JP7605487B2 - Attractants for the azalea mealybug and parasitoid wasps of scale insects - Google Patents

Description

The present invention relates to an attractant for male azalea mealybugs and parasitic wasps of scale insects, and more specifically to a composition for attracting male azalea mealybugs, a composition for disrupting communication between male and female azalea mealybugs, a composition for attracting parasitic wasps of scale insects, a device for capturing male azalea mealybugs, a method for disrupting communication between male and female azalea mealybugs, and a method for attracting parasitic wasps of scale insects, as well as compounds suitable for the above.

The azalea mealybug (Crisicoccus azaleae) is known as a pest that attacks fruit trees such as pears and persimmons, and horticultural plants such as azaleas. Insecticides are used to control them, but the overuse of insecticides has a negative impact on beneficial insects such as honeybees, so efficient control using as little insecticide as possible is desirable. To do this, it is necessary to accurately grasp the amount and timing of occurrence of the pest.

Traps using attractants such as sex pheromones are used as a means of monitoring the occurrence of pests. Sex pheromones are chemical substances generally secreted by adult female insects, and they have a species-specific and strong attractant effect on adult male insects of the same species. Therefore, if the chemical structure of sex pheromones could be clarified and sex pheromone traps could be industrially synthesized and supplied, it would be possible to efficiently and easily investigate the occurrence of pests (Non-Patent Document 1). It is also known that sex pheromones can be used as mating disruptants (Non-Patent Document 2), and registration of pesticides is also underway. Sex pheromones often attract not only male pests, but also their natural enemies (Non-Patent Document 3). The attracted natural enemies prey on or parasitize pests in the vicinity, so the attractants for the natural enemies may be used as an alternative to insecticides for pest control (Non-Patent Documents 4 and 5).

Sex pheromones for many pest species have already been identified and are being used as materials, including traps, for pest management (e.g., Patent Documents 1 and 2). In addition, Non-Patent Document 6 describes a method for synthesizing various capsicumoids. However, none of the documents describes the sex pheromones or attractants of the azalea mealybug.

Patent No. 4734553 Patent No. 5857369

Nobuo Sawamura et al., Prediction of emergence of larvae of the Japanese persimmon mealybug (Hemiptera: Pseudococcidae) using sex pheromones and effective accumulated temperature, Journal of the Japanese Society of Applied Entomology and Zoology, Vol. 59, No. 4, 2015, p. 183-189. https://doi.org/10.1303/jjaez.2015.183 Mayumi Teshiba et al., Mating disruption effect of sex pheromone components on the Fuji mealybug Planococcus kraunhiae (Kuwana) (Hemiptera: Pseudococcidae), Journal of the Japanese Society of Applied Entomology and Zoology, Vol. 53, No. 4, 2009, p. 173-180. https://doi.org/10.1303/jjaez.2009.173 Franco JC, Silva EB, Cortegano E et al (2008) Kairomonal response of the parasitoid Anagyrus spec. nov. near pseudococci to the sex pheromone of the vine mealybug. Entomol Exp Appl 126:122-130. https://doi.org /10.1111/j.1570-7458.2007.00643.x Teshiba M, Tabata J (2017) Suppression of population growth of the Japanese mealybug, Planococcus kraunhiae (Hemiptera: Pseudococcidae), by using an attractant for indigenous parasitoids in persimmon orchards. Appl Entomol Zool 52:153-158. https://doi.org/10.1007/s13355-016-0452-1 Jun Tabata, et. al., Cyclolavandulyl butyrate: an attractant for a mealybug parasitoid, Anagyrus sawadai (Hymenoptera: Encyrtidae), Applied Entomology and Zoology, Vol. 46, No. 1, pp. 117-123, February 2011 Kaga H, Goto K, Takahashi T, Hino M, Tokuhashi T, Orito K. 1996. A general and stereoselective synthesis of the capsaicinoids via the orthoester Claisen rearrangement. Tetrahedron 52: 8451-8470

If the sex pheromone or attractant of the azalea mealybug were identified, it would be possible to efficiently monitor and control the azalea mealybug. Therefore, the present invention aims to provide a composition or compound that can attract the azalea mealybug.

