CN112825865B

CN112825865B - Insecticidal composition, application thereof and insecticide

Info

Publication number: CN112825865B
Application number: CN202011618058.4A
Authority: CN
Inventors: 徐文静; 高鹏; 李启云; 隋丽; 张正坤; 赵宇; 张�杰; 凤桐
Original assignee: Jilin Academy of Agricultural Sciences
Current assignee: Jilin Academy of Agricultural Sciences
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-07-12
Anticipated expiration: 2040-12-31
Also published as: CN112825865A

Abstract

The invention relates to the technical field of agriculture, and particularly relates to an insecticidal composition and application thereof. The insecticidal composition consists of beauveria bassiana and bacillus thuringiensis. Experiments show that after the beauveria bassiana and the bacillus thuringiensis are compounded according to a certain proportion, the insecticidal composition has obvious synergistic effect on control of broccoli pests and cabbage pests, the control effect is similar to that of a chemical insecticide, the control effect period is longer, the frequency of applying the insecticide can be reduced, the using amount of the chemical insecticide is reduced, and the yield of cruciferous vegetables can be obviously increased.

Description

Insecticidal composition, application thereof and insecticide

Technical Field

The invention relates to the technical field of agriculture, and particularly relates to an insecticidal composition, application thereof and an insecticide.

Background

The cruciferous vegetables are of various types, are important vegetables for residents in China, and the eating safety of the cruciferous vegetables seriously influences the happiness of the residents in China. However, cruciferous vegetable pests are rampant and include diamondback moth, cabbage caterpillar, cabbage looper, beet armyworm, prodenia litura, phyllotreta striolata and the like, the problems of multiple varieties, short life generation, generation overlapping and serious pest resistance are caused, the cruciferous vegetable pests are one of crops which are known to be extremely difficult to control at present, the pesticide application times are as many as ten times or even more than twenty times in a harvesting season of 90 days, and multiple drugs are required to be doubled and used jointly, so the edible safety of harvested vegetables is great, and the safety of food at the entrance of residents is urgently required to be ensured by adopting a low-toxicity safe control mode.

At present, the pest control of cruciferous vegetables mainly adopts a chemical control method. But with the use of a large amount of chemical pesticides, the chemical pesticides pose great threats to human health and living environment. The problem of pest resistance is also becoming more serious. Compared with the prior art, the biological control method has the advantages of safety, effectiveness and the like.

Beauveria bassiana is a biological insecticide widely applied, is a broad-spectrum insect pathogenic fungus, and has aerial spores which are adsorbed on the body surface of an insect to form attachment cells, metabolizes insect body wall degrading enzymes under a proper condition, extends out of a bud tube, penetrates through the body wall of the insect to enter the blood cavity of the insect, and is propagated, spread, transported and metabolized in the blood cavity of the insect to finally cause the insect to die; the beauveria bassiana in dead insect cadavers is continuously propagated, a large amount of new aerial spores are formed on the body surfaces of the insects and are further diffused and spread, so that the beauveria bassiana has the characteristics of low lethal speed, strong spreading performance, strong diffusing capacity, long lasting period and the like for preventing and treating pests; the aerospores produced by asexual propagation of beauveria bassiana are pathogenic active units, the number of the live spores is positively correlated with the pathogenicity of the beauveria bassiana, and the activity capacity is generally expressed by the number of the live spores. . The bacillus thuringiensis is one of the most widely applied bacterial insecticides at present, can generate parasporal crystal protein, has strong specificity on pests, and has the advantages of quick control effect, good insecticidal effect, good environmental compatibility and the like, when the bacillus thuringiensis is eaten to act on the midgut, the spores germinate in the midgut to damage the intestinal wall and enter a blood cavity, and finally the pests are killed by septicemia; the content of parasporal crystallin is a key factor of toxicity, and the higher the content is, the stronger the insecticidal capacity is, so that the production can detect the insecticidal activity of each batch of strains, and generally IU is used for expressing the insecticidal capacity. At present, beauveria bassiana and bacillus thuringiensis are mainly used as biological insecticides to be used independently, although the biological insecticides have the advantages of safety, effectiveness and the like, each insecticide has the defects, the control effect on pests is not ideal enough, and the report that the two insecticides are combined to be used for controlling the pests in the whole growth period of cruciferous vegetables is not seen yet.

Disclosure of Invention

The invention aims to provide a pesticide composition, and application and a pesticide thereof.

The invention provides an insecticidal composition, which consists of beauveria bassiana and bacillus thuringiensis.

In some embodiments, the beauveria bassiana content is 0.1-10 hundred million/g based on the number of live spores; the content of the bacillus thuringiensis is 1.6-160 ten thousand IU/g calculated by activity unit ten thousand IU of the produced parasporal crystal protein.

Beauveria bassiana plays a role as live spores, and the number of the live spores represents the using amount; bacillus thuringiensis is a parasporal crystal protein produced by the Bacillus thuringiensis to play a role, and is expressed by an activity unit IU after insecticidal activity is detected.

In some embodiments, the beauveria bassiana content is 0.1-8 hundred million/g based on the number of live spores; the content of the bacillus thuringiensis is 1.6-128 ten thousand IU/g based on the activity unit ten thousand IU of the parasporal crystal protein generated by the bacillus thuringiensis.

In some preferred embodiments, the beauveria bassiana content is 0.25 to 2.5 hundred million/g based on the number of live spores; the content of the bacillus thuringiensis is 1.6-16 ten thousand IU/g calculated by activity unit ten thousand IU of the parasporal crystal protein produced by the bacillus thuringiensis.

The bacillus thuringiensis is a bacterial insecticide, can produce parasporal crystal protein, acts on the midgut after being eaten by lepidoptera larvae, spores germinate in the midgut to damage the intestinal wall and enter a blood cavity, and finally causes the pests to become septicemia and die. Beauveria bassiana is an entomopathogenic fungus and has the characteristics of broad spectrum, transmissibility, popularity, diffusivity and the like. The two insecticides have obviously different mechanisms of action and belong to two insecticides with completely different mechanisms of action. The two types of pesticides are compounded, and the cotoxicity coefficient CTC of the beauveria bassiana and the bacillus thuringiensis in different proportions is calculated according to a cotoxicity coefficient method, wherein the antagonistic action is realized when the CTC is less than 80, the additive action is realized when the CTC is more than or equal to 80 and less than or equal to 120, and the synergistic action is realized when the CTC is more than 120. The result shows that the number of live spores (hundred million spores/ml) of the beauveria bassiana and the activity unit (ten thousand IU/ml) of the bacillus thuringiensis are compounded according to the proportion of (0.1-6.4) to (1.6-102.4), the CTC is more than 120, and the synergistic effect is achieved.

In some embodiments, the number of live spores (hundred million spores/ml) of beauveria bassiana and the activity unit (ten thousand IU/ml) of bacillus thuringiensis are compounded according to the ratio of (0.4-1.6) to (6.4-25.6), the CTC is more than 120, and the synergistic effect is achieved. Wherein, the compounding synergistic effect is particularly remarkable according to the proportion of (0.4-1.2) to (12.8-25.6). The control period is longer, and the yield of the cruciferous vegetables can be obviously increased.

In some embodiments, the composition of the present invention is used for controlling cabbage looper larvae, wherein the ratio of beauveria bassiana to bacillus thuringiensis (one hundred million spores per ten thousand IU), preferably (0.4-1.2): 12.8-25.6), and specifically may be 1.6:6.4, 1.2:12.8, 1:16, 0.8:19.2 or 0.4: 25.6.

In some embodiments, the composition of the present invention is used for controlling corn borer, wherein the ratio of beauveria bassiana to bacillus thuringiensis (hundred million spores per ten thousand IU) is preferably (0.25-2.25): 1.6-14.4), specifically 0.25:14.4, 0.75:11.2, 1.25:8, 1.75:4.8 or 2.25: 1.6.

The invention also provides application of the insecticidal composition in controlling brassicaceous vegetable pests and/or corn pests.

In some embodiments, the cruciferous vegetable pests include beet armyworm, cabbage looper, cabbage caterpillar, and diamond back moth. The corn pest is corn borer

The invention also provides a method for controlling the pests of cruciferous vegetables and the application of the insecticidal composition.

In some embodiments, the application is by spraying, soil dressing, or seed dressing.

The invention also provides a pesticide, which comprises the insecticidal composition and an agriculturally and pharmaceutically acceptable auxiliary material.

The insecticidal composition of the invention can be prepared into various dosage forms according to the conventional preparation method in the field, for example, the agriculturally and pharmaceutically acceptable auxiliary materials, such as one or more of wetting agent, dispersing agent, penetrating agent, antifreezing agent, thickening agent, synergist, film-forming agent and filler, can be added into the effective amount of the insecticidal composition of the invention, and various common preparations, such as wettable powder, oil suspension, tank mix, suspension emulsion or seed coating agent, can be prepared according to the conventional preparation method. The invention is preferably prepared into wettable powder, oil suspension, water suspension granules, seed coating agent and the like.

The insecticidal composition consists of beauveria bassiana and bacillus thuringiensis. Experiments show that after the beauveria bassiana and the bacillus thuringiensis are compounded according to the proportion of the invention, the insecticidal composition has obvious synergistic effect on controlling broccoli pests and cabbage pests, the control effect is similar to that of a chemical insecticide, the control effect period is longer, the frequency of applying the insecticide can be reduced, the using amount of the chemical insecticide is reduced, and the yield of cruciferous vegetables can be obviously increased.

Drawings

FIG. 1 shows the compatibility of example 1Bb and Bt on the culture medium, 1A: growing on LB culture medium at 25 deg.C for 24 hr; 1B: growing on LB culture medium at 25 deg.C for 48 hr; 1C: growing on PDA culture medium at 25 deg.C for 48 hr;

FIG. 2 shows the concentration of Bb at 50% of the number of dead insects in 3 days of combined treatment of Bb and Bt of example 2;

fig. 3 shows the feeding situation and the catalepsy situation of the corn borers of different treatment groups of example 3, 3A: feeding the corn borers for 2 days; 3B: feeding for 5 days for corn borer catalepsy;

fig. 4 shows the effect of Bb and Bt in control of ostrinia nubilalis in example 3, 4A: correcting mortality when feeding for 3 days; 4B: correcting the stiff worm rate when feeding for 3 and 5 days;

fig. 5 shows the correlation analysis results of the virulence and concentration of Bb and Bt in the control of zea mays borer in example 3, 5A: correcting the linear relation between mortality and Bt concentration when feeding for 3 days; 5B: correcting the linear relation between the stiff worm rate and the Bb concentration when feeding for 5 days;

FIG. 6 shows the dynamic variation of population of a broccoli pest within 7 days of application in example 4;

FIG. 7 shows the population reduction of broccoli pest within 7 days of the application in example 4;

FIG. 8 shows the dynamic variation of the population of the autumn stubble cabbage pest within 9 days of the application in example 5;

FIG. 9 shows the population decline of the autumn stubble cabbage pest in 9 days after the application of example 5;

FIG. 10 shows the effect of the insecticidal composition of the invention on the production of broccoli in example 6;

FIG. 11 shows the input-output of biopharmaceutical planted vegetables of example 6;

FIG. 12 shows the effect of the insecticidal composition of the present invention on the yield improvement of autumn cabbage in example 7;

FIG. 13 shows the input-output of biopharmaceutical planted vegetables of example 7;

FIG. 14 shows the number of worms on days 10 and 22 after application in example 8;

figure 15 shows the change in the number of stiff insects at 10 and 22 days of application in example 8.

Detailed Description

The invention discloses an insecticidal composition, application thereof and an insecticide, and a person skilled in the art can realize the insecticidal composition by appropriately improving process parameters by referring to the content. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.

The description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The invention is further illustrated by the following examples:

example 1

The beauveria bassiana (Bb) high spore powder and the bacillus thuringiensis (Bt) wettable powder are diluted by 10 degrees of gradient⁶Taking two bacterial suspensions with the same volume to prepare a mixed bacterial liquid Bb + Bt, then respectively taking 100 mu l of three bacterial suspensions of Bb, Bt and Bb + Bt to coat on an LB (Bt growth optimal culture medium) culture medium and a PDA (Bb growth optimal culture medium), carrying out inverted culture at 25-28 ℃, observing the growth condition of colonies on the LB culture medium after 24 hours, and observing the growth condition of colonies on the PDA culture medium after 48 hours. Bt is found to grow colonies on LB when the Bt is cultured for 24 hours, the growth state of Bt in the mixed bacteria is close to that of Bt single bacteria, Bb does not grow (figure 1A), and the Bb + Bt mixed bacteria on the LB culture medium have no influence on the growth of Bt; when the Bb + Bt mixed bacteria are cultured for 48 hours, the growth state of Bt is close to that of Bt single bacteria, Bb grows a little, Bb and Bt have no obvious colony growth boundary around Bb and Bt, Bb grows on LB (figure 1B), and the growth vigor is slightly worse than that of PDA (figure 1C), which indicates that Bb can grow on LB culture medium, but has no influence on the growth of Bt; when Bb grew on the PDA medium after 48 hours of culture, the Bb growth state in the Bb + Bt mixed bacteria was close to that of Bb, and Bt did not grow (FIG. 1C), indicating that Bt in the Bb + Bt mixed bacteria on the PDA medium had no effect on the growth of Bb. This shows that Bb does not affect the growth of Bt on LB culture medium, Bt does not affect the growth of Bb on PDA culture medium, there is no growth inhibition between them, it has good growth compatibility, this provides data support for the two to combine to use and control the agricultural pest.

Example 2 verification of compounding ratio by cabbage looper larva indoor toxicity test

Beauveria bassiana adopts D1-5(Bb), and the concentration is 500 hundred million live spores/g; the bacillus thuringiensis adopts G033A (Bt) with the concentration of 32000IU/mg (3200 ten thousand IU/G), compound proportion and gradient development tests are set according to tables 1 and 2, a feeding method is adopted to detect the toxicity of liquid medicine to larvae, wherein each concentration gradient is 5 times repeated, 10-day old cabbage noctuid larvae are repeated, the number of dead larvae and stiff insects is investigated when the treatment is carried out for 1, 3, 5 and 7 days, obtained data is analyzed by SPSS to obtain LC50, the effect of compound medicines is evaluated by a co-toxicity coefficient method, antagonism is carried out when CTC <80, addition is carried out when CTC <80, synergy is carried out when CTC >120, and remarkable synergy is carried out when CTC > 200. The co-toxicity coefficient statistics of the compounding results are shown in table 3, LC50 of the number of the stiff insects after compounding is shown in figure 2, and the results show that the compounding can enhance the insecticidal activity of Bt and also enhance the quantity of the stiff insects generated by Bb.

TABLE 1Bb and Bt compounding test proportion setting

TABLE 2 gradient setup for Bb and Bt combinations

TABLE 3 Co-toxicity coefficient of Bb and Bt combinations

Compounding ratio	Linear regression equation	R2	LD50	TTI	CTC
						Bb	y＝0.001x+1	0.998	49000.00	-
Bt	y＝0.003x+33.73	0.99	5423.33	-
						Bb/Bt＝8/2	y＝0.004x+10.25	0.931	9937.50	45.27	120.55
Bb/Bt＝6/4	y＝0.007x+3.826	0.9858	5771.75	66.65	140.98
						Bb/Bt＝5/5	y＝0.010x+12.5	0.999	3750.00	74.59	193.89
Bb/Bt＝4/6	y＝0.009x+17.5	0.998	3450.00	81.28	193.41
						Bb/Bt＝2/8	y＝0.008x+22.5	0.991	3055.56	91.92	193.10

Example 3 corn borer control test

The compound proportion is set according to the table 4 for carrying out the experiment, the feeding method is adopted to detect the toxicity of the liquid medicine to the larvae, the specific processing method and the data analysis method refer to the example 2, and the results are shown in the figures 3-5

TABLE 4 Bb and Bt compounding test proportion settings

The results of FIGS. 3-5 show that: when the ratio of beauveria bassiana to bacillus thuringiensis (hundred million spores/ten thousand IU) is (0.25-2.25): (1.6-14.4) (Table 4), the state of the larvae in the CK group is good when the animals are fed for 2 days, and the feeding traces are left on the leaves, while the feeding action of the larvae is severely inhibited by the composition treatment group and the single-agent treatment group (Bb or Bt), and the feeding traces are difficult to see on the leaves (FIG. 3A). The photographs of the insect cadavers at 5 days of feeding showed: the CK group larvae survived well, the Bt group showed a large number of dead larvae but no catalepsy symptom larvae, all the Bb-containing treatment groups showed dead bodies, and all the larvae in the mixed agent treatment group were dead (see FIG. 3B).

The results of the corrected mortality data for the larvae fed for 3 days showed that: the lethality of the mixed preparation is obviously higher than that of the single preparation, wherein the lethality of Bb1+ Bt9, Bb3+ Bt7 and Bb5+ Bt5 is higher than 90 percent and is obviously higher than that of Bb10 (see figure 4A); data of the dead larva corrected when the feed is fed for 5 days are displayed: the site containing Bb was significantly higher than the single dose, where the mortality of Bb9+ Bt1, Bb7+ Bt3 was not significantly different from that of Bb10, and the difference of Bb5+ Bt5 and Bb10 was significant (see FIG. 4B).

Analysis of fig. 3, the mortality rate of the Bb + Bt group was 79.5% to 93.3% when fed for 3 days (fig. 4A) with few stiff insects, whereas all the tested larvae of the Bb + Bt combination test group had died totally when fed for 5 days (fig. 4B), indicating that the dead larvae of the Bb + Bt group should be transformed from dead larvae and that the transforming ability was positively correlated with the amount of Bb.

Referring to fig. 5A-B, corrected mortality at 3 days of feeding and Bb concentration at linear regression analysis of Bt, Bb concentration were excluded variables with the linear equation Y3.126X +49.168, R0.551, P < 0.001; when the feed is fed for 5 days, the corrected mortality rate and the Bt and Bb concentrations are subjected to linear regression analysis, the Bt concentration is an excluded variable, Y is 33.407X +14.907, R is 0.883, and P is less than 0.001, which indicates that the Bb intervention component in the corrected mortality rate is possibly larger than the Bt intervention component in the corrected mortality rate, Bb has a certain effect on early Bt lethal larvae, and further indicates that Bb + Bt lethal larvae can be converted into catalepsy larvae in a large quantity.

The results of fig. 5 and table 4 show that the 5-day mortality rate of Bb5+ Bt5 group has no difference significance with Bb9+ Bt1 and Bb7+ Bt3, has more efficient lethal and rigidity-causing effects, and the cost of Bb in production is far higher than that of Bt, so the Bb can be used for preventing and controlling the corn borer in the field according to the proportion.

Example 4 combination of Beauveria bassiana and Bacillus thuringiensis for controlling Sichuan broccoli pests in spring stubbles

The western blue flower of northeast spring stubbles is in a rapid vegetative growth stage in middle ten days of June, the pests mainly adopt diamond back moths, and the insecticidal composition (Bb and Bt live spore ratio is 1:1) is applied when the pests raise heads again and is prepared from beauveria bassiana D1-5 strain tank mix and bacillus thuringiensis G033A wettable powder. )

Application of the insecticidal composition of the invention (Bt, 3.5X 10)¹⁰IU/hectare; bb, 3.5X 10¹³Live spores/hectare) and the 7-day dynamic situation of pests applying 2 times of lambda-cyhalothrin are shown in figures 6-7.

The results show that the number of pests is rapidly reduced after the lambda-cyhalothrin is applied (figure 6), the control effect reaches 91% on day 1, the control effect reduces 79% on day 3, and the control effect reduces 18% on day 7 (figure 7); the number of the pests of the beauveria bassiana and the bacillus thuringiensis combined technology is slowly reduced within 7 days (figure 6), the control effect reaches 33% on the 1 st day, the control effect is improved to 78% on the 3 rd day, the control effect reaches 90% on the 5 th day, the control effect reaches 83% on the 7 th day (figure 7), the change trend of the number of live pests is opposite to that of chemical pesticides, the longer the control time is, the fewer the live pests are, and the longer the control time is, the longer the duration period is, and the control effect is similar to that of the chemical pesticides.

Example 5 combination of Beauveria bassiana and Bacillus thuringiensis for controlling insect pest population change of autumn-stubble Chinese cabbage

The cabbage of northeast autumn stubble is in rapid vegetative growth stage in mid-August, and is mainly prepared from beet armyworm, cabbage looper, cabbage caterpillar and diamond back moth by applying Beauveria bassiana D1-5 strain barrel mixing agent (Bb, 5.0 × 10) when the pest raises head again¹³Viable spores/hectare) and bacillus thuringiensis G033A wettable powder (Bt, 4.0 × 10)¹⁰IU/hectare), and 9-day dynamics of pests with 2-fold application of lambda-cyhalothrin and emamectin benzoate as follows: lambda-cyhalothrin andafter the emamectin benzoate is applied, the number of pests is rapidly reduced (figure 8), the control effect reaches 94% on the 1 st day, the control effect is reduced to 83% on the 5 th day, and the control effect is reduced to 38% on the 9 th day (figure 9); the quantity of the pests is slowly reduced within 9 days by combining the beauveria bassiana and the bacillus thuringiensis (figure 8), the control effect reaches 28% on the 1 st day, the control effect is improved to 86% on the 5 th day, the control effect reaches 90% on the 7 th day, the control effect reaches 89% on the 9 th day (figure 9), the change trend of the number of live insects is opposite to that of chemical pesticides, the longer the control time is, the fewer the live insects are, the longer the control time is, the longer the control effect is, and the control effect is similar to that of the chemical pesticides.

Example 6 comparison of control methods for pests of broccoli in spring crop

According to the table 5, the broccoli was cultivated in spring, wherein the amount of chemical pesticide was doubled (1.5 times of the amount of voge), the combined application of beauveria bassiana (Bb) and bacillus thuringiensis (Bt) was reduced twice, and two modes of seed coating and spray control were adopted. The dosage of the Beauveria bassiana D1-5 strain tank-mixing agent is 1.5 multiplied by 10 when the seeds are coated¹²The dosage of viable spores per kilogram of seeds and the wettable powder of the bacillus thuringiensis G033A is 2.5 multiplied by 10⁹Mixing the IU and the Kg of seeds with 50ml of auxiliary agent mate, stirring the mixture evenly by a sand mill, adding a film forming agent and a pigment, mixing the seeds evenly, adding 50g of the mixture into 1kg of the seeds for coating, and airing the seeds after coating evenly for seedling culture; the two dosages of beauveria bassiana before the pest control by spraying are 3.5 multiplied by 10¹³The last two applications are 7.0 × 10¹³The first three times of the using amount of the bacillus thuringiensis is 4.0 multiplied by 10¹⁰IU/hectare, the two subsequent doses are 7.0 × 10¹⁰IU per hectare. The combination technology of the beauveria bassiana and the bacillus thuringiensis can obviously increase the yield of the broccoli (figure 10), the yield is increased by 11%, the medicine cost is increased by 59%, and the income is increased by 8.9% (figure 11), which indicates that the beauveria bassiana and the bacillus thuringiensis are combined to prevent and treat the spring stubble broccoli, so that the medicine using times can be reduced, and the yield of the broccoli can be obviously increased.

Method for cultivating broccoli in spring stubble in Table 5

Example 7 comparison of pest control methods for autumn cabbage

According to the table 6, the autumn-stubble Chinese cabbage is cultivated, the dosage of chemical pesticides is doubled (1.5 times of the dosage of voge), the combined technical pesticide application of beauveria bassiana (Bb) and bacillus thuringiensis (Bt) is reduced by two times, and two modes of seedling raising soil mixing pesticide and spraying prevention and control are adopted. The dosage of the beauveria bassiana D1-5 strain tank-mixing agent is 7.0 × 10 when the seedling soil is mixed with the pesticide¹¹The dosage of the wettable powder of the bacillus thuringiensis G033A is 9.0 multiplied by 10 for each cubic meter of soil⁸IU/cubic meter soil, diluting the two after being uniformly stirred, spraying the diluted solution by 10 times into 1 cubic meter seedling raising soil, and uniformly stirring the solution by using tools such as shovels and the like; the twice dosage of beauveria bassiana (balsamo) Vuillemin for preventing and controlling pests by spraying is 3.5 multiplied by 10¹³The dosage of the second two active spores is 7.0 multiplied by 10¹³The three-time dosage of the first Bacillus thuringiensis is 4.5 multiplied by 10 per hectare of live spores¹⁰IU/hectare, the last two 9.0X 10¹⁰IU/hectare. The combination technology of the beauveria bassiana and the bacillus thuringiensis can obviously increase the yield of autumn-stubbles of Chinese cabbages (figure 12), the yield is increased by 12 percent, the medicine cost is increased by 58 percent, and the income is increased by 9.4 percent (figure 13), which indicates that the beauveria bassiana and the bacillus thuringiensis can be used together to prevent the pests of the autumn-stubbles of Chinese cabbages and also obviously increase the yield of the Chinese cabbages.

TABLE 6 autumn cabbage cultivation method

Example 8 Effect of controlling autumn-stubble broccoli pests under the influence of Tertiary typhoon

Three typhoons occur in northeast of 2020 in autumn, and the pest is controlled by spraying technology after the first typhoon, wherein the amount of Beauveria bassiana is 4.0 × 10¹³The dosage of the bacillus thuringiensis is 5.0 multiplied by 10¹⁰IU/hectare, raining within 24 hours of application, and the population and the number of runt worms were investigated on days 10 and 22. The number of live insects indicates the combined technology of beauveria bassiana and bacillus thuringiensisThe control effect is best, and the lasting period reaches 22 days; the control effect of the bacillus thuringiensis is reduced when the bacillus thuringiensis is used for controlling the pests for 10 days, and the number of live pests is obviously increased when the bacillus thuringiensis is used for 22 days; the control effect of the beauveria bassiana is equivalent to that of the bacillus thuringiensis in 10 days, and better than that of the bacillus thuringiensis in 22 days (figure 14), which shows that the beauveria bassiana and the bacillus thuringiensis have the advantages of two insecticides after being combined; the number of stiff insects at day 10 showed no stiff insects for the control and bacillus thuringiensis, but stiff insects appeared at day 22, indicating that beauveria bassiana had spread to the control and bacillus thuringiensis control areas within 22 days (figure 15); the beauveria bassiana group had the largest number of stiff insects, and the second group (fig. 15) was probably related to the stomach toxicity of bacillus thuringiensis, and after the pests took food, the intestines and stomach were difficult to eat, refused to take food again, and had metastasis or death, so the actual stiff insects observed in the group were few.

Example 9 sustained control Effect test

In the spring of 2020, beauveria bassiana and bacillus thuringiensis are used for jointly preventing and controlling lepidoptera pests of spring-stubble Chinese cabbages twice at the Taojiatun of the city of the prince of Jilin province, the insecticidal composition is not used in autumn-stubble Chinese cabbages, but a large amount of muscardines are found on the leaf of the Chinese cabbages when the growth condition of the Chinese cabbages is checked in the field at the end of 9 months (after three typhoons), which indicates that the beauveria bassiana applied in spring festival still plays a lasting effect, and the lasting period can reach 4 months.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and amendments can be made without departing from the principle of the present invention, and these modifications and amendments should also be considered as the protection scope of the present invention.

Claims

1. The insecticidal composition is applied to control of cruciferous vegetable pests and/or corn pests and comprises beauveria bassiana and bacillus thuringiensis, wherein the ratio of the beauveria bassiana to the bacillus thuringiensis is hundred million/thousand IU and is 0.8:19.2 or 0.4: 25.6.

2. The use of claim 1, wherein the brassicaceous vegetable pests include beet armyworm, cabbage looper, cabbage caterpillar and diamondback moth, and the corn pest is corn borer.

3. A method for controlling pests of cruciferous vegetables is characterized by applying an insecticidal composition, wherein the insecticidal composition consists of Beauveria bassiana and Bacillus thuringiensis, and the ratio of Beauveria bassiana to Bacillus thuringiensis is 0.8:19.2 or 0.4:25.6 in hundred million IU.

4. The method of claim 3, wherein the application is spraying or soil mixing.