CN114651793B

CN114651793B - Artificial breeding of trichogramma obscura and method for preventing and treating spodoptera frugiperda by using trichogramma obscura

Info

Publication number: CN114651793B
Application number: CN202210472954.7A
Authority: CN
Inventors: 严珍; 岳建军
Original assignee: Dai Medical College Of West Yunnan University Of Applied Technology; Institute of Medicinal Plant Development of CAMS and PUMC
Current assignee: Dai Medical College Of West Yunnan University Of Applied Technology; Institute of Medicinal Plant Development of CAMS and PUMC
Priority date: 2022-05-01
Filing date: 2022-05-01
Publication date: 2023-04-18
Anticipated expiration: 2042-05-01
Also published as: CN114651793A

Abstract

The invention discloses artificial breeding of trichogramma obscurus and a method for preventing and controlling spodoptera frugiperda by using the trichogramma obscurus. The bred trichogramma obscura has similar or superior main biological indexes to those of the trichogramma obscura bred by the original host spodoptera frugiperda, the population quantity and the quality of the trichogramma obscura are obviously improved, a better field prevention and control effect is obtained, and an unexpected effect is achieved.

Description

Artificial breeding of trichogramma obscura and method for preventing and treating spodoptera frugiperda by using trichogramma obscura

Technical Field

The invention belongs to the field of biological control, and particularly relates to artificial breeding of trichogramma obscura and a method for controlling spodoptera frugiperda by using the trichogramma obscura.

Background

Spodoptera frugiperdaSpodoptera frugiperda(Smith) is a worldwide agricultural significant invasive pest, and has recently invaded many countries in Africa and Asia. The insect was first reported in 1797 in georgia in the united states, followed by subsequent outbreaks of disasters in florida, honduras, brazil, etc. In year 2018, in the year 5, the insect invades Indian of Asia for the first time, the insect spreads harm in the south east Asia, in year 2018, in month 12, in month 11, the Spodoptera frugiperda migrates from Burma into Yunnan Pu' er region of China, in year 2019, the insect invades 26 provinces of China except Sinkiang, qinghai and northeast province, the host range is very wide, and the insect has obvious effects on important medicinal plants and crops such as rhizoma Zedoariae, coix lacryma-jobi, corn, wheat, sorghum, sugarcane and the likeThe safety production of (2) poses a serious threat; taking the harm to corn as an example, the yield can be reduced by 30-60 percent generally, the yield of corn in serious areas can be reduced by more than 70 percent, even the corn is absolutely harvested in serious conditions, and China provides a 'worm mouth grain-deprivation' strategy aiming at the insect joint defense joint control in time. The Spodoptera frugiperda has the characteristics of strong migratory flight capability, large food intake, strong reproductive capacity, easy drug resistance generation and the like, so that the control effect on Spodoptera frugiperda is not ideal at the present stage.

At present, the control of spodoptera frugiperda is still mainly based on traditional chemical control, a series of 3R problems are easily generated, the spodoptera frugiperda is harmful to environment, human beings and non-target organisms, the implementation of environmental protection and ecological safety policies in China is contrary to, and a set of green comprehensive control technology for the spodoptera frugiperda is urgently needed to be developed and popularized as a substitute technology. The biological control of pests is a green control technology, and biological control of pests by using natural enemies becomes one of international research hotspots in recent years, and the biological control has a wide application prospect.

Trichogramma (a)Trichogramma) Is a parasitic natural enemy with wide application. The female bees lay eggs in host pest eggs, the bee eggs grow in the host eggs, and grow into imagoes after egg, larva, prepupa and pupa stages, finally the trichogramma imagoes bite the host eggs and break the shells to emerge, and the host Spodoptera frugiperda dies; subsequently, the eclosion female trichogramma offspring continuously searches for new host egg laying parasitism, and the continuous control effect of 'controlling insects by insects and biologically preventing' is achieved. The trichogramma is used for biologically preventing and controlling pests, and has the obvious advantages of safety, greenness, no pollution, strong specificity, continuous control and the like. At present, trichogramma is used as an important biological control factor, and in order to improve the application effect of the trichogramma, indoor bee breeding and field bee releasing technologies are core technologies for controlling pests by using the trichogramma. When a large amount of trichogramma is bred indoors, the optimal feeding condition for improving the quality of trichogramma is determined on the basis of not influencing the quality and the application effect of the trichogramma; when the bees are put in the field, the bee putting time, the number of the bees, the number of the bee putting intervals, the number of the bee putting times and other key factors are comprehensively considered.

