put new broad bean seedlings with aphids into the breeding cage for adult Ischiodon scutellaris to continue laying eggs. Regularly replace the pollen and nectar in the culture dish to supplement nutrition for adult Ischiodon scutellaris, so as to improve the survival rate of adult Ischiodon scutellaris and the hatching rate of Ischiodon scutellaris eggs.

[0015] Further, when creating an environment suitable for the breeding and egg-laying of adult Ischiodon scutellaris in the breeding cage, the following method is adopted: The breeding cage uses an insect breeding cage of 60cm * 60cm * 90cm. An LED lamp with ultraviolet lamp beads is set on the cage top. The light intensity on the cage top is 30000Lux, the temperature is 25 ± 1°C, the humidity is 50% - 70%, and the photoperiod is 14L:10D; Two culture dishes are placed in the breeding cage. One contains absorbent cotton moistened with 15% honey water, and the other contains crushed bee pollen. The culture dishes are elevated to facilitate adult Ischiodon scutellaris to feed; A water bottle is set in the breeding cage, and fresh Bidens pilosa flowers collected are inserted into the water bottle to assist in providing fresh pollen.

[0016] Further, during the transportation and release of Ischiodon scutellaris, after the pupal card device is packed, it is put into a cardboard box, and the cardboard box is filled with newspapers or cotton to improve the shock absorption effect during transportation.

[0017] Further, during the transportation and release of Ischiodon scutellaris, regarding the structure of the pupal card device: The pupal card device includes a plastic culture dish and a sealing cover fitted at the opening of the plastic culture dish. A card is fixed at the bottom of the plastic culture dish. Several circular adhesive areas are arranged in an array on the card. The diameter of each circular adhesive area is 3mm, and the circular adhesive areas are used for the adhesion and attachment of Ischiodon scutellaris pupae. The interval between adjacent circular adhesive areas is 10mm.

[0018] Further, during the transportation and release of Ischiodon scutellaris, before the pupal card device is transported to the corresponding release location on the island, provide absorbent cotton with 15% honey water and pollen as food for some emerged adult Ischiodon scutellaris to improve the release survival rate of adult Ischiodon scutellaris.

[0019] The present invention has the following beneficial effects:

[0020] ① Combine the breeding processes of broad bean seedlings and aphids with the growth process of hoverflies. The Aphis craccivora Koch propagated on broad bean seedlings can promote female hoverflies to lay eggs. After the eggs hatch, the aphids can be eaten by the larvae to promote the development of hoverfly larvae and improve the growth efficiency, facilitating the development of newly hatched larvae into pupae.

[0021] ② Harvest the broad bean seedlings and put them into a gauze net to facilitate rapid sieving and collection of hoverfly pupae, thereby improving the collection efficiency of hoverfly pupae.

[0022] ③ When managing adult hoverflies, create an environment suitable for the breeding and egg-laying of adult hoverflies in the breeding cage, such as providing ultraviolet lamps, absorbent cotton moistened with 15% honey water, crushed bee pollen, and Bidens pilosa flowers, thereby improving the mating enthusiasm of male and female adult hoverflies, increasing the egg-laying rate of female adult hoverflies, and further achieving large-scale promotion of the breeding of hoverfly larvae.

[0023] ④ When transporting hoverfly pupae in the open sea, use a storage environment of 4°C, which can greatly extend the storage duration of hoverfly pupae. At the same time, after the hoverfly pupae are stored and transferred to an environment of 25°C, a high emergence rate can be effectively guaranteed. Meanwhile, during transportation, store the hoverfly pupae in a pupal card device, which can protect the hoverfly pupae from being squeezed, and the plastic petri dish can provide a certain activity space for the adult hoverflies that emerge prematurely, thereby improving the survival rate of hoverflies.

[0024] ⑤ By setting a specially designed pupal card device, the hoverfly pupae can be better pasted within the circular sticky area, and adjacent hoverfly pupae can maintain a better safe distance to prevent squeezing. At the same time, when the pupal card device is released at the corresponding release point in the island area, it can be released in multiple ways, such as taking out the card, threading a thin line through the hollow area of the card and hanging it on a branch, or fixing the plastic petri dish on a plant. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the hoverfly larva rearing device of the present invention.

[0026] Figure 2 It is a schematic diagram of the hoverfly adult breeding cage of the present invention.

[0027] Figure 3 It is a schematic diagram of the pupal card device of the present invention.