（１）
（式中、Ｒ¹及びＲ²は、それぞれ独立して、炭素数１～３のアルキル基である）
で表される化合物を含む、アザレアコナカイガラムシのオスを誘引するための及び／又はアザレアコナカイガラムシのオス－メス間の交信を撹乱するための組成物。
〔２〕カイガラムシ類を誘引する他の有効成分及び／又はカイガラムシ類のオス－メス間の交信を撹乱する他の有効成分をさらに含む、前記〔１〕に記載の組成物。
〔３〕式（１）：

（１）
（式中、Ｒ¹及びＲ²は、それぞれ独立して、炭素数１～３のアルキル基である）
で表される化合物を含む、カイガラムシ類の寄生蜂を誘引するための組成物。
〔４〕前記寄生蜂が、トビコバチを含む、前記〔３〕に記載の組成物。
〔５〕前記寄生蜂を誘引する他の有効成分をさらに含む、前記〔３〕又は〔４〕に記載の組成物。
〔６〕Ｒ¹が、エチル基又はイソプロピル基であり、及び／又は、
Ｒ²が、メチル基又はエチル基である、前記〔１〕～〔５〕のいずれか１項に記載の組成物。
〔７〕前記化合物が、以下の化学式：

のいずれかで表される構造を有する、前記〔１〕～〔６〕のいずれか１項に記載の組成物。
〔８〕式（１）：

（１）
（式中、Ｒ¹及びＲ²は、それぞれ独立して、炭素数１～３のアルキル基である）
で表される化合物を含む、アザレアコナカイガラムシのオスの捕獲装置。
〔９〕式（１）：

（１）
（式中、Ｒ¹及びＲ²は、それぞれ独立して、炭素数１～３のアルキル基である）
で表される化合物を、アザレアコナカイガラムシの生息場所又は生息が疑われる場所に適用する工程を含む、アザレアコナカイガラムシのオス－メス間の交信を撹乱するための及び／又はカイガラムシ類の寄生蜂を誘引するための方法。
〔１０〕以下の化学式：

のいずれかで表される化合物。 As a result of intensive research aimed at solving the above problems, the present inventors have found that a compound having a specific structure has activity to attract male azalea mealybugs and parasitic wasps of mealybugs, and have completed the present invention. That is, the present invention provides the following composition, trapping device, method, and compound.
[1] Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A composition for attracting male azalea mealybugs and/or disrupting male-female mating of azalea mealybugs, comprising a compound represented by the formula:
[2] The composition described in [1] above, further comprising another active ingredient that attracts scale insects and/or another active ingredient that disrupts male-female mating of scale insects.
[3] Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A composition for attracting parasitic wasps of scale insects, comprising a compound represented by the formula:
[4] The composition described in [3] above, wherein the parasitic wasp includes an entocrine wasp.
[5] The composition described in [3] or [4] above, further comprising another active ingredient that attracts the parasitic wasp.
[6] R ¹ is an ethyl group or an isopropyl group, and/or
The composition according to any one of the above items [1] to [5], wherein R ² is a methyl group or an ethyl group.
[7] The compound has the following chemical formula:

The composition according to any one of items [1] to [6] above, having a structure represented by any one of the following:
[8] Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A trapping device for male azalea mealybugs containing a compound represented by the formula:
[9] Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A method for disrupting male-female mating of azalea mealybugs and/or for attracting parasitic wasps of scale insects, comprising a step of applying a compound represented by the formula:
[10] A compound having the following chemical formula:

A compound represented by any one of the following:

According to the present invention, by using the compound represented by the above formula (1), it is possible to attract male azalea mealybugs, disrupt communication between male and female azalea mealybugs, or attract parasitic wasps of scale insects. Therefore, it is possible to efficiently control azalea mealybugs.

（１）
（式中、Ｒ¹及びＲ²は、それぞれ独立して、炭素数１～３のアルキル基である）
で表される化合物を１種以上含んでいる。当該化合物は、害虫であるアザレアコナカイガラムシの未交尾のメスから放出される性フェロモン又はその類似体である。 The present invention will now be described in further detail.
The composition of the present invention comprises a compound represented by the formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
The compound is a sex pheromone released from unmated females of the pest insect, an azalea mealybug, or an analog thereof.

