AU2017388833A1 - Method for controlling pests of tea - Google Patents

Abstract

The present invention proposes a novel method which is for controlling pests of tea, which uses heated water, without using any pesticides, and with which it is possible to more effectively control pests of tea. The proposed method for controlling pests is characterized by applying a treatment in which a mist of heated water is brought into contact with tea leaves such that the surface temperature thereof becomes 45-55°C.

Description

Title of Invention: METHOD FOR CONTROLLING PESTS OF TEA

Technical Field [0001]

The present invention relates to a method for controlling pests of tea, which is for exterminating or controlling pests in tea plant.

Background Art [0002]

Various types of pests grow in fields such as a tea field, and thus control of pests is essential to cultivate a healthy tea plant. Tea manufacturers have been tackled this problem by spraying an appropriate amount of an appropriate agent at an appropriate time.

[0003]

As for such methods of control of tea by spraying an agent, Patent Literature 1 (Japanese Patent Laid-Open

No. 7-31350), for example, discloses an apparatus for spraying an agent on tea plant uniformly and efficiently in a short time, in which many nozzles are protruded from the lower surface of a substantially arcuate substrate having a grip member and the agent is supplied to the respective nozzles, in the operation of extermination or control of pests attached to, e.g., branches of tea plant, such as scale insects.

[0004]

Furthermore, Patent Literature 2 (Japanese Patent

Laid-Open No. 7-289057) discloses a method for controlling pest of tea plant using a device for plucking tea leaves, which integrally has a plucking mechanism that advances along a tea ridge to pluck tea leaves and an application mechanism that applies an agent to the tea plant, wherein the application mechanism applies the agent to cut ends of plucking of the tea plant immediately after the plucking mechanism plucks the tea leaves.

[0005]

Meanwhile, the concern with methods of control using an agent such as chemical fertilizer or pesticide is their harmful effects on the health of human bodies and environmental pollution. Thus, methods of controlling pests using little or no chemical fertilizer or pesticide have been proposed. Today about 100 pesticide components are registered particularly for tea in Japan, but those pesticide components may not have been approved or standards for pesticide residues are very low in many foreign countries. Thus, for the export of tea, there is an urgent need to consider a method of control without using pesticide.

[0006]

To this end, Patent Literature 3 (Japanese Patent

Laid-Open No. 2016-152794) discloses a method for controlling pest with hot water by spraying hot water on a farm field which has been specially maintained and spraying a solution for organic farming on the surface of leaves of crops when eggs, larvae or adults of pest are attached thereon.

[0007]

Patent Literature 4 (Japanese Patent Laid-Open No.

2016-158522) discloses a method for controlling a moisture-phobic pest, wherein a sensor for detecting the degree of wetting is installed in a field at a position close to an environment in which the moisture-phobic pest lives and water is sprinkled on the field according to the detection value of the sensor to create a situation in which the moisture-phobic pest is repelled or is difficult to live.

[0008]

Furthermore, Patent Literature 5 (Japanese Patent

Laid-Open No. 2011-212012) discloses, as a method of control without using pesticide, a method for controlling pests of a plant seedling, wherein saturated steam flow adjusted to a predetermined temperature is generated in a treatment space surrounding the plant seedling so that the saturated steam flow flows horizontally above the plant seedling and the plant seedling is exposed to the saturated steam flow for a period of time in which it does not suffer from heat damage.

[0009]

Non-patent literature 1 discloses that if a plant such as strawberries is placed in a high temperature condition of 40 to 50°C for several ten seconds to several minutes, the plant acts in various ways and acquires resistance to diseases, becoming less likely to suffer from disease such as powdery mildew.

Citation List

Patent Literature [0010]

Patent Literature 1: Japanese Patent Laid-Open No. 731350

Patent Literature 2: Japanese Patent Laid-Open No. 7289057

Patent Literature 3: Japanese Patent Laid-Open No. 2016

152794

Patent Literature 4: Japanese Patent Laid-Open No. 2016

158522

Patent Literature 5: Japanese Patent Laid-Open No. 2011

212012

Non-patent Literature [0011]

Non-patent Literature 1: Tatsuo Sato, Control of Plant

Disease Using Heat Shock Treatment, Vegetable

Information, February, 2013.

Summary of Invention

Technical Problem [0012]

Tea is a peculiar perennial plant and its characteristic is that tea leaves are harvested several times a year. The time of plucking varies depending on the region. In Shizuoka Prefecture, for example, usually the first crop tea is plucked in mid-April to mid-May, then 45 to 50 days after the plucking of the first crop tea, while waiting next shoots to grow, the second crop tea is plucked, and then after waiting about 3 months until autumn, the autumn and winter crop tea is plucked.

