Stronematode noctuid biocontrol reagent for preventing and treating various pests and application of Stronematode noctuid biocontrol reagent

Abstract

The invention discloses a sternematode noctuid biocontrol reagent for preventing and treating various pests and application of the sternematode noctuid biocontrol reagent. The various pests comprise prodenia litura, mythimna separata, pea aphid and cotoneaster brachycarpus. According to the invention, the infection activity difference of different strains of sternematode noctuid on four different agricultural pests is researched, and the prevention and control effects of different strains of sternematode noctuid on different insects are understood. Meanwhile, the invention also studies the sensitivity difference of biocontrol natural enemy insects such as scleroderma guani and dastarcus helophoroides to the sternematode noctuid, and comprehensively discusses the application prospect of the sternematode noctuid from two aspects of the infection activity to pests and the infection activity to the natural enemy insects. The method not only lays a foundation for combined biological control of natural enemy insects and entomopathogenic nematodes, but also is helpful for defining the optimal application scene in agricultural production, so that the efficiency and the overall effect of biological control are improved, and particularly, a better control effect can be generated in a complex pest control environment.

Description

Technical Field

[0001] The invention relates to the technical field of biological control of pests, and in particular to a biological control agent for Steinernema carinii used for controlling various pests and an application thereof. Background Art

[0002] Crop pests are one of the most important disasters in my country's agricultural production. They are characterized by a wide variety, great impact, and frequent outbreaks. The scope and severity of their occurrence often cause significant losses to my country's national economy, especially agricultural production. Spodoptera litura ), commonly known as flower insects and black-headed insects, belongs to the family Noctuidae of the order Lepidoptera and is one of the main pests in my country's agricultural production. Its host range is extremely wide, covering 99 families and more than 290 plant species. It is an intermittent, voracious, omnivorous pest. The larvae mainly feed on the leaves, buds, flowers and fruits of plants. Its wide host spectrum and voracious nature have caused it to cause catastrophic damage many times, posing a serious threat to agricultural production. Sticky insect ( Mythimna separata ) also belongs to the Noctuidae family of the Lepidoptera order, and is one of the important agricultural pests in my country. In China, except for Xinjiang, the armyworm is widely distributed throughout the country. It has many host plants, including cereal crops such as wheat, rice, millet, and corn, as well as more than 104 plant species from 16 families such as cotton, beans, and a variety of vegetables. The larvae mainly feed on plant leaves, and when a large outbreak occurs, they can eat all the crop leaves, causing serious losses. The armyworm is gregarious, migratory, omnivorous, and voracious, making it a major agricultural pest nationwide. Pea aphid ( Acyrthosiphonpisum ) belongs to the Aphididae family of the order Homoptera. It is a major pest of peas, broad beans, alfalfa and vetch. It can also harm legumes such as Astragalus, Lathyrus, and Sweet Clover, as well as other plants such as shepherd's purse. The pea aphid is one of the largest aphids in field plants. In addition to directly harming plants, it can also spread a variety of plant viruses, causing comprehensive damage. Xenocatantops brachycerus ) is a herbivorous insect that mainly feeds on plant leaves. Unlike most locusts that prefer grass plants, the short-horned locust has a wide range of food, covering a variety of dicotyledonous plants, such as Paulownia, Rubus, Prunus, Polygonum, Ailanthus, Rhus chinensis, etc. Its wide range of food habits makes it potentially harmful in agricultural and forestry ecosystems. For a long time, many emergency measures have been launched at home and abroad, including the use of a variety of pyrethroids, organophosphorus insecticides, Bt preparations and a variety of field control measures. Although a large number of natural enemies have been killed, the safety of agricultural products has been reduced, and pests have developed drug resistance, creating obstacles to the sustainable development of my country's agricultural production. These pests have become important targets that need to be controlled urgently due to their wide host range, strong gluttony characteristics and significant harm to agricultural production.

[0003] At present, the domestic control of these pests mainly relies on several new chemical pesticides with strong insecticidal activity, such as avermectin benzoate, chlorantraniliprole, spinetoram and related compound preparations, and has achieved certain control effects in production. However, the long-term and large-scale application of chemical pesticides not only causes environmental pollution, but also easily causes pests to develop resistance. With the advancement of science and technology, biological control methods, such as the application of insect pathogenic nematodes, are becoming an important direction for sustainable control, taking into account long-term environmental and health benefits.

