Controlling insect behavior via taste

Abstract

To provide a means for solving the problem that omnivorous insects for biological pesticides damage crops themselves.SOLUTION: Provided is an omnivorous insect with suppressed herbivory characterized by the deletion or suppression of the expression of taste genes related to herbivory behavior.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an omnivorous insect whose herbivorous behavior is suppressed. Such an omnivorous insect is useful as a natural enemy insect for biological pesticides because its herbivorous damage to crops is suppressed. [Background technology]

[0002] Excessive reliance on pesticide use is the cause of problems such as the development of drug resistance in pests and health damage caused by residual pesticides. There is also a considerable social need for organic agricultural products that do not use chemical pesticides or chemical fertilizers. As one method of achieving pesticide-free cultivation, crop production is carried out using biological pesticides such as natural enemy insects, and this has created a market worth several billion yen in Japan. Natural enemy preparations are suitable for organic and reduced-pesticide cultivation as there is no limit to the number of times they can be used, and their introduction also has the advantage of reducing the labor required for spraying pesticides.

[0003] The tobacco beetle, which is considered promising as a natural enemy formulation against tobacco whiteflies and thrips in tomato cultivation, was approved as a biological pesticide in 2021 and launched by Agrisect Co., Ltd. as "Bakotop." As this species is an omnivorous beetle, it can easily multiply on natural enemy-preserving plants such as sesame, allowing it to ambush in fields before pests emerge. However, if the population density increases too much, it can cause damage to the crops themselves. This characteristic is said to be one of the reasons why it took so long to register it as a biological pesticide.

[0004] As a means of solving the problem of damage to crops caused by this increase in population density, methods have been proposed such as using pesticides to exterminate the tobacco whitefly and capturing the whitefly using a light source that takes advantage of the fact that the tobacco whitefly is specifically attracted to purple light (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 022333 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, several means have been proposed to solve the problem of damage to crops caused by omnivorous insects such as the tobacco whitefly, but density control by using pesticides loses the original benefits of introducing natural enemies, such as compatibility with organic and pesticide-reduced cultivation and reducing the labor required for pesticide spraying, and there is a problem that collection using purple light requires a dedicated collection device. The object of the present invention is to provide a means to solve the above problems of omnivorous insects used as biological pesticides. [Means for solving the problem]

[0007] As a result of extensive research to solve the above-mentioned problems, the inventors discovered that the tobacco whitefly has a taste gene related to its herbivorous behavior, and that by suppressing the expression of this gene, the herbivorous behavior of the tobacco whitefly, i.e., the damage it causes to crops, can be suppressed. Based on this finding, the inventors have completed the present invention.

[0008] That is, the present invention provides the following (1) to (15). (1) An omnivorous insect in which herbivorous behavior is suppressed, characterized in that a taste gene related to herbivorous behavior is deleted or the expression thereof is suppressed.

[0009] (2) The omnivorous insect according to (1), characterized in that the omnivorous insect is an insect of the Miridae family or Anthocoridae family.

[0010] (3) The omnivorous insect according to (1), characterized in that the omnivorous insect is a tobacco grasshopper.

[0011] (4) An omnivorous insect described in any of (1) to (3), characterized in that the taste gene related to herbivorous behavior is (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28, (b) a gene including, as a part thereof, a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 4, 8, 10, 12, 14, 16, 20, 22, 24, or 26, or (c) a homologue of the above genes.

[0012] (5) A biological pesticide comprising the omnivorous insect according to any one of (1) to (4).

[0013] (6) A method for producing an omnivorous insect in which herbivorous behavior is suppressed, the method comprising a step of deleting or suppressing expression of a taste gene related to herbivorous behavior in the omnivorous insect.

[0014] (7) The method for producing an omnivorous insect according to (6), wherein the omnivorous insect is an insect of the Miridae family or Anthocoridae family.

[0015] (8) The method for producing an omnivorous insect according to (6), wherein the omnivorous insect is a tobacco grass borer.

[0016] (9) A method for producing an omnivorous insect described in any one of (6) to (8), characterized in that the taste gene related to herbivorous behavior is (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28, (b) a gene including in part a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 4, 8, 10, 12, 14, 16, 20, 22, 24, or 26, or (c) a homologue of the above genes.