The compound represented by the formula (1) can be synthesized by any method commonly used in the art, and may be synthesized in accordance with the method for producing the compound described in Non-Patent Document 3 (particularly, compound 3B in Scheme 1). For example, the compound represented by the formula (1) may be synthesized by preparing an unsaturated fatty acid in which R ¹ is hydrogen in the formula (1) and subjecting it to a general dehydration condensation reaction or transesterification reaction with ethanol or isopropanol.

（Ｅ）－イソプロピル ７－メチルオクト－４－エノアート（化合物Ｂ）：

及び（Ｅ）－エチル ７－メチルノン－４－エノアート（化合物Ｃ）：

のいずれかであってもよい。ある態様では、本発明の組成物は、化合物Ａ～Ｃの２種又は３種を同時に含んでもよい。本発明の組成物が、化合物Ａ～Ｃのすべてを含むとき、その配合比は、特に制限されないが、例えば、質量比で約１０～約８：約５～約４：約１～約０．５であってもよい。 In one embodiment, R ¹ may be an ethyl group or an isopropyl group, and/or R ² may be a methyl group or an ethyl group. More specifically, the compound represented by formula (1) is (E)-isopropyl 7-methylnon-4-enoate (compound A):

(E)-Isopropyl 7-methyloct-4-enoate (Compound B):

and (E)-ethyl 7-methylnon-4-enoate (compound C):

In one embodiment, the composition of the present invention may simultaneously contain two or three of the compounds A to C. When the composition of the present invention contains all of the compounds A to C, the blending ratio thereof is not particularly limited, and may be, for example, a mass ratio of about 10 to about 8: about 5 to about 4: about 1 to about 0.5.

The compound represented by formula (1) functions as a sex pheromone released by female azalea mealybugs, so the composition of the present invention can be used to attract male azalea mealybugs. Therefore, the composition can be used to investigate the occurrence of azalea mealybugs or to attract and capture (or kill) them. In addition, if the sex pheromone released by female azalea mealybugs or an analogue thereof is artificially filled in their habitat or a place where they are suspected to be living, male azalea mealybugs will not be able to distinguish the female's true habitat and will not be able to reach the female. Therefore, the composition of the present invention can also be used to disrupt communication between male and female azalea mealybugs.

The compound represented by formula (1) also has the effect of attracting parasitic wasps, which are natural enemies of scale insects. That is, the composition of the present invention can also be used to attract the parasitic wasps. The parasitic wasp adults lay eggs inside the bodies of scale insects, and the larvae that hatch from the eggs grow by feeding on the bodies of the host scale insects. The parasitic wasp is not particularly limited, but examples thereof include cysts of the genus Anagyrus.

In one embodiment, the composition of the present invention further comprises an organic solvent. The organic solvent may be any organic solvent commonly used in the art, without particular limitation. For example, the organic solvent may be a hydrocarbon organic solvent such as pentane or hexane.

In one embodiment, the composition of the present invention is in the form of a solution or emulsion. The concentration of the compound in the composition of the present invention is not particularly limited as long as the desired action is achieved, but for example, when the purpose is to investigate the occurrence of azalea mealybugs or to attract and capture (or attract and kill) them, the concentration may be about 0.001 to about 100.0 mg/mL, preferably about 0.1 to about 10 mg/mL. When the purpose is to disrupt the communication between male and female azalea mealybugs, the concentration of the compound in the composition of the present invention may be, for example, about 0.1 to about 1000 mg/mL, preferably about 0.5 to about 500 mg/mL. When the purpose is to attract the parasitic wasps, the concentration of the compound in the composition of the present invention may be, for example, about 0.001 to about 100.0 mg/mL, preferably about 0.1 to about 50 mg/mL.

In one embodiment, the composition of the present invention is in a form impregnated in a sustained release carrier. The sustained release carrier may be any of those commonly used in the art, without particular limitation. For example, the sustained release carrier may be a container such as a cap (septum), a thin tube, a laminated bag, or a capsule, made of a material having a release amount control function, such as rubber, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, or polyvinyl chloride, and is preferably a septum or thin tube made of rubber or polyethylene.