[0004] Insect pathogenic nematodes are an important biological control resource that can specifically infect and parasitize insects. Their species mainly include Steinernema spp. Steinernema ) and Heterorhabditis ( Heterorhabditis ). These nematodes have a wide host range and strong active search ability, can effectively find and parasitize target pests, and have the advantages of no pollution to the environment, safety for humans and animals, easy cultivation and low cost. In addition, they can be mixed with chemical pesticides for application to enhance the control effect. Although studies have reported that insect pathogenic nematodes have good control effects on certain specific pests, different insect pathogenic nematodes have different infective activities on different pests, and different strains of the same insect pathogenic nematode also have different infective activities on different pests. Therefore, studying the infective activity of different types of nematodes or different strains of nematodes on different insects helps to understand their control spectrum and advantageous control targets, and can better realize their biological control potential. Summary of the invention

[0005] The object of the present invention is to provide a biological control method for various pests.

[0006] In order to achieve the above object, the present invention first provides a new use of Steinernema carinata.

[0007] The invention provides the use of Steinernema carinata in preventing and controlling pests; the pests are Spodoptera litura and / or armyworm and / or pea aphid and / or short-horned locust.

[0008] The present invention also provides the use of the noctuid nematode Steinernema carinata in preparing a product for controlling pests; the pests are Spodoptera litura and / or armyworm and / or pea aphid and / or short-horned locust.

[0009] In order to achieve the above object, the present invention provides new uses of the noctuid nematode Steinernema carinata and natural enemy insects.

[0010] The invention provides application of Steinernema carinata and natural enemy insects in preventing and controlling pests; the natural enemy insects include Acanthoptera floridula and / or Scleroderma guani.

[0011] The present invention also provides the use of the noctuid nematode Steinernema carinata and natural enemy insects in preparing products for controlling pests; the natural enemy insects include the flower beetle and / or the scleroderma guani.

[0012] Furthermore, the pests include pests controllable by the noctuid nematode Steinernema carinata and / or pests controllable by natural enemy insects. Furthermore, the pests that can be controlled by the Steinernema carinata include pests of the Noctuidae family, pests of the Aphididae family, pests of the Acrididae family and pests of the Tephritidae family.

[0013] The natural enemy insects that can control pests include the flower parasitic beetle and / or the scleroderma guanyi.

[0014] Furthermore, the Noctuidae pests include Spodoptera litura, Armyworm and Fall Armyworm.

[0015] The Aphididae pests include the pea aphid.

[0016] The Acrididae pests include the short-horned locust.

[0017] The pests that can be controlled by the flower beetle include longhorn beetle pests, such as the arborvitae glabrata beetle, pine brown beetle, mulberry beetle, rust-colored grain beetle and the like.

[0018] The Scleroderma guanii can prevent and control pests including pole-boring pests, such as longhorn beetles on pine trees, poplar trees, peach trees, apricot trees, plum trees and other trees and various fruit trees.

[0019] In order to achieve the above object, the present invention also provides a composition for controlling pests.

[0020] The composition for controlling pests provided by the invention comprises Steinernema carinata and natural enemy insects; the natural enemy insects comprise Acanthocephalus floridula and / or Scleroderma guani.

[0021] Furthermore, the composition also includes deionized water.

[0022] The use of the above composition in controlling pests or preparing products for controlling pests also falls within the protection scope of the present invention.

[0023] In order to achieve the above object, the present invention finally provides a method for controlling pests.

[0024] The method for controlling pests provided by the present invention is as follows 1) or 2): 1) The method comprises the following steps: applying Steinernema carinata to pests; the pests are Spodoptera litura and / or armyworm and / or pea aphid and / or short-horned locust; 2) The method comprises the following steps: applying the noctuid nematode and natural enemy insects to pests; the natural enemy insects include the flower beetle and / or the scleroderma guanyi; the pests include the above-mentioned pests that can be controlled by the noctuid nematode and / or the above-mentioned natural enemy insects that can be controlled by the pests. In the above method 1), the method of applying the Steinernema carinae to the pests can be dripping the suspension of the Steinernema carinae onto the body surface of the pest larvae or dripping the suspension of the Steinernema carinae into a container (plastic box or cup) containing the pests.