[0017] (10) An agent for suppressing herbivorous behavior of omnivorous insects, comprising a double-stranded RNA of a taste gene involved in herbivorous behavior.

[0018] (11) The herbivorous behavior inhibitor according to (10), wherein the omnivorous insect is an insect of the Miridae family or Anthocoridae family.

[0019] (12) The herbivorous behavior inhibitor according to (10), wherein the omnivorous insect is a tobacco grass borer.

[0020] (13) An agent for inhibiting herbivorous behavior according to any one of (10) to (12), characterized in that the taste gene related to herbivorous behavior is (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28, (b) a gene including in part a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 4, 8, 10, 12, 14, 16, 20, 22, 24, or 26, or (c) a homologue of the above genes.

[0021] (14) A pest control agent comprising a double-stranded RNA of a taste gene involved in herbivorous behavior.

[0022] (15) The pest control agent according to (14), characterized in that the taste gene related to herbivorous behavior is (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28, (b) a gene including, as a part thereof, a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 4, 8, 10, 12, 14, 16, 20, 22, 24, or 26, or (c) a homologue of the above-mentioned gene. Effect of the Invention

[0023] The present invention provides a novel omnivorous insect whose herbivorous behavior is suppressed. Such an omnivorous insect is useful as a natural enemy insect for biological pesticides because its herbivorous damage to crops is suppressed. [Brief description of the drawings]

[0024] [Figure 1] Heat map of taste genes. The horizontal axis indicates the ID of the homologous gene, and the vertical axis indicates the various species of the mist lizard. The closer to black the color, the higher the expression. [Diagram 2]Box plot of the number of sucking marks on tomato agar. The top of the whiskers indicates the maximum value, the top of the box indicates the third quartile, the thick line in the middle indicates the median, the bottom of the box indicates the first quartile, and the bottom of the whiskers indicates the minimum value. The dotted line indicates the median value in the control area, which is an indication of the suppression of herbivory behavior by each gene. [Diagram 3] Box plot of the number of eggs predated by the striped meal moth. The top of the whiskers indicates the maximum value, the top of the box indicates the third quartile, the thick line in the middle indicates the median, the bottom of the box indicates the first quartile, and the bottom of the whiskers indicates the minimum value. The dotted line indicates the median value in the control group, which is an indication of the suppression of carnivorous behavior by each gene. [Figure 4] Relative expression level of the 12765 gene when EGFP and dsRNA of ID: 12765 were injected. It was confirmed that the relative expression level was suppressed to 50% or less when dsRNA of the 12765 gene was injected. [Diagram 5] Evaluation of the effect on the plant of individuals with the herbivory gene knockout. In the control area, the petiole discolored and became ring-shaped, whereas in the RNAi area, there was only a slight discoloration (arrow). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present invention will be described in detail below. (1) Omnivorous insects and methods for producing omnivorous insects The omnivorous insect of the present invention is an omnivorous insect in which herbivorous behavior is suppressed, characterized in that a gustatory gene related to herbivorous behavior is deleted or the expression of which is suppressed. The method for producing an omnivorous insect of the present invention is a method for producing an omnivorous insect in which herbivorous behavior is suppressed, characterized in that it includes a step of deleting or suppressing the expression of a gustatory gene related to herbivorous behavior in the omnivorous insect.

[0026] In the present invention, the term "omnivorous insect" refers to an insect that has both herbivorous and carnivorous properties. Since the omnivorous insect of the present invention is mainly used as a biological pesticide for pest control, it is preferable that the insect is a natural enemy insect that preys on pests. In addition, the omnivorous insect is preferably an insect of the order Hemiptera, for example, an insect of the family Miridae or an insect of the family Anthocoridae. Examples of insects of the Miridae family include insects of the genus Nesidiocoris, such as N. tenuis (Reuter), and examples of insects of the Anthocoridae family include insects of the genus Orius, such as O. sauteri (Poppius), O. strigicollis (Poppius), O. minutus (Linnaeus), O. nagaii Yasunaga, and O. tantillus (Motschulsky). Of these, the tobacco stink bug is preferred.

