JP7630155B2 - Methods for controlling long-horned beetles - Google Patents

Description

The present invention relates to a novel method for controlling female long-horned beetles such as the spotted long-horned beetle.

The spotted longhorn beetle is known as a difficult-to-control pest of fruit trees, causing severe damage in citrus orchards that are poorly maintained due to the aging of producers. At present, it cannot be said that a method for controlling the spotted longhorn beetle has been established. For over 20 years, the inventors have been conducting research to find an effective method of control by elucidating the chemical communication of this pest. Last year, they succeeded in identifying the contact pheromones of adult females (Non-Patent Document 1), and further found that female extracts containing these contact pheromones have high settlement activity against males.

At present, the entomopathogenic fungus agent " ^BiolisaTM Longhorn Beetle Slim" is sold by Idemitsu Agri Co., Ltd. as a registered microbial pesticide for use against the Asian longhorn beetle.

Longhorn beetles of the Anoplophora genus, including the Spotted Longhorn Beetle, are known worldwide as invasive alien species. They have invaded North America and Europe from their native China via potted plants and other sources, causing problems. Due to taxonomic confusion, the Japanese Spotted Longhorn Beetle is considered to be the same species as A. chinensis, which is distributed in China, and this has caused inconveniences such as restrictions on the export of bonsai and other products to this day. Since there is no established method of controlling Spotted Longhorn Beetles worldwide, infested trees are identified and surrounding trees are thoroughly cut down. Therefore, there is a high demand for a method of controlling Spotted Longhorn Beetles, including this species.

Nao Tsujii, Takue Yasui, Tetsuya Yasuda, Sadao Wakamura, Junji Akino, Midori Fukaya, Toshio Suzuki, Takashi Hoshi, Hisahiro Hagiwara, and Yuji Ono, "Male long-horned beetles of the spotted long-horned beetle show mating behavior to a synthetic mixture that reproduces the sex pheromone composition of the female body surface," National Agriculture Research Center Research Results Information, National Agriculture and Food Research Organization, 2019, <http://www.naro.affrc.go.jp/project/results/4th_laboratory/carc/2019/carc19_s20.html>

There has been no technology to keep Asian longhorn beetles in a fixed place for a long time. The insect pathogenic fungus agent "BiolisaTM ^Kamikiri Slim" is a nonwoven fabric about 2cm wide and 50cm long with fungal conidia attached. When Asian longhorn beetles walk on the fabric, the conidia attach to their body surface, and they die one to two weeks after infection. It is wrapped around the branching part of the main trunk close to the ground, based on the observation that females often walk around this area when they are laying eggs near the ground.

^BiorisaTM Longhorn Beetle Slim only becomes effective when the Asian longhorn beetle "walks" on the product. The current design, which is based on this accidental event, has been effective to a certain extent and has been registered as a pesticide, but there was a problem in that it lacked certainty.

In light of this background, the present invention aims to provide a new means of controlling pest insects of the family Cerambycidae, such as the Asian longhorn beetle.

As a result of extensive research into solving the above problems, the inventors have found that by installing an apparatus comprising a member to which the contact pheromone of adult female Asian longhorn beetles is attached and a member to which entomopathogenic bacteria is attached in a location to be controlled, a large amount of entomopathogenic bacteria can be attached to the body surface of male Asian longhorn beetles. The inventors have also found that the entomopathogenic bacteria attached to the body surface of male Asian longhorn beetles is transmitted to females through the male's mating behavior with females, making it possible to control not only male Asian longhorn beetles but also females. The present invention was completed based on these findings.

That is, the present invention provides the following (1) to (5).
(1) A method for controlling female longhorn beetle insects, the method comprising the step of installing an apparatus comprising a member having a contact sex pheromone of an adult female longhorn beetle attached thereto and a member having an insect pathogen attached thereto, in a location to be controlled.

(2) The method according to (1), characterized in that the insect of the family Cerambycidae is an insect of the subfamily Myrmecoidea.

(3) The method according to (1), characterized in that the insect of the family Cerambycidae is a long-horned beetle.

(4) The method according to any one of (1) to (3), wherein the entomopathogenic fungus is an entomopathogenic filamentous fungus.

(5) The method according to any one of (1) to (3), characterized in that the entomopathogenic fungus is Beauveria brongiatii.

The present invention provides a novel method for controlling female longhorn beetles. The control method of the present invention can control not only male longhorn beetles, such as the Asian longhorn beetle, but also female longhorn beetles that are pests.

