Semi-artificial diet for Tuta absoluta larvae, preparation method and application thereof

Abstract

The present invention discloses a semi-artificial diet for Tuta absoluta larvae, a preparation method thereof and an application thereof. In the present invention, 1000 mL of water is boiled, and after it is stable, 0.5 - 1 g of sorbic acid, 0.5 - 1 g of sodium p-hydroxybenzoate and 0.1 - 0.2 g of thiabendazole are added, and quickly stirred and melted. Subsequently, compound vitamins are added, and after stirring evenly, 500 - 550 g of malt embryos are added and stirred into a dough. When the temperature drops below 30 °C, 150 - 200 g of tomato leaf powder is added and stirred and mixed evenly to obtain the semi-artificial diet for Tuta absoluta larvae. The components of the semi-artificial diet of the present invention can not only meet the nutritional requirements of test insects, but also have an optimal compound ratio of different components, and particularly give the best nutritional ratio. At this ratio, the survival rate, pupation rate and emergence rate from larvae to pupae are high, and the deformity rate of pupae is low.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and in particular relates to a semi-artificial feed for tomato leafminer larvae, and a preparation method and application thereof. Background Art

[0002] Tuta absoluta (Meyrick), also known as the tomato leafminer, belongs to the Gelechiidae family of the Lepidoptera order. It is native to western South America and is known as the "Ebola virus" on tomatoes. Its larvae feed on leaves, tops, axillary buds, tender stems, calyxes and the inside of fruits. In severe cases, it can cause 80% to 100% yield loss. It is one of the most destructive invasive pests in the world. In 2017, the tomato leafminer was introduced to Yili, Xinjiang, my country. Subsequently, it broke out in Yunnan, Shaanxi, Beijing, Gansu and other places with the help of seedling transportation and natural migration, causing huge economic losses to local commercial tomatoes and even making tomato products difficult to circulate. In order to control this pest, many domestic experts and scholars have conducted multi-faceted research on the tomato leafminer. However, since the tomato leafminer is a leafmining pest, the cultivation of experimental populations is very cumbersome, and it is difficult to obtain uniform test subjects. Therefore, the development of artificial feed for the tomato leafminer has become necessary.

[0003] Artificial insect diets are an important basis for large-scale insect breeding. Using artificial diets to feed insects can not only solve the key problem of feed shortages caused by seasonal changes in many cases, but also make insects develop uniformly and physiologically consistent, obtain uniform test materials, and make scientific research more successful. In addition, the method of using artificial diets to feed test subjects can be directly used in insect nutritional physiology research, insect biology research, and pest control research; in addition, artificial diets can break host restrictions and save insect breeding costs.

[0004] Many scientific research institutions in China have successively done a lot of work in the practical technologies and related theoretical fields such as artificial diets for insects, artificial diet processing technologies, insect rearing technologies, large-scale rearing and reproduction of natural enemy insects, etc. In particular, many breakthroughs have been made in artificial diets. In insect rearing, in order to meet the growth and development of insects, the general main nutritional elements include carbohydrates (sucrose), proteins and amino acids (wheat germ, soybeans, yeast powder and casein), lipids (corn oil, soybean oil) and sterols (cholesterol), vitamins, inorganic salts and natural nutrients (host tissues). In addition, in order to extend the storage time of the diet, preservatives (methyl p-hydroxybenzoate, sorbic acid, formaldehyde, sodium benzoate, propionic acid, sodium propionate, nitrapyrin and chlortetracycline, kanamycin, oxytetracycline, etc.) also need to be added. However, the growth, development and reproductive characteristics of different species of insects are different, and the nutritional component requirements and the proportion of nutritional balance requirements are not exactly the same. Therefore, the artificial diets for rearing different species of insects are not exactly the same. As a pest newly invading China in recent years, there is currently no artificial or semi-artificial diet that can successfully rear the larvae of the tomato leafminer in the field of scientific research. It can only be reared by relying on tissues such as tomato cultivation plants or fresh tomato excised leaves. Although there are relatively many types of diets for Lepidoptera insects at home and abroad currently, none of them can successfully rear the larvae of the tomato leafminer. Since a large number of test insects with consistent physiological standards are often required in the process of scientific research, and the tomato leafminer is a leafmining insect, its instars are difficult to observe in fresh plants or tissues, and the physiological standards cannot be controlled, which brings great resistance to scientific research and experiments. Summary of the Invention