[0027] A taste gene related to herbivorous behavior is usually a taste receptor gene having a seven-transmembrane structure common to G protein-coupled receptors (GPCRs), but may be a gene other than a taste receptor gene. A taste receptor gene expressed in an omnivorous insect and also expressed in a herbivorous insect closely related to the omnivorous insect can be used as a taste gene related to herbivorous behavior. Specific examples of taste genes related to herbivorous behavior include (a) genes encoding the amino acid sequence represented by SEQ ID NO: 6, 18, or 28, (b) genes including a part of a base sequence encoding the amino acid sequence represented by SEQ ID NO: 2, 4, 8, 10, 12, 14, 16, 20, 22, 24, or 26, and (c) homologs of the above genes. The taste gene related to herbivorous behavior can also be a gene encoding an amino acid sequence highly identical to the amino acid sequence shown in SEQ ID NO: 6, 18 or 28, or a gene including in a portion thereof a nucleotide sequence encoding an amino acid sequence highly identical to the amino acid sequence shown in SEQ ID NO: 2, 4, 8, 10, 12, 14, 16, 20, 22, 24 or 26. The taste gene related to herbivorous behavior can also be a gene encoding an amino acid sequence having one or more (preferably one or several) mutations such as deletion, substitution, addition, etc. in the amino acid sequence shown in SEQ ID NO: 6, 18 or 28, or a gene including in a portion thereof a nucleotide sequence encoding an amino acid sequence having one or more (preferably one or several) mutations such as deletion, substitution, addition, etc. in the amino acid sequence shown in SEQ ID NO: 2, 4, 8, 10, 12, 14, 16, 20, 22, 24 or 26. In addition, the taste genes related to herbivorous behavior can be genes consisting of the base sequence shown in SEQ ID NO: 5, 17 or 27, or genes partially containing the base sequence shown in SEQ ID NO: 1, 3, 7, 9, 11, 13, 15, 19, 21, 23 or 25. Furthermore, the taste genes related to herbivorous behavior can be genes consisting of a base sequence highly identical to the base sequence shown in SEQ ID NO: 5, 17 or 27, or genes partially containing a base sequence highly identical to the base sequence shown in SEQ ID NO: 1, 3, 7, 9, 11, 13, 15, 19, 21, 23 or 25.In the above, "high identity" refers to 90% or more identity, 95% or more identity, 97% or more identity, 98% or more identity, or 99% or more identity.

[0028] Suppression of expression of taste genes related to herbivorous behavior may affect genes in the genome (e.g., suppression of gene expression by genome editing) or may not affect genes in the genome (e.g., suppression of gene expression by RNAi or antisense methods). In addition, suppression of gene expression may be complete (i.e., taste genes related to herbivorous behavior are not expressed) or incomplete (i.e., taste genes related to herbivorous behavior are expressed but at a reduced level). Techniques for suppressing expression of specific genes are well known to those skilled in the art, and therefore those skilled in the art can suppress expression of taste genes related to herbivorous behavior according to these known techniques.

[0029] In the present invention, "omnivorous insects whose herbivorous behavior is suppressed" refers to omnivorous insects whose herbivorous behavior is reduced compared to wild-type omnivorous insects or control omnivorous insects. As shown in the Examples described later, an example of a control omnivorous insect is an omnivorous insect in which expression suppression treatment has been performed on a gene that insects do not normally have, such as the EGFP gene. Omnivorous insects whose herbivorous behavior is suppressed include both omnivorous insects in which both herbivorous behavior and carnivorous behavior are suppressed, and omnivorous insects in which only herbivorous behavior is suppressed and carnivorous behavior is normal, but omnivorous insects in which only herbivorous behavior is suppressed and carnivorous behavior is normal are preferred.

[0030] (2) Biological pesticides The biological pesticide of the present invention is characterized by containing the above-mentioned omnivorous insect of the present invention. The biological pesticide of the present invention can be prepared and used in the same manner as known biological pesticides containing natural enemy insects.

[0031] The omnivorous insects contained in the biopesticide may be any of eggs, larvae, and adults, or may be a mixture of these. The biopesticide of the present invention may consist of only omnivorous insects, but may also contain other components contained in biopesticides that include natural enemy insects, such as bulking agents, heat retaining agents, moisturizing agents, and shock absorbing materials.