[0025] Furthermore, the Steinernema carinae suspension may be a nematode suspension obtained by mixing Steinernema carinae with a solvent.

[0026] Furthermore, the solvent may be deionized water.

[0027] In the above method 1), when the pest is Spodoptera litura, the ratio of the SF-SN strain of the noctuid nematode to the Spodoptera litura may be 25-400 SF-SN strains of the noctuid nematode: 1 larva of the Spodoptera litura; preferably 44 SF-SN strains of the noctuid nematode: 1 larva of the Spodoptera litura. The ratio of the IGA strain of the noctuid nematode to the Spodoptera litura may be 25-400 IGA strains of the noctuid nematode: 1 larva of the Spodoptera litura; preferably 43 IGA strains of the noctuid nematode: 1 larva of the Spodoptera litura.

[0028] When the pest is an armyworm, the ratio of the SF-SN strain of the noctuid nematode to the armyworm may be 25-400 SF-SN strains of the noctuid nematode: 1 armyworm larva; preferably 395 SF-SN strains of the noctuid nematode: 1 armyworm larva. The ratio of the IGA strain of the noctuid nematode to the armyworm larva may be 25-400 IGA strains of the noctuid nematode: 1 armyworm larva; preferably 393 IGA strains of the noctuid nematode: 1 armyworm larva.

[0029] When the pest is pea aphid, the ratio of the SF-SN strain of Noctuidae to the pea aphid can be 25-400 SF-SN strains of Noctuidae: 1 wingless adult aphid of pea aphid; preferably 28 SF-SN strains of Noctuidae: 1 wingless adult aphid of pea aphid. The ratio of the IGA strain of Noctuidae to the pea aphid can be 25-400 IGA strains of Noctuidae: 1 wingless adult aphid of pea aphid; preferably 20 IGA strains of Noctuidae: 1 wingless adult aphid of pea aphid.

[0030] When the pest is the short-horned outer spot-legged grasshopper, the ratio of the noctuid nematode SF-SN strain to the short-horned outer spot-legged grasshopper can be 25-400 noctuid nematode SF-SN strains: 1 short-horned outer spot-legged grasshopper adult; preferably 56 noctuid nematode SF-SN strains: 1 short-horned outer spot-legged grasshopper adult. The ratio of the noctuid nematode IGA strain to the short-horned outer spot-legged grasshopper can be 25-400 noctuid nematode IGA strains: 1 short-horned outer spot-legged grasshopper adult; preferably 54 noctuid nematode IGA strains: 1 short-horned outer spot-legged grasshopper adult.

[0031] In any of the above methods or applications, the pest control is manifested as increasing the pest mortality rate.

[0032] In any of the above methods or applications, the Steinernema carinata nematode is an infective stage of Steinernema carinata.

[0033] In any of the above methods or uses, the Steinernema carinii nematode is the SF-SN strain of Steinernema carinii or the IGA strain of Steinernema carinii.

[0034] In any of the above methods or applications, the Spodoptera litura is a larva of Spodoptera litura, preferably a 5th instar larva of Spodoptera litura.

[0035] In any of the above methods or applications, the sticky insects are sticky insect larvae, preferably 5th instar sticky insect larvae.

[0036] In any of the above methods or uses, the pea aphid is an adult pea aphid, preferably a wingless adult pea aphid.

[0037] In any of the above methods or applications, the short-horned locust is an adult short-horned locust.

[0038] Any of the above products can be a biocontrol agent.