[0005] In order to solve the problems existing in the prior art in the above background technology, the purpose of the present invention is to provide a semi-artificial diet for tomato leafminer larvae and its preparation method, to obtain physiologically uniform tomato leafminer test insects on the basis of saving labor costs and material costs. Using dry tomato leaf powder and malt embryo as carbon source substances, supplemented with compound vitamins and preservatives to make a semi-artificial diet. In addition, a small amount of fungicide (Tecto) is particularly added, which can effectively extend the shelf life of the artificial diet and cause minimal harm to tomato leafminer larvae.

[0006] The present invention is realized as follows. A semi-artificial diet for tomato leafminer larvae, the diet includes water and additives mixed in the water. Among them, in 1000 mL of water, the additives include the following components: 500 - 550 g of malt embryo, 150 - 200 g of tomato leaf powder, 0.5 - 1 g of sorbic acid, 0.5 - 1 g of sodium p-hydroxybenzoate, 0.1 - 0.2 g of Tecto, compound vitamins: Vb1: 1 - 1.5 mg, Vb2: 1 - 1.5 mg, Vb6: 1.5 - 2 mg, Vb12: 5 - 6 μg, Vc: 50 - 60 mg, biotin: 20 - 30 μg.

[0007] Preferably, in 1000 mL of water, the additives include the following components: 500 g of wheat germ, 200 g of tomato leaf powder, 0.5 g of sorbic acid, 0.5 g of sodium p - hydroxybenzoate, 0.1 g of thiabendazole, compound vitamins: Vb1: 1.5 mg, Vb2: 1.5 mg, Vb6: 2 mg, Vb12: 6 μg, Vc: 60 mg, biotin 30 μg.

[0008] The present invention further discloses a method for preparing the above semi - artificial diet for Tuta absoluta larvae, which comprises the following steps: Boil the water, add sorbic acid, sodium p - hydroxybenzoate and thiabendazole after it stabilizes, quickly stir and melt them, then add the compound vitamins, stir evenly, add the wheat germ, stir into a dough shape, when the temperature drops below 30 °C, add the ground tomato leaf powder, stir and mix evenly to obtain the semi - artificial diet for Tuta absoluta larvae.

[0009] The present invention further discloses the semi - artificial diet for Tuta absoluta larvae obtained by the above method.

[0010] The present invention further discloses the application of the above semi - artificial diet in the preparation of diets for Tuta absoluta larvae.

[0011] The present invention overcomes the deficiencies of the prior art and provides a semi - artificial diet for Tuta absoluta larvae, its preparation method and application. In the present invention, the dry tomato leaf powder is the main nutrient for Tuta absoluta, the wheat germ is the main carbon source substance, the compound vitamins are used to maintain the normal physiological needs of insects, sorbic acid and sodium p - hydroxybenzoate are preservative additives, and thiabendazole is a bactericide.

[0012] Among them, methyl paraben has good effects on various molds, yeasts, and bacteria; sorbic acid has inhibitory effects on molds, yeasts, and many aerobic bacteria, but is almost ineffective against anaerobic spore-forming bacteria and Lactobacillus acidophilus; Tecto is a systemic fungicide that has a strong inhibitory effect on the vast majority of fungi and plays a good role in preventing fungal contamination of the feed for Tuta absoluta, and its fungicidal spectrum against fungi is wider than that of methyl paraben and sorbic acid. Generally speaking, methyl paraben and sorbic acid have good bactericidal effects on bacteria and yeasts, and Tecto has good inhibitory effects on fungi such as ascomycetes, basidiomycetes, and deuteromycetes. Since in this invention, in order to balance the nutrition of Tuta absoluta larvae, it is necessary to add the dried and ground powder of tomato leaves. This component is processed from the fresh tissue part of the tomato plant, and only measures such as cleaning can be used to minimize the amount of plant pathogens carried, and measures such as high-temperature sterilization cannot be relied on to eliminate the pathogens. At the same time, during the production process of this feed, when adding the tomato leaf powder, a relatively low temperature also needs to be maintained to prevent the change of the nature of nutrients due to temperature reasons. Therefore, it is necessary to add Tecto to inhibit the large growth of plant pathogens carried by the tomato leaf powder. Tecto is used as the fungal inhibitor in this invention because the drug has good safety and a wide fungicidal spectrum. If Tecto is missing in the feed of this invention, it has no direct significant impact on the rearing of Tuta absoluta larvae, but many fungi grow rapidly, the shelf life is shortened, which will have a greater impact on the survival of the target insects, and at the same time, it will increase the labor cost and material cost when replacing the feed. Sorbic acid, sodium p-hydroxybenzoate, and Tecto are used to prevent feed deterioration, and generally can maintain the quality unchanged for 5 - 6 days in an indoor environment.

