Female codling moth adult attractant and application thereof

Abstract

The invention discloses a codling moth female imago attractant and application thereof, and provides the codling moth female imago attractant to solve the technical problems that an agent adopted in an existing codling moth prevention and treatment technology is serious in pollution, and a sex pheromone attractant can only trap male insects. Comprising nonanal, leaf alcohol acetate, geranyl acetate, methyl salicylate, butyl hexanoate and sorbate, the attractant is simple in formula, the trapping and killing effect on codling moths is remarkable, the lasting period is long, and the utilization rate is high; when the insect trapping agent is applied to an orchard, the average trapping amount of codling moth female adults reaches 6.91 + / -1.89 in 3 days, the codling moth female adults can be effectively trapped, and the insect trapping agent has wide practicability in the field of prevention and control of fruit borers.

Description

Technical Field

[0001] The invention relates to the technical field of pest control in forestry and fruit industry, and in particular to the technical field of an attractant for female adults of codling moth and application thereof. Background Art

[0002] The codling moth, Cydia pomonella (L.), is a devastating fruit borer of pome fruit trees worldwide. Due to the damage caused by the codling moth, crops such as apples and walnuts in my country have suffered huge losses. In traditional integrated pest control, chemical pesticides are mostly used to control codling moth. However, excessive use of pesticides has caused codling moth to develop resistance to many insecticides, reducing the effectiveness of control. The response of codling moth populations resistant to insecticides to plant volatiles is significantly higher than that of sensitive populations, which indicates that plant-derived volatiles may have a better control effect in areas where insecticides are widely used.

[0003] In recent years, chemical ecological regulation has gradually received attention. The chemical ecological regulation methods of codling moth mainly include sex pheromone regulation and host plant odor regulation. Existing research focuses on pheromone regulation, while research on plant odor regulation is relatively rare. Although the use of sex pheromones to trap codling moth has a certain effect on reducing the density of male insects, it is ineffective for female insects. Each female codling moth lays up to 160 to 240 eggs, so the number of female adults in the field is closely related to the degree of damage to fruit trees.

[0004] The codling moth has a strong reaction to a variety of compounds in volatiles such as apples and pears. For example, (E,E)-α-farnesene and butyl hexanoate, two main substances volatilized from the headspace of apple trees, can attract female adults of the codling moth. It has been reported in the literature that (E,E)-α-farnesene is an oviposition stimulant for female adults and has a good attraction effect on female adults; butyl hexanoate has an attraction effect on pregnant female adults; pear ester (E,Z)-2,4-decadienoate is the main volatile of pear fruit, and its attraction effect on codling moth is even comparable to that of sex pheromones. In addition, studies have shown that female adults of the codling moth will lay eggs within 10 to 15 cm of the fruit, indicating that certain volatile components in the fruit may have an attraction effect on the oviposition and feeding of the codling moth. Therefore, the timely development of attractants for female codling moths can further control the population, prevent the spread of the population, and achieve good prevention and control effects. Summary of the invention

[0005] In view of the technical problems that the existing control technology of codling moth uses serious pollution caused by the chemical control, and the sex pheromone attractant can only trap male insects, the present invention aims to provide an attractant for female adults of codling moth and its application. The attractant is configured by volatiles screened by antennal potential reaction and olfactory reaction, has a simple formula, has a significant effect on the trapping and killing of codling moth, is safe for natural enemies and the environment, has a long lasting effect period, and has a high utilization rate. When applied in orchards, the average 3-day trapping amount of female adults of codling moth reaches 6.91±1.89 heads, which can effectively trap female adults of codling moth and has wide practicality in the field of fruit-boring pest control.

[0006] In order to achieve the above technical effects, the present invention is implemented through the following technical solutions.

[0007] The invention provides an attractant for female adults of codling moth. The formula of the attractant comprises: methyl salicylate, pear ester, geranyl acetate, nonanal, leaf acetate and butyl caproate.