[0039] The present invention cultivates and breeds the noctuid Steinernema nematode, and applies suspensions of different doses and strains of the noctuid Steinernema nematode to the cutworm, the armyworm, the pea aphid and the short-horned outer spot-legged grasshopper, thereby exploring the infection activity of the noctuid Steinernema nematode on the cutworm, the armyworm, the pea aphid and the short-horned outer spot-legged grasshopper, and confirms for the first time that the noctuid Steinernema nematode can effectively control the cutworm, the armyworm, the pea aphid and the short-horned outer spot-legged grasshopper, and has a wide range of application value in the field of biological control technology of field pests. At the same time, the present invention also studies the sensitivity difference of the biological control natural enemy insects, the swell-legged beetle of Guan and the flower beetle to the noctuid Steinernema nematode, and finds that these two biological control natural enemy insects are not sensitive to the SN and IGA strains of the noctuid Steinernema nematode, and the premise that the noctuid Steinernema nematode has no infection activity on these natural enemy insects makes the method of combining the natural enemy insects with the insect pathogenic nematode for pest biological control have a good application prospect.

[0040] Beneficial effects of the present invention: 1. The present invention studies the differences in the infectivity of different strains of Spodoptera carinata to four different agricultural pests, and understands the control effects of different strains of Spodoptera carinata to different insects, which helps to reveal its advantages and control spectrum in the control of specific pests, optimize the screening and application strategies of nematodes, and achieve more accurate biological control of pests. It has important practical significance for reducing dependence on chemical pesticides, formulating more effective comprehensive management strategies, and protecting the ecological environment.

[0041] 2. The present invention studies the invasive activity against pests and the invasive activity against natural enemy insects, and comprehensively discusses the application prospects of the noctuid nematode, which not only lays the foundation for the combined biological control of natural enemy insects and insect pathogenic nematodes, but also helps to clarify its optimal application scenarios in agricultural production, thereby improving the efficiency and overall effect of biological control, especially in the face of complex pest control environments, which will produce better control effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The infectivity of different doses of Steinernema carinii to Spodoptera litura. Note: The left one is the SF-SN strain, and the right one is the IGA strain.

[0043] Figure 2 The infectivity of different doses of Steinernema carinii to armyworms. Note: The left one is the SF-SN strain, and the right one is the IGA strain.

[0044] Figure 3 The infectivity of different doses of Steinernema carinata to pea aphids. Note: The left one is the SF-SN strain, and the right one is the IGA strain.

[0045] Figure 4 The infectivity of different doses of Steinernema carinata to the short-horned grasshopper. Note: The left one is the SF-SN strain, and the right one is the IGA strain.

[0046] Figure 5 The infective activity of different strains of Steinernema carinii against the flower beetle and Scleroderma guanyi. Note: The left one is the flower beetle, and the right one is the Scleroderma guanyi. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0048] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0049] Steinernema carinii in the following examples S.feltiae The IGA strain is recorded in the document "Li Chunjie, Wang Xinpeng, Huang Minghui, et al. Molecular identification of insect pathogenic nematodes [J]. Soil and Crops, 2020, 9(4): 380-387".

[0050] Steinernema carinii in the following examples S.feltiae The SF-SN strain is a product of Weifang Hongrun Agricultural Technology Co., Ltd.

[0051] The 5th instar larvae of Spodoptera litura and the 5th instar larvae of armyworm in the following embodiments are products of Jiyuan Baiyun Industrial Co., Ltd., Henan Province.

[0052] The wingless adult pea aphids and the adult short-horned locusts in the following examples were obtained by field collection (Nanyang, Henan) and identification.

[0053] Scleroderma guanii in the following examples Scleroderma guani Xiao et Wu and the Flowering Gar Dastarcus helophoroides All of them are products of Henan Jiyuan Baiyun Industrial Co., Ltd.

[0054] Example 1: Study on the infective activity of Steinernema carinii against Spodoptera litura, Mythimna separata, Aphid pea and Locusta shorthornedi 1. Breeding of Steinernema carinata and pests 1. Rearing of Steinernema carinii The wax moth is used as an insect host to artificially culture and breed the noctuid nematode indoors. The specific method is as follows: 20 mature larvae of the wax moth are placed in a sterilized nematode infection box covered with double gauze, and the infective stage noctuid nematode is mixed with deionized water to prepare a nematode suspension of a certain concentration and dripped on the body surface of the mature larvae of the wax moth to form a continuous infection of the wax moth. After 3 days, the wax moth corpse is transferred to a 6 cm culture dish covered with double filter paper, 2-3 insect corpses are placed in each culture dish, and then the small culture dish containing the insect corpse is placed in a 9 cm culture dish containing deionized water, and placed in a lightless nematode incubator, and cultured under the conditions of temperature 25°C and humidity 65±5%. After 7 days, the progeny infective stage noctuid nematode crawls from the wax moth corpse into the water in the large culture dish, and the water in the large culture dish is collected in a 50 ml centrifuge tube, and the nematodes are collected by repeated precipitation three times. The collected nematodes were placed in a cell culture flask for future use.