[0013] In addition, the malt embryo and the ground powder of tomato leaves in this invention are key nutritional components and cannot be replaced. In terms of the optimal ratio, if the optimal ratio of the two changes, it is not conducive to the improvement of the survival rate of Tuta absoluta larvae, and at the same time increases the proportion of deformed pupae.

[0014] Compared with the disadvantages and deficiencies of the prior art, this invention has the following beneficial effects:

[0015] (1) The semi-artificial feed components for the larvae of Tuta absoluta in this invention can not only meet the nutritional requirements of the test insects, but also have an optimal compound ratio of different components, and particularly give the best nutritional ratio. At this ratio, the survival rate from larvae to pupae is 82.26% - 85.71%, the pupation rate is 90.19% - 94.12%, the deformed pupa rate is only 6.25% - 8.33%, and the emergence rate is 68.63 - 77.78%. It can fully meet the research work such as conventional new pesticide bioassay, insect toxicology, and physiology.

[0016] (2) The present invention innovates the feeding method of the larvae of Tuta absoluta, enabling the large-scale and uniform artificial feeding of the larvae of Tuta absoluta, which is more labor-saving and cost-effective compared to the current feeding method of Tuta absoluta. Detailed implementation mode

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] Embodiment 1

[0019] Boil 1000 mL of water. After it stabilizes, add 0.5 g of sorbic acid, 0.5 g of sodium p-hydroxybenzoate and 0.1 g of thiabendazole, and quickly stir and melt. Then add compound vitamins (Vb1: 1.5 mg, Vb2: 1.5 mg, Vb6: 2 mg, Vb12: 6 μg, Vc: 60 mg, biotin 30 μg), stir evenly and then add 500 g of malt embryo, stir into a dough shape. When the temperature drops to 28 °C, add 200 g of ground tomato leaves, stir and mix evenly to obtain the semi-artificial feed 1 for the larvae of Tuta absoluta.

[0020] Embodiment 2

[0021] Boil 1000 mL of water. After it stabilizes, add 1 g of sorbic acid, 1 g of sodium p-hydroxybenzoate and 0.1 g of thiabendazole, and quickly stir and melt. Then add compound vitamins (Vb1: 1.5 mg, Vb2: 1.5 mg, Vb6: 2 mg, Vb12: 6 μg, Vc: 60 mg, biotin 30 μg), stir evenly and then add 550 g of malt embryo, stir into a dough shape. When the temperature drops to room temperature, add 200 g of ground tomato leaves, stir and mix evenly to obtain the semi-artificial feed 2 for the larvae of Tuta absoluta.

[0022] Embodiment 3

[0023] Boil 1000 mL of water. After it stabilizes, add 0.5 g of sorbic acid, 0.5 g of sodium p-hydroxybenzoate and 0.2 g of thiabendazole, and quickly stir and melt. Then add compound vitamins (Vb1: 1 mg, Vb2: 1 mg, Vb6: 1.5 mg, Vb12: 5 μg, Vc: 50 mg, biotin 20 μg), stir evenly and then add 500 g of malt embryo, stir into a dough shape. When the temperature drops to 20 °C, add 150 g of ground tomato leaves, stir and mix evenly to obtain the semi-artificial feed 3 for the larvae of Tuta absoluta.

[0024] Comparative example

[0025] Boil 1000 mL of water. After it stabilizes, add 0.5 g of sorbic acid, 0.5 g of sodium p - hydroxybenzoate, and 0.1 g of thiabendazole, and quickly stir to melt. Subsequently, add compound vitamins (Vb1: 1.5 mg, Vb2: 1.5 mg, Vb6: 2 mg, Vb12: 6 μg, Vc: 60 mg, biotin 30 μg). After stirring evenly, add 600 g of wheat germ, and stir into a dough - like shape. When the temperature drops to 28 °C, add 200 g of tomato leaf powder, and stir and mix evenly to obtain the semi - artificial diet 4 for tomato leafminer larvae.

