Method for feeding clanis giganteus

Abstract

The invention discloses a method for feeding clanis giganteus. The method comprises the steps of collecting eggs, feeding in an egg stage, feeding in a larva stage, feeding in a pupal stage and the like. Through accurate feeding management steps, the problem that the survival rate of the current artificially-fed clangiotridae is not high is solved. The breeding method for the clanis giganteus is easy to operate, the survival rate in the whole growth period is high, the egg laying amount of imagoes is high, and a large number of hosts can be provided for breeding of the two natural enemies.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural insect breeding, and particularly relates to a method for breeding Hippotion velox. Background Art

[0002] Hippotion velox belongs to Lepidoptera, Sphingidae, Hippotion, and is a leaf-eating insect. In the Xisha Islands of Sansha City, China, Hippotion velox has about 10 generations a year. The larvae have 6 instars. The food intake of the 1st - 3rd instar larvae is relatively small, the food intake of the 4th instar larvae increases, and the 5th - 6th instars reach the gluttonous stage, with the food intake accounting for 90% of the entire growth period. It often eats up the leaves branch by branch, and when the tender branches at the tree top are eaten up, it will move to other places. When it occurs severely, it eats up all the leaves of the tree, resulting in a reduction in the photosynthetic area and nutrient accumulation of the tree body, and a decline in the tree vigor. The adults are active at night and hide during the day, mate at night, and lay eggs every other day. In the Xisha area, the egg stage is 5 - 7 days, and each female can lay 150 - 400 eggs, with strong reproductive ability.

[0003] Currently, in the control of Hippotion velox in the Xisha Islands, it mainly relies on chemical pesticides and insecticidal lamps. While pesticides control Hippotion velox, the number of natural enemies in the field decreases sharply, resulting in a large outbreak of the Hippotion velox population during the dry season, and basically forming a periodic severe hazard every year. At the same time, pesticides will also damage other insects, water, soil and other environments on the Xisha Islands and reefs, severely threatening the already fragile reef ecosystem. The insecticidal lamp only has a significant trapping effect on the adult Hippotion velox, and has no effect on the larvae. The damage of the sphinx moth to the trees is mainly caused by the larvae. Therefore, the role of the insecticidal lamp is only to reduce the population base of the next generation. Simply relying on trapping adults cannot effectively control the outbreak of Hippotion velox. Therefore, the development of biological control methods has great application value in preventing and controlling the harm of Hippotion velox and protecting the ecological security of the reefs.

[0004] Natural enemy insects are an important part of biological control and play an extremely important role in controlling the population density of pests. Field investigations in the Xisha Islands found that there are more than 2 parasitic natural enemies of Hippotion velox, Trichogramma and Brachymeria lasus. Trichogramma parasitizes eggs (the field parasitism rate can reach more than 70%), and Brachymeria lasus parasitizes pupae (the field parasitism rate can reach more than 20%). Both parasitic wasps are solitary parasites, with a short development cycle and a high reproduction coefficient, which play an important role in controlling the population number of Hippotion velox. Combined with light trapping during the adult stage, it has good development and application prospects.

[0005] The industrialized reproduction of natural enemies is an important link in the utilization of natural enemies. Industrialized reproduction either uses easily reared alternative hosts or breeds a large number of natural hosts. The latter is more suitable for maintaining the vitality of natural enemies and their host selection preferences. However, there is currently a lack of effective methods for artificially rearing the natural host, the oblique-lined hawkmoth (Theretra nessus), which has hindered the large-scale breeding of parasitic natural enemy insects such as Trichogramma and Brachymeria using the oblique-lined hawkmoth as a natural host.