[0055] 2. Effects of different doses and strains of Steinernema carinii on the infectivity of Spodoptera litura, Armyworm, Pea Aphid, and Short-horned Locust 1. Experimental methods 1) Preparation of the suspension of Steinernema carinata The SF-SN strain of Steinernema carinii in the infective stage was mixed with deionized water to prepare SF-SN nematode suspensions with concentrations of 250 IJs / mL, 500 IJs / mL, 1000 IJs / mL, 2000 IJs / mL, 3000 IJs / mL, and 4000 IJs / mL, respectively.

[0056] The infective IGA strain of Spodoptera carinii was mixed with deionized water to prepare IGA nematode suspensions with concentrations of 250 IJs / mL, 500 IJs / mL, 1000 IJs / mL, 2000 IJs / mL, 3000 IJs / mL, and 4000 IJs / mL, respectively.

[0057] 2) How Spodoptera litura infects In twelve-well plates covered with 2.5 cm wet filter paper, 0.5 cm × 0.5 cm × 0.5 cm of Spodoptera litura feed (Spodoptera litura feed consists of 8.1 g soybean powder, 3.8 g wheat germ powder, 3.3 g yeast powder, 1.3 g agar, 0.5 g preservative, 0.3 g mildew inhibitor and 82.7 g water) were added, and the 5th instar larvae of Spodoptera litura with relatively uniform size were selected and placed in different twelve-well plates, with one worm in each well to prepare the Spodoptera litura infection system. Then, 100 μL of SF-SN nematode suspension or IGA nematode suspension of different concentrations was added to each well, so that the ratio of Spodoptera litura to Spodoptera litura larvae was 25:1, 50:1, 100:1, 200:1, 300:1, and 400:1, respectively.

[0058] 3) Infection method of armyworm In twelve-well plates covered with 2.5 cm wet filter paper, 0.5 cm × 0.5 cm × 0.5 cm sticky insect feed (sticky insect feed consists of 8 g soybean powder, 4 g yeast powder, 4.5 g wheat flour, 6.5 g corn flour, 0.35 g acetic acid, 0.35 g ascorbic acid, 0.075 g benzoic acid, 0.25 g sodium benzoate, 0.062 g cholesterol, 1.8 g agar and 77 g water) was added respectively. The 5th instar larvae of sticky insects with relatively uniform size were selected and placed in different twelve-well plates, with one worm in each well to prepare the sticky insect infection system. Then, 100 μL of SF-SN nematode suspension or IGA nematode suspension of different concentrations was added to each well, so that the ratio of Steinernema carinii to sticky insect larvae was 25:1, 50:1, 100:1, 200:1, 300:1, and 400:1, respectively.

[0059] 4) How pea aphids infect Fresh broad bean stems and leaves were added to a 5 cm sauce cup covered with moist filter paper, and wingless adult pea aphids of relatively uniform size were selected and placed in the cup, with 10 insects placed in each cup to prepare the pea aphid infection system. Then 1000 μL of SF-SN nematode suspension or IGA nematode suspension of different concentrations was added to each well, so that the ratio of Steinernema carinii to wingless adult pea aphids was 25:1, 50:1, 100:1, 200:1, 300:1, and 400:1, respectively.

[0060] 5) Infection method of the short-horned locust Add an appropriate amount of fresh alfalfa to a 9 cm plastic box covered with moist filter paper, select short-horned spot-legged grasshopper adults of relatively uniform size and put them into the plastic box, with 10 worms placed in each box to prepare the short-horned spot-legged grasshopper infection system. Then add 1000 μL of different volumes of SF-SN nematode suspension or IGA nematode suspension to each box, so that the ratio of Steinernema carinii to short-horned spot-legged grasshopper adults is 25:1, 50:1, 100:1, 200:1, 300:1, and 400:1, respectively.