[0028] In the figure: 1. Frame body; 2. Plant growth lamp; 3. Insect rearing cage A; 4. Insect rearing cage B; 5. Insect rearing cage C; 6. Insect rearing cage D; 7. Breeding cage; 8. Led lamp; 9. Broad bean seedlings with Aphis craccivora Koch; 10. Bidens pilosa; 11. Petri dish A; 12. Petri dish B; 13. Plastic petri dish; 14. Card; 15. Circular sticky area; 16. Hollow area. Detailed implementation manners

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Terms such as "upper", "inner", "middle", "left", "right", and "one" cited in this specification are only for the convenience of clear description and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationship shall also be regarded as the scope of implementation of the present invention without substantial change in the technical content.

[0030] In view of the harsh environment on the island, the ecological system often faces a shortage of pollinating insects, resulting in limited reproduction of native plants. Therefore, it is proposed to introduce Ischiodon scutellaris in the island. By virtue of the characteristics of strong flight ability, wide flower-visiting range, and tolerance to harsh environment of Ischiodon scutellaris, the problem of limited reproduction of native plants on the island can be overcome. Therefore, the research on the artificial breeding of Ischiodon scutellaris and the pollination method of island plants is proposed to provide a low-cost artificial breeding technology for Ischiodon scutellaris and establish a plan for releasing and colonizing it in the sea island environment to improve the pollination success rate of island plants.

[0031] The following is a detailed introduction to the technical solution of the artificial breeding of Ischiodon scutellaris and the pollination method of island plants of the present invention:

[0032] The artificial breeding technology of Ischiodon scutellaris of the present invention mainly uses Vicia faba bean aphids (Aphis craccivora) as the feed for the larvae of Ischiodon scutellaris for large-scale production.

[0033] An artificial breeding and island pollination method for Ischiodon scutellaris, as Figures 1 to 3 shown, Ischiodon scutellaris can be simply referred to as aphid fly, and includes the following methods:

[0034] 1) Artificial breeding of Aphis craccivora: Plant broad bean seedlings in an insect rearing cage to multiply Vicia faba bean aphids for the adult aphid flies to lay eggs and for the larvae of aphid flies to feed on.

[0035] Specifically, during the artificial breeding process of Aphis craccivora, broad beans are planted in a rearing cage of 40 cm × 40 cm × 40 cm to propagate Aphis craccivora. The rearing cage is placed in an incubator with a temperature of 25 ± 1 °C, a humidity of 50%-70%, a photoperiod of 14L:10D, and a light intensity of 9000 Lux at the top of the cage. Broad beans are planted using a plant nursery substrate (a mixture of peat soil, perlite, vermiculite, and coconut coir), and the nursery pots are plastic pots with a diameter of 10 cm - 12 cm. The broad bean seeds are soaked in water for 24 hours and then disinfected with chlorine dioxide disinfectant tablets to improve the emergence rate. One end of the black line of the broad bean is inserted downward into the soil by half, and then covered with about 1 cm of nursery soil layer. 7 - 9 broad bean seeds are planted in each nursery pot, and broad beans are planted 3 times a week to continuously supply broad bean seedlings. When the broad bean seedlings grow to 3 cm - 5 cm (or 6 d - 7 d after the broad bean seedlings are planted), Aphis craccivora is inoculated. 20 - 30 adult aphids are inoculated on each seedling. After 2 d - 3 d of inoculating the adult aphids, it is available for the adult female of Allograpta exotica to lay fly eggs (i.e., the eggs of Allograpta exotica). A large number of Aphis craccivora (subsequently abbreviated as aphids) are produced after 6 ± 1 d of inoculating the adult aphids for the larvae of Allograpta exotica to feed on.

[0036] 2) Rearing of the larvae of Allograpta exotica: The larvae of Allograpta exotica are reared with Aphis craccivora in the rearing cage. After 6 days of development, the larvae of Allograpta exotica can develop from newly hatched larvae to pupae.