[0006] Currently, when artificially rearing the oblique-lined hawkmoth, it is difficult to simulate the complexity of its natural habitat in the rearing environment, resulting in a slow growth rate, disrupted development cycle, and low survival rate of the reared oblique-lined hawkmoths. Secondly, there is a lack of feed suitable for the oblique-lined hawkmoth. When attempting to rear the oblique-lined hawkmoth with plants, there are differences in the nutrient content and secondary metabolite content of different plants, which can affect the growth of the oblique-lined hawkmoth larvae. And there are few plants suitable for artificially rearing the oblique-lined hawkmoth. In summary, the current status of rearing the oblique-lined hawkmoth has hindered the biological control process of breeding parasitic natural enemy insects using it as a natural host. There is an urgent need to develop a scientific, efficient, and suitable method for large-scale artificial rearing of the oblique-lined hawkmoth to promote the biological control work of the oblique-lined hawkmoth in the Xisha Islands and protect the ecological security of the island reefs. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention develops a method for successive rearing of the oblique-lined hawkmoth for the large number of hosts, the oblique-lined hawkmoth, required for the industrialized reproduction of Trichogramma and Brachymeria.

[0008] The technical solution of the present invention is as follows:

[0009] A method for rearing the oblique-lined hawkmoth, comprising the following steps:

[0010] S1. Collecting eggs

[0011] Put the pupae of the hawkmoth about to emerge into the mating and egg-laying shed. In the shed, hang the leaves of Excoecaria agallocha and / or Scaevola taccada, and wrap the end of the petiole with a wet cotton ball; collect the eggs during the peak period of adult emergence; replace the leaves hung in the mating and egg-laying shed every day, remove the cotton ball wrapped on the leaf stalk, and collect the leaves with eggs into the egg-stage insect rearing box;

[0012] S2. Rearing during the egg stage

[0013] Place the egg-stage insect rearing box in the insect rearing room until hatching, transfer the newly hatched larvae to the insect rearing box for the low-instar larvae stage, and spray clear water to supplement the moisture of the leaves after transferring the newly hatched larvae, with the standard that the leaves are not significantly wet;

[0014] S3. Rearing during the larval stage

[0015] Place the insect rearing boxes for the early larval stage in the insect rearing room for rearing. Collect the just molted 4th instar larvae from the insect rearing boxes for the early larval stage and transfer them to the insect rearing boxes for the 4th instar larvae. Collect the just molted 5th instar larvae from the insect rearing boxes for the 4th instar larvae and transfer them to the insect rearing boxes for the late larval stage until rearing reaches the prepupa stage; during the rearing process, replace the leaves in the insect rearing boxes every day.

[0016] S4. Rearing during the pupal stage

[0017] Collect the prepupae every day, place the leaves wrapping the prepupae in a new insect rearing box. During the entire pupal stage rearing, do not replace the leaves and the insect rearing box, nor spray clear water to increase humidity. Until the color of the pupa turns dark brown, transfer it to the greenhouse and wait for eclosion.

[0018] Preferably, in step S3, during the larval stage rearing process, replace the leaves in the insect rearing box twice a day.

[0019] Preferably, the time interval for replacing the leaves twice a day is more than 8 hours.

[0020] Preferably, the environmental conditions for larval stage rearing are: temperature 24 - 32 °C, relative air humidity 60% - 75%.

[0021] More preferably, the environmental conditions for larval stage rearing are: temperature 28 °C, relative air humidity 75%.

[0022] Furthermore, through long-term research and observation, it was unexpectedly found that the wetness of the leaves during the larval stage is an important factor leading to a large number of larval deaths. Therefore, it is necessary to keep the leaf surface dry when rearing larvae.

[0023] Preferably, the total number of insects reared in the insect rearing boxes for the early larval stage does not exceed 100, the total number of insects reared in the insect rearing boxes for the 4th instar larvae does not exceed 50, and the total number of insects reared in the insect rearing boxes for the late larval stage does not exceed 20.

[0024] Preferably, the specification of the rearing box is length × width × height = 25 cm × 18 cm × 35 cm.

[0025] Preferably, the photoperiod for larval rearing is 6 - 18L:6 - 18D.

[0026] Preferably, the light intensity is 2500 ± 200 lx.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The rearing method of Clanis bilineata tsingtauica in the present invention is simple to operate, has a high survival rate throughout the growth period, a high egg-laying amount of adults, and can provide a large number of hosts for the reproduction of two natural enemies. Especially for Trichogramma evanescens parasitizing eggs, a large number of fresh eggs can be obtained as planned. Specific embodiments

[0029] To better understand the technical content of the present invention, the following further describes the present invention in conjunction with specific embodiments.

[0030] In the following examples and comparative examples, the light intensity for feeding is 2500 ± 200 lx

[0031] Example 1

[0032] A method for raising Psilogramma increta, comprising the following steps:

[0033] S1. Collecting eggs

[0034] Psilogramma increta has obvious generations, with one generation every 1 - 1.5 months in the wild of the Xisha Islands. For indoor feeding, prepare for egg collection at the beginning of the emergence of adults in each generation, and collect eggs during the peak emergence period of adults. Replace the leaves of Pisonia grandis R.Br. (scientific name) hanging in the indoor mating and egg-laying shed every day, remove the cotton balls wrapped on the leaf stalks, and collect the leaves with eggs into the insect rearing box (length × width × height = 25 cm × 18 cm × 35 cm). Eggs and leaves collected on different dates are placed in insect rearing boxes marked with different egg-laying dates and put into an insect rearing room with a temperature of about 28°C and a relative air humidity of about 75%.

[0035] S2. Rearing during the egg stage

[0036] During the rearing period, observe the hatching situation of eggs every day. After observing and transferring the newly hatched larvae, use a spray bottle to spray an appropriate amount of clear water to supplement the moisture of the leaves, with the standard that the leaves are not significantly wet. Once the eggs hatch, they become newly hatched larvae. Collect all newly hatched larvae every day and concentrate them in the insect rearing box for the low-instar larvae stage. At the same time as collecting the newly hatched larvae, remove the leaves on which all the eggs have hatched and put them into the incinerator for incineration.

[0037] S1. Rearing during the larval stage

[0038] Check the hatching situation of the eggs of Psilogramma increta in the insect rearing box during the egg stage twice a day (with an interval of more than 8 hours), and transfer and collect the newly hatched larvae with a small brush dipped in water, and concentrate them in the insect rearing box for the low-instar larvae stage and mark the hatching date. Newly hatched larvae hatched on the same day can be placed in the same rearing box, with a total number of no more than 100 in each rearing box, and placed in an insect rearing room with a temperature of about 28°C and a relative air humidity of about 75% for rearing.

[0039] When replacing the leaves in the insect rearing box during the larval stage twice a day (with an interval of more than 8 hours), collect the newly molted 4th instar larvae from the insect rearing box for the low-instar larvae stage, and collect the newly molted 5th instar larvae from the insect rearing box for the 4th instar larvae. Larvae of the same instar molted on the same day can be placed in the same rearing box, with a total number of no more than 50 in each rearing box, and placed in an insect rearing room with a temperature of about 28°C and a relative air humidity of about 75% for rearing.

[0040] Replace the leaves in all the insect rearing boxes for low-instar larvae (instars 1-3), 4th instar larvae, and high-instar larvae (instars 5-6) twice a day (with an interval of more than 8 hours), and keep the leaves in the insect rearing boxes sufficient for the larvae being reared to feed on. When replacing the fresh leaves, clean the residual leaves and feces, and collect them for incineration in an incinerator.

[0041] Collect the prepupae together with the leaves wrapping them and place them in the insect rearing boxes every day. During the entire pupal stage of rearing, do not replace the leaves and the insect rearing cages, and do not spray clear water to increase the humidity either. Until the color of the pupa turns dark brown, transfer it to the greenhouse and wait for eclosion.

[0042] For the leaves used in rearing low-instar larvae, 4th instar larvae, and high-instar larvae, there is no need to wrap the leaf stalks with cotton balls to keep the humidity, nor is it necessary to spray clear water on the leaves to increase the humidity. When rearing the larvae, it is necessary to keep the leaf surface dry, and maintain the freshness of the leaves by replacing an appropriate amount of leaves every day. Once there is an obvious wet phenomenon on the leaf surface, it will cause a large number of larvae to die.

[0043] Because low-instar larvae are fragile, when replacing the leaves for larvae of instars 1-3, there is no need for manual assistance to transfer them. Just directly cover the fresh leaves on the original leaves, and the larvae of the sphinx moth will climb onto the fresh leaves by themselves. When manual assistance is necessary to transfer the larvae, gently stir the insect body with a wet brush and move it onto the fresh leaves.

[0044] The rearing effects of this example are shown in Tables 1-3 below.

[0045] In addition, through a large number of screenings, we further found that replacing the leaves of Excoecaria agallocha with the leaves of Scaevola sericea Vahl also has a similar rearing effect. The hatching rate of eggs reaches more than 90%, the survival rate of 1-3 instar larvae reaches more than 87%, the survival rate of 4th instar larvae reaches more than 97%, and the survival rate of 5-6 instar larvae reaches more than 98%.

[0046] In order to explore the effects of different temperatures on the egg hatching rate and larval survival rate, we conducted the following comparative experiments.

[0047] Comparative Example 1

[0048] Among the temperature settings of Comparative Example 1, and between it and Example 1, only the temperature settings are different, and other rearing methods are the same as those in the example.

[0049] A total of 5 test temperatures were set in Comparative Example 1, which were 20°C, 24°C, 28°C, 32°C, and 36°C respectively. We statistically analyzed the egg hatching rate and the survival rate of each instar larvae at these five test temperatures, and the statistical results are shown in Table 1.

[0050] Table 1 Egg hatching rate of Theretra nessus and survival rate of its larvae under different constant temperatures

[0051]

[0052]

[0053] As can be seen from Table 1: (1) Theretraea japonica can complete development at the 5 tested temperatures, but the hatching rate of eggs and the survival rate of larvae at different instars are different. (2) The hatching rate of eggs and the survival rate of low-instar (1st - 3rd instar) larvae are the highest at 28°C, and are significantly higher than those at other temperatures; the survival rate of 4th instar larvae and high-instar (5th - 6th instar) larvae increases significantly at each temperature. (3) The hatching rate of eggs and the survival rate of low-instar (1st - 3rd instar) larvae are very low at 20°C and 36°C; the survival rate of larvae at each stage is significantly lower than that at other temperatures at 36°C. (4) Based on the above results, the most suitable temperature for rearing Theretraea japonica indoors under constant temperature is about 28°C.

[0054] Comparative Example 2

[0055] In order to explore the effects of different relative air humidities on the hatching rate of eggs and the survival rate of larvae, we conducted the following comparative experiments.

[0056] Between the humidity settings of Comparative Example 2 and between them and the Examples, only the temperature settings are different, and other rearing methods are the same as those in Example 1.

[0057] Comparative Example 2 was set with 3 tested humidities, namely 60%, 75% and 90%. We statistically analyzed the hatching rate of eggs and the survival rate of larvae at each instar under these three tested humidities, and the statistical results are shown in Table 2.

[0058] Table 2 Hatching rate of eggs of Theretraea japonica and survival rate of its larvae under different relative air humidities

[0059]

[0060] As can be seen from Table 2: (1) Theretraea japonica can complete development at the 3 tested humidities, but the hatching rate of eggs and the survival rate of larvae at different relative humidities are different. (2) The hatching rate of eggs and the survival rate of low-instar (1st - 3rd instar) larvae are the highest at 75% humidity, and are significantly higher than those at other humidities; the survival rate of 4th instar larvae and high-instar (5th - 6th instar) larvae increases significantly at each humidity. (3) The hatching rate of eggs and the survival rate of larvae at each instar are significantly lower under 90% relative humidity than those under the other two humidity settings, indicating that high humidity is more unfavorable for the growth and development of Theretraea japonica larvae. (4) Based on the above results, the most suitable relative air humidity for rearing Theretraea japonica indoors is about 75%.

[0061] Comparative Example 3

[0062] In order to explore the effects of different photoperiods on the survival rate of larvae, we conducted the following comparative experiments.

[0063] For Comparative Example 3, between each photoperiod setting and between it and Example 1, only the photoperiod setting is different, and other feeding methods are the same as those in Example 1.

[0064] Comparative Example 3 was set with 3 test photoperiods, namely, the light time and dark time within 24 hours were 6h:18h, 12h:12h, and 18h:6h respectively. We counted the survival rates of larvae at each instar under these three photoperiods, and the statistical results are shown in Table 3.

