A method for controlling hibiscus mealybugs using sex pheromone aversion agents

Abstract

The invention provides a method for controlling hibiscus mealybugs by using sex pheromone disorienting agents, by using hibiscus mealybugs sex pheromones to prepare disorienting agents, interfering with the mating information transmission of male and female hibiscus mealybugs, thereby controlling hibiscus mealybugs, and reducing the mating rate by more than 65%, and long-term release can reduce the hibiscus mealybug population by more than 70%, and the lasting effect reaches 60 to 120 days. The control method provided by the invention has strong specificity, simple and easy-to-obtain device, low raw material cost, little environmental impact, strong lasting effect, can cover the entire growth cycle of hibiscus mealybugs, and is easy to promote and apply.

Description

Technical Field

[0001] The invention belongs to the field of agricultural pest control, and in particular relates to a method for controlling hibiscus mealybugs by using sex pheromone aversion agents. Background Art

[0002] Phenacoccus solenopsis Tinsley, also known as cotton mealybug, belongs to the order Hemiptera, family Pseudococcidae, genus Phenacoccus. Phenacoccus solenopsis was first native to North America and invaded my country in 2008. So far, it has invaded dozens of provinces and cities in my country, with distribution in both the north and south. It has strong adaptability and is an important invasive pest in agriculture and forestry. Phenacoccus solenopsis Tinsley is polyphagous and has a wide range of hosts, including food crops, vegetable crops, ornamental flowers, garden plants and cash crops, causing serious economic losses every year. Due to the characteristics of small individuals, strong secretiveness, high reproductive capacity, overlapping generations, strong stress resistance and wax shell on the back of the body, Phenacoccus solenopsis Tinsley has obvious ecological advantages, and chemical control is difficult to achieve ideal results. Therefore, it is urgent to develop "green control" technology for hibiscus mealybugs, and sex pheromone technology has become an ideal choice.

[0003] At present, my country still mainly uses chemical control to control Phenacoccus hibiscus, while the development of physical control and biological control technologies lags behind significantly. The use of a large number of chemical pesticides has caused a significant increase in the resistance level of Phenacoccus hibiscus, and on the other hand, it has caused environmental pollution. Under the guidance of the current concepts of "green control" and "integrated control of agricultural pests", the development of pheromone technology has become a top priority, among which the pheromone method plays a huge role.

[0004] The disorientation method refers to releasing artificially synthesized insect pheromone compounds in the field to interfere with the normal sexual information communication between male and female individuals of the insect species, thereby achieving the purpose of prevention and control. This method mainly applies the principle of chemical ecology to prevent normal mating of insects within the species, thereby reducing the population. The concentration of sex pheromones used in the disorientation method is higher than the concentration generally used for prediction.

[0005] Japanese scientists Tabata et al. (2016) extracted and separated a sex pheromone component of the mealybug Phenacoccus hibiscus, whose chemical name is: (R)-isopentenoic acid-(2,2-dimethyl-3-isopropylcyclobutyl) methyl ester (Journal of Chemical Ecology. 2016, 42(11): 1-8.). The structural formula is as follows:

[0006]

[0007] Studies have shown that this compound is the main component of the sex pheromone of Phenacoccus hibiscus. However, there is no report on the use of this sex pheromone component to control Phenacoccus hibiscus. Summary of the invention

[0008] In order to solve the above problems, the present invention provides a method for controlling hibiscus mealybugs by using sex pheromone disorienting agents, by using hibiscus mealybugs sex pheromones to prepare disorienting agents, interfering with the mating information transmission of male and female hibiscus mealybugs, thereby controlling hibiscus mealybugs, generally reducing the mating rate by more than 65%, and long-term release can reduce the hibiscus mealybug population by more than 70%. The disorienting agent in the control method provided by the present invention has strong specificity, a simple and easy-to-obtain device, a feasible method, little environmental impact, a long-lasting effect, and is easy to promote and apply.

[0009] The inventor synthesized (R)-isopentenoic acid-(2,2-dimethyl-3-isopropylcyclobutyl) methyl ester, wherein the chemical purity was 90% and the optical purity was 92%. Indoor and field activity analysis proved that the sex pheromone of the hibiscus mealybug had a good attractant effect on male insects. Therefore, based on the large-scale synthesis of the compound, the present invention proposes a method for controlling the hibiscus mealybug using the sex pheromone aversion agent, which solves the problem of prediction, forecasting and prevention and control of the hibiscus mealybug by interfering with the mating process between male and female hibiscus mealybugs.