Since control of such tea plant whose leaves are harvested several times a year needs to be performed a few times per time of plucking, pesticide which has been sprayed in the period of earlier tea may remain and the type of pesticides and their concentration in tea leaves may be increased in the later period of plucking the third crop, the fourth crop or the autumn and winter crop tea. Furthermore, increased frequency of use of pesticide may require cost higher than that for usual crops. Thus, a novel and effective method of controlling pests without using pesticide has been needed.

[0013]

Accordingly, an object of the present invention is to provide a novel method for controlling pests of tea more effectively using heated water without using pesticide .

Solution to Problem [0014]

The present invention proposes a method for controlling pests of tea, comprising carrying out a treatment to bring a mist of heated water into contact with tea leaves in such a manner that the temperature of the surface of the tea leaves is 45°C to 55°C.

Advantageous Effects of Invention [0015]

The method for controlling pests of tea proposed by the present invention can control pests of tea effectively by using heated water without using pesticides .

Description of Embodiments [0016]

The present invention will be hereinafter described with reference to embodiments. However, the present invention is not limited to the embodiments described below.

[0017] <Present control method>

The method for controlling pests of tea according to an embodiment of the present invention (referred to as the present control method) comprises carrying out a treatment to bring a mist of heated water (referred to as heated mist) into contact with tea leaves in such a manner that the temperature of the surface of the tea leaves is 45°C to 55°C.

[0018] (Subject tea)

The tea which is the subject of the present control method may be tea which is grown for the purpose of extracting tea leaves plucked or a processed product of tea leaves into liquid and drinking the liquid. The tea may be that grown for the purpose of eating tea leaves plucked.

Specific examples include tea grown as middle-grade tea, powdered tea, refined tea, oolong tea, black tea and other teas for beverage.

[0019] (Subject disease and pest)

Examples of diseases which are the subject of the present control method include anthrax, gray blight, brown blight, net blister blight and white rash.

Examples of pests causing damage include Empoasca onukii (hereinafter referred to as a plant hopper), Tetranychus kanzawai, Pseudaulacaspis pentagona, Scirtothrips dorsalis, Adoxophyes honmai and Caloptilia theivora. The disease and pest are not limited thereto.

[0020] (Heated mist)

Water for the heated mist may be water such as tap water or well water.

A chemical may be added if necessary.

[0021]

It is preferable that the temperature of the heated mist is adjusted to 45°C to 55°C. A heated mist of 45°C or more is effective for controlling disease and pest. A heated mist of 55°C or less is capable of preventing occurrence of heat damage.

From the above point of view, the temperature of the mist of water to be in contact with tea leaves is adjusted to preferably 45°C to 55°C, more preferably 47°C or more and 54°C or less, and particularly preferably

50°C or more and 53°C or less.

[0022]

For the method of forming a mist of water, water which has been heated may be formed into mist, or water which has been formed into mist may be heated. Specific examples thereof may include a method in which steam prepared by using a boiler is cooled or a method in which fine droplets of water are sprayed into hot air. The method is not limited thereto.

[0023] (Method of bringing heated water into contact with tea leaves and tea plant)

It is preferable that the heated mist is brought into contact with, out of at least tea plant and tea leaves, tea leaves at the surface portion of the leaf layer. It is also preferable that the heated mist is brought into contact with tea leaves at the portion of shoots to be plucked.

Bringing the mist into contact with tea leaves at the surface portion of the leaf layer enables control of conidia of disease and pests existing in the vicinity of shoots and affecting their growth and quality.

Furthermore, bringing the mist into contact with tea leaves at the portion of shoots to be plucked enables direct control of shoots.

It is particularly preferable that the mist is also brought into contact with the cut surface of stems and young leaves with pubescence. Furthermore, usually it is preferable that the mist is brought into contact with leaves called mother leaves, which have been hardened and are located below the plucking surface. It is also preferable that the mist is brought into contact with branches and stems.

Bringing the heated mist into contact with the cut surface of the stem enables effective control of gray blight. Bringing the heated mist into contact with young leaves with pubescence enables effective control of anthrax. Furthermore, bringing the heated mist into contact with mother leaves, branches and stems enables control of conidia and pests attached to them.

[0024]

It is preferable that the heated mist is brought into contact with tea leaves and tea plant and the temperature of the surface of tea leaves is adjusted to

45°C to 55°C.