A diagram showing the time it took for a male to hold a black glass ball (female model). FIG. 3A shows the reaction of males in the untreated group in Example 2, FIG. 3B shows the reaction of males in the female extract treatment group, and FIG. 3C shows the males holding a black glass marble. A diagram showing the number of conidia attached to the Spotted Longhorn Beetle. Male A: The number of conidia attached to a male that was kept together with Biolisa ^™ Longhorn Beetle Slim + untreated black glass beads for one hour, Male B: The number of conidia attached to a male that was kept together with Biolisa ^™ Longhorn Beetle Slim + black glass beads treated with female extract for one hour, Female B: The number of conidia attached to a female that was placed in the same case as Male B for one hour. A graph showing the mortality rate of Asian longhorn beetles one week after walking on Biorisa ^TM Longhorn Beetle Slim. FIG. 2 shows an experimental scheme of Example 2. A photo of a male holding a glass ball treated with a female extract that was placed on ^BiorisaTM Longhorn Beetle Slim for one hour. The whitish parts at the tips of the legs and on the ventral side of the abdomen are conidia.

The present invention will be described in detail below.
The present invention relates to a method for controlling female longhorn beetle insects, the method being characterized by a step of installing an apparatus comprising a member to which the contact pheromone of an adult female longhorn beetle insect is attached and a member to which an entomopathogenic fungus is attached, at a location to be controlled.

The insects to be controlled are not particularly limited as long as they belong to the family Cerambycidae, but are preferably insects belonging to the subfamily Cerambycidae, more preferably insects belonging to the genus Anoplophora, and even more preferably the spotted longhorn beetle (Anoplophora malasiaca). A specific example of an insect belonging to the family Cerambycidae other than the spotted longhorn beetle is the red-necked longhorn beetle (Aromia bungii).

The contact pheromone of the female adult can be the sex pheromone of the longhorn beetle to be controlled. For example, when the longhorn beetle is the target of control, the contact pheromone of the female longhorn beetle can be used. Compounds having the contact pheromone action of the longhorn beetle have been identified, and for example, the hydrocarbon group described in JP-A-11-80039, the ketone group described in JP-A-4023721, and the compound group having a 3-oxabicyclo[3.3.0]octane skeleton described in JP-A-4621904 and JP-A-2017-95381 are known to have such an action. Specific examples of the compound group having a 3-oxabicyclo[3.3.0]octane skeleton can include compounds represented by the following formula.

As a contact pheromone for adult females, one or a mixture of two or more of the above-mentioned compounds can be used. However, it is not necessary to use a purified compound with pheromone activity; for example, an extract of a female insect belonging to the family Cerambycidae can be used.

The member to which the contact pheromone of a female adult is attached (hereinafter sometimes referred to as the "pheromone member") is preferably similar in color, shape, and size to a female individual of the Longicornidae family, so that a male individual will mistakenly recognize it as a female individual and will likely engage in mating attempt behavior. Specifically, the color of the pheromone member is preferably a dark color such as black. The shape of the pheromone member is preferably cylindrical, prismatic, spherical, elliptical, or capsule-like. The size of the pheromone member varies depending on the insect of the family Cerambycidae that is the target of control, but when the target of control is the Asian longhorn beetle, if it is cylindrical, it is preferably 20 mm to 40 mm in length and 5 mm to 15 mm in diameter, if it is prismatic, it is preferably 20 mm to 40 mm in length, 5 mm to 15 mm in width, and 5 mm to 15 mm in height, if it is spherical, it is preferably 5 mm to 15 mm in diameter, and if it is oval or capsule-shaped, it is preferably 20 mm to 40 mm in length and 5 mm to 15 mm in maximum diameter. There are no particular limitations on the material of the pheromone member, and it can be, for example, glass, metal, plastic, gelatin, etc.

There are no particular limitations on the means for attaching the contact pheromone to the component, and the contact pheromone may be applied to or impregnated into the component so that it can be detected by the male. Alternatively, a sheet coated with the contact pheromone may be attached to the component.

The insect pathogenic fungus used is preferably an insect pathogenic filamentous fungus, more preferably a filamentous fungus belonging to the genus Beauveria or Metarhizium, further preferably Beauveria brongniartii or Beauveria bassiana, and particularly preferably Beauveria brongniartii. Note that Biolisa ^TM Longhorn Beetle Slim used in the examples contains Beauveria brongniartii as an active ingredient.

The member to which the entomopathogens are attached (hereinafter sometimes referred to as the "entomopathogen member") is preferably in a sheet-like shape. By making it in a sheet-like shape, the pheromone member can be easily placed on it, and when a male individual performs a mating attempt behavior (behavior of embracing the pheromone member), the male individual's legs come into contact with the entomopathogen member, and the entomopathogens can be attached to the legs.

The material of the insect pathogen component is not particularly limited and can be nonwoven fabric, woven fabric, paper, etc.

There are no particular limitations on the means for attaching the insect pathogen to the component, and the component may be coated or impregnated with a suspension of the insect pathogen.

In a device equipped with a pheromone member and an insect pathogen member, the pheromone member is placed near the center of the insect pathogen member (which is usually in the form of a sheet, as described above). With this structure, when a male individual performs a mating attempt, the male individual's legs come into contact with the insect pathogen member, and a large amount of insect pathogens can be attached, especially to the legs.

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

Example 1: Evaluation of male fixation to female extract Behavioral experiments were conducted between 9:00 and 17:00 (8 hours) at a room temperature of 25°C. For the experiment, eggs were collected from Spotted Longhorn Beetles collected in the field, and then grown to adulthood in the laboratory. Capsule-shaped black glass beads (12 mm in diameter, 35 mm in length) were used as female models. The black glass beads were attached to circular filter paper (15 cm in diameter) with double-sided tape, and treated with an amount of female extract equivalent to one female.

Males were placed in plastic cups with either a black glass marble coated with the female extract or an untreated black glass marble. The males' behavior was photographed every 10 minutes with a camera placed directly above, and the photos were checked to calculate the time they spent holding the black glass marble (mating attempt behavior). The time each male held the marble the longest was recorded. The results are shown in Figure 1. Figures 2A and B show the experiment in progress, and Figure 2C shows the male holding the black glass marble.

The males continued to hold the black glass marble treated with the female extract for an average of about 5 hours (out of the total experimental time of 8 hours) (Figure 1). A statistically significant difference was confirmed compared to untreated black glass marbles. In the untreated group, the males wandered around the case without holding the marble (Figure 2A), whereas in the female extract-treated group, the males continued to hold the marble while changing positions (Figure 2B).

Example 2: Evaluation of the number of conidia attached to pathogenic fungi when a black glass ball and Biorisa ^™ Longhorn Beetle Slim were combined (1) Biorisa ^™ Longhorn Beetle Slim (Idemitsu Agri Co., Ltd.) was cut into a size of 2.5 x 5.0 cm, and a black glass ball that was untreated or treated with female extract was placed in the center. Biorisa ^™ Longhorn Beetle Slim and a black glass ball were placed in the center of a plastic case (30 x 22 cm, height 6 cm), and a male was introduced nearby and allowed to freely interact with them for 1 hour. After collection, the number of conidia attached to each male individual in the untreated and female extract-treated areas was counted. The results are shown in Figure 3.

While almost no conidia were attached to the untreated males (Fig. 3 Male A), a large amount of conidia was attached to the males treated with the female extract (Fig. 3 Male B).

(2) Males equivalent to Male B that had been allowed to move freely for 1 hour in the female extract treatment area were prepared and were then introduced to females. All males exhibited mating behavior toward the females. After the males and females were allowed to meet, they were left in a plastic case for 1 hour. After 1 hour, the females were collected and the number of conidia attached to their body surface was counted. The results are shown in Figure 3.

Many conidia were attached even to female individuals that were not directly in contact with Biorisa ^TM Longhorn Beetle Slim (Figure 3, Female B).

Example 3: Evaluation of mortality rate versus walking time on Biorisa ^™ Long-horned Beetle Slim Biorisa ^™ Long-horned Beetle Slim (3 x 22 cm) was placed in the center of a plastic case (30 x 22 x 6 cm), and adult beetles were introduced onto Biorisa ^™ Long-horned Beetle Slim, and allowed to walk for 3 seconds (passing through) or 60 seconds. They were then individually fed and maintained, and the survival and death rates were recorded after one week. The results are shown in Figure 4.

The mortality rate was about 50% when the walking time was 3 seconds, whereas it was close to 100% when the walking time was 60 seconds (Figure 4).

Since this invention relates to pest control, it can be used in industries such as the pesticide industry.

Claims (5)

A method for controlling female Longhorn beetle insects, comprising an apparatus comprising a member having a contact pheromone of an adult female Longhorn beetle attached thereto and a member having an insect pathogen attached thereto, the method comprising the steps of: 1) installing the apparatus in a sheet-like shape; and 2) positioning the member having the contact pheromone attached thereto in such a manner that when a male Longhorn beetle insect performs a mating attempt behavior toward the member having the contact pheromone attached thereto, the feet of the male will come into contact with the member having the insect pathogen attached thereto . The method according to claim 1, characterized in that the insect of the family Cerambycidae is an insect of the subfamily Myrmecoidea. The method according to claim 1, characterized in that the insect of the family Cerambycidae is a long-horned beetle. The method according to any one of claims 1 to 3, characterized in that the entomopathogenic fungus is an entomopathogenic filamentous fungus. The method according to any one of claims 1 to 3, characterized in that the entomopathogenic fungus is Beauveria brongniartii.