[0010] In one aspect, the present invention provides a method for controlling Phenacoccus sibiricus by using a disorienting agent, comprising the following steps:

[0011] 1) preparing disorienting agent release equipment;

[0012] 2) Fixing the disorienting agent release equipment in the field;

[0013] The disorienting agent contains the sex pheromone of Phenacoccus hibiscus L. (R)-isopentenoic acid-(2,2-dimethyl-3-isopropylidenecyclobutyl) methyl ester;

[0014] Furthermore, the disorienting agent releasing device in step 1) is a PVC tube, and the loading amount of the disorienting agent is 0.5 to 20 mg.

[0015] In some embodiments, the disorienting agent is loaded into a PVC tube as a slow-release device using paraffin oil as a solvent, and then both ends of the PVC tube are sealed to obtain a disorienting agent release device. The PVC tube material has gaps, and as long as the compound is volatile, it can be slowly released from the PVC tube.

[0016] Furthermore, step 2) is to fix the disorienting agent releasing equipment in the field and evenly distribute them, with 50 to 700 disorienting agent releasing devices being set per hectare of land.

[0017] In some methods, the disorienting agent release device can be fixed on the field crops or fixed poles and evenly placed in the field. The disorienting agent is slowly released into the environment through the PVC pipe. When its environmental concentration reaches a certain level, it can interfere with the chemical communication between male and female hibiscus mealybugs, interfere with the normal mating process, reduce the mating rate, and achieve the purpose of reducing the population.

[0018] Furthermore, the disorienting agent also includes a synergist, and the synergist is any one or more of myrcene, α-pinene, β-pinene, cis-3-hexenol or linalool.

[0019] Furthermore, the mass ratio of the sex pheromone to the synergist is 1:0.01-1.

[0020] Furthermore, the synergist is myrcene, α-pinene, β-pinene, cis-3-hexenol and linalool, wherein, by mass fraction, myrcene is 1 to 99 parts, α-pinene is 10 to 40 parts, β-pinene is 5 to 90 parts, cis-3-hexenol is 1 to 95 parts and linalool is 1 to 9 parts.

[0021] Furthermore, the disorienting agent includes, by mass fraction, 40 parts of (R)-isoprenoic acid-(2,2-dimethyl-3-isopropylcyclobutyl)methyl ester, 8 parts of myrcene, 3 parts of α-pinene, 6 parts of β-pinene, 9 parts of cis-3-hexenol and 1 part of linalool.

[0022] Furthermore, the disorienting agent also includes a solvent and an antioxidant, the solvent is paraffin oil, and the antioxidant is any one of butylated hydroxyanisole, dibutylhydroxytoluene, propyl gallate, tert-butylhydroquinone or tocopherol.

[0023] Field tests show that the method for controlling hibiscus mealybugs using a disorienting agent provided by the present invention is simple and easy to implement, has obvious effects, and can significantly reduce the mating rate of hibiscus mealybugs by more than 65%. Long-term release can reduce the population of hibiscus mealybugs by more than 70%. The method has good stability and a long lasting effect. Through field experiments, the lasting effect can reach 60 to 120 days.

[0024] In another aspect, the present invention provides a use of an aversion agent for preparing a preparation for controlling Phenacoccus hibiscus powder, wherein the aversion agent comprises a sex pheromone, and the sex pheromone is (R)-isopentenyl-(2,2-dimethyl-3-isopropylcyclobutyl) methyl ester.

[0025] Furthermore, the disorienting agent also includes a synergist, and the synergist is any one or more of myrcene, α-pinene, β-pinene, cis-3-hexenol or linalool.

[0026] Furthermore, the aversion agent includes sex pheromone, and the sex pheromone is (R)-isopentynoic acid-(2,2-dimethyl-3-isopropylidenecyclobutyl)methyl ester.

[0027] Furthermore, the disorienting agent also includes a synergist, and the synergist is any one or more of myrcene, α-pinene, β-pinene, cis-3-hexenol or linalool.

[0028] Furthermore, the mass ratio of the sex pheromone to the synergist is 1:0.01-1.

[0029] Furthermore, the synergist is myrcene, α-pinene, β-pinene, cis-3-hexenol and linalool, wherein, by mass fraction, myrcene is 1 to 99 parts, α-pinene is 10 to 40 parts, β-pinene is 5 to 90 parts, cis-3-hexenol is 1 to 95 parts and linalool is 1 to 9 parts.

[0030] Furthermore, the disorienting agent includes, by mass fraction, 40 parts of (R)-isoprenoic acid-(2,2-dimethyl-3-isopropylcyclobutyl)methyl ester, 8 parts of myrcene, 3 parts of α-pinene, 6 parts of β-pinene, 9 parts of cis-3-hexenol and 1 part of linalool.

[0031] The method of the present invention has the following beneficial effects: the method has strong specificity, is a specific directional agent for hibiscus mealybugs, does not use chemical pesticides, and has no effect on non-target organisms including natural enemies; the method has a simple and easy release device, and the raw materials are low in cost and readily available; the method is less affected by the natural environment and is suitable for use in various environments; the method has a long effective period of 60 to 120 days, and can cover the entire growth cycle of hibiscus mealybugs; the method has a strong ability to interfere with mating, and can reduce the mating rate by more than 65%, and long-term release can reduce the population of hibiscus mealybugs by more than 70%. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the examples. It should be pointed out that the examples described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0033] In the following examples, the hibiscus mealybug sex pheromone (R)-isoprenoic acid-(2,2-dimethyl-3-isopropylcyclobutyl) methyl ester is the hibiscus mealybug sex pheromone, which has a chemical purity of 90% and an optical purity of 92%. It is synthesized in the laboratory, and the synthesis method is referenced to the synthesis method of the hibiscus mealybug sex pheromone in Zhang A, Nie J (2005) Enantioselective synthesis of the female sexpheromone of the pink hibiscus mealybug, Maconellicoccus hirsutus. J Agric Food Chem 53: 2451–2455; myrcene was purchased from Aladdin Reagent Co., Ltd.; α-pinene was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; β-pinene was purchased from Aladdin Reagent Co., Ltd.; cis-3-hexenol was purchased from Sinopharm Chemical Reagent Co., Ltd.; and linalool was purchased from Aladdin Reagent Co., Ltd.

[0034] Example 1 Determination of release rate of disorienting agent

[0035] Using paraffin oil as solvent, two groups of 8 mg of disorienting agents were added into PVC tubes (purchased from Ningbo Newcom Biotechnology Co., Ltd., length 5-20 cm, inner diameter 0.5-1.2 mm, wall thickness about 0.05 mm), wherein the first group of disorienting agents was the sex pheromone of Phenacoccus hibiscus (R)-isopentenylic acid-(2,2-dimethyl-3-isopropylcyclobutyl) methyl ester, and the second group of disorienting agents included (R)-isopentenylic acid-(2,2-dimethyl- 3-isopropylcyclobutyl) methyl ester 40 parts, myrcene 8 parts, α-pinene 3 parts, β-pinene 6 parts, cis-3-hexenol 9 parts and linalool 1 part; the contents of the two groups of disorienting agents in the PVC pipes were determined at 1 month, 2 months and 3 months respectively, and the content of the sex pheromone of the hibiscus mealybug (R)-isopentenoic acid-(2,2-dimethyl-3-isopropylcyclobutyl) methyl ester in the remaining disorienting agents was detected by GC. The specific release rate is shown in Table 1.

[0036] Table 1 Release rate of disorienting agent

[0037]

[0038] As shown in Table 1, when the first group is used, the remaining sex pheromone content still reaches 35% after 3 months; when the second group of aversion agents is used, the remaining sex pheromone content reaches 56% after 3 months. It can be seen that the aversion agent provided by the present invention has a very long lasting effect, and when the aversion agent (the second group) is composed of sex pheromones and synergists, the lasting effect can be further extended.

[0039] Example 2 Preparation of a disorienting agent release device

[0040] A conventional PVC tube is used, which is 5 to 20 cm long, 0.5 to 1.2 mm in inner diameter, and about 0.05 mm in wall thickness. 0.5 to 20 mg of active ingredients of a disorienting agent are added to the PVC tube, liquid paraffin is used as a solvent, and 0.5 to 3 mg of an antioxidant is added, wherein the antioxidant is one of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PG), tertiary butylhydroquinone (TBHQ), and tocopherol. Finally, the two ends of the PVC tube are sealed to obtain the required two sets of disorienting agent release devices.