The trichogrammaceae has abundant resources, and nearly 90 genera and more than 800 genera have been reported all over the world. Barefoot eyesThe fitness relation between bees and their hosts is complex, and different species of trichogramma have different suitable host ranges relatively, and generally speaking, the host range of trichogramma is narrow, which results in the need of using corresponding pests as hosts when artificial propagation of trichogramma is carried out. The selection of hosts is less, which results in higher cost of artificial propagation of trichogramma. In a large number of trichogramma, only limited trichogramma which can use spodoptera frugiperda as a host are reported at present, but no report of further development and application or poor biological control effect is found. Such as trichogramma of rice stem borerTrichogrammajaponicum、Tricholoma matsutake trichogrammaTrichogrammadendrolimiYellow-eyed waspTrichogrammachilonisCorn borer trichogrammaTrichogrammaostriniaeHebi Ling trichogrammaTrichogrammabilingensisAlthough all parasitize Spodoptera frugiperda to varying degrees, the parasitism varies greatly, with the stronger trichogramma dendrolimi, the second of the Green trichogramma, the remaining 3 being almost infeasible or poorly parasitizable. Therefore, the mining of the local dominant natural enemy resources of the insect and the development and utilization of the local dominant natural enemy resources have important significance.

Therefore, how to develop a method for expanding and propagating trichogramma and a green prevention and control application technology for carrying out major invasion of pest spodoptera frugiperda by using trichogramma is a key technical problem which needs to be solved urgently by technical personnel in the field.

Dark trichogrammaTrichogrammapintoiVoegele is a new natural enemy of Spodoptera frugiperda, a member of the family Heterochaeta of the order Hymenoptera, which was first discovered and identified by the inventors on a population of Spodoptera frugiperda. The bee is researched and found to have a good control effect on host spodoptera frugiperda, and the parasitic bee is a local dominant natural enemy of spodoptera frugiperda in the southwest of Yunnan, and is a local natural enemy resource with potential to be developed. Therefore, an accurate green prevention and control technology for preventing and controlling spodoptera frugiperda by using the trichogramma atroviride is further utilized, so that farmers can save the cost of using pesticides and increase income and decline, and the agricultural safety of China and the healthy and sustainable development of related industrial chains are promoted.

Disclosure of Invention

Based on the above, the invention particularly provides a method for propagating trichogramma reevesii indoors by utilizing spodoptera litura eggs, and an application method for preventing spodoptera frugiperda by utilizing trichogramma reevesii.

The technical scheme adopted by the invention is as follows:

in a first aspect of the present invention, there is provided:

the artificial breeding method of the dark trichogramma comprises the following steps:

s1) breeding prodenia litura, and preparing an egg card from prodenia litura eggs;

s2) mixing the male bees and the female bees of the dark trichogramma to mate;

s3) transferring the mated female bees into a container filled with an egg card, and timely providing nutrient solution for supplementing nutrition to the adult bees;

s4) obtaining a bee card when the female bee spawns into the spodoptera litura egg;

and S5) enabling the dark trichogramma eggs in the bee card to develop into adult bees, and providing nutrient solution in due time during the raising period of the adult bees.

In some examples of artificial breeding methods, the mated female bees are cultured in a container at a temperature of 22 to 29 ℃, a relative humidity of 60 to 80%, a light cycle L: d is 0.

In some examples of artificial breeding methods, the nutrient solution is an aqueous solution of a mixture of sucrose, glucose and honey.

In some examples of artificial farming methods, the nutrient solution is sucrose: glucose: honey =1:1:1 in water.

In some examples of artificial breeding methods, the day-old of the spodoptera litura eggs is 1-2 days old.

In some examples of artificial breeding methods, the culture conditions for the trichogramma obscurus adult bees are: the temperature is 22-29 ℃, and the relative humidity is 60-80%.

In a second aspect of the present invention, there is provided:

the method for preventing and controlling Spodoptera frugiperda by using the trichogramma obscura comprises the following steps:

s1) preparing a dark trichogramma bee card according to the method of the first aspect of the invention;

s2) carrying out field bee releasing work in the spodoptera frugiperda full-growth stage and the egg-laying initial stage, wherein:

releasing bees for the first time: the bee releasing time is the initial stage of the Spodoptera frugiperda oviposition;

releasing bees for the second time: after the bee releasing interval of the first time is 5-7 days, the bee releasing is carried out for the second time;

releasing bees for the third time: and after the bee releasing interval of the second time is 5-7d, releasing the bees for the third time.

In some examples of the method, the temperature of the bee is 22-30 ℃, the relative humidity is 70-90%, and the wind power is not more than 3 grades on sunny days.

In some examples of the method, the time of releasing bees is from 30 to 19.

In some examples of methods, a black trichogramma bee card is placed in the leaf sheath of the leaf of the plant near the heart when the bee is released.

In some examples of methods, the number of bees is 6000 to 8000 bees per acre at a time.

The invention has the beneficial effects that:

according to the artificial breeding method of the trichogramma obscurus, which is disclosed by the invention, easily obtained prodenia litura eggs can be selected as the substitute hosts, so that the cost and difficulty of artificial breeding of the trichogramma obscurus are effectively reduced, and the possibility of controlling spodoptera frugiperda by using the trichogramma obscurus is provided.

According to the artificial breeding method of the trichogramma obscurus, provided by the invention, the appropriate alternative host spodoptera litura egg (see the comparison in tables 1-5) is preferably selected for breeding, the main biological indexes of bred trichogramma are similar to or superior to those of a control group (the bee bred at the original host spodoptera frugiperda night) and the field application of spodoptera frugiperda control is further carried out (table 6), so that the population quantity and the quality of the trichogramma are remarkably improved, and a better field control effect is obtained.

Drawings

FIG. 1 is a photograph of a scottiferae trichogrammae being parasitized by spodoptera frugiperda egg masses.

FIG. 2 is a photograph of a darkish trichogramma bee that proliferates in an egg chamber using spodoptera litura.

Fig. 3 is a photograph of an adult trichogramma obscura.

FIG. 4 is a photograph of corn destruction by Spodoptera frugiperda larvae prior to biocontrol. The spodoptera frugiperda larvae in the corn field are seriously damaged, and a large number of holes are formed in corn ears and corn stalks.

FIG. 5 is a photograph of spodoptera frugiperda egg masses in a corn field.

FIG. 6 is a photograph of larvae of Spodoptera frugiperda in a corn field after initial incubation.

FIG. 7 is a photograph of a scottitis carinata parasitizing an egg of Spodoptera frugiperda.

Detailed Description

The inventor researches and discovers that the trichogramma atrophaea can use the spodoptera litura eggs as alternative hosts, the method for breeding the host spodoptera litura is simple, and a large number of neat and consistent host egg masses can be quickly obtained for the trichogramma atrophaea to parasitize.

In a first aspect of the present invention, there is provided:

s2) mixing the male bees and the female bees of the dark trichogramma to mate;

s4) obtaining a bee card when the female bee spawns into the prodenia litura;

and S5) enabling the dark trichogramma eggs in the bee cards to develop into adult bees, and providing nutrient solution timely during the adult bee raising period.

In some examples of artificial breeding methods, the post-mating female bees are cultured in a container at a temperature of 22 to 29 ℃, a relative humidity of 60 to 80%, a light cycle L: d is 0. Research shows that under the condition, the method is more beneficial to the female bees to lay eggs and is beneficial to obtaining higher-quality bee cards.

The nutrient solution can be designed according to the needs of trichogramma obscurus, and generally speaking, the nutrient solution mainly contains water-soluble sugar to supplement the energy needs of the trichogramma obscurus. In some examples of artificial breeding methods, the nutrient solution is an aqueous solution of a mixture of sucrose, glucose and honey.

In some examples of artificial breeding methods, the day-old of the spodoptera litura eggs is 1-2 days old. Researches show that the prodenia litura egg of the day age is more beneficial to obtaining the bee card with high bee emergence rate.

In some examples of artificial breeding methods, the culture conditions for the trichogramma obscurus adult bees are: the temperature is 22-29 ℃, and the relative humidity is 60-80%. Under the condition, the vitality of the dark trichogramma is maintained, and meanwhile, the male bee and the female bee are mated.

In a second aspect of the present invention, there is provided:

bee releasing for the first time: the bee releasing time is the initial stage of the Spodoptera frugiperda oviposition;

In some examples of the method, the temperature of the bee is 22-30 ℃, the relative humidity is 70-90%, and the wind power is not more than 3 grades on a sunny day. The bee is put down under the condition, the survival rate of the trichogramma atrox can be better ensured, and meanwhile, the trichogramma atrox is favorable for the trichogramma atrox to lay eggs into spodoptera frugiperda eggs.

In some examples of the method, the time of releasing bees is from 30 to 19. Research shows that the trichogramma obscura is more beneficial to the trichogramma obscura to lay eggs into spodoptera frugiperda eggs.

In some examples of methods, the trichogramma obscura cards are placed in the leaf sheaths of the leaves of the plants near the heart when the bees are released. These locations are egg laying sites preferred by spodoptera frugiperda and are beneficial to improving the biological control effect.

The number of bees can be adjusted according to the serious program of Spodoptera frugiperda pests, and in some method examples, the number of bees is 6000-8000 bees/mu each time. With this amount of bee release, satisfactory biocontrol effects can be obtained.

Example 1

The artificial propagation method of the trichogramma obscurus and the preparation of the trichogramma obscurus bee card comprise the following steps:

step one, preparing an egg card: preparing an egg card by using prodenia litura eggs;

(1) Breeding the prodenia litura eggs: placing the spodoptera litura eggs in a disinfected insect breeding box, setting the temperature in a bee breeding room to be 20-30 ℃, setting the relative humidity to be 70% +/-5%, and naturally illuminating to ensure that the eggs are hatched into larvae;

(2) Feeding the spodoptera litura larvae to adults: adding the disinfected corn leaves into an insect breeding box for feeding larvae, and adding new corn leaves in time when the feed of the corn leaves in the insect breeding box is less until the larvae pupate and the adults eclose;

(3) Eclosion of prodenia litura adults to spawn: transferring the eclosion adult insects into a gauze insect breeding cage (length, width, height =60cm, 50cm, 40cm), providing sterilized corn seedlings for mating activities and oviposition, providing cotton balls dipped with nutrient supplement mixed liquor with the concentration of 5-15% during the oviposition period as adult supplementary nutrients, and feeding the adult insects with the nutrient supplement mixed liquor for 1 time each morning and afternoon;

(4) Collecting prodenia litura eggs: and (3) shearing the spodoptera litura eggs on the corn leaves by using the disinfected scissors, placing the cut spodoptera litura eggs into an insect breeding box, reserving a part of eggs, continuously breeding the spodoptera litura for seed conservation, and using the rest eggs for bee breeding.

(5) Preservation of prodenia litura eggs: the collected spodoptera litura egg blocks are wrapped by gauze, placed in a 50ml centrifuge tube, sealed by a cotton plug and stored at 12 ℃ for short-term storage for later use, and need to be used in 7 d.

(6) Breeding the next generation of prodenia litura eggs: and (4) taking out a part of collected eggs, intensively putting the collected eggs into another insect breeding box, and culturing the next generation according to the processes of the steps (1) to (4).

(7) And (3) killing eggs and sterilizing: placing the collected prodenia litura eggs which are produced primarily in an insect breeding box, and carrying out ultraviolet embryo killing and sterilization treatment for 30 min for later use;

(8) And (4) removing fuzz from the host eggs subjected to embryo killing and sterilization in the step (6) by using glue, and adhering the host eggs on parchment paper of 1.0 multiplied by 1.0 cm to prepare the egg cards.

Step two, trichogramma breeding:

(1) Mixing female bee and male bee according to the proportion of 1:2, observing and confirming mating (figure 1), introducing mated female bee into finger-shaped tube with egg card, and plugging with medical cotton plug, wherein the density of female bee is 1 head/egg card;

(2) Cotton balls dipped with a 10% supplemented nutrient mixture (sucrose: glucose: honey =1, prepared by adding water) were provided as adult supplemented nutrients, and the supplemented nutrient mixture was fed 1 time each day in the morning and afternoon, and the finger tubes were placed at 28 ℃, at a relative humidity of 70%, and in a light cycle L: d is 0, and the trichogramma bee is allowed to lay bee eggs into host eggs on the egg cards under the condition of 24 hours, and the development is carried out in the host eggs until adult bees drill out the host eggs to emerge (shown in the attached figures 2-3).

The preparation method of the supplementary nutrient mixed liquor comprises the following steps:

take 15% of the supplementary nutrient mixture as an example. 5.0g of sucrose, 5.0g of glucose and 5.0g of honey are respectively weighed, namely the sucrose: glucose: the mass ratio of the honey is 1:1:1, then adding the mixture into a 250 beaker, weighing 85g of water, and uniformly stirring to obtain a 15% supplementary nutrient mixed solution. Subpackaging into 50ml centrifuge tubes, and storing in refrigerator for later use.

Example 2

A method for preventing Spodoptera frugiperda by using trichogramma obscura comprises the following steps (figures 4-7):

(1) Selecting a dark trichogramma egg card: using prodenia litura eggs as substitute hosts to breed bees indoors and manufacture egg cards; selecting a bee card with bee yield more than or equal to 85 percent for releasing bees in the corn field;

(2) Determining the spodoptera frugiperda blooming period and the spawning initial period, and carrying out field bee releasing work;

the specific bee releasing time is determined by comprehensively considering the local climate and the spodoptera frugiperda population dynamic factors, and the bee releasing theoretical principle is that the egg laying period of the spodoptera frugiperda is consistent with the emergence period of the trichogramma obscura; the bee-keeping interval period is less than the development period of Spodoptera frugiperda, so that the whole egg-laying period of Spodoptera frugiperda is within the control range of dark trichogramma. Taking the state of Xishuangbanna, yunnan as an example, the method is recommended to be carried out from 5 to 6 in the first ten days of the year (5 to 6 months in the peak period of the Spodoptera frugiperda imagoes in Xishuangbanna, yunnan).

(3) Releasing bees for the first time: the bee releasing time is the initial stage of the Spodoptera frugiperda oviposition;

firstly, scientifically arranging and placing bee spots in the field, and performing the bee spots by using a Z-shaped field design method; the trichogramma egg card is placed in the middle of the corn plant near the leaf sheath of the heart leaf. After the egg card is taken out, the egg card needs to be put into the field for use on the same day.

Secondly, the dark trichogramma egg cards are evenly arranged in the field.

Finally, selecting sunny days and days without strong wind for releasing bees; the reaction is generally carried out at a temperature of 22-30 ℃ and a humidity of 70-90% in the afternoon of the day at a temperature of 30-19. The bee holding amount is controlled to be 8000-12000 bees/mu each time.

(4) Releasing bees for the second time: and after the bee is put for the first time for 5-7 days, the bee is put for the second time. The bee releasing method is the same as the first method.

(5) Releasing bees for the third time: and after the bee is placed for the second time for 5-7 days, the bee is placed for the third time. The bee releasing method is the same as the first method.

Influence of different ages of prodenia litura eggs on parasitic rate and emergence rate of trichogramma obscura

In the implementation processes of example 1 and example 2, the results of tests such as the influence of different day ages of spodoptera litura eggs on the parasitism rate and emergence rate of trichogramma obscura (20 repetitions), the influence of spodoptera litura on the life of trichogramma obscura (20 repetitions), the influence of spodoptera litura on the progeny morphological index of trichogramma obscura (30 repetitions), the comparison of the number of outgrowth of parasitic single eggs of trichogramma obscura (30 repetitions), the parasitism rate of trichogramma eggs of spodoptera zealand (5 repetitions), and the like are shown in tables 1 to 6:

TABLE 1 Effect of different ages of day of Prodenia litura eggs on the parasitic rate and emergence rate of trichogramma obscura

As can be seen from Table 1, the parasitic rate and the emergence rate index are comprehensively considered, and 1-2 days old spodoptera litura eggs are determined to be selected as hosts to breed the trichogramma obscura, so that the parasitic rate is higher than 70%, and the emergence rate is higher than 92%.

TABLE 2 Effect of Spodoptera litura on the longevity of the dark trichogramma

As can be seen from Table 2, the service lives of both the female bees and the male bees are not obviously different from those of the control group, the prodenia litura is used as a substitute host, the service lives of the bred female bees and the bred male bees are respectively 7d and 4d, and the breeding period is higher than that of the natural host Spodoptera frugiperda.

TABLE 3 influence of Prodenia litura on the morphological index of the generation of dark trichogramma

As can be seen from Table 3, the size of the bee was determined by measuring the length of the tibia of the hind paw of the bee, and the size of the bee was not significantly different from that of the control group.

TABLE 4 comparison of parasitic single spawn and bee number ratio of scottitus nudus

As can be seen from Table 4, there was no significant difference compared with the control group, and the number of bees of a single host egg was 1.

TABLE 5 Effect of Spodoptera litura on the offspring sex ratio of Trichogramma obscura

As can be seen from Table 5, the progeny bees of the spodoptera litura eggs and the control group (Spodoptera frugiperda eggs) as hosts are female.

The research results in tables 1 to 5 show that the parasitic rate, the emergence rate, the service life, the size, the single egg emergence of the host and the ratio of offspring of the trichogramma obliqua are comprehensively considered, the spodoptera litura is used as a substitute host, and the bred trichogramma and the trichogramma obliqua bred by the spodoptera litura which is a natural host are good in main biological indexes, so that the spodoptera litura can be determined to be a suitable substitute host for the trichogramma.

TABLE 6 parasitism rate of Trichoplusia amada on spodoptera frugiperda eggs in corn field

As can be seen from Table 6, the parasitized rate of spodoptera frugiperda egg masses and the ratio of parasitized eggs in each spodoptera frugiperda egg mass were significantly greater after releasing bees than in the control group before releasing bees, and the difference between 2 surveys after releasing bees was not significant.

The foregoing is a more detailed description of the invention and is not to be taken in a limiting sense. It will be apparent to those skilled in the art that simple deductions or substitutions without departing from the spirit of the invention are within the scope of the invention.

Claims

1. The artificial breeding method of the dark trichogramma comprises the following steps:

s2) mixing the male bees and the female bees of the dark trichogramma to mate;

s3) transferring the mated female bees into a container filled with an egg card, wherein the temperature of the mated female bees cultured in the container is 22-29 ℃, the relative humidity is 60-80%, and the photoperiod L: d is 0: glucose: honey =1:1:1 in water;

2. The artificial breeding method according to claim 1, wherein: the day age of the spodoptera litura eggs is 1-2 days old.

3. The method for preventing and controlling Spodoptera frugiperda by using the trichogramma obscura comprises the following steps:

s1) preparing a dark trichogramma bee card according to the method of claim 1 or 2;

releasing bees for the third time: and after the bee is placed for the second time for 5-7 days, the bee is placed for the third time.

4. The method of claim 3, wherein: the temperature of the bee releasing is 22-30 ℃, the relative humidity is 70-90%, and the wind power is not more than 3 grades in sunny days.

5. The method according to claim 3 or 4, characterized in that: the time of releasing bees is from 30 to 19 at 16 pm.

6. The method according to claim 3 or 4, characterized in that: when the bees are put in, the dark trichogramma bee cards are placed at the leaf sheaths of the leaves of the plants close to the heart.

7. The method according to claim 3 or 4, characterized in that: the bee-keeping quantity is 6000-8000 bees/mu each time.