[0008] Preferably, the formula of the attractant for female adults of codling moth comprises, by weight, 3-5 parts of methyl salicylate, 4-6 parts of pear ester, 3-5 parts of geranyl acetate, 3-5 parts of nonanal, 5-7 parts of leaf acetate, and 4-6 parts of butyl caproate.

[0009] More preferably, the formula of the attractant for female adults of codling moth comprises, by weight, 3 parts of methyl salicylate, 4 parts of pear ester, 4 parts of geranyl acetate, 4 parts of nonanal, 6 parts of phytol acetate and 6 parts of butyl caproate.

[0010] At the same time, the present invention provides a method for using an attractant for female adults of codling moth. When in use, a slow-release bottle is used as a carrier, the configured attractant for female adults of codling moth is added into the slow-release bottle, and a trap composed of a sticky insect board and a triangular trap is used for trapping.

[0011] The method for using the female adult codling moth attractant is as follows: placing the drug prepared by the attractant formula in a trap, hanging the trap on a branch on the south side of a walnut tree at a height of 2 / 3 from the ground, with adjacent traps at a distance of more than 15m, replacing the sticky insect board every 3 days, and replacing the attractant every 9 days.

[0012] Furthermore, the present invention provides an application of an attractant for female adults of codling moth in the preparation of orchard pest control drugs.

[0013] Through the above technical scheme, the present invention obtains the following technical effects:

[0014] (1) The present invention provides an attractant for adult codling moth, comprising nonanal, leaf acetate, geranyl acetate, methyl salicylate, butyl caproate, and pear acetate. Volatiles of host plants of codling moth are used as attractants in combination with sticky insect boards and triangular traps. The attractant has the characteristics of good attracting effect and no adverse effect on the environment.

[0015] (2) The present invention provides an attractant for adult codling moth and its application. Through continuous monitoring in the field for 33 days, it was found that the attraction effect of a single volatile compound was weak, while the attraction effect of a volatile compound prepared with 3 parts of methyl salicylate, 4 parts of pear ester, 4 parts of geranyl acetate, 4 parts of nonanal, 6 parts of phytosteryl acetate and 6 parts of butyl caproate was better, with an average capture rate of 6.91±1.89 female adults of codling moth in 3 days. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] none. DETAILED DESCRIPTION

[0017] The following will be combined with the contents in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention, but the present invention is not limited to the following embodiments. All raw and auxiliary materials, reagents and equipment selected in the present invention are conventionally selected in the art.

[0018] Example 1: Electroantennographic responses of codling moth to volatiles from several host plants

[0019] Selection of volatiles: Ten substances in walnuts, including myrcene, eucalyptol, ocimene, linalool, nonanal, methyl salicylate, α-farnesene, heptaldehyde, geranyl acetate and phytyl acetate, as well as butyl caproate and pear acetate with attractive effects in apples and pears were selected for the experiment.

[0020] Test insect rearing: Test insects were collected in Layika Township, Hotan County, Hotan Prefecture, Xinjiang, and the mature larvae were collected and brought back indoors for use. Mature larvae of codling moth were raised individually in a petri dish, and the male and female were identified after pupation. Ten pairs of adults were raised in each insect cage with a side length of 25 cm. All test insects were raised in an artificial phenological box, and the conditions of the phenological box were: temperature 25±0.5℃, relative humidity 70%±5%, photoperiod 16L:8D, and light intensity 600lx.