[0037] Specifically, during the process of rearing the larvae of Allograpta exotica, the larvae of Allograpta exotica are reared in a rearing cage of 40 cm × 40 cm × 40 cm. The rearing cage is placed in an incubator with a temperature of 25 ± 1 °C, a humidity of 50%-70%, a photoperiod of 14L:10D, and a light intensity of 9000 Lux at the top of the cage. The broad bean seedlings with the eggs of Allograpta exotica in the adult breeding box are transferred to the larval rearing cage. After 2 d, the eggs of Allograpta exotica hatch into larvae. The hatched larvae start to feed on aphids. When it is observed that the aphids on the broad bean seedlings will be completely eaten after 4 d - 5 d, the broad bean seedlings with the larvae of Allograpta exotica are cut from the roots and transferred to new broad bean seedlings with aphids in the larval rearing cage. The larvae of Allograpta exotica will transfer to the new broad bean seedlings by themselves to feed on aphids. The larvae of Allograpta exotica can pupate after 6 ± 1 d of development, that is, develop from newly hatched larvae to pupae. Only one supplement of aphids is needed during the larval rearing period.

[0038] 3) Collection of the pupae of Allograpta exotica: The broad bean seedlings with the mature larvae of Allograpta exotica are harvested and placed in a plastic box with a gauze opening for continued rearing. The collected pupae of Allograpta exotica are placed in a petri dish for preservation until all the larvae in the plastic box pupate.

[0039] Specifically, during the collection process of the pupae of Ischiodon scutellaris, when the mature larvae of the hoverfly start to excrete black feces, it indicates that the larvae of the hoverfly have completed their development and are about to pupate. At this time, the broad bean seedlings with mature larvae of the hoverfly are harvested and placed in a plastic box of 6.5 cm * 11.8 cm * 17.5 cm with a screen opening for continued rearing. The pupae of the hoverfly are collected every day and placed in a petri dish for preservation and the date is recorded until all the larvae in the plastic box have pupated.

[0040] During the breeding process of the above methods 1), 2), and 3), it mainly involves the process of the Ischiodon scutellaris hatching from eggs into larvae and then pupating from larvae. Therefore, a special rearing device for hoverfly larvae was developed, as Figure 1 shown, including a frame 1. The frame 1 can be a multi-layer frame 1 or a single-layer frame 1. A plant growth lamp 2 is provided on the top surface of each layer of the frame 1 to provide the necessary light intensity for the growth of broad bean seedlings and promote the photosynthesis of broad bean seedlings. At least four kinds of insect cages with different functions are arranged on the frame 1, which are named insect cage A3, insect cage B4, insect cage C5, and insect cage D6 respectively. Among them, broad bean seedlings without Aphis fabae are placed in the insect cage A3, and the broad bean seedlings have not germinated or have not reached the growth height; broad bean seedlings with Aphis fabae but without a large number of Aphis fabae are placed in the insect cage B4, which can be used to attract female hoverflies in the breeding cage 7 of hoverfly adults to lay eggs; broad bean seedlings with fully grown Aphis fabae are placed in the insect cage C5, which can be used to feed the larvae of hoverflies; broad bean seedlings with hoverfly eggs or hoverfly larvae are placed in the insect cage D6, and the hoverfly larvae are removed when they grow to be almost pupating in the insect cage D6.

[0041] 4) Management of Ischiodon scutellaris adults: After the hoverfly adults emerge, they need to feed on pollen and nectar to supplement nutrition, and need certain light conditions to stimulate their flight and egg-laying. The egg-laying and breeding of hoverfly adults are carried out in the breeding cage 7.

[0042] Create an environment suitable for the breeding and egg-laying of hoverfly adults in the breeding cage 7: The breeding cage 7 is a 60 cm * 60 cm * 90 cm insect cage, and an led lamp 8 with ultraviolet lamp beads inside is set on the cage top (ultraviolet light can promote the ovarian development of hoverflies), the light intensity on the cage top is 30000 Lux, the temperature is 25 ± 1 °C, the humidity is 50% - 70%, and the photoperiod is 14L:10D; Two petri dishes are placed in the breeding cage 7. One contains absorbent cotton moistened with 15% honey water, and the other contains crushed bee pollen (the bee honey is a mixture of corn bee pollen and rape bee pollen in equal amounts). The petri dishes are raised to facilitate the hoverfly adults to feed; A water bottle is set in the breeding cage 7, and fresh Bidens pilosa flowers collected are inserted into the water bottle to assist in providing fresh pollen.

