阅读说明：本技术 一种核型多角体病毒防治棉铃虫的农药及其制备方法和应用 (Pesticide for preventing and treating cotton bollworm by using nuclear polyhedrosis virus and preparation method and application thereof ) 是由 柴连琴 荆玉谱 张林杰 刘鹏飞 孟景会 张海燕 王喆 于 2020-06-12 设计创作，主要内容包括：本发明属于生物防治棉铃虫技术领域,通过在棉铃虫核型多角体病毒中添加含有蜕皮酮的露水草提取物能够大大提高防治老熟棉铃虫的效果,同时防治低龄棉铃虫效果比传统方法更好。按每只6龄棉铃虫5毫克露水草提取物(30％蜕皮酮)和2.0×10<Sup>6</Sup> PIB核型多角体病毒的用量,可以显著增强核型多角体病毒防治老熟棉铃虫效果。本发明所提供的农药,3龄以下幼虫48小时内死亡率达到100％；对于防控老熟棉铃虫起效快、效率高、减少产卵量,对防控次年棉铃虫的爆发具有显著作用,填补了目前没有有效杀灭棉铃虫的空白。(The invention belongs to the technical field of biological prevention and control of cotton bollworms, and can greatly improve the effect of preventing and controlling mature cotton bollworms by adding a dew grass extract containing ecdysone into cotton bollworm nuclear polyhedrosis virus, and simultaneously has better effect of preventing and controlling the cotton bollworms with low age than the traditional method, wherein 5mg of dew grass extract (30 percent of ecdysone) and 2.0 × 10 are added for each cotton bollworm with 6 ages 6 The usage amount of the PIB nuclear polyhedrosis virus can obviously enhance the effect of the nuclear polyhedrosis virus on preventing and treating the aged cotton bollworm. The pesticide provided by the invention has the mortality rate of 100% in 48 hours for larvae below 3 years old; the composition has the advantages of quick response, high efficiency and reduced egg laying amount for preventing and controlling the aged cotton bollworms, has obvious effect on preventing and controlling the next-year cotton bollworm outbreak, and fills the blank that the cotton bollworms are not effectively killed at present.)

1. A pesticide for biologically preventing and treating cotton bollworm by using nuclear polyhedrosis virus is characterized by that its effective components are nuclear polyhedrosis virus and extract of aquatic weed containing ecdysone, and the effective dose of said pesticide is that the content ratio of nuclear polyhedrosis virus and ecdysone is 2.0 × 10⁶-2.5×10⁶PIB：1.5-1.8mg。

2. The pesticide of claim 1, wherein the effective amount of said pesticide is 2.0 × 10⁶PIB：1.5mg。

3. The pesticide of claim 1, wherein the nuclear polyhedrosis virus biological control of cotton bollworm comprises: the mass fraction of the ecdysone in the extract of the common dew containing the ecdysone is 30 percent.

4. A preparation method of a pesticide for biologically preventing and controlling cotton bollworms by using nuclear polyhedrosis virus is characterized by comprising the following steps:

(1) dissolving the extract of the dewy grass containing the effective amount of the ecdysone with a certain amount of water, and uniformly mixing to obtain a solution of the extract of the dewy grass;

(2) and mixing the dew grass extract solution with the solution containing the nuclear polyhedrosis virus with the effective amount to obtain the pesticide.

5. The method for preparing a pesticide for biologically controlling Heliothis armigera by using nuclear polyhedrosis virus according to claim 1, which comprises the following steps:

(1) dissolving herba Eragrostidis extract containing 1.6-2.0Kg ecdysone with water, and mixing well to obtain herba Eragrostidis extract solution;

(2) the extract solution of the dewed grass is mixed with a solution containing 2.8 × 10¹²PIB-3.5×10¹²And mixing the solutions of the PIB nuclear polyhedrosis virus to obtain the pesticide.

6. Use of a nucleopolyhedrosis virus pesticide, as claimed in any one of claims 1-3, for the biological control of cotton bollworms.

7. The use of a nucleopolyhedrovirus pesticide for the biological control of Heliothis armigera as claimed in claim 6, wherein the application method comprises applying a pesticide containing 1.6-2.0Kg of ecdysone and 2.8 × 10 Kg of ecdysone per mu¹²PIB-3.5×10¹²The pesticide of the PIB nuclear polyhedrosis virus is diluted into a certain volume and is uniformly mixed and sprayed.

Technical Field

The invention belongs to the technical field of biological prevention and control of cotton bollworms, and particularly relates to a pesticide for preventing and controlling cotton bollworms by using nuclear polyhedrosis virus, and a preparation method and application thereof.

Background

The cotton bollworm is a parasitic pest with serious harm, and the 5-6-year old aged cotton bollworm larvae enter a binge eating period and have the greatest harm to crops. The cotton bollworm is the species with the largest egg laying amount in insects, the single female moth can lay more than 3000 eggs at most, if the prevention and control are not in place, one overwintering female pupa can propagate millions of larvae in the next year by 1 year on average, and more than one hundred million larvae are grown, so that a small amount of old cotton bollworms with net leakage completely have destructive effect. However, the effect of chemical pesticide or biological pesticide on preventing and controlling the aged cotton bollworm is poor at present. With the wide planting of transgenic Bt cotton, although the damage to cotton fields is reduced to a certain extent, cotton bollworms damage various crops such as corn, wheat and the like and vegetables such as tomato, pepper and the like, and meanwhile, resistant cotton bollworms appear in fields, so that the cotton bollworms still pose great threat to national food safety and are still key points in pest prevention and control. Although the chemical pesticide has fast effect on preventing and treating larvae of 2-3 years old, the chemical pesticide has great risk on biological safety and ecological safety, so that the development of the biological pesticide for preventing and treating the aged cotton bollworms is urgently needed. The nucleopolyhedrosis virus is the earliest commercialized virus biological pesticide, is an important pathogenic microorganism of lepidoptera insects, can infect other larvae with disease insect excrement and dead insects, can also be transmitted to offspring through eggs, is suitable for low-age larvae below 3 ages, and has almost no control effect on aged cotton bollworms above 3 ages, especially at 6 ages.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a pesticide for preventing and treating cotton bollworm by using nuclear polyhedrosis virus, and a preparation method and application thereof. Effectively kill the cotton bollworm and prevent and control the outbreak of the cotton bollworm.

The technical scheme adopted by the invention is as follows:

nuclear polyhedronThe effective amount of the pesticide is that the content ratio of the nuclear polyhedrosis virus to the ecdysone is 2.0 × 10⁶-2.5×10⁶PIB：1.5-1.8mg。

Preferably, the effective amount of the pesticide is that the content ratio of the nuclear polyhedrosis virus to the ecdysone is 2.0 × 10⁶PIB：1.5mg。

Preferably, the pesticide for biologically controlling cotton bollworm by using nuclear polyhedrosis virus comprises 30 mass percent of ecdysone extracted from the common dew plant containing ecdysone.

A preparation method of a pesticide for biologically preventing and controlling cotton bollworms by using nuclear polyhedrosis virus specifically comprises the following steps:

(1) dissolving the extract of the dewy grass containing the effective amount of the ecdysone with a certain amount of water, and uniformly mixing to obtain a solution of the extract of the dewy grass;

(2) and mixing the dew grass extract solution with the solution containing the nuclear polyhedrosis virus with the effective amount to obtain the pesticide.

Preferably, the preparation method of the pesticide for biologically controlling the cotton bollworm by the nuclear polyhedrosis virus specifically comprises the following steps:

(1) dissolving herba Eragrostidis extract containing 1.6-2.0Kg ecdysone with water, and mixing well to obtain herba Eragrostidis extract solution;

(2) the extract solution of the dewed grass is mixed with a solution containing 2.8 × 10¹²PIB-3.5×10¹²And mixing the solutions of the PIB nuclear polyhedrosis virus to obtain the pesticide.

An application of the nuclear polyhedrosis virus as agricultural chemical in preventing and eliminating cotton bollworm is disclosed.

Preferably, the application of a nuclear polyhedrosis virus pesticide in biological control of cotton bollworm is that the pesticide contains 1.6-2.0Kg of ecdysone and 2.8 × 10 Kg per mu¹²PIB-3.5×10¹²Pesticide dilution of PIB nuclear polyhedrosis virusUniformly mixed and sprayed according to a certain volume.

The invention has the beneficial effects that:

1. the nuclear polyhedrosis virus pesticide provided by the invention is characterized in that 5mg of dew grass extract (30% ecdysone) and 2.0X 106 PIB nuclear polyhedrosis virus are fed to 6-year-old cotton bollworms, the prevention and treatment effect is optimal, and the cotton bollworms can be effectively killed.

2. The pesticide for preventing and controlling the cotton bollworm by the nuclear polyhedrosis virus provided by the invention has quick insecticidal effect, and the death rate of the 6-year cotton bollworm on day 3 is obvious; the insecticidal efficiency is improved, and the survival rate at the 4 th day is reduced by 28.4%; the survival rate at day 5 was 52.5%, and the survival rate at day 7 was only 34.7%. Usually, the nuclear polyhedrosis virus is used for preventing and treating 3-year-old larvae, the prevention and treatment effect is poor after 3 years old, and if the method is used for preventing and treating 3-year-old larvae, the death rate reaches 100% within 48 hours. Therefore, the method has obvious effects on reducing the harm of the aged cotton bollworms to the crops in the current year, reducing the egg laying amount and preventing and controlling the outbreak of the cotton bollworms in the next year. Meanwhile, the killing effect on the cotton bollworms before 3 years old is better than that of the traditional pesticide.

Drawings

FIG. 1 feeding 5mg of Cyanotis japonica extract (30% ecdysone) and 2.0 × 10⁶Survival Rate of 3-instar Cotton bollworm at PIB Nuclear polyhedrosis Virus

Figure 2 feeding ecdysone pure products 20E and 2.5 × 10⁶Survival rate of 6-instar cotton bollworm of PIB nuclear polyhedrosis virus

FIG. 3 viral infection induced upregulation of VHDLR expression

FIG. 4 silencing VHDLR leads to a reduction in the amount of viral infection

Blocking of VHDLR by the antibody of figure 5 reduced viral infection.

Detailed Description