When the temperature of the surface of tea leaves is

45°C or more, disease and pest are effectively controlled. When the temperature of the surface of tea leaves is 55°C or less, occurrence of heat damage can be prevented.

From the above point of view, the temperature of the surface of tea leaves when the heated mist is brought into contact with tea leaves and tea plant is adjusted to preferably 45°C to 55°C, more preferably 46°C or more and

53°C or less, and particularly preferably 50°C or more and 52°C or less.

Here, the temperature of the surface of tea leaves may be adjusted by the temperature of the heated mist and the time of contact.

[0025]

It is preferable that the time of contact of the heated mist with tea leaves (simply referred to as the contact time) is adjusted based on the temperature of this water.

It is preferable that as a guide, the temperature of water to be brought into contact with tea leaves and the contact time of water to be brought into contact with tea leaves are adjusted such that the product of the temperature of the heated mist (A) and the contact time (h) , A x h, is 45°C x 6 s to 55°C x 15 s.

For example, carrying out a treatment to bring the heated mist of 45°C into contacted with tea leaves for a contact time of 6 seconds or less can prevent heat damage while achieving an excellent effect of control.

Meanwhile, a contact time of 15 seconds or less is equivalent to the contact time in conventional methods of control.

From the above point of view, the product of the temperature of the heated mist (A) and the contact time (h) , A x h, is adjusted to preferably 45°C x 6 s to 55°C x 15 s, more preferably 46°C x 6 s or more and 53°C x 12 s or less, and particularly preferably 50°C x 3 s or more and 52°C x 10 s or less.

[0026]

Furthermore, by adjusting temperature A (°C) of water to be brought into contact with tea leaves and time h (seconds) of bringing the heated mist into contact with tea leaves such that {temperature A (°C) of heated mist 30°C}^A 2 x {time h (seconds) of bringing heated mist into contact with tea leaves] 4- 100 is 50 or less, more preferably 10 or more and 40 or less, and particularly preferably 12 or more and 30 or less, the effect of control can be achieved in shorter time.

[0027] (Timing of control treatment)

From the viewpoint of effective control of diseases such as anthrax and gray blight, the above treatment,

i.e., the treatment to bring mist of heated water into contact with tea leaves is carried out within preferably weeks, more preferably a week, and particularly preferably a day from the time when tea leaves are plucked or trimmed.

[0028]

The above plucking of tea leaves is not particularly limited as long as it is for harvesting tea leaves.

Plucking for harvesting the first crop tea or the second crop tea is particularly preferred.

Furthermore, the above trimming of tea leaves means work to prune the plucking surface after plucking tea leaves. Trimming after plucking of the first crop tea or the second crop tea is particularly preferred.

[0029]

It is particularly preferable that control is carried out after the plucking of the first crop tea and before the plucking of the second crop tea. However, control may also be performed before the plucking of the first crop tea or after the plucking of the second crop tea .

Control is performed preferably within 14 days from the day of the plucking of the first crop tea, more preferably within 7 days from the day of the plucking, and further preferably within 3 days from the day of the plucking.

Since plucking hurts tea plant, conidia of gray blight, for example, may be incorporated thereinto through the cut. Thus, it is preferable to carry out control immediately after plucking tea. This can also reduce conidia of anthrax and can reduce plant hoppers before sprouting.

[0030]

Furthermore, from the viewpoint of preventing occurrence of anthrax and plant hoppers, control is carried out preferably within 10 to 25 days, and particularly preferably within 15 to 20 days from the day of plucking of the first crop tea, when the second crop tea sprouts and the control is most effective.

[0031]

Meanwhile, from the viewpoint of preventing, e.g., gray blight, since portions cut by the blade of a plucker, which is a likely source of infection of gray blight, are infected, the above treatment, i.e., the treatment to bring a mist of heated water into contact with tea leaves is carried out within preferably 24 hours, more preferably 18 hours, and particularly preferably 12 hours from the time when tea leaves are plucked or trimmed.

[0032] <Method of producing tea>

Tea plant may be grown using the present control method and tea leave may be plucked at intervals in 2 to stages out of the stages of the first crop tea (March to May), the second crop tea (June to July), the third crop tea (July to August), and the autumn and winter crop tea (autumn).

In Kagoshima prefecture, for example, usually the first crop tea is plucked in mid-April to mid-May, then to 50 days after the plucking of the first crop tea, waiting next shoots to grow, the second crop tea is plucked, and then 40 to 45 days after the plucking of the second crop tea, the third crop tea is plucked, and 50 to days after the plucking of the third crop tea, the fourth crop tea is plucked.