[0032] The pests to be controlled are those that the omnivorous insect used preys on, for example, when the tobacco whitefly is used, the pests to be controlled are whiteflies, thrips, spider mites, etc. The target crops can also be determined according to the omnivorous insect used, for example, when the tobacco whitefly is used, the target crops are cucumbers, tomatoes, etc.

[0033] The amount of the biopesticide of the present invention to be used can be appropriately determined depending on the omnivorous insects to be used, the pests to be controlled, the crops to be used, and the like.

[0034] (3) Herbivory inhibitors The herbivorous behavior inhibitor of the present invention is an inhibitor of herbivorous behavior of omnivorous insects, and is characterized by containing double-stranded RNA of a taste gene related to herbivorous behavior. As mentioned above, some omnivorous insects, such as the tobacco whitefly, can damage crops themselves if their population density increases too much. The herbivorous behavior inhibitor of the present invention is used for such omnivorous insects, and inhibits the herbivorous behavior of the omnivorous insects to prevent damage to crops.

[0035] The "omnivorous insect" and "gustatory gene related to herbivorous behavior" in the herbivorous behavior inhibitor of the present invention have the same meaning as the "omnivorous insect" and "gustatory gene related to herbivorous behavior" in the omnivorous insect of the present invention described above.

[0036] The double-stranded RNA of a taste gene related to herbivorous behavior is an RNA that suppresses the expression of the taste gene related to herbivorous behavior by the RNAi method, and is composed of a sense strand having a base sequence corresponding to a part of the taste gene related to herbivorous behavior, and its antisense strand. Which region of the base sequence of the taste gene related to herbivorous behavior this double-stranded RNA has can be appropriately determined depending on the type of the taste gene related to herbivorous behavior. The length of the double-stranded RNA is not particularly limited as long as it is long enough to suppress the expression of the taste gene related to herbivorous behavior, but is preferably 200 to 800 bp, and more preferably 400 to 600 bp.

[0037] The herbivorous behavior inhibitor of the present invention can be prepared in the same manner as a general pest control agent using the RNAi method. The form of the herbivorous behavior inhibitor of the present invention is not particularly limited, and can be, for example, a solid, liquid, or gel form. Specific examples of the formulation include dust, granule, wettable powder, water-soluble, emulsion, liquid, oil, aerosol, microcapsule, paste, smoke, fumigant, and coating agent. The content of the active ingredient (double-stranded RNA) in the herbivorous behavior inhibitor of the present invention varies depending on the formulation, but can be, for example, 0.1 to 50% by weight.

[0038] The herbivorous behavior inhibitor of the present invention can be used in the same manner as a general pest control agent using the RNAi method. The herbivorous behavior inhibitor of the present invention exerts its effect by having omnivorous insects take in the double-stranded RNA, which is an active ingredient, and the method of taking in may be oral or parenteral. As a method of taking in orally, a method of coating, scattering, or spraying the herbivorous behavior inhibitor of the present invention on crops that may be damaged by omnivorous insects can be mentioned. In addition, it is also possible to have omnivorous insects take in the double-stranded RNA, which is an active ingredient, by including the herbivorous behavior inhibitor of the present invention in food that omnivorous insects prefer and having the omnivorous insects eat it.

[0039] (4) Pest control agents The pest control agent of the present invention is characterized by containing double-stranded RNA of a taste gene related to herbivorous behavior. The herbivorous behavior inhibitor of the present invention described above can inhibit the herbivorous behavior of insects (omnivorous insects and herbivorous insects), and can therefore inhibit feeding damage by pests to useful crops. Therefore, the herbivorous behavior inhibitor of the present invention can also be used as a pest control agent.

[0040] The pests to be controlled are not particularly limited, and any pest that damages useful crops can be controlled. The pest control agent of the present invention can be prepared in the same manner as the herbivorous behavior inhibitor of the present invention, and can be used in the same manner as the herbivorous behavior inhibitor of the present invention for insects other than the target insects. EXAMPLES

[0041] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0042] (1) Materials and methods (1-1) Test insects The experiment used a strain of tobacco stink bugs that had been reproduced indoors and sold by Agrisect. They were reared in plastic containers, fed with eggs of the striped mealworm moth, and aromaticus leaves were used as an egg-laying substrate and for humidity control. Rearing conditions were a room temperature of 25 ± 1°C, humidity of 60-70%, and a light regime of 16 hours light and 8 hours dark.

[0043] To search for taste genes related to herbivorous behavior, we used the red-striped rice cricket A. fasciaticollis and the red-bearded green rice cricket A. caelestiales collected from the NARO farm in Owashi, Tsukuba, Ibaraki Prefecture, and the transcriptome data of A. fasciaticollis and two closely related species A. lineolatus published in the NCBI sequence read archive.

[0044] (1-2) Search for herbivory genes Total RNA was extracted according to the RNAeasy extraction protocol, and after quality check, libraries were prepared using TruSeq stranded mRNA. After library preparation, sequences were sequenced with an Illumina Novaseq 6000 read length of 150 bp. The sequence after sequencing was trimmed with trimmomatic, a tool for removing adapter sequences, and quality check was performed using FastQC. Then, de novo assembly was performed using Trinity to obtain transcriptome sequences. Expression data was obtained by pseudo-aligning the raw RNA-seq data against various transcriptome sequences using Kalisto, a software for quantifying gene expression levels. In addition, various amino acid sequence data obtained by de novo assembly were analyzed using Olthofinder, a software for analyzing homologous genes, to identify homologous gene groups (orthogroups: OGs) in various species. From the OG, we extracted a group of genes that are thought to function as insect taste receptors, and by comparing their expression profiles, we searched for genes common to herbivores and omnivores.

[0045] (1-3) Functional analysis of herbivory genes Using RNA interference, which suppresses the function of genes with sequences complementary to dsRNA by administering double-stranded RNA (dsRNA) of a gene sequence to an organism, we performed a functional analysis of the genes that were commonly expressed in both herbivores and omnivores. A 500 bp region was selected from the sequence and dsRNA was synthesized. 2 μl of dsRNA was sandwiched between thin layers of parafilm, and final-stage larvae of the tobacco grass bug were released on top of it, covered with a 30 mm diameter glass petri dish, and reared for three days. No food or water was given to the bugs in the petri dish, and the only water they could ingest was water containing dsRNA, which they obtained by inserting their proboscis into the parafilm. After three days, the tobacco grass bugs were then reared in a 1.5% agarose medium containing 10% commercially available tomato juice for two days, and allowed to freely suck tomato agar. The number of sucking marks on the tomato agar was then counted under a microscope. We compared the number of sap sucked from tomato agar by the tobacco grass bug, which orally ingested EGFP dsRNA as a control, with each gene and identified genes that sucked less sap than EGFP, i.e., genes whose herbivorous behavior was suppressed.

[0046] (1-4) Evaluation of the impact of loss of herbivorous genes on carnivorous behavior In order to investigate the effect of the genes shown in the previous section to suppress herbivorous behavior on carnivorous behavior, we conducted an experiment to feed on eggs of the striped moth. As in the above experiment, we used insects that had been orally administered only water containing dsRNA for three days. A 5 mm x 20 mm double-sided tape was attached to filter paper, and eggs were attached evenly on the tape. The insects were raised for one day in a 30 mm diameter glass petri dish with filter paper on the bottom. Eggs are usually oval in shape, but ingested eggs become crushed. Therefore, carnivorous behavior was evaluated by counting the number of crushed eggs. In this experiment, we clarified whether the number of eggs consumed was equivalent to that of EGFP, i.e., whether carnivorous behavior was reduced.

[0047] (1-5) Evaluation of the impact of herbivore gene loss on plants To investigate the effects of the genes shown in the previous section to suppress herbivorous behavior on the plant body, a sap-sucking experiment was carried out using tomato seedlings. As in the above experiment, this experiment used insects that had been orally administered only water containing dsRNA for three days. Cherry tomato cultivar Aiko was used for the tomato seedlings, and seedlings that had grown to about 30-40 cm after sowing in culture soil were used. A single leaf was covered with a drainage net, and five insects that had been orally administered the same dsRNA were released inside and collected five days later. Five days after collection, the number and severity of ring-shaped feeding marks were compared between individuals that had received dsRNA for each gene and EGFP.

[0048] (1-6) Gene expression level survey of RNA interference individuals To investigate whether RNA interference was functioning in the individuals orally administered with dsRNA, real-time PCR was performed and the expression levels were quantified using the ΔΔCt method.

[0049] (2) Results (2-1) Search for herbivory genes (Fig. 1) We found 20 taste genes that were highly expressed in two or more of the omnivorous and five herbivorous species of the grass worm, and performed BLAST searches of the sequences to perform functional annotation. We then excluded olfactory receptors (ORs) and co-receptors (ORCOs) that were thought to be less related to taste perception, ultimately narrowing down the list to 14 genes (15994, 64457, 3628, 81322, 6075, 2178, 11358, 16532, 8865, 71395, 16621, 25, 31188, and 12765). The base sequences of 15994, 64457, 3628, 81322, 6075, 2178, 11358, 16532, 8865, 71395, 16621, 25, 31188, and 12765 are shown in SEQ ID NOs: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, and 27, respectively.

[0050] (2-2) Functional analysis of herbivory genes (Fig. 2) Although the number of sucking marks varied among individuals, the average number of sucking marks was 175.00 in the area where EGFP dsRNA was orally administered. In particular, among the areas where dsRNA of taste receptor genes was orally administered, there were 10 areas (15994, 64457, 3628, 81322, 2178, 11358, 8865, 16621, 31188, 12765) that had fewer sucking marks than the average for EGFP, i.e., areas where sucking behavior was suppressed.

[0051] (2-3) Evaluation of the impact of loss of herbivorous genes on carnivorous behavior (Fig. 3) The average number of eggs preyed in the area where EGFP dsRNA was orally administered was 104.64. Among the areas where dsRNA of the taste receptor gene was orally administered, the egg predation amount was about 20% lower than the control area in 64457, 2178, 11358, and 31188, while the reduction in the amount of predation, that is, the suppression of carnivorous behavior, could not be confirmed in the other areas. However, since there is not enough evidence at present about the relationship between the reduction in the amount of eggs preyed and the control effect, it cannot be discussed whether it is disadvantageous for natural enemies.

[0052] (2-4) Gene expression level survey of RNA interference individuals (Figure 4) Regarding the effect of RNAi interference by oral administration of dsRNA to the tobacco grass worm, the expression level of the gene id 12765 was quantified. As a result, the expression level was suppressed to a maximum of 13% of the control group, and approximately 50% on average. From this, it is believed that gene expression was suppressed in the individuals used in the above experiment as well.

[0053] (2-5) Evaluation of the impact of herbivore gene loss on plants (Fig. 5) In the control area where EGFP dsRNA was orally administered, the petioles changed color and became ring-shaped protuberances, but in the RNA interference area, there was only a slight discoloration. Loss of function of the taste gene suppressed lignification (ring-shaped protuberances), a characteristic feeding scar caused by the tobacco whitefly. These results suggest that by controlling the taste gene, it is possible to reduce feeding damage to plants not only by natural enemy insects but also by pest insects. [Industrial Applicability]

[0054] Since the present invention relates to a biological pesticide, it can be used in industries such as agriculture.

Claims

1. An omnivorous insect in which herbivorous behavior is suppressed, the insect having 1) a gustatory gene related to herbivorous behavior is deleted or expression is suppressed, and 2) the gustatory gene related to herbivorous behavior is (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28, (b) a gene including a part of a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 8, or 22, or (c) a gene encoding an amino acid sequence in which one or several deletions, substitutions, or additions have occurred in the amino acid sequence represented by SEQ ID NO: 6, 18, or 28, and the suppression of the deletion or expression is a signal that the insect is a carnivorous insect. (d) a gene that suppresses herbivorous behavior without suppressing carnivorous behavior, the gene comprising a nucleotide sequence encoding an amino acid sequence in which one or more deletions, substitutions or additions have occurred in the amino acid sequence represented by SEQ ID NO: 2, 8 or 22, and when the deletion or expression is suppressed, the gene suppresses herbivorous behavior without suppressing carnivorous behavior; (e) a gene consisting of a nucleotide sequence having 90% or more identity to the nucleotide sequence represented by SEQ ID NO: 5, 17 or 27, and when the deletion or expression is suppressed, the gene suppresses herbivorous behavior without suppressing carnivorous behavior; (f) An omnivorous insect, characterized in that (a) a gene comprising, in a portion thereof, a base sequence having 90% or more identity with the base sequence represented by SEQ ID NO: 1, 7, or 21, and which suppresses herbivorous behavior without suppressing carnivorous behavior when the gene is deleted or its expression is suppressed; (g) a gene comprising, in a portion thereof, a base sequence encoding the amino acid sequence represented by SEQ ID NO: 4, 14, or 26; (h) a gene comprising, in a portion thereof, a base sequence encoding an amino acid sequence in which one or more deletions, substitutions, or additions have occurred in the amino acid sequence represented by SEQ ID NO: 4, 14, or 26, and which suppresses herbivorous behavior when the gene is deleted or its expression is suppressed; or (i) a gene comprising, in a portion thereof, a base sequence having 90% or more identity with the base sequence represented by SEQ ID NO: 3, 13, or 25, and which suppresses herbivorous behavior when the gene is deleted or its expression is suppressed.

2. 2. The omnivorous insect according to claim 1, wherein the omnivorous insect is an insect of the Miridae family or Anthocoridae family.

3. 2. The omnivorous insect according to claim 1, characterized in that the omnivorous insect is a tobacco grass borer.

4. A biological pesticide comprising an omnivorous insect described in any one of claims 1 to 3.

5. A method for producing an omnivorous insect in which herbivorous behavior is suppressed, comprising: 1) a step of deleting or suppressing expression of a taste gene related to herbivorous behavior in an omnivorous insect; and 2) the taste gene related to herbivorous behavior is (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28; (b) a gene including, as a part thereof, a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 8, or 22; or (c) a gene encoding an amino acid sequence in which one or more deletions, substitutions, or additions have occurred in the amino acid sequence represented by SEQ ID NO: 6, 18, or 28, and the deletion or expression is (d) a gene which, when suppressed, suppresses herbivorous behavior without suppressing carnivorous behavior, and which includes a base sequence encoding an amino acid sequence in which one or more deletions, substitutions or additions have occurred in the amino acid sequence represented by SEQ ID NO: 2, 8, or 22, and which, when the deletion or expression is suppressed, suppresses herbivorous behavior without suppressing carnivorous behavior; (e) a gene consisting of a base sequence having 90% or more identity to the base sequence represented by SEQ ID NO: 5, 17, or 27, and which, when the deletion or expression is suppressed, suppresses herbivorous behavior without suppressing carnivorous behavior; (f) a gene consisting of a base sequence having 90% or more identity to the base sequence represented by SEQ ID NO: 5, 17, or 27, and which, when the deletion or expression is suppressed, suppresses herbivorous behavior without suppressing carnivorous behavior. A method for producing an omnivorous insect, characterized in that the gene is a gene that contains, in part, a base sequence having 90% or more identity to the base sequence represented by SEQ ID NO: 1, 7, or 21, and that suppresses herbivorous behavior without suppressing carnivorous behavior when the gene is deleted or its expression is suppressed; (g) a gene that contains, in part, a base sequence that codes for the amino acid sequence represented by SEQ ID NO: 4, 14, or 26; (h) a gene that contains, in part, a base sequence that codes for an amino acid sequence in which one or more deletions, substitutions, or additions have occurred in the amino acid sequence represented by SEQ ID NO: 4, 14, or 26, and that suppresses herbivorous behavior when the gene is deleted or its expression is suppressed; or (i) a gene that contains, in part, a base sequence that has 90% or more identity to the base sequence represented by SEQ ID NO: 3, 13, or 25, and that suppresses herbivorous behavior when the gene is deleted or its expression is suppressed.

6. 6. The method for producing an omnivorous insect according to claim 5, wherein the omnivorous insect is an insect of the Miridae family or Anthocoridae family.

7. 6. The method for producing an omnivorous insect according to claim 5, wherein the omnivorous insect is a tobacco grass borer.

8. An agent for suppressing herbivorous behavior of omnivorous insects, comprising: 1) a double-stranded RNA of a taste gene related to herbivorous behavior; and 2) the taste gene related to herbivorous behavior is (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28; (b) a gene including, as a part thereof, a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 8, or 22; or (c) a gene encoding an amino acid sequence in which one or several deletions, substitutions, or additions have occurred in the amino acid sequence represented by SEQ ID NO: 6, 18, or 28, and when the deletion or expression is suppressed, carnivorous behavior is suppressed. (d) a gene that contains, as a part of the base sequence, a base sequence encoding an amino acid sequence in which one or more deletions, substitutions or additions have occurred in the amino acid sequence represented by SEQ ID NO: 2, 8, or 22, and that suppresses herbivorous behavior without suppressing carnivorous behavior when the deletion or expression is suppressed; (e) a gene consisting of a base sequence having 90% or more identity to the base sequence represented by SEQ ID NO: 5, 17, or 27, and that suppresses herbivorous behavior without suppressing carnivorous behavior when the deletion or expression is suppressed; (f) a gene consisting of a base sequence having 90% or more identity to the base sequence represented by SEQ ID NO: 5, 17, or 27, and that suppresses herbivorous behavior without suppressing carnivorous behavior when the deletion or expression is suppressed; A herbivorous behavior inhibitor characterized in that (a) a gene comprising, in a portion thereof, a base sequence having 90% or more identity with the base sequence represented by SEQ ID NO: 1, 7, or 21, and which suppresses herbivorous behavior without suppressing carnivorous behavior when its deletion or expression is suppressed; (g) a gene comprising, in a portion thereof, a base sequence encoding the amino acid sequence represented by SEQ ID NO: 4, 14, or 26; (h) a gene comprising, in a portion thereof, a base sequence encoding an amino acid sequence in which one or more deletions, substitutions, or additions have occurred in the amino acid sequence represented by SEQ ID NO: 4, 14, or 26, and which suppresses herbivorous behavior when its deletion or expression is suppressed; or (i) a gene comprising, in a portion thereof, a base sequence having 90% or more identity with the base sequence represented by SEQ ID NO: 3, 13, or 25, and which suppresses herbivorous behavior when its deletion or expression is suppressed.

9. 9. The herbivorous behavior inhibitor according to claim 8, wherein the omnivorous insect is an insect of the Miridae family or Anthocoridae family.

10. 9. The herbivorous behavior inhibitor according to claim 8, wherein the omnivorous insect is a tobacco grass bug.

11. 1) The invention comprises a double-stranded RNA of a taste gene related to herbivorous behavior, and 2) the taste gene related to herbivorous behavior is selected from the group consisting of: (a) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28; (b) a gene including, in part, a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 8, or 22; (c) a gene encoding an amino acid sequence represented by SEQ ID NO: 6, 18, or 28 in which one or more deletions, substitutions, or additions have occurred, and which, when the deletion or expression is inhibited, suppresses herbivorous behavior without suppressing carnivorous behavior; (d) a gene including, in part, a base sequence encoding an amino acid sequence represented by SEQ ID NO: 2, 8, or 22 in which one or more deletions, substitutions, or additions have occurred, and which, when the deletion or expression is inhibited, suppresses herbivorous behavior without suppressing carnivorous behavior; (e) a gene consisting of a base sequence having 90% or more identity to the base sequence represented by SEQ ID NO: 5, 17, or 27, and which, when the deletion or expression is inhibited, suppresses herbivorous behavior without suppressing carnivorous behavior; or (f) A pest control agent characterized in that it is a gene which, in part, comprises a base sequence having 90% or more identity with the base sequence represented by SEQ ID NO: 1, 7, or 21, and which, when its deletion or expression is suppressed, suppresses herbivorous behavior without suppressing carnivorous behavior; (g) a gene which, in part, comprises a base sequence encoding the amino acid sequence represented by SEQ ID NO: 4, 14, or 26; (h) a gene which, in part, comprises a base sequence encoding an amino acid sequence in which one or more deletions, substitutions, or additions have occurred in the amino acid sequence represented by SEQ ID NO: 4, 14, or 26, and which, when its deletion or expression is suppressed, suppresses herbivorous behavior; or (i) a gene which, in part, comprises a base sequence having 90% or more identity with the base sequence represented by SEQ ID NO: 3, 13, or 25, and which, when its deletion or expression is suppressed, suppresses herbivorous behavior.

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