The amount of the compound impregnated per the sustained release carrier is not particularly limited as long as the desired action is achieved, but for example, when the purpose is to investigate the occurrence of azalea mealybugs or to attract and capture (or attract and kill) them, it may be about 0.01 to about 1000 mg per about 1 cm ³ of the sustained release carrier, and preferably about 0.1 to about 1 mg. When disrupting the communication between male and female azalea mealybugs, the amount of the compound impregnated per the sustained release carrier may be, for example, about 1.0 to about 1000 mg, and preferably about 50 to about 500 mg. When attracting the parasitic wasps, the amount of the compound impregnated per the sustained release carrier may be, for example, about 0.01 to about 1000 mg, and preferably about 0.1 to about 5 mg.

The sustained release carrier can be used in combination with a trap for capturing pests (attached to the trap). The trap can be any trap commonly used in the art, without any particular limitations. For example, the trap may be a sticky trap, a water basin trap, or a suction trap, and is preferably a sticky trap. There is no particular limitation on the number of sustained release carriers attached to the trap, and it may be adjusted appropriately depending on the size and purpose of use of each, but for example, about 1 to about 10 sustained release carriers may be attached to the trap.

The composition of the present invention, particularly the composition impregnated in the sustained release carrier, may be installed outdoors. The installation density of the sustained release carrier outdoors is not particularly limited, but for example, when one sustained release carrier is attached to the trap for the purpose of investigating the occurrence of azalea mealybugs or attracting and capturing (or attracting and killing) them, the installation density may be about 1 to about 1000 per 10 ares, preferably about 10 to about 500 per 10 ares. The interval between the sustained release carriers is not particularly limited, but may be, for example, about 1 to about 100 m, preferably about 5 to about 15 m. When disrupting communication between male and female azalea mealybugs, the installation density of the sustained release carrier outdoors may be, for example, about 50 to about 500 per 10 ares, and the interval between the sustained release carriers may be, for example, about 0.5 to 100 m, preferably about 1.4 to about 10 m. When attracting the parasitic wasps, the installation density of the controlled release carriers outdoors may be, for example, about 1 to about 1000 per 10 ares, and the interval between the controlled release carriers may be, for example, about 1 to 100 m, and is preferably about 5 to about 15 m.

The installation position of the composition of the present invention, particularly the composition impregnated in the sustained release carrier, is not particularly limited, but may be, for example, at a height of about 10 to about 200 cm above the ground, and preferably at a height of about 30 to about 160 cm. In addition, the installation time of the composition is not particularly limited, but may be, for example, during the adult emergence period of azalea mealybugs.

In one embodiment, the composition of the present invention is in a form impregnated into agricultural or horticultural materials such as nets and ropes. When materials impregnated with the composition of the present invention are widely installed in a field, they are particularly useful for disrupting mating between male and female azalea mealybugs. The method of impregnating the materials is not particularly limited, but for example, the composition in a solution state may be impregnated by spraying or applying it to the materials. The amount of the compound sprayed or applied is not particularly limited as long as the desired effect is achieved, but for example, when disrupting mating between male and female azalea mealybugs, the amount of the compound impregnated in the material when installed in a field may be about 2.5 to about 250 g per 10 ares.

The composition of the present invention may further contain any excipients and/or additives that are commonly used in the art, as long as they do not impair the object of the present invention, and may further contain other active ingredients that attract scale insects, other active ingredients that disrupt male-female mating of scale insects, and/or other active ingredients that attract the parasitic wasps.

In another aspect, the present invention also relates to a trapping device for male azalea mealybugs, comprising a compound represented by formula (1). The trapping device can be used to investigate the occurrence of azalea mealybugs or to attract and capture (or attract and kill) them. In one aspect, the trapping device of the present invention may further comprise the sustained release carrier and/or the trap described above. The timing of installation of the trapping device of the present invention is not particularly limited, and may be, for example, during the adult emergence period of azalea mealybugs.

In another aspect, the present invention also relates to a method for disrupting male-female communication of azalea mealybugs, comprising the step of applying a compound represented by formula (1) to a place where the azalea mealybugs live or a place where they are suspected to live. The present invention also relates to a method for attracting parasitic wasps of scale insects, comprising the step of applying a compound represented by formula (1) to a place where the azalea mealybugs live or a place where they are suspected to live. The method of applying the compound is not particularly limited, and for example, the compound may be diluted in a solvent that can disperse the compound uniformly and sprayed on the desired place, or the compound may be impregnated into the sustained release carrier or the agricultural or horticultural material described above and placed on the desired place.