[0043] A plurality of pairs of newly emerged adult aphid flies are selected and placed in a breeding cage 7. After feeding on pollen and honey water to supplement nutrition for 2 days, the male and female adult aphid flies fly, chase and mate under the stimulation of strong light and ultraviolet light on the top of the cage. After the adult aphid flies mate, broad bean seedlings with aphids are placed in the breeding cage 7 to induce the adult aphid flies to lay eggs. The broad bean seedlings with aphid fly eggs are transferred to the larval cage every day for egg hatching and larval feeding, and new broad bean seedlings with aphids are placed in the breeding cage 7 for the adult aphid flies to continue laying eggs. The pollen and nectar in the culture dish are regularly replaced to supplement nutrition for the adult aphid flies. By using this method of feeding, it is observed that the life span of adult aphid flies can reach 2-3 weeks, among which the life span of female aphid flies is longer than that of male aphid flies, the amount of aphid fly eggs laid per day is up to 38, the hatching rate of aphid fly eggs is 76.3%, and the emergence rate of aphid fly pupae is 92.5%.

[0044] In the breeding process of the above method 4), the main thing involved is the egg-laying and breeding of adult hoverflies. Therefore, a special hoverfly adult breeding cage 7 is developed, such as Figure 2 As shown, the size of the breeding cage 7 is 60cm*60cm*90cm, and the cage top of the breeding cage 7 is provided with an ultraviolet LED lamp 8. The breeding cage 7 is provided with broad bean seedlings 9 with black bean aphids, and the broad bean seedlings are from the insect cage B4, which are used to lure female aphid fly adults to lay eggs, and then put into the insect cage D6, waiting for the aphid fly larvae to grow in the insect cage D6 until they are about to pupate; the breeding cage 7 is provided with fresh Bidens pilosa 10 to provide fresh pollen as a supplement for the aphid fly adults; the breeding cage 7 is also provided with two culture dishes, respectively named culture dish A11 and culture dish B12, the culture dish A11 is filled with crushed bee pollen and is padded with a cylindrical plastic bottle, and the culture dish B12 is filled with cotton wool moistened with 15% honey water and is padded with a cylindrical plastic bottle.

[0045] 5) Transportation and release of short-spined syrphid flies: Syrphid fly pupae were kept in pupal card devices at a temperature of 4°C and then transported to offshore islands for release.

[0046] Short-spined syrphid flies are released to offshore islands to pollinate island plants. Since the distance is often very long, there are relatively strict requirements for the storage, transportation and release of syrphid flies. Syrphid flies do not need to eat during their pupal stage, and the entire insect state is static, which is very suitable for long-distance transportation. Under environmental conditions of 25°C, the pupal period of short-spined syrphid flies is about 6 days, and the time window suitable for transportation is relatively short. In order to prolong the pupal period, syrphid fly pupae can be stored under low temperature conditions. Therefore, the following comparative experimental tests were conducted to obtain the optimal temperature for prolonging the storage time of syrphid fly pupae:

[0047] The same amount of hoverfly pupae (50) were stored at three temperatures, namely 4°C, 8°C and 12°C. After 10 days, 15 days and 20 days, the hoverfly pupae were moved to 25°C and their emergence was observed.

[0048] Table 1 Effects of Different Temperatures and Storage Durations on the Emergence Rate of the Pupae of Ischiodon scutellaris

[0049]

[0050] As can be seen from Table 1, after the pupae of Ischiodon scutellaris were stored at 4°C for 10 days, 15 days, and 20 days and then transferred to 25°C, they emerged about 5 days later, and the emergence rates were 93.5%, 91.7%, and 79.3% respectively; after being stored at 8°C for 10 days, 15 days, and 20 days and then transferred to 25°C, the pupae of Ischiodon scutellaris emerged about 5 days later, and the emergence rates were 83%, 70.3%, and 67.8% respectively; after being stored at 12°C for 10 days, 15 days, and 20 days and then transferred to 25°C, the pupae of Ischiodon scutellaris emerged about 5 days later, and the emergence rates were 88.5%, 68.2%, and 65.3% respectively.

[0051] It can be seen from this that the success rate of the pupae of Ischiodon scutellaris emerging after being stored at 4°C for 10d - 15d and then transferred to 25°C is higher, and this storage duration can meet the actual transportation time.

[0052] During the long-distance transportation of the pupae of Ischiodon scutellaris, the pupae may be damaged due to jolting, affecting the survival rate. Therefore, setting the pupae of Ischiodon scutellaris in a pupae card device for transportation can, on the one hand, reduce the damage caused by the extrusion between the pupae during transportation, and on the other hand, facilitate the subsequent release of adults.