[0041] Example 3 Verification of the effect of the disorienting agent on controlling Phenacoccus sangifera

[0042] The test site is selected as a plot where Phenacoccus hibiscus occurs. The experimental time is from May to September, i.e., the season when Phenacoccus hibiscus occurs. The disorienting agent release device is fixed on the crop or fixed pole. The number of disorienting agent release devices placed per hectare is 50 to 700. The detection and population statistics are carried out after 30 days, 60 days and 120 days of placement. The population statistics method is to count the number of male Phenacoccus hibiscus trapped in the traps in the treatment area and the control area and calculate the inhibition of mating rate and the proportion of population reduction, wherein the inhibition of mating rate (also known as the disorientation rate) (%) = (1-the amount of insects trapped in the treatment area / the amount of insects trapped in the control area) * 100%, and the control effect (%) = (1-the number of damaged plants in the treatment area / the number of damaged plants in the control area) * 100%.

[0043] The disorienting agent release devices are divided into three groups:

[0044] Group 1: All (R)-isoprenoic acid-(2,2-dimethyl-3-isopropylidenecyclobutyl)methyl ester is the active ingredient;

[0045] The second group: by mass fraction, including 40 parts of (R)-isoprenoic acid-(2,2-dimethyl-3-isopropylidenecyclobutyl)methyl ester, 8 parts of myrcene, 3 parts of α-pinene, 6 parts of β-pinene, 9 parts of cis-3-hexenol and 1 part of linalool;

[0046] The third group: calculated by mass fraction, including 8 parts of myrcene, 3 parts of α-pinene, 6 parts of β-pinene, 9 parts of cis-3-hexenol and 1 part of linalool, but excluding (R)-isoprenoic acid-(2,2-dimethyl-3-isopropylcyclobutyl)methyl ester.

[0047] The dosage of the disorienting agent and the specific number of placement of the disorienting agent devices were set up three times each, and the specific field effects are shown in Tables 2, 3, and 4.

[0048] Table 2. Effects of three groups of hibiscus mealybug aversion agents placed for 30 days

[0049]

[0050]

[0051] Table 3. Effects of three groups of hibiscus mealybug aversion agents placed for 60 days

[0052]

[0053] Table 4. Effects of three groups of hibiscus mealybug aversion agents placed for 60 days

[0054]

[0055] It can be seen from Tables 2-4 that with the increase of dosage and the number of placed aversion agents, the inhibitory effect on the mating of Phenacoccus hibiscus powdery mildew is more obvious. Therefore, based on the field test results of the present invention, a dosage of 0.5 to 20 mg of aversion agent is generally used, and the number of placements in the field is 50 to 700 per hectare.

[0056] Comparing the control effects of the first, second and third groups of aversion agents, it can be clearly seen that the effect of the second group of aversion agents is significantly improved, which is significantly better than the use of sex pheromones alone (the first group), while the effect of the synergist alone (the third group) is relatively weak. It can be seen that when sex pheromones are used in combination with synergists, they have a significant synergistic effect on inhibiting the mating rate and control effect of hibiscus mealybugs.

[0057] The method of preventing and controlling hibiscus mealybugs by using a disorienting agent is suitable for comprehensive prevention and control, has no pollution to the environment, and is suitable for large-scale promotion and use.

[0058] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for controlling Phenacoccus sibiricus by using a disorienting agent, characterized in that: The following steps are involved: Prepare disorienting agent release equipment; Fixing the disorienting agent release equipment in the field; The disorienting agent is composed of the sex pheromone of hibiscus mealybug (R)-isopentenyl acid-(2,2-dimethyl-3-isopropylidenecyclobutyl) methyl ester and a synergist. The synergist is composed of myrcene, α-pinene, β-pinene, cis-3-hexenol and linalool. The synergist contains 40 parts of (R)-isopentenyl acid-(2,2-dimethyl-3-isopropylidenecyclobutyl) methyl ester, 8 parts of myrcene, 3 parts of α-pinene, 6 parts of β-pinene, 9 parts of cis-3-hexenol and 1 part of linalool by mass. The synergist is used to prolong the effective period of the sex pheromone of hibiscus mealybug.

2. The method according to claim 1, characterized in that Step 1) The disorienting agent releasing device is a PVC tube, and the loading amount of the disorienting agent is 0.5-20 mg.

3. The method according to claim 2, characterized in that Step 2) To fix the disorienting agent release equipment in the field and evenly distribute it, 50 to 700 disorienting agent release devices are set per hectare of land.

4. The method according to any one of claims 1 to 3, characterized in that The disorienting agent also includes a solvent and an antioxidant, wherein the solvent is paraffin oil, and the antioxidant is any one of butylated hydroxyanisole, dibutylhydroxytoluene, propyl gallate, tert-butylhydroquinone or tocopherol.

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