[0033]

In crude tea factories, tea leaves plucked are steamed in steam to inactivate oxidase in raw tea leaves (parching) and then subjected to a series of processes including rough rolling, rolling, middle rolling, fine rolling and drying to be processed into crude tea, and then may be further processed according to the purpose of use .

[0034] <Explanation of terms>

As used herein, the expression X to Y (X, Y representing an arbitrary number) means not only X or more and Y or less, but also preferably more than X and preferably less than Y unless otherwise specified.

Furthermore, the expressions X or more (X representing an arbitrary number) and Y or less (Y representing an arbitrary number) include the meaning preferably more than X and preferably less than Y

Examples [0035]

Hereinafter the present invention will be described in more detail with reference to the following Examples and Comparative Examples.

[0036] <Test 1>

A mist of water (heated mist) of different temperatures was sprayed on tea plant at the stage of sprouting of the first crop tea, which is the most vulnerable to the external environment, and conditions in which no heat damage occurred were investigated.

[0037]

In a field in Shizuoka Prefecture, a heated mist of to 65°C was prepared and sprayed on tea plant and tea leaves of a tea variety Yabukita using a commercially available nozzle (20 heads) used for controlling tea for seconds to 10 seconds. The temperature of the surface of tea leaves (leaf temperature) was measured and the occurrence of heat damage was observed.

[0038]

In this case, the mist of water of 40 to 65°C was prepared by mixing vapor produced by using a commercially available boiler, SB-110 (made by Marubun Seisakusyo Co.,

Ltd.), and air in a mixer, measuring the temperature of the mixed gas of vapor and air discharged from the nozzle, and adjusting the amount of air incorporated into the mixer based on the temperature measured to obtain a mist of water, i.e., a heated mist, having the intended temperature .

For the leaf temperature of tea leaves, the temperature of the surface of mother leaves at the surface portion of the leaf layer was measured using an infrared thermometer (SK-8700II made by Sato Keiryoki

Mfg., Co ., Ltd.)

For the determination of the occurrence of heat damage, the heat damage was determined to be occurred when the leaves were found to fall before they grew, for example, falling as if they were melted or falling while turning dark red; the heat damage was determined to be occurred in some portions when some leaves were found to be in such a condition, and determined to be none when there were no such conditions.

[0039]

I

CD

CN

I [Table 1]

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[0040] <Results>

While no heat damage occurred when a heated mist of to 50°C was applied even for a long period of time (10 seconds), heat damage occurred in some portions when a heated mist of 55°C was applied for 10 seconds. When the temperature of the heated mist was more than 60°C, heat damage occurred in a shorter period of time.

The treatment time of control should be less than 6 seconds from the viewpoint of work efficiency. Since heat damage occurs when a heated mist of 60°C is brought into contact for 3 seconds, the substantial limit of the treatment time is considered to be 6 seconds for a heated mist of 55°C.

[0041] <Test 2>

The appropriate timing for performing the control treatment to bring a mist of heated water (heated mist) into contact with tea leaves was investigated.

[0042]

A control treatment was performed in a field in

Shizuoka Prefecture, in which a heated mist of 50°C prepared in the same manner as in Test 1 was sprayed on tea plant and tea leaves of a tea variety Yabukita for seconds in the same manner as in Test 1 to adjust the leaf temperature to 50°C, within 24 hours (May 7) after trimming for the purpose of leveling the plucking surface after plucking of the first crop tea (April 23), in the one-leaf stage (May 21) and the three-leaf stage (June

13), respectively.

Then, on the day of plucking of the second crop tea (June 26), the occurrence of anthrax, which is likely to develop in the second crop tea of yabukita, and the occurrence of gray blight and insect pest, which are highly sensitive to yabukita, were observed.

which no disease occurred were determined as and cases in which the disease occurred were as X (occurred), respectively.

[0043]

Cases in

O (none) determined

I o

CO

I [Table 2]

Test region 20	Conventional control
Test region 19	No treatment
Test region 18		o	o
Test region 17	o		o
Test region 16	o	o
Test region 15	o	o	o
Test region 14			o
Test region 13		o
Test region 12	o
	Immediately after trimming (May 7)	One-leaf stage (May 21)	Three-leaf stage (June 13)
Timing of treatment

o	o	o
X	X	X
O	O	O
O	O	O
O	O	O
o	o	o
o	o	o
o	o	o
o	o	o
Anthrax	Gray blight	Insect pest damage
Effect of control

[0044] <Results>

Effects of control equivalent to those in conventional control were achieved in test regions 12 to

18, and thus it has been found that control using steam is effective at any stage.

By contrast, in test region 19 in which no treatment was performed, damage due to plant hoppers was significant with 90% of shoots with four to five leaves and a bud, i.e., the second crop tea, damaged. The occurrence of anthrax and gray blight was therefore not directly observed, while the occurrence of anthrax and gray blight was observed at the end of a ridge in a neighboring field in which conventional control was insufficient. Considering that anthrax is spread by diffusion of conidia through rain drops and gray blight is spread by diffusion of conidia due to rain and attachment of conidia to a plucker, the treatment of control of bringing a heated mist into contact with tea leaves has been found to be effective.

[0045]

Next, steps to the onset of disease and stages in which control using steam is most effective will be considered.

Anthrax is a disease infected through pubescence on young shoots. The disease develops after an incubation period of 14 to 20 days (8 to 15 days at the shortest) after attachment to pubescence.

It has been found that methods for controlling such anthrax is most effective at the stage in which shoots with pubescence open (within 2 weeks after plucking or trimming of the first crop tea).

Meanwhile, gray blight is a disease infected mainly through the surface cut in plucking. Its conidia germinate 2 to 3 hours after attachment and the disease develops after an incubation period of 5 to 10 days. It has been said that in conventional control, control (spraying of agent) needs to be performed within a day after plucking, and the longer the interval, the less effective the control.

The control of gray blight may be most effectively performed within a day after plucking or trimming.

Since plant hoppers sucks the sap of only young shoots, it is most effective to perform control at the stage in which shoots open (within 2 weeks after plucking of the first crop tea).

[0046]

The treatment of control of bringing a heated mist into contact with tea leaves and tea plant has been found to be effective even at stages other than the above stages (e.g., test regions 13, 14) . This can be explained as follows.

Spraying of pesticide is roughly classified into spraying of a preventive agent and spraying of a therapeutic agent. The above treatments performed within a day after plucking or within 2 weeks after the plucking of the first crop tea are all intended for prevention. This is based on the idea that preventing development of disease leads to production of tea leaves with good quality. However, disease may develop even after performing control and thus therapeutic agents are used in conventional control. The time of use of pesticide is clearly defined, and usually a preventive agent should only be used until 30 days before plucking of the second crop tea and a therapeutic agent should only be used until 14 days before plucking of the second crop tea. Therefore, pesticide cannot be sprayed in a prescribed period before plucking, and thus disease has been spread. However, since no pesticide is used in the treatment of control of bringing a heated mist into contact with tea leaves and tea plant, the treatment can be carried out at a required time.

[0047] <Test 3>

The relation between the leaf temperature when a mist of heated water (heated mist) was brought into contact with tea leaves and the effect of control was examined.

[0048]

A control treatment was performed in a field in

Shizuoka Prefecture, in which a heated mist of a temperature shown in Table 3 prepared in the same manner as in Test 1 was sprayed on tea plant and tea leaves of a tea variety Yabukita in the same manner as in Test 1 for the treatment time shown in Table 3 to adjust the leaf temperature to the temperature shown in Table 3, within 24 hours after plucking of the third crop tea (August 1).

Then, on the day of plucking of the fourth crop tea (October 2), the occurrence of anthrax, gray blight and insect pest was observed. Cases in which no disease occurred were determined as O (good) and cases in which the disease occurred were determined as X (bad), respectively.

[0049]

I [>

cn

I [Table 3]

Test region 32	ίΤϊ ίΤϊ	o	IT) IT)
Test region 31	ίΤϊ ίΤϊ	80	ίΤϊ ίΤϊ
Test region 30	ίΤϊ ίη		Π ίη
Test region 29	π ίΤϊ	O	π ίΤϊ
Test region 28	π ίΤϊ	80	Π ίΤϊ
Test region 27	Π ίΤϊ		Ο ίΤϊ
Test region 26	Ο •η	O	Ο ίΤϊ
Test region 25	Ο •η	80	Ο ίΤϊ
Test region 24	Ο •η		80 ’'Φ
Test region 23	•η ’'φ	O	ίΤϊ ’'φ
Test region 22	’'φ	80	ίΤϊ ’'φ
Test region 21	’'φ		’'φ
	Temperature A of heated mist (°C)	Treatment time h (seconds)	Leaf temperature (°C)
Conditions

o	o	o
o	o	o
o	o	o
o	o	o
o	o	o
o	o	o
o	o	o
o	o	o
o	o	o
o	o	o
X	X	X
Anthrax	Gray blight	Insect pest damage
Effect of control

[0050] <Results>

Examples described above and the results of the tests which have been carried out according to the present invention show that pests of tea can be controlled by bringing a heated mist into contact with tea plant and tea leaves in such a manner that the temperature of the surface of the tea leaves is 45°C or more .

Furthermore, the occurrence of heat damage in test region 32 shows that when the temperature of steam is 50 to 55°C and [temperature A (°C) of heated mist - 30°C}^A 2 x [time h (seconds) of bringing heated mist into contact with tea leaves] 4- 100 is 50 or less, the effect of control can be achieved in a shorter treating time and heat damage does not occur.

[0051] <Test 4>

The relation among the leaf temperature when a mist of heated water (heated mist) was brought into contact with tea leaves, the frequency of treatment, and the effect of controlling pest was examined.

[0052]

A treatment was performed in a field in Shizuoka

Prefecture, in which a heated mist of a temperature shown in Table 5 prepared in the same manner as in Test 1 was sprayed on tea plant and tea leaves of a tea variety

Yabukita in the same manner as in Test 1 for the treatment time shown in Table 4 to adjust the leaf temperature to the temperature shown in Table 4, every 10 days after plucking of the second crop tea for a total of times (June 13 to October 13).

An insect pest trap (Bug-Scan manufactured by

Biobest, 10 cm x 13 cm) was installed at three places in the respective test regions on August 22 during the treatment period and collected on October 13. Then the number of pests attached to the trap was counted, and the effect of controlling pests in tea plant and tea leaves was investigated. The results are shown in Table 4.

For pests, a typical pest of tea leaves and tea plant, Empoasca onukii, was selected. The effect of controlling the pest was evaluated based on the average species population of Empoasca onukii attached to the insect pest trap installed at three places in the respective test regions.

[0053] [Table 4]

	Test region 33	Test region 34	Test region 35	Test region 36	Test region 37
Conditions	Temperature A of heated mist (°C)	45	50	55	55	Conventional control
Treatment time h (seconds)	6	10	3	6
Leaf temperature (°C)	45	50	52	55

Species population	Trap 1	49	50	48	47	359
Trap 2	44	39	33	34	100
Trap 3	51	44	44	41	281
Average species population	48	44	42	41	247

[0054] <Results>

The average species population of Empoasca onukii was smaller in all test regions 33 to 36 in which a heated mist was brought into contact with tea plant and tea leaves than that in the test region in which conventional control was performed. This shows that bringing a heated mist into contact with tea plant and tea leaves has an effect of controlling pests.

Claims (8)

1. Claims [Claim 1]

   A method for controlling pests of tea, comprising a treatment to bring a mist of heated water into contact with tea leaves and tea plant in such a manner that the temperature of the surface of the tea leaves is 45°C to

   55°C.
2. [Claim 2]

   The method for controlling pests of tea according to claim 1, wherein a mist of water adjusted to 45°C to 55°C is brought into contact with tea leaves.
3. [Claim 3]

   The method for controlling pests of tea according to claim 1 or 2, comprising adjusting the temperature (°C) of a mist of water to be brought into contact with tea leaves and the time (seconds) of bringing the mist of water into contact with the tea leaves such that {temperature (°C) of mist of water to be brought into contact with tea leaves - 30°C}^A 2 x {time (seconds) of bringing mist of water into contact with tea leaves} a100 is 50 or less.
4. [Claim 4]

   The method for controlling pests of tea according to any one of claims 1 to 3, wherein the treatment to bring a mist of heated water into contact with tea leaves is carried out within 2 weeks from the time when tea leaves are plucked or trimmed.
5. [Claim 5]

   The method for controlling pests of tea according to any one of claims 1 to 3, wherein the treatment to bring a mist of heated water into contact with tea leaves is carried out within 24 hours from the time when tea leaves are plucked or trimmed.
6. [Claim 6]

   The method for controlling pests of tea according to claim 4 or 5, wherein the plucking of tea leaves is for harvesting a first crop tea or a second crop tea.
7. [Claim 7]

   The method for controlling pests of tea according to claim 4 or 5, wherein the trimming is performed after plucking a first crop tea or after plucking a second crop tea .
8. [Claim 8]

   A method of producing tea, comprising using the method for controlling pests of tea according to any one of claims 1 to 7.