[0061] Ten insects were used as one replicate, and three replicates were set for each dose treatment. For Spodoptera litura, Mythimna separata, and Short-horned Locust, no response to needle prick was considered death, and for pea aphid, no response to brush touch was considered death. The mortality was observed and recorded every 12 h for a total of 7 days, and the control group was treated with deionized water of the same dose. After 7 days, the corrected mortality and LC50 value (half-lethal concentration) were statistically analyzed. The culture environment was an RXZ-500B intelligent artificial climate chamber with a light cycle of 14L:10D, a temperature of 25℃, and a humidity of 65±5%. Corrected mortality = [(treatment mortality-control mortality) / (1-control mortality)]×100%.

[0062] 2. Experimental results 1) Mortality By counting the mortality rates of four insects infected at different times by different doses of Steinernema carinii, it was found that the mortality rate of Steinernema carinii against Spodoptera litura, armyworm, pea aphid, and short-horned grasshopper increased with the increase of nematode dose ( Figure 1-Figure 4 Among them, the corrected mortality rate of Spodoptera litura infected by nematodes can reach 100% at a medium concentration (100 IJs / head), and its corrected mortality rate can be close to 20% at a low concentration (25 IJs / head). Figure 1 The corrected mortality of armyworms infected with a higher concentration (300 IJs / head) of Steinernema carinii for 7 days can reach up to 53.33%, while the corrected mortality of armyworms infected with a lower concentration (25 IJs / head) of nematodes is less than 5% ( Figure 2The corrected mortality of pea aphids in the presence of medium concentrations (100 IJs / head) of nematodes can reach 100%, and the corrected mortality of pea aphids in the presence of low concentrations (25 IJs / head) of nematodes is around 50% ( Figure 3 The corrected mortality of the short-horned locust infected with different concentrations of Steinernema carinata ranged from 20% (25 IJs / head) to 100% (100 IJs / head and above) ( Figure 4 ). The above results show that the noctuid nematode Steinernema carinata has a good control effect on Spodoptera litura, armyworm, pea aphid, and short-horned grasshopper, among which the control effect of SF-IGA strain is relatively better than that of SN strain.

[0063] 2) LC50 value By counting the LC50 values ​​of the noctuid nematode against four insects, it was found that the LC50 of the SF-SN strain of noctuid nematode against Spodoptera litura was 44:1; the LC50 of the SF-SN strain of noctuid nematode against the short-horned locust was 56:1; the LC50 of the SF-SN strain of noctuid nematode against armyworm was 395:1; the LC50 of the SF-SN strain of noctuid nematode against pea sprouts was 28:1. The LC50 of the IGA strain of noctuid nematode against Spodoptera litura was 43:1; the LC50 of the IGA strain of noctuid nematode against the short-horned locust was 54:1; the LC50 of the IGA strain of noctuid nematode against armyworm was 393:1; the LC50 of the IGA strain of noctuid nematode against pea sprouts was 20:1.

[0064] Table 1. LC50 values ​​of Steinernema carinii against four insects

[0065] Note: Different letters in the upper right corner of the same column represent significant differences between the two treatments (SN and IGA) (p < 0.05) Example 2: Study on the infective activity of Steinernema carinii against Scleroderma guanii and Psoralea floridula Flower Velvet Beetle Dastarcus helophoroides Scleroderma guanii Scleroderma guaniXiao et Wu are all natural enemy insects and are commonly used biological control materials. These biological materials have their own characteristics in biological control. Flower beetles can be used to control longhorn beetle pests such as Platycladus orientalis, pine brown longhorn beetles (the carrier of pine wood nematodes), mulberry longhorn beetles, and rust-colored grain beetles. Guan's scleroderma can be used to control longhorn beetles and other stem borers on trees such as pine, poplar, peach, apricot, and plum, as well as various fruit trees. There are significant differences between the noctuid nematode and these biological control pests. In order to explore the differences in the sensitivity of Guan's scleroderma and flower beetles to noctuid nematodes, under laboratory conditions, the SN strain and IGA strain of noctuid nematodes were used to conduct natural infection experiments on adults of Guan's scleroderma and flower beetles. The specific steps are as follows: 1. Experimental Methods 1. Preparation of nematode suspension The SN strain and IGA strain of Steinernema carinii at the infective stage were mixed with deionized water to prepare a nematode suspension with a concentration of 10000 IJs / mL.

[0066] 2. Infection by Steinernema carinata (1) Natural infection of the flower beetle Place moistened filter paper in a breathable sauce cup, select 10 flower beetles of relatively uniform size and place them in it, add 100 μL of nematode suspension with a concentration of 10,000 IJs / mL to each sauce cup, and add the same dose of deionized water to the control group, with three replicates in total. Place the sauce cup in an artificial climate chamber (L:D=0:24, 25°C, RH=60±5%), observe the death every 24 hours, and use the lack of reaction when touched by tweezers as the standard of death, and observe for a total of 4 days.

[0067] (2) Natural infection of Scleroderma guanii Place moistened filter paper in a 1.5 ml centrifuge tube, select 10 Scleroderma guani of relatively uniform size and place them in it, add 100 μL of nematode suspension with a concentration of 10,000 IJs / mL to each tube, add the same dose of deionized water to the control group, and set up three replicates. Place the centrifuge tube in an artificial climate box (L:D=0:24, 25°C, RH=60±5%), observe the death every 24 hours, and use the lack of reaction to the brush touch as the death standard, and observe for a total of 4 days.

[0068] 2. Experimental Results The results are as follows Figure 5As shown in the figure, the results show that: with the increase of infection time, the corrected mortality of the flower beetle and the tube-legged beetle infected by nematodes is zero, indicating that these two insects are not sensitive to the SN and IGA strains of the noctuid nematode. Therefore, in the face of a complex pest control environment, the advantages of natural enemy insects and insect pathogenic nematodes can be combined for joint biological control. The premise that the noctuid nematode has no infective activity against these natural enemy insects makes this joint control scheme have a good application prospect and can produce better control effects.

[0069] The present invention has been described in detail above. It will be apparent to those skilled in the art that the present invention may be implemented in a wide range under equivalent parameters, concentrations and conditions without departing from the spirit and scope of the present invention and without the need for unnecessary experimentation. Although the present invention provides specific embodiments, it should be understood that further improvements may be made to the present invention. In short, according to the principles of the present invention, this application intends to include any changes, uses or improvements to the present invention, including changes made by conventional techniques known in the art that depart from the scope disclosed in this application. Applications of some of the basic features may be made within the scope of the following appended claims.

Claims

1. Use of Steinernema carinata in controlling pests or preparing products for controlling pests; The pests are Spodoptera litura and / or armyworm and / or pea aphid and / or short-horned locust.

2. The use according to claim 1, characterized in that: The pest control is manifested in increasing the pest mortality rate.

3. The use according to claim 1 or 2, characterized in that: The Steinernema carinii nematode is the SF-SN strain of Steinernema carinii or the IGA strain of Steinernema carinii.

4. Use of the noctuid nematode Steinernema carinata and natural enemy insects in controlling pests or preparing products for controlling pests; The natural enemy insects include the flower beetle and / or the scleroderma guanyi.

5. The use according to claim 4, characterized in that: The Steinernema carinii nematode is the SF-SN strain of Steinernema carinii or the IGA strain of Steinernema carinii.

6. A composition for controlling pests, comprising Steinernema carinata and natural enemy insects; the natural enemy insects include the flower beetle and / or Scleroderma guani.

7. The composition according to claim 6, characterized in that: The Steinernema carinii nematode is the SF-SN strain of Steinernema carinii or the IGA strain of Steinernema carinii.

8. Use of the composition according to claim 6 or 7 in controlling pests or preparing products for controlling pests.

9. A method for controlling pests, comprising the following 1) or 2): 1) The method comprises the following steps: applying Steinernema carinata to pests; 2) The method comprises the following steps: applying the noctuid nematode Steinernema carinata and natural enemy insects to the pests.

10. The method according to claim 9, characterized in that: The Steinernema carinii nematode is the SF-SN strain of Steinernema carinii or the IGA strain of Steinernema carinii.

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