[0026] Effect implementation example

[0027] Put the prepared semi - artificial diet into a polyethylene triangular bag. Cut a small hole with a diameter of about 0.5 cm at the top of the triangular bag. Fill the diet into a medical 96 - well plate (the carrier for the diet) by extrusion. It is appropriate to fill the diet to about 2 / 3. Then, use a sterilized glass rod to compact the diet. After completing the filling of the whole diet, pick 1st - instar tomato leafminer larvae reared on indoor potted seedlings, and transfer them to the small holes of the 96 - well plate with a moist small brush. Then, cover the 96 - well plate with a blow - molding paper of appropriate size and cover the lid to prevent the larvae from escaping. Finally, place the 96 - well plate with the larvae in an intelligent climate chamber at a temperature of 27 ± 1 °C, a humidity of 75%, L:D = 16:8, and a daylight illumination of 3000 Lx for cultivation. The 96 - well plate is fully transparent, and the growth progress of the larvae can be observed through the side of the plate (the part reserved during diet filling).

[0028] When most of the larvae grow to the 4th instar, count the larval survival rate; after the counting is completed, continue the cultivation. After most of them pupate, count the pupation rate and the rate of deformed pupae; transfer all the normal pupae to a new 96 - well plate, one pupa per well, and continue the cultivation under the same cultivation conditions as the larvae, and observe and count the emergence rate and the rate of deformed pupae.

[0029] During the above - mentioned experimental process, the larval survival rate and pupation rate are set with 3 replicates, with 96 larvae in each group, that is, each plate is one group of replicates, and one larva is inoculated into each well of the 96 - well plate; the emergence rate statistics are set with 3 replicates, with 30 pupae in each group.

[0030] Statistical results of each diet are shown in Table 1 below:

[0031] Table 1 Statistical results of the experiment

[0032] Semi-artificial diet Survival rate from larva to pupa Pupation rate Malformation rate of pupa Emergence rate Semi-artificial diet 1 82.26％～85.71％ 90.19％～94.12％ 6.25％～8.33％ 68.63～77.78％ Semi-artificial diet 4 78.56％～83.42％ 81.25％～88.25％ 9.50％～12.10％ 61.63％～69.50％

[0033] The above - mentioned are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A semi-artificial diet for Tuta absoluta larvae, characterized in that, The feed includes water and additives mixed evenly in the water. Among them, in 1000 mL of water, the additives include the following components: 500 - 550 g of malt embryo, 150 - 200 g of tomato leaf powder, 0.5 - 1 g of sorbic acid, 0.5 - 1 g of sodium p - hydroxybenzoate, 0.1 - 0.2 g of thiabendazole, compound vitamins: Vb1: 1 - 1.5 mg, Vb2: 1 - 1.5 mg, Vb6: 1.5 - 2 mg, Vb12: 5 - 6 μg, Vc: 50 - 60 mg, biotin 20 - 30 μg.

2. The semi-artificial feed according to claim 1, characterized in that, In 1000 mL of water, the additives include the following components: 500 g of malt embryo, 200 g of tomato leaf powder, 0.5 g of sorbic acid, 0.5 g of sodium p - hydroxybenzoate, 0.1 g of thiabendazole, compound vitamins: Vb1: 1.5 mg, Vb2: 1.5 mg, Vb6: 2 mg, Vb12: 6 μg, Vc: 60 mg, biotin 30 μg.

3. The preparation method of the semi-artificial diet for the larvae of Tuta absoluta as claimed in claim 1 or 2, characterized in that, The method includes the following steps: Boil the water. After it stabilizes, add sorbic acid, sodium p - hydroxybenzoate and thiabendazole, and quickly stir to melt. Then add the compound vitamins, stir evenly and then add the malt embryo, stir into a dough - like shape. When the temperature drops below 30 °C, add the ground tomato leaf powder and stir to mix evenly to obtain the semi - artificial feed for Tuta absoluta larvae.

4. Use of the semi - artificial feed according to claim 1 or 2 in the preparation of the feed for Tuta absoluta larvae.