[0053] As Figure 3 shown, regarding the structure of the pupae card device: The pupae card device includes a plastic culture dish 13 with a diameter of 9 cm, and a sealing cover fitted at the opening of the plastic culture dish 13. A card 14 is fixed at the bottom of the plastic culture dish 13. The card 14 is circular, and 58 circular adhesive areas 15 are arranged in an array on the card 14. The diameter of each circular adhesive area 15 is 3 mm. The circular adhesive areas 15 are used for the adhesion and attachment of the pupae of Ischiodon scutellaris. The interval between adjacent circular adhesive areas 15 is 10 mm, providing sufficient space for the emergence of adjacent pupae. A hollowed-out area 16 is also provided on the circular card 14, and a thin line can be passed through it to facilitate the suspension of the pupae card device.

[0054] During use, 58 pupae of Ischiodon scutellaris are added to the plastic culture dish 13, and the bottom of the plastic culture dish 13 is shaken appropriately to make the pupae of Ischiodon scutellaris adhere to each circular adhesive area 15. After the Ischiodon scutellaris are loaded on the circular card 14, the sealing cover is fitted on the plastic culture dish 13, and then the bottom of the plastic culture dish 13 and the sealing cover are fixed with a 10-mm-wide tape. Then, after the pupae card device is packed, it is placed in a cardboard box, and the cardboard box is filled with newspapers or cotton to improve the shock absorption effect during transportation.

[0055] During the transportation and release of *Ischiodon scutellaris*, before the transportation pupae card device reaches the corresponding release location on the island, defatted cotton and pollen with 15% honey water are provided as food for some emerged *Ischiodon scutellaris* adults to improve the release survival rate of the *Ischiodon scutellaris* adults. After reaching the release location, for the emerged adults, areas close to many flowering plants can be selected for direct release. For the unemerged fly pupae, the card 14 can be removed from the plastic petri dish 13 and hung on the branch by threading a thin line through the hollow area of the card 14. After the *Ischiodon scutellaris* is released, it searches for the pollen and nectar of flowering plants to supplement nutrition, pollinates the flowering plants, mates and lays eggs on the aphid-infested plants 1-2 days later, and the larvae feed on aphids to control their numbers. The next generation of adults can be seen about 15 days later.

[0056] The artificial breeding and island pollination method of *Ischiodon scutellaris* of the present invention has the following beneficial effects compared with the prior art:

[0057] ① Combining the breeding processes of broad bean seedlings and aphids with the growth process of *Ischiodon scutellaris*, the black bean aphids propagated on the broad bean seedlings can promote female *Ischiodon scutellaris* to lay fly eggs, and the aphids can be eaten by the larvae after the fly eggs hatch, which has promoted the development of *Ischiodon scutellaris* larvae and improved the growth efficiency to facilitate the development of newly hatched larvae to pupae.

[0058] ② By harvesting the broad bean seedlings and putting them into the gauze net, it is convenient to quickly sieve and collect the *Ischiodon scutellaris* pupae, thereby improving the collection efficiency of the *Ischiodon scutellaris* pupae.

[0059] ③ When managing the *Ischiodon scutellaris* adults, an environment suitable for the breeding and egg-laying of the *Ischiodon scutellaris* adults is created in the breeding cage 7, such as providing ultraviolet lamps, defatted cotton moistened with 15% honey water, crushed bee pollen, and *Bidens pilosa* flowers, thereby improving the mating enthusiasm of male and female *Ischiodon scutellaris* adults, and at the same time increasing the egg-laying rate of female *Ischiodon scutellaris* adults, and then achieving large-scale promotion of the breeding of *Ischiodon scutellaris* larvae.

[0060] ④ When transporting the *Ischiodon scutellaris* pupae in the open sea, a preservation environment of 4°C can greatly extend the preservation time of the *Ischiodon scutellaris* pupae. At the same time, after the *Ischiodon scutellaris* pupae are preserved and transferred to an environment of 25°C, a high emergence rate can be effectively guaranteed. At the same time, during the transportation process, the *Ischiodon scutellaris* pupae are stored in the pupae card device, which can protect the *Ischiodon scutellaris* pupae from being squeezed, and the plastic petri dish 13 can provide a certain activity space for the prematurely emerged *Ischiodon scutellaris* adults, thereby improving the survival rate of the *Ischiodon scutellaris*.

[0061] ⑤ By setting a specially designed pupae card device, the *Ischiodon scutellaris* pupae can be better pasted in the circular viscous area 15, and the adjacent *Ischiodon scutellaris* pupae can maintain a better safety distance to prevent extrusion. At the same time, when the pupae card device is at the corresponding release point in the island area, it can also be released in various ways, such as taking out the card 14 and hanging it on the branch by threading a thin line through the hollow area of the card 14, or fixing the plastic petri dish 13 on the plant.

[0062] The embodiments of the present invention are not limited thereto. According to the above content of the present invention, using the common general technical knowledge and conventional means in the art, without departing from the above basic technical idea of the present invention, the present invention can also be modified, replaced or combined in many other forms, all of which fall within the scope of the protection of the present invention.

Claims

1. An artificial breeding method of Eristalinus punctatus and a method for pollinating island plants, characterized in that, Including the following methods: Artificial breeding of aphids: Plant broad bean seedlings in an insect rearing cage to propagate Aphis craccivora Koch for adult Sphaerophoria scripta to lay fly eggs and for Sphaerophoria scripta larvae to feed on; Rearing of Sphaerophoria scripta larvae: Rearing Sphaerophoria scripta larvae with Aphis craccivora Koch in an insect rearing cage. After 6 days of development, the Sphaerophoria scripta larvae can develop from newly hatched larvae to pupae; Collection of Sphaerophoria scripta pupae: Harvest the broad bean seedlings with mature Sphaerophoria scripta larvae and place them in a plastic box with a mesh opening for continued rearing. Put the collected Sphaerophoria scripta pupae in a petri dish for preservation and record the date until all the larvae in the plastic box pupate; Transportation and release of Sphaerophoria scripta: Under the temperature condition of 4°C, keep the Sphaerophoria scripta pupae in a pupal card device and then transport them to a remote offshore island for release.

2. The artificial breeding method of Eristalinus punctatus and the method for pollinating island plants according to claim 1, characterized in that, During the artificial breeding process of aphids, the following method is adopted: Plant broad beans in an insect rearing cage of 40cm×40cm×40cm to propagate Aphis craccivora Koch. The insect rearing cage is placed in an incubator with a temperature of 25±1°C, a humidity of 50%-70%, a photoperiod of 14L:10D, and a light intensity of 9000 Lux at the top of the cage. Use plant nursery soil as the substrate to plant broad beans. The nursery pots are plastic pots with a diameter of 10cm-12cm. Soak the broad bean seeds in clean water for 24 hours and then disinfect them with chlorine dioxide disinfectant tablets to improve the emergence rate. Insert the black end of the broad bean downward into the soil by half and then cover it with about 1cm of nursery soil layer. Plant 7-9 broad bean seeds in each nursery pot and plant broad beans 3 times a week to continuously supply seedlings. When the broad bean seedlings grow to 3cm-5cm, inoculate Aphis craccivora. Inoculate 20-30 adult aphids on each seedling. After 2d-3d of inoculating adult aphids, it can be used for adult Sphaerophoria scripta to lay eggs. After 6±1d of inoculating adult aphids, a large number of Aphis craccivora Koch are produced for Sphaerophoria scripta larvae to feed on.

3. The artificial breeding method of Eristalinus punctatus and the method for pollinating island plants according to claim 1, characterized in that, During the rearing process of Sphaerophoria scripta larvae, the following method is adopted: Rearing Sphaerophoria scripta larvae in an insect rearing cage of 40cm×40cm×40cm. The insect rearing cage is placed in an incubator with a temperature of 25±1°C, a humidity of 50%-70%, a photoperiod of 14L:10D, and a light intensity of 9000 Lux at the top of the cage. Transfer the broad bean seedlings with Sphaerophoria scripta eggs in the adult breeding box to the larval rearing cage. After 2d, the larvae hatch and start feeding on aphids. When it is observed that the aphids on the broad bean seedlings will be completely eaten after 4d-5d, cut the broad bean seedlings with Sphaerophoria scripta larvae from the roots and move them to new broad bean seedlings with aphids in the larval rearing cage. The Sphaerophoria scripta larvae will transfer to the new broad bean seedlings by themselves to feed on aphids. The Sphaerophoria scripta larvae can pupate after 6±1d of development, that is, develop from newly hatched larvae to pupae. Only one supplement of aphids is needed during the larval rearing period.