（Ｅ）－イソプロピル ７－メチルオクト－４－エノアート（化合物Ｂ）：

又は（Ｅ）－エチル ７－メチルノン－４－エノアート（化合物Ｃ）：

にも関している。化合物Ａ～Ｃは、上述した本発明の組成物、捕獲装置、及び方法に好適に使用できる新規化合物である。上述したように、化合物Ａ～Ｃは、当技術分野で通常使用される任意の方法により合成することができる。 In another aspect, the present invention provides (E)-isopropyl 7-methylnon-4-enoate (Compound A):

(E)-Isopropyl 7-methyloct-4-enoate (Compound B):

Or (E)-ethyl 7-methylnon-4-enoate (compound C):

The present invention also relates to the compound A to C. Compounds A to C are novel compounds suitable for use in the above-mentioned compositions, capture devices, and methods of the present invention. As described above, compounds A to C can be synthesized by any method commonly used in the art.

The present invention will be described in detail below with reference to examples, but the scope of the present invention is not limited to these examples.

1. Isolation of a substance that attracts males of Azalea mealybugs About 200 virgin adult females of Azalea mealybugs 7 to 30 days after emergence were allowed to parasitize butternut squash and sealed in a 1.0 liter glass container. Volatile compounds containing sex attractants released into the air were then sucked in with an air pump and collected with 1.5 g of adsorbent (Tenax TA, mesh size 20-35; manufactured by GL Sciences). This was repeated for 28 days, with 4 containers per day.

The amount of sex attractant released by a total of approximately 22,400 females per day was collected, and the crude extract was extracted with a total of approximately 240 mL of hexane. 0.1 female equivalent of this (1/10 of the amount of pheromone released by one female per day) was impregnated into a 1 cm2 filter paper and placed in a 9 cm diameter petri dish containing adult males, and the activity of attracting the males was observed.

Next, the crude extract was poured into a column chromatograph packed with silica gel (0.2 g) and fractionated and eluted using 2 mL of pentane containing 0, 5, 15, or 50% diethyl ether. The attractant activity of 0.1 female equivalents of each eluted fraction was examined in the same manner as the crude extract test, and the 5% diethyl ether fraction was found to have attractant activity.

The 5% diethyl ether fraction was further fractionated using a high-performance liquid chromatograph equipped with an Inertsil SIL 100A column (particle size 5 μm, inner diameter 4.6 mm, length 250 mm; manufactured by GL Sciences). Hexane containing 3% diethyl ether was run at a flow rate of 1 mL/min, and the attractant activity of 0.1 female equivalents of each eluted fraction was examined in the same manner as in the crude extract test. The fraction eluted between 8.5 and 10.0 minutes showed attractant activity.

The fraction eluted from 8.5 to 10.0 minutes was further fractionated using a gas chromatograph (Agilent) equipped with a DB-1 column (inner diameter 0.25 mm, length 30 m). Analysis was performed under conditions in which the temperature inside the column oven was raised from an initial temperature of 60°C (held for 1 minute) to 200°C at 10°C per minute, and three components were detected: a substance eluted at 10.8 minutes (compound A), a substance eluted at 9.4 minutes (compound B), and a substance eluted at 10.3 minutes (compound C). The ratio of compounds A, B, and C (peak area ratio in the gas chromatography results) was approximately 10:5:1.

2. Analysis of isolated compounds (1) Compound A
Compound A was analyzed by a mass spectrometer (Agilent). The molecular weight was measured to be 212.17518 by high-resolution mass spectrometry, and the molecular formula was estimated to _{be C13H24O2} . The EI mass spectrum [m/z (relative _intensity %)] is as follows.
41 (31.7), 43 (25.9), 55 (28.8), 57 (33.4), 67 (20.6), 68 (38.2), 69 (39.3), 70 (86.6), 71 (39.5), 81 (22.8), 83 (25.0), 84 (22.1), 95 (24.0), 96 (29.1), 97 (28.9), 109 (36.9), 113 (30.0), 114 (49.1), 123 (33.3), 135 (28.8), 141 (24.3), 152 (100), 153 (29.4), 212 (3.9)