[0065] Table 3 Survival rates of Smerinthus planus larvae under different photoperiods

[0066]

[0067] It can be seen from Table 3 that Smerinthus planus larvae can complete development well under the 3 test photoperiods, and different photoperiods have no effect on the survival rates of larvae at different instars.

[0068] In summary, by comparing Comparative Example 1 to Comparative Example 3, we found that only by using the feeding method described in the present application (placing eggs, 1st - 3rd instar larvae, 4th instar larvae, and 5th - 6th instar larvae at a temperature of about 28°C, while maintaining the relative air humidity at about 75%, and feeding with the leaves of Excoecaria acerifolia and Scaevola sericea) can the hatching rate of Smerinthus planus eggs and the survival rate of larvae be maximized. In particular, the survival rate of low - instar larvae can be maximized, thus providing a large number of host eggs for the parasitism of Trichogramma and Microterys clauseni; moreover, the feeding method of Smerinthus planus larvae in the present application is simple to operate and the feeding conditions are easy to control.

[0069] The above are only some embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for raising a clouded slash moth, characterized in that: The following steps are involved: S1. Collecting eggs Put the hawkmoth pupae that are about to emerge into the mating and egg-laying shed, hang leaves of Tung oil tree and / or Pittosporum stoloniferum in the shed, and wrap the ends of the petioles with wet cotton balls; collect eggs at the peak of adult emergence; replace the leaves hanging in the mating and egg-laying shed every day, remove the cotton balls wrapped on the leaf stalks, and collect the leaves with eggs into the egg-raising box; S2. Egg feeding Place the egg-stage insect box in the insect-raising room until it hatches, transfer the newly hatched larvae to the low-age larvae insect box for breeding, and spray clean water to replenish the leaves with moisture after transferring the newly hatched larvae. The standard is that the leaves are not obviously wet. S3. Larval feeding The low-age larvae-stage insect-raising boxes are placed in the insect-raising room for breeding, and the 4th-instar larvae that have just molted are collected from the low-age larvae-stage insect-raising boxes and transferred to the 4th-instar larvae-raising boxes, and the 5th-instar larvae that have just molted are collected from the 4th-instar larvae-raising boxes and transferred to the high-age larvae-raising boxes, until they are raised to prepupae; during the breeding process, the leaves in the insect-raising boxes are replaced every day; S4. Pupal feeding Collect prepupae every day and place the leaves wrapped in the prepupae in a new insect box. During the entire pupal period, the leaves and insect boxes do not need to be replaced, and there is no need to spray water to increase the humidity. After the color of the pupae turns dark brown, they are transferred to the greenhouse to wait for emergence.

2. The method for raising the clouded slash moth according to claim 1, characterized in that: In step S3, the leaves in the insect box are replaced twice a day during the larval rearing process.

3. The method for raising the clouded slash moth according to claim 2, characterized in that: The interval between replacing leaves twice a day should be more than 8 hours.

4. The method for raising the clouded slash moth according to claim 1, characterized in that: The environmental conditions for larval rearing are: temperature 24-32°C, relative air humidity 60%-75%.

5. The method for raising the clouded slash moth according to claim 4, characterized in that: The environmental conditions for larval rearing were: temperature 28°C, relative air humidity 75%.

6. The method for raising the clouded slash moth according to claim 1, characterized in that: The leaf surface needs to be kept dry when raising larvae.

7. The method for raising the clouded slash moth according to claim 1, characterized in that: The total number of larvae raised in the insect boxes for the lower larvae shall not exceed 100, the total number of larvae raised in the insect boxes for the 4th instar larvae shall not exceed 50, and the total number of larvae raised in the insect boxes for the higher larvae shall not exceed 20.

8. The method for raising the clouded slash moth according to claim 1, characterized in that: The specifications of the breeding box are length × width × height = 25cm × 18cm × 35cm.

9. The method for raising the clouded slash moth according to claim 1, characterized in that: The photoperiod for larval rearing is 6-18L:6-18D.

10. The method for raising the clouded slash moth according to claim 9, characterized in that: The light intensity is 2500±200lx.

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