[0021] When conducting the experiment, male and female adults that had mated and were 3 to 5 days old were selected for testing. Since the peak period of daily egg-laying for female insects is 19:00-21:00, this period was chosen to conduct the experiment. The antennae of the adults were cut off from the base for subsequent measurement tests. Under the MP-15 micromanipulator, the two ends of the antennae were connected to a glass capillary filled with physiological saline, and the other side of the capillary was connected to the insect antennae potential measurement system with a silver wire. 10 μL of volatile substance samples of different concentrations diluted with n-hexane were extracted with a pipette and dropped onto a folded filter paper. After volatilization for 20 seconds, the filter paper was placed in a Pasteur tube with tweezers. The Pasteur tube was connected to a stainless steel tube (inner diameter 10 mm) with an air flow (0.5 L min) filtered and humidified by activated carbon. -1 ). The antennae were 0.5 cm away from the end of the stainless steel tube, and the two ends were sealed with sealing film. The solvent was allowed to evaporate for 1 min before measurement. The antennae were stimulated with a stimulating airflow generator, and the stimulation period was 500 ms, with a stimulation interval of about 30 s. The flow rate of the continuous airflow was the same as the flow rate of the stimulating airflow, which was 4 mL / s. Only one antennae were taken from each adult of the codling moth, and 6 antennae were tested for each treatment. Each antennae was repeated 3 times. A blank control test was performed before and after each test to reduce the error, and n-hexane was used as the blank control.

[0022] Example 2: Analysis of electroantennographic responses of codling moth to volatiles from several host plants

[0023] According to the antennal potential data analysis in Tables 1 and 2, female codling moths responded strongly to nonanal, geranyl acetate, and linalool. When the nonanal concentration was 20 mg·mL -1 The EAG response value was the largest at 3.43±0.23mv. Male insects also responded strongly to nonanal, with a concentration of 20mg·mL -1 When the concentration of linalool was 2 mg·mL, the olfactory differentiation of male and female adults of codling moth was not obvious. -1 , 20mg·mL -1 , 200mg·mL -1 There were extremely significant differences in the expression of the single sample t test, P < 0.05). The adults of codling moth were sensitive to the concentration of each compound, and there were significant differences between the different concentrations of each compound. The different concentrations would cause significant changes in the EAG response value. This shows that the perception of codling moth to compounds is closely related to the concentration of the compounds in nature.

[0024] Table 1 The antennal potential responses of codling moth to different volatiles

[0025]

[0026] Note: The unit in the table is mV. Different lowercase letters indicate significant differences between females, and different uppercase letters indicate significant differences between males (T test, P<0.05)

[0027] Table 2 Analysis of variance of antennal potential and olfactory selection

[0028]

[0029] Note: The t-test and one-way ANOVA were used to analyze variance in the EAG response; the Wilcoxon signed-rank test was used to determine the differences between means in the odor selection test.

[0030] Example 3: Olfactory responses of codling moth to volatiles from several host plants

[0031] Myrcene, eucalyptol, ocimene, linalool, nonanal, methyl salicylate, α-farnesene, heptaldehyde, geranyl acetate, phytol acetate, butyl caproate and pear ester were selected for the experiment. The four-arm olfactometer was used to study the tendency of adult codling moths, and three gradients of 10, 100 and 1000 μg were set for each volatile active ingredient. The four-arm olfactometer test referred to the previous method. For each odor compound, 50 male and female insects were grouped into a group, and 10 insects were tested each time. Their choice behavior within 5 minutes was measured and repeated five times. Before the test, the components of the four-arm olfactometer were cleaned with absorbent cotton and alcohol, and used after drying and deodorization. The four-arm olfactometer was connected to the oil-free vacuum pump and other accessories with a silicone tube, and a trial run was performed for 3 minutes to test the overall airtightness and adjust the fixed flow rate of the flowmeter. In order to shield the influence of the light source on the codling moth, a weak constant light source of 10w was provided above the main chamber of the olfactometer. The active ingredient was diluted with the standard and evenly dripped on a circular filter paper with a diameter of 3 cm. The active ingredient on each filter paper was set to three gradients of 10, 100, and 1000 μg. The filter paper was folded and placed in the flavor source bottle as the test group, and the filter paper with n-hexane added was placed in the control flavor source bottle as the control group. -1 Purified humidified air was delivered at a constant rate. All tests were conducted at room temperature (25±2°C). The direction of the four-arm olfactometer was turned 90° for each test group to avoid mechanical errors.

[0032] Example 4: Analysis of the olfactory response of codling moth to volatiles from several host plants

[0033] According to the olfactory selection in Table 2 and the data analysis in Table 3, the olfactory behavior of the codling moth is similar to the trend of the EAG response. 100 mg nonanal has a better attraction effect on female adults (19.80±1.39), and 1000 mg methyl salicylate has a better attraction effect on male adults (20.80±2.13). Eucalyptol and linalool have a repellent effect on codling moth, and the female insects have a greater selection mean for these two repellent volatiles than male insects. Other compounds have an attractive effect. Geranyl acetate can attract codling moth when the active ingredient content is low, and has a repellent effect on codling moth when the active ingredient content is high. The selection of volatiles by female and male codling moth is roughly similar, with significant differences only in the selection of 100 mg and 1000 mg of heptanal active ingredients, 0 mg and 10 mg of linalool, 0 mg of eucalyptol and 10 mg of pear ester. In addition, concentration has a great influence on the selection of codling moth. Among the eleven volatiles tested, different contents of active ingredients caused significant differences in the selection of codling moth.

[0034] Table 3 Olfactory selection of codling moth adults for different volatiles

[0035]

[0036]

[0037] Note: Different lowercase letters indicate significant differences between females, and different uppercase letters indicate significant differences between males (Wilcoxon test, P<0.05)

[0038] Example 5: Using a single factor to attract codling moth in the field

[0039] According to EAG and olfactory selection experiments, 10 volatiles that have a positive attraction to codling moth were selected for field trapping experiments, which started before the peak of adult emergence and lasted for one month in 5 different test plots in Layika Township, Hotan Prefecture, Xinjiang. 1 mL of each volatile was added to a slow-release bottle and added every 6 days. The method of combining triangular traps and slow-release bottles was used for field trapping in 5 different test plots in Layika Township, Hotan Prefecture, Xinjiang, with 10 sets of traps hung in each plot.

[0040] According to the data analysis in Table 4, the results show that the trapping effect of single volatiles on codling moth is poor, and the amount of insects attracted is low. The volatile with the best trapping effect is butyl hexanoate, with an average trapping amount of 1.55±0.43 per 3 days, and the effect is poor. The average trapping amount per 3 days is only 0.18±0.12. It can be seen that there is no significant difference in the amount of insects attracted among the 10 volatiles (df=109, F=1.531, p=0.147).

[0041] Table 4 The trapping effect of individual volatiles on adults of codling moth

[0042]

[0043]

[0044] Example 6: Screening of compounds using orthogonal methods in the field

[0045] According to the analysis of the experimental results of Example 1 to Example 4, 10 volatiles that have a positive attraction to codling moth were selected for field trapping tests, starting before the peak of adult emergence and lasting for one month in 5 different test plots in Layika Township, Hotan Prefecture, Xinjiang. Using a sustained-release bottle, different types of compound combinations were added to the bottle, and each slow-release bottle with added compounds was combined with a sticky insect board to form a trap, and the total amount of insects attracted by each formula was recorded on each monitoring day.

[0046] According to the data in the intuitive analysis table in Table 5, the range is E>F>D>I>B>A>J>C>H>G, indicating that in the trapping test of female adults of codling moth, the influence of each factor is ranked as acacia ester>geranyl acetate>ocimene>butyl caproate>pear ester>nonanal>lecithin acetate>methyl salicylate>heptanal>myrcene; the mean value is ranked as F>I>B>A>J>C>G>H>D>E, indicating that without adding The order of influence on the trapping amount is geranyl acetate > butyl hexanoate > pear acetate > nonanal > leaf acetate > methyl salicylate > myrcene > heptaldehyde > ocimene > acaciaene; the order of mean 2 is E > D > H > G > C > J > A > B > I > F, indicating that the order of influence on the trapping amount after addition is acaciaene > ocimene > heptaldehyde > myrcene > methyl salicylate > leaf acetate > nonanal > pear acetate > butyl hexanoate > geranyl acetate.

[0047] Table 5 Intuitive analysis table of orthogonal test for volatile screening

[0048]

[0049]

[0050] Note: In the table, A = nonanal, B = pear ester, C = methyl salicylate, D = ocimene, E = α-farnesene, F = geranyl acetate, G = myrcene, H = heptanal, I = butyl hexanoate, J = phytol acetate; 1 means 0.5 mL of the compound was added, 2 means no addition

[0051] According to the results of the variance analysis table in Table 6, except for heptanal and myrcene, there are significant differences in variance between the remaining 8 volatiles and the trapping effect. After removing ocimene and acacia with mean K2>K1, six volatiles that can significantly increase the trapping amount can be obtained: nonanal, phytol acetate, geranyl acetate, methyl salicylate, butyl caproate, and pear acetate.

[0052] Table 6 Analysis of variance table of orthogonal test for volatile screening

[0053] source S df F Sig. Nonanal 93.341 1 13.254 0.000** Pear esters 114.614 1 16.275 0.000** Methyl salicylate 44.917 1 6.378 0.013* Ocimene 186.735 1 26.516 0.000** Acacia rare 418.371 1 59.407 0.000** Geranyl acetate 248.189 1 35.242 0.000** Myrcene 0.371 1 0.053 0.819 Heptanal 4.008 1 0.569 0.452 Butyl hexanoate 126.068 1 17.901 0.000** Leaf acetate 65.523 1 9.304 0.003** error 845.091 120

[0054] Note: * indicates that the volatiles have significant differences (P<0.05), ** indicates that the volatiles have extremely significant differences (P<0.01)

[0055] Example 7: Optimization of the method for trapping female adults of codling moth in the field and the formula of attractant

[0056] During the implementation period, the present invention trapped a total of 614 female adults of codling moth, accounting for 63%, indicating that the present formula has a better effect of attracting female adults. When luring female adults of codling moth, a slow-release bottle is used as a carrier, nonanal, leaf acetate, geranyl acetate, methyl salicylate, butyl caproate, and pear ester are added to the bottle respectively, and a uniform liquid is configured, which is combined with sticky insect boards and triangular traps for trapping. The traps are randomly hung on branches on the south side of the walnut tree with a crown width 2 / 3 of the height from the ground with thin iron wires, and the adjacent traps are more than 15m apart. The sticky insect boards are replaced every 3d, and the attractants are replaced every 9d.

[0057] The formula of the designed attractant is shown in Table 7, which includes 3-5 parts of methyl salicylate, 4-6 parts of pear ester, 3-5 parts of geranyl acetate, 3-5 parts of nonanal, 5-7 parts of leaf acetate, and 4-6 parts of butyl caproate. The experimental results are shown in Tables 8 and 9. From the variance analysis, it can be seen that these six volatiles have no significant effect on the capture amount of female adults, indicating that they work together. According to the range analysis in Table 8, the order of priority of the influencing factors is C>E>D>A>B>F, that is, geranyl acetate is the main influencing factor of the capture rate of the attractant for codling moth adults, followed by leaf acetate, nonanal, methyl salicylate, pear acetate and butyl caproate. According to the results of the k1, k2 and k3 values ​​of each indicator in Table 8, the optimal level combination of each factor is determined to be A1B1C2D2E2F3, that is, the optimized formula for the preparation method of the attractant for codling moth adults is: 3 parts of methyl salicylate, 4 parts of pear acetate, 4 parts of geranyl acetate, 4 parts of nonanal, 6 parts of leaf acetate and 6 parts of butyl caproate, and the experimental results show that the formula combination can capture 6.91±1.89 female adults of codling moth.

[0058] Table 7 Orthogonal test factors and level design table for volatile screening

[0059]

[0060] Table 8 Visual analysis of formula optimization for female adults of codling moth

[0061]

[0062]

[0063] Table 9 Analysis of variance for optimization of trapping formula for female adults of codling moth

[0064] factor F df F sig A 497.44 2.00 1.31 0.35 B 439.11 2.00 1.16 0.39 C 1876.78 2.00 4.94 0.07 D 1187.11 2.00 3.13 0.13 E 1850.78 2.00 4.87 0.07 F 188.78 2.00 0.50 0.64 error 949.78 5.00

[0065] The present invention provides an attractant for codling moth adults and its application, and clarifies the attracting effects of volatiles of 12 main host plants of codling moth on codling moth. Using the electroantennometric test (EAG) combined with a four-arm olfactometer, ten substances in walnuts, including myrcene, eucalyptol, ocimene, linalool, nonanal, methyl salicylate, α-farnesene, heptaldehyde, geranyl acetate and phytol acetate, as well as butyl hexanoate and pear acetate in apples and pears that have the effect of attracting codling moth adults were tested, and the attracting activity of host plant volatiles on codling moth was clarified. The results showed that the EAG response of codling moth adults and females to nonanal was the strongest, and the nonanal concentration was 20 mg·ml -1 The EAG response value was the largest at 3.43±0.23mv. In addition, geranyl acetate and linalool could also induce stronger EAG responses of female codling moth. The results of behavioral selection test showed that linalool, eucalyptol and high doses of geranyl acetate would repel codling moth, while myrcene, ocimene, nonanal, methyl salicylate, α-farnesene, heptaldehyde and low concentrations of geranyl acetate would attract codling moth. Through continuous monitoring for 33 days in the field, the attraction effect of a single volatile was weak, while the attraction effect of the combined volatiles was better. The optimized formula: 3 parts of methyl salicylate, 4 parts of pear ester, 4 parts of geranyl acetate, 4 parts of nonanal, 6 parts of phytol acetate and 6 parts of butyl caproate. The prepared attractant had an average of 6.91±1.89 female adults of codling moth in 3 days.

[0066] The embodiments described above are only some embodiments of the present invention, not all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but only represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the concept of the present invention belong to the scope of protection of the present invention.

Claims

1. An attractant for female adults of codling moth, characterized in that: The attractant comprises: methyl salicylate, pear ester, geranyl acetate, nonanal, leaf acetate and butyl caproate.

2. The attractant for female adults of codling moth as claimed in claim 1, characterized in that: The attractant formula includes, by weight: 3-5 parts of methyl salicylate, 4-6 parts of pear ester, 3-5 parts of geranyl acetate, 3-5 parts of nonanal, 5-7 parts of leaf acetate, and 4-6 parts of butyl caproate.

3. The attractant for female adults of codling moth as claimed in claim 2, characterized in that: The attractant formula includes, by weight, 3 parts of methyl salicylate, 4 parts of pear ester, 4 parts of geranyl acetate, 4 parts of nonanal, 6 parts of leaf acetate, and 6 parts of butyl caproate.

4. A method for using a codling moth female adult attractant, characterized in that: When in use, a slow-release bottle is used as a carrier, and the configured female adult codling moth attractant is added into the slow-release bottle, and the trap composed of a sticky insect board and a triangular trap is used for trapping.

5. A method for using a medicine containing the attractant for female adults of codling moth according to any one of claims 1 to 3, characterized in that: The drug is placed in a trap, and the trap is hung on a branch on the south side of a walnut tree at a height of 2 / 3 of the ground. Adjacent traps are spaced more than 15 m apart, and the sticky insect board is replaced every 3 days, and the attractant is replaced every 9 days.

6. Use of an attractant for female adults of codling moth in the preparation of orchard pest control drugs.

Images