Compound A was analyzed by a nuclear magnetic resonance spectrometer (NMR; manufactured by JEOL Ltd.) The measured values of ¹ H-NMR and ¹³ C-NMR are as follows.
δ _H : 5.40 (1H, ddd), 5.35 (1H, ddd), 5.03 (1H, q), 2.30 (2H, m), 2.20 (2H, t), 1.95 (1H, m), 1.77 (1H, m), 1.30 (1H, m), 1.29 (1H, m), 1.07 (1H, m), 1.04 (6H, d), 0.84 (3H, t), 0.83 (3H, d)
δ _C : 171.9, 130.3, 129.9, 67.2, 40.0, 35.0, 29.3, 28.4, 21.8, 19.1, 11.6

These analytical results showed that Compound A had the following chemical structure:

(2) Compound B
Compound B was analyzed by a mass spectrometer (Agilent). The molecular weight was measured to be 198.15836 by high-resolution mass spectrometry, and the molecular formula was estimated to _{be C12H22O2} . The EI mass spectrum [m/z (relative _intensity %)] is as follows.
41 (26.4), 43 (42.1), 55 (30.9), 56 (27.8), 67 (21.2), 68 (27.2), 69 (42.3), 71 (37.8), 81 (21.6), 95 (48.1), 96 (35.7), 97 (20.1), 101 (32.1), 110 (37.9), 113 (28.1), 114 (20.1), 138 (100), 139 (45.2), 198 (1.8)

Compound B was analyzed by NMR. The measured values of 1H-NMR and 13C-NMR are as follows.
δ _H : 5.38 (1H, dt), 5.35 (1H, dt), 5.03 (1H, sep), 2.30 (2H, dt), 2.20 (2H, t), 1.81 (2H, dd), 1.49 (1H, m), 1.04 (6H, d), 0.84 (6H, d)
δ _C : 171.8, 130.2, 129.6, 66.9, 42.0, 34.5, 28.4, 28.2, 22.1, 21.6

These analytical results showed that Compound B had the following chemical structure:

(3) Compound C
Compound C was analyzed by a mass spectrometer (Agilent). The EI mass spectrum [m/z (relative intensity %)] is as follows.
41 (30.9), 55 (31.9), 57 (29.7), 67 (29.2), 68 (41.7), 69 (38.2), 70 (38.3), 71 (33.2), 81 (27.8), 84 (44.7), 95 (28.2), 96 (29.5), 97 (25.8), 101 (21.6), 110 (24.8), 123 (33.5), 152 (100), 198 (5.3)

Compound C was analyzed by NMR. The measured values of ¹ H-NMR and ¹³ C-NMR were as follows:
δ _H : 5.39 (1H, ddd), 5.35 (1H, ddd), 3.96 (2H, q), 2.29 (2H, m), 2.20 (2H, t), 2.20 (2H, t), 1.95 (1H, m), 1.77 (1H, m), 1.30 (1H, δ _C : 172.4, 130.3, 129.8, 60.0, 39.9, 35.0, 34.5, 29.3, 28.3, 19.1, 14.3, 11.6.

These analytical results showed that compound C had the following chemical structure:

3. Synthesis Example Compound B was synthesized via the compound described in Non-Patent Document 3 (Compound 3B in Scheme 1). Specifically, 3 mL of a THF solution containing 3-methylbutanal (860 mg) was added to 11 mL of a THF solution (about 1.0 M) of vinylmagnesium bromide over 15 minutes under ice cooling, and the mixture was returned to room temperature and stirred for 16 hours. The reaction was stopped by adding 10 mL of saturated ammonium chloride water, and 3 mL of a 10% aqueous sulfuric acid solution was added, followed by extraction with diethyl ether (10 mL x 3 times). The organic layer was washed with saturated saline, dried over magnesium sulfate, and passed through a silica gel column to obtain 5-methyl-1-hexen-3-ol in a yield of 79%. This allyl alcohol (627 mg) was dissolved in orthotriethylacetate (6.29 g), and propionic acid (25 mg) was added as a catalyst, followed by heating to 138° C. under argon. After 3 hours, 10 mL of water was added, and the mixture was extracted with hexane (10 mL x 3 times). This was dried over magnesium sulfate, concentrated, and passed through a silica gel column to obtain a compound (compound 3B in scheme 1 of non-patent document 3) in which R ¹ is ethyl and R ² is methyl in formula (1) described herein in 83% yield. 110 mg of this compound was dissolved in a mixed solution of 9 mL of isopropanol and 1 mL of concentrated hydrochloric acid, stirred at 52° C. for 16 hours, added with 10 mL of water, and extracted with hexane (10 mL x 3 times). This was washed successively with 10 mL of saturated aqueous sodium bicarbonate solution and 10 mL of saturated saline, dried over magnesium sulfate, concentrated, and passed through a silica gel column to obtain compound B in 85% yield. Compounds A and C were synthesized in the same manner as compound B, except that 3-methylpentanal was used instead of 3-methylbutanal.