4. The artificial breeding method of Eristalinus punctatus and the pollination method for island plants according to claim 1, characterized in that During the collection process of Sphaerophoria scripta pupae, the following method is adopted: When the mature Sphaerophoria scripta larvae start to excrete black feces, it indicates that the Sphaerophoria scripta larvae have completed development and are about to pupate. At this time, harvest the broad bean seedlings with mature Sphaerophoria scripta larvae and place them in a 6.5cm×11.8cm×17.5cm plastic box with a mesh opening for continued rearing. Collect the Sphaerophoria scripta pupae every day and put them in 1 petri dish for preservation and record the date until all the larvae in the plastic box pupate.

5. The artificial breeding method of Eristalinus punctatus and the method for pollinating island plants according to claim 1, characterized in that, It also includes the following methods: Management of adult Ischiodon scutellaris Wiedemann: Create an environment suitable for the breeding and egg-laying of adult Ischiodon scutellaris Wiedemann in a breeding cage; Select multiple pairs of newly emerged adult Ischiodon scutellaris Wiedemann and put them into the breeding cage. After supplementing nutrition by feeding on pollen and honey water for 2 days, under the stimulation of strong light and ultraviolet light, male and female adult Ischiodon scutellaris Wiedemann fly and chase each other and mate; After the adult Ischiodon scutellaris Wiedemann mate, put broad bean seedlings with aphids into the breeding cage to induce adult Ischiodon scutellaris Wiedemann to lay eggs; Transfer the broad bean seedlings with Ischiodon scutellaris Wiedemann eggs into the larval cage every day for egg hatching and larval rearing, and put new broad bean seedlings with aphids into the breeding cage for adult Ischiodon scutellaris Wiedemann to continue laying eggs. Regularly replace the pollen and nectar in the culture dish to supplement nutrition for adult Ischiodon scutellaris Wiedemann, so as to improve the survival rate of adult Ischiodon scutellaris Wiedemann and the hatching rate of Ischiodon scutellaris Wiedemann eggs.

6. The artificial breeding method of **Ischiodon scutellaris** and the method for pollinating island plants according to claim 5, characterized in that, When creating an environment suitable for the breeding and egg-laying of adult Ischiodon scutellaris Wiedemann in the breeding cage, the following method is adopted: The breeding cage uses an insect breeding cage of 60cm * 60cm * 90cm. An LED lamp with ultraviolet lamp beads is set on the top of the cage. The light intensity on the top of the cage is 30000Lux, the temperature is 25 ± 1°C, the humidity is 50%-70%, and the photoperiod is 14L:10D; Two culture dishes are placed in the breeding cage. One contains absorbent cotton moistened with 15% honey water, and the other contains crushed bee pollen. The culture dishes are raised to facilitate adult Ischiodon scutellaris Wiedemann to feed; A water bottle is set in the breeding cage, and fresh Bidens pilosa L. flowers collected are inserted into the water bottle to assist in providing fresh pollen.

7. The artificial breeding method of Eristalinus punctatus and the method for pollinating island plants according to claim 1, characterized in that, During the transportation and release of Ischiodon scutellaris Wiedemann, after the pupal card device is packed, it is put into a cardboard box, and the cardboard box is filled with newspapers or cotton to improve the shock absorption effect during transportation.

8. The artificial breeding method of **Ischiodon scutellaris** and the method for pollinating island plants according to claim 1, wherein, During the transportation and release of Ischiodon scutellaris Wiedemann, regarding the structure of the pupal card device: The pupal card device includes a plastic culture dish and a sealing cover fitted at the opening of the plastic culture dish. A card is fixed at the bottom of the plastic culture dish, and several circular sticky areas arranged in an array are set on the card. The diameter of each circular sticky area is 3mm, and the circular sticky areas are used for the adhesion and attachment of Ischiodon scutellaris Wiedemann pupae. The interval between adjacent circular sticky areas is 10mm.

9. The artificial breeding method of **Sphegina brevispina** and the method for pollinating island plants according to claim 1, characterized in that During the transportation and release of Ischiodon scutellaris Wiedemann, before the transported pupal card device reaches the corresponding release site on the island, provide absorbent cotton with 15% honey water and pollen as food for some emerged adult Ischiodon scutellaris Wiedemann to improve the release survival rate of adult Ischiodon scutellaris Wiedemann.

Images