4. Attraction test of male adult azalea mealybugs A 0.1 mL hexane solution containing 0.1 mg of either compound A, compound B, or compound C was prepared, and this was impregnated into a rubber septum. Then, one rubber septum was attached to a commercially available small adhesive board (10 cm x 20 cm) as an attraction source to prepare a trapping device. In addition, taking into account the natural abundance ratio, a trapping device was similarly prepared using a mixture of compound A (0.1 mg), compound B (0.05 mg), and compound C (0.01 mg). Two of these trapping devices were placed outdoors and left for one week, and the number of male adult azalea mealybugs captured was counted. The results are shown in Table 1.

All of compounds A to C were able to attract adult male azalea mealybugs. Furthermore, when compounds A to C were mixed, a greater number of adult male azalea mealybugs were attracted. Compounds that act as sex pheromones like these are expected to be useful for disrupting male-female communication.

5. Attractive test of parasitic wasps A 0.1 mL hexane solution containing a mixture of compound A (0.1 mg), compound B (0.05 mg), and compound C (0.01 mg) was prepared and impregnated into a rubber septum. Then, one rubber septum was attached to a commercially available small adhesive board (10 cm x 20 cm) as an attractant to prepare a trapping device. For comparison, a trapping device was similarly prepared using 0.1 mg of cyclolavanduryl butyrate (CLB), a known entocrine wasp attractant (Non-Patent Document 5). Each of these trapping devices was placed outdoors and left for 4 weeks, and the captured insects were observed. As a result, not only CLB but also compounds A to C were used to capture entocrine wasps of the genus Anagyrus. The number of captured entocrine wasps was counted and is shown in Table 2.

Compounds A to C were able to attract parasitic wasps in the same way as CLB. Compounds A to C are easier to synthesize than CLB, so they are considered preferable in practical terms.

From the above, it was found that the compound represented by the above formula (1) has the effect of attracting male azalea mealybugs. Therefore, the compound represented by the above formula (1) can be used to capture male azalea mealybugs or to disrupt communication between male and female azalea mealybugs. It was also found that the compound represented by the above formula (1) has the effect of attracting parasitic wasps of scale insects. Therefore, by using the compound represented by the above formula (1), it is possible to efficiently control azalea mealybugs.

Claims (10)

Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A composition for attracting male azalea mealybugs and/or disrupting male-female mating of azalea mealybugs, comprising a compound represented by the formula: The composition according to claim 1, further comprising another active ingredient that attracts scale insects and/or another active ingredient that disrupts male-female mating of scale insects. Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A composition for attracting parasitic wasps of scale insects, comprising a compound represented by the formula: The composition of claim 3, wherein the parasitic wasp comprises an entchyster. The composition according to claim 3 or 4, further comprising another active ingredient that attracts the parasitic wasps. R ¹ is an ethyl group or an isopropyl group, and/or
The composition according to any one of claims 1 to 5, wherein ^R2 is a methyl group or an ethyl group. The compound has the following chemical formula:

The composition according to any one of claims 1 to 6, having a structure represented by any one of the following: Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A trapping device for male azalea mealybugs containing a compound represented by the formula: Formula (1):

(1)
(In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms.)
A method for disrupting male-female mating of azalea mealybugs and/or for attracting parasitic wasps of scale insects, comprising a step of applying a compound represented by the formula: The chemical formula:

A compound represented by any one of the following: