JP2014133760A - Oviposition inhibitor for hemiptera pest, thysanoptera pest or acarina pest - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oviposition inhibitor effective for Hemiptera pests, such as Aleyrodidae and Pentatomidae, Thysanoptera pests, or Acarina pests.SOLUTION: An oviposition inhibitor of the invention contains, as an active ingredient, squalene. The invention includes an oviposition inhibitor composition containing the oviposition inhibitor and a base material.

Description

  TECHNICAL FIELD The present invention relates to an egg-laying inhibitor of a hemipod pest, thrips pest, or mite pest that contains squalene as an active ingredient.

  Crop damage caused by hemipods such as whiteflies and stink bugs is becoming more serious.

  For example, whiteflies are insects of the order Hemiptera, Whiteflies, which are widely distributed around the world and are sucking harmful pests parasitic on crops such as tomatoes, strawberries and cucumbers. Examples of the whitefly include Trileuredes vaporiarum, Silverleaf whitefly, Bemisia tabaci, strawberry whitefly, and the like. However, the nomenclature of whitefly species is not uniform. In addition to the above, silver leaf whitefly and tobacco whitefly are treated as the same species, and silver leaf whitefly is called tobacco whitefly biotype B (Bemisia tabaci B-biotype), and tobacco whitefly is called Although it may be called tobacco whitefly biotype Q (Bemisia tabaci Q-biotype), in this specification, it explains along the former nomenclature.

  Onsite whitefly is a typical phagocytic insect, and its range of host plants such as asteraceae, cucurbitaceae, solanaceae, mallowaceae is very wide, and is thought to cause an increase in distribution and an increase in development. Adult white larvae of the whitefly white lice inhibit the growth of crops due to the occurrence of soot disease due to sucking juice, excrement called honeydew, and transmission of viral diseases. On the other hand, silver leaf whiteflies are similar to Onsuji whiteflies in both form and ecology, and bring the same harmful effects to crops. Moreover, as a harmful effect peculiar to silver leaf whitefly, the occurrence of colored abnormal fruits in tomatoes and whitening (silver ring) seen in many green-yellow vegetables can be mentioned. This symptom is caused by a larval infestation, which is the origin of the silver leaf name.

  In addition to the crop damage described above, recently, damage caused by whiteflies has become serious due to the emergence of drug-resistant ones that have acquired resistance to existing insecticides. The same problem as described above is observed not only in whiteflies, but also in bugs other than whiteflies such as stink bugs, aphids and scale insects, and also in thrips pests.

  Then, the technique which contains a various compound as an active ingredient as an insecticide and control agent for a hemipoda insect is proposed (for example, patent documents 1-3). Further, Patent Document 4 discloses a control agent for the beetle bug that contains a specific extract component of red pine.

  In addition, crop damage caused by mite-like pests such as plant parasitic spider mites, fliesid mites, dust mites, and acarids is also known. The body length of mites is very small. For example, the body length of spider mites is about 0.5 mm, and the body length of dust mites is about 0.2 mm, but the fertility is very high. Cause damage. As a method for controlling tick insect pests, in addition to a method using a huge ventilation fan, mist, etc. by utilizing the property of being vulnerable to sunlight and wind and rain, extermination by natural enemy insects such as thrips is performed. Patent Document 5 discloses a control agent containing a novel quinoline derivative as an active ingredient.

JP 2007-70334 A JP 2007-2111015 A JP-A-6-41086 JP-A-8-53318 JP 2009-155340 A

  An object of the present invention is to provide an egg-laying inhibitor for hemipod pests such as whiteflies and stink bugs, thrips pests, or mite pests. As for the Hemiptera pests, it is to provide a Hemiptera pest egg laying inhibitor that can exert an excellent control effect by strongly suppressing the oviposition behavior of the Hemiptera pests.

  The egg-laying inhibitor of the Hemiptera pests, Thripidae pests, or Acarina pests, which has solved the above problems, has a gist in that it contains squalene as an active ingredient.

  In a preferred embodiment, the Hemiptera pest is a whitefly, stink bug, or aphid.

  The present invention also includes an egg-laying inhibitor composition containing the above-mentioned egg-laying inhibitor and a base material.

  ADVANTAGE OF THE INVENTION According to this invention, the egg-laying inhibitor which can exhibit a remarkable extermination action with respect to all of the Hemiptera pests, Thripidae pests, and Mite pests, such as whitefly and stink bugs, was able to be provided. The squalene used in the present invention is extremely useful as an oviposition inhibitor for hemiptera pests, and all have very little influence on the human body. Therefore, unlike the harmful substances generally used for pest control, the egg-laying inhibitor of the present invention is useful in that it does not adversely affect crops and soil, and does not cause environmental destruction. In addition, since the egg-laying inhibitor of the present invention does not exhibit a control effect by insecticidal action, recently, control techniques using natural enemy insects that have been introduced in recent years, that is, ladybirds, parasitic bees that are used as natural enemies, It can also be used in combination with control techniques using insects such as predatory stink bugs and lacewing. Furthermore, since the use of the insecticide can be reduced by using the egg-laying inhibitor of the present invention, there is an advantage that cultivation of reduced agricultural chemicals and agricultural chemical-free crops becomes possible.

FIG. 1 is a schematic view of an apparatus used in Example 1 for a whitefly biological test (spawning inhibition test). FIG. 2 is a flowchart showing the procedure of the extraction / fractionation method of the test plant in Example 1. FIG. 3 is a graph showing the results of a biological test using a fraction fraction of a crude methanol extract in Example 1. In FIG. 3, “water fraction” or the like is abbreviated as “water” or the like. FIG. 4 is a graph showing the results of a biological test using a fractionated fraction by a silica gel open column in Example 1. In FIG. 4, “hexane fraction” or the like is abbreviated as “hexane” or the like, and “ether / hexane” is abbreviated as “E / H”. FIG. 5 is a chromatogram obtained by HPLC analysis of the hexane fraction (silica gel-hexane fraction) using a silica gel open column in Example 1. 6 is a graph showing the results of a biological test using the HPLC fraction of silica gel-hexane fraction in Example 1. FIG. 7 is a ¹³ C-NMR spectrum of fraction B (top) and squalene (bottom) of the silica gel-hexane fraction in Example 1. FIG. 8 is a ¹ H-NMR spectrum of fraction B (top) and squalene (bottom) of the silica gel-hexane fraction in Example 1. FIG. FIG. 9 is a graph showing the activity (spawning inhibition rate) due to a change in squalene concentration in Example 1. FIG. 10 is a chromatogram obtained by HPLC analysis of the 5% ether / hexane fraction (silica gel-5% ether / hexane fraction) using a silica gel open column in Example 1. FIG. 11 is a graph showing the biological test results of Compound C in the silica gel-5% ether / hexane fraction in Example 1. FIG. 12 is a ¹³ C-NMR spectrum of compound C in silica gel-5% ether / hexane fraction in Example 1. FIG. 13 is a ¹ H-NMR spectrum of compound C in silica gel-5% ether / hexane fraction in Example 1. FIG. 14 is a schematic view of an apparatus used in a biological test (spawning inhibition test) for stink bugs in Example 2. FIG. 15 is a graph showing the results of a biological test in Example 2. FIG. 16 is a graph showing the control effect of whitefly in Example 3. FIG. 17 is a graph showing the control effect of southern thrips in Example 3. FIG. 18 is a graph showing the control effect of dust mites in Example 3. FIG. 19 is a graph showing the control effect of cotton aphids in Example 3. FIG. 20 is a graph showing the control effect of Chrysanthemum aphids in Example 4. FIG. 21 is a graph showing the effect of controlling spider mite by squalene in Example 5.

  The inventors of the present invention have made extensive studies in order to provide a control agent for hemipod pests, thrips pests, or mite pests such as whiteflies and stink bugs. As a result, the acyclic triterpene squalene has a strong egg-laying inhibitory effect against hemipod pests such as whiteflies and stink bugs and is extremely useful as a control agent against hemipod pests; Furthermore, the above-described squalene was found to be extremely useful as a control agent against mite-like pests, and the present invention was completed.

  Here, the ability to control (exterminate) the Hemiptera pests by the egg-laying inhibitory action is very useful. Some insecticides, such as insecticides, kill insects and exert their controlling action. However, insecticides cannot sufficiently prevent crop damage caused by insects before exerting the insecticidal effect. In addition, most insecticides are very toxic, such as killing insects non-selectively, and there is a problem that they cannot be used in combination with a control technique using natural enemy insects. On the other hand, some pest control agents, such as repellents, control pests by keeping them away from the crop, but repellents, for example, vinyl cultivation before the pests come into contact with the repellent There is a problem that the spawning behavior by the pests that have invaded can not be effectively prevented, and the control effect of the next generation is not sufficient. On the other hand, if the insect pest can be controlled by strongly inhibiting the egg-laying behavior of the hemiptera insect as in the present invention, it is extremely useful in that the above problem can be solved.

  First, the active ingredient (squalene) used in the present invention will be described.

  Squalene is one of acyclic triterpenes (having 30 carbon atoms) consisting of six isoprene residues, and is represented by the following formula. Squalene is abundant in shark liver oil and has been used as a raw material for cosmetics, surface active agents, etc., but it has been used in the past, for example, Hemiptera pests, Thrips pests, and Mite pests. The control action against is not known.

  Squalene is commercially available, and commercially available squalene may be used in the present invention.

  Alternatively, since squalene is contained in a large amount in shark liver oil and the like and also in plants, squalene extracted by a known extraction method can also be used. The method for extracting squalene is detailed in, for example, documents such as Siti Zullaikah et al. (Bioresource Technology 100, 2009, 299-302) and Setiyo Gumawan et al. (Industrial & Engineering Chemistry Research, 2008, 47, 7013-7018). These are described, and these may be referred to for details. In the examples described later, experiments were conducted using squalene obtained by extraction from plants of the genus Schefflera heptaphylla from Vietnam.

  The egg-laying inhibitor of the present invention may further contain, in addition to the above active ingredients, additives usually used for controlling agents. Examples of the additive include adjuvants ordinarily used in preparations, and can be appropriately selected and used as long as the effects of the present invention are not impaired. Specifically, for example, surfactants such as nonionic surfactants and anionic surfactants; dispersants such as casein, gelatin and polysaccharides; thickeners such as xanthan gum and carboxymethylcellulose; sodium benzoate, para Preservatives such as hydroxybenzoic acid; stabilizers such as acidic isopropyl phosphate; and adjuvants such as soybean oil. Additives commonly used in the agrochemical field include, for example, spreading agents (nonionic surfactants, nonionic surfactants + anionic surfactants, etc.), emulsifiers, dispersants, wetting agents, etc. May be.

  The dosage form of the egg-laying inhibitor according to the present invention is not particularly limited, and for example, it may be a dosage form usually used for agricultural chemicals (for example, powder, granule, bait). In consideration of easiness of spraying to the hemiptera pests, it is preferable to use a solution dissolved in a solvent. Specifically, a solution such as a wettable powder, an emulsion, or a flowable agent is preferable. As a usable solvent, it is preferable to select and use a solvent that can dissolve squalene, which is an active ingredient, and is harmless to humans and causes less environmental pollution. As such a solvent, for example, ethanol, hexane or the like widely used for food additives or food processing is preferably used.

  When squalene is used as a liquid agent, the preferable concentration of squalene for obtaining an excellent control effect is generally 0.001% by mass or more, more preferably 0.002% by mass or more. From the viewpoint of the control effect, the higher the squalene concentration, the better. However, considering the balance with the economy and the like, it is generally preferably 10% by mass or less, and more preferably 0.1% by mass or less. Specifically, the concentration of squalene can be appropriately controlled according to the degree of purification of squalene, the usage environment, and the like.

  In the present invention, a molded product (product) in which the above egg-laying inhibitor is supported on a substrate may be used. For example, squalene, which is an active ingredient, may be directly supported on a base material, or may be supported on a base material in the form of a solution obtained by dissolving an active ingredient in a solvent. Or you may carry | support the egg-laying inhibitor containing an active ingredient and an additive on a base material. The base material is not particularly limited as long as it is usually used as a control agent. For example, paper and fiber products such as paper, fiber, fabric, and filter; building material products such as wood and gypsum board; film and plastic , Materials such as metal and glass.

  The method of supporting the substrate is not particularly limited, and a commonly used method may be appropriately employed depending on the type of the substrate. For example, after processing the base material into a product, a method of coating the surface of the product with a squalene solution or immersing the product in the product may be mentioned. Or you may employ | adopt methods, such as mixing a base material and squalene, before processing into a product.

  The compounding amount of the active ingredient supported on the base material may be appropriately controlled according to the type and use of the base material to be used. For example, the preferable concentration of squalene with respect to a substrate such as papers and fabrics is generally 0.001 to 50% by mass. Of course, this is not intended to be limited to this.

  Examples of the Hemiptera (Cemiptera) pests to be controlled according to the present invention include, for example, silver-free whitefly, tobacco whitefly, strawberry whitefly, whitefly whitefly and other whiteflies; cotton aphids, bark aphids, pea aphids, apple aphids, apple aphids, Aphidaceae such as Japanese radish aphids; Carcass departments such as Japanese beetle; Leafhoppers such as rice scallops and apple madara beetles; Scarabaeidae; Steller's beetle, Aokusakamushi, Inokamemushi, Stinkidae; Family: Helicobacteridae; Nagamekamushiidae; Mekuramemushiidae; Rice-scale scale insects such as the rice beetle and citrus scale insects; Ringokijirami, and the like psyllid family such as Nashikijirami.

  Examples of the thrips (total lepidoptera) pests to be controlled according to the present invention include, for example, the southern thrips, the thrips, the thrips, the thrips, the thrips of thrips, the thrips of thrips, and the thrips of thrips.

  In addition, examples of mite pests to be controlled according to the present invention include spider mites such as nymph mite, citrus spider mite, kanzawa spider mite, spider mite, spider mite, reindeer spider mite, apple spider mite; Mite, mite, cyclamen mite, mite, mite, mite, mite, mite, etc.

  The method for using the egg-laying inhibitor according to the present invention is not particularly limited, and a commonly used method may be employed. Specifically, for example, there is a method of spraying, spraying, impregnating, etc., a solvent prepared to a predetermined concentration at the time of use with respect to the above-mentioned hemiptera pests and agricultural products. Or you may install the molded article which carry | supported the egg-laying inhibitor on the base material as mentioned above.

  If the egg-laying inhibitor of the present invention is used, as for the Hemiptera pests, as shown in the examples to be described later, the egg-laying of Hemiptera pests such as whiteflies is effectively inhibited. Effectively demonstrated. Further, it is presumed that the thrips pests and mite pests exert a controlling action by the air gate blockage, similar to hydroxypropyl starch solution which is a known air gate blocker.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples, and can be implemented with appropriate modifications within a range that can meet the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention.

Example 1
In this example, it was examined that squalene and vitamin E obtained by the known extraction procedure shown in FIG. 2 show a strong egg-laying inhibitory activity against whitefly, a typical gardening pest, using fresh leaves of the scorpion department of the urchinaceae family. It was. According to this extraction procedure, squalene is extracted in the hexane fraction by the silica gel open column, and vitamin E is extracted in the 5% ether / hexane fraction by the silica gel open column. Details will be described below.

1. Test insect Silver leaf whiteflies (Bemisia argentifolii) collected in a house in the Faculty of Agriculture, Kochi University were used.

2. Biological test (spawning inhibition test)
The following egg-laying inhibition test was conducted using a solution obtained by dissolving 1 g of a plant (extract obtained from 1 g of a plant) equivalent to 1 g of a plant extracted / fractionated by the following 4 methods.

  First, a cucumber leaf (leaf disc) having a diameter of 15 mm is immersed in the above solution and immediately taken out and air-dried. Next, 10 whiteflies were placed in a commercially available 50 ml vial, and the leaf disk and filter paper moistened with deionized water (filter paper with a diameter of 90 mm) between the inner lid and the outer lid with a hole with a diameter of 10 mm. And was bred at about 27 ° C. for 24 hours (see FIG. 1).

  After the test, the back of the leaf disc was observed under a microscope to examine the number of eggs laid. Each sample was repeated 6 times, and the experimental results were tested by T-test. When the risk factor p was p <0.01, it was judged that there was an egg-laying inhibitory activity.

  For comparison, each time a biological test was performed, a control group to which no sample was applied was provided, and a comparative study with an experimental group to which the sample was applied was performed. In both the biological test control group and each experimental group, n = 6. The reason why the control group is provided every time the biological test is performed is that the number of eggs laid varies depending on the time of collecting whiteflies, and this makes it easy to compare the average number of eggs laid in the same experimental system.

3. Test plant The fresh leaves of the genus Schefflera heptaphylla from Vietnam, which were cultivated in a house in the Faculty of Agriculture, Kochi University, were used.

4). Extraction and fractionation method of test plant The test plant was extracted and fractionated by the procedure shown in FIG.

4-1. Extraction method After adding 1500 mL of 100% methanol to 900 g of fresh leaves of the test plant and immersing for 3 days, the extract and the extraction residue (live leaves) were separated by filtration. To this extraction residue, 1500 mL of methanol was further added and immersed for 3 days, and the extract and the extraction residue (live leaves) were separated by filtration. The extract thus obtained was concentrated under reduced pressure using an evaporator to obtain a crude methanol extract, and then methanol was added to adjust the concentration to 5 g / mL.

4-2. Fractionation of crude methanol extract The crude extract of 800 g equivalent of raw leaves of the above-mentioned test plant (extract obtained from 800 g of plant body) was evaporated to dryness and suspended in 360 ml of water. 3 times, 3 times with 250 ml of diethyl ether, 3 times with 250 ml of ethyl acetate, water-saturated butanol (water dissolved to the maximum extent in butanol, in which 7.7% of water was dissolved in butanol I) Partitioned 3 times with 250 ml to obtain each fraction.

4-3. Fractionation of hexane fraction by silica gel open column The hexane fraction corresponding to 700 g of fresh leaves of the test plant obtained by fractionation of the crude methanol extract was charged into a silica gel open column (100 g, 40 mmφ × 1000 mm). Thereafter, elution was successively performed with hexane, 5% by volume ether / hexane, 10% by volume ether / hexane, 50% by volume ether / hexane, ether and methanol to obtain respective fractions.

5. 5. Activity of fraction of said test plant 5-1. Activity of fractions of crude methanol extract The biological test was performed using samples of each fraction obtained from the crude methanol extract. Specifically, a solution prepared by dissolving 1 g of an equivalent amount of 1 g of each fraction in 1 ml of each solvent was used as a sample for a biological test. For example, hexane was used as a solvent for dissolving the sample of the hexane fraction.

  The result is shown in FIG. Table 1 shows the average number of eggs laid and the T-test value of each fraction. As shown in FIG. 3 and Table 1, the hexane fraction showed the highest egg-laying inhibitory activity (p = 0.020), but almost no inhibitory activity was observed in the other fractions.

5-2. Activity of fractions by silica gel open column 4-3. Hexane fraction, 5% ether / hexane fraction, 10% ether / hexane fraction, 50% ether / hexane fraction obtained from silica gel open column from hexane fraction of crude methanol extract as described in The biological test was performed using each sample of the ether fraction and the methanol fraction. Specifically, a solution in which 1 g of a plant corresponding to each fraction was dissolved in 1 ml of each solvent was used as a sample for a biological test. For example, hexane was used as a solvent for dissolving the sample of the hexane fraction.

  The results are shown in FIG. From these results, the hexane fraction showed the highest egg-laying inhibitory activity (p = 0.00027), and then the 5% ether / hexane fraction showed high activity (p = 0.020).

6). Analysis of components contained in hexane fraction by silica gel open column (hereinafter abbreviated as “silica gel-hexane fraction”) Components contained in silica gel-hexane fraction having the highest activity were analyzed as follows.

6-1. Equipment used (1) HPLC
Pump: HITACHI L-7100 Pump
Detector: HITACHI L-7490 RI Detecter
(2) NMR
JEOL JNM-LA400
¹³ C-NMR: 100 MHz
¹ H-NMR: 400 MHz

6-2. HPLC analysis As a result of HPLC analysis of the silica gel-hexane fraction, the chromatogram shown in FIG. 5 was obtained. The HPLC analysis conditions are as shown in FIG.

6-3. HPLC Fraction Activity Samples obtained by isolating and purifying fraction A to fraction D (denoted as “Fr. A” to “Fr. D” in FIG. 5) of the above chromatogram are prepared, and the above biological tests are performed. It was. These results are shown in FIG. In FIG. 6, “MIX” is a mixture of fractions A, B, C, and D. As shown in FIG. 6, fraction B showed the most excellent egg-laying inhibitory activity.

6-4. Structural analysis of fraction B The structural analysis of fraction B showing the most excellent egg-laying inhibitory activity was performed. ^From the analysis results of ¹³ C-NMR and ¹ H-NMR, the fraction B was identified as squalene. The ¹³ C-NMR and ¹ H-NMR of fraction B are shown in FIG. 7 and FIG.

6-5. Change in activity depending on squalene concentration As described above, it was found that fraction B having the highest egg-laying inhibitory activity was squalene. Next, using squalene as the solvent, the squalene concentration was changed, and biological tests were performed. The change in activity was investigated. Specifically, the average number of eggs laid (A) in the experimental group at each squalene concentration and the average number of eggs laid (B) in the control group without squalene were calculated, and the rate of inhibition of egg production (%) was calculated based on the following formula. .
Spawning inhibition rate (%) = {(B−A) / B} × 100

  The result is shown in FIG. As shown in FIG. 9, the egg-laying inhibition rate tended to increase as the squalene concentration increased. Specifically, a high inhibitory activity of about 90% was observed at 20 ppm, which is a concentration equivalent to the concentration contained in the plant body, and an inhibitory activity of about 100% was observed at 100 ppm. When this experimental result was tested by T-test, a result of p <0.01 was obtained when the squalene concentration was 20 ppm or more. Therefore, it is presumed that the limit active concentration of squalene from which significant egg-laying inhibitory activity is obtained is approximately 20 ppm.

7). Analysis of components contained in 5% ether / hexane fraction (hereinafter abbreviated as “silica gel-5% ether / hexane fraction”) by silica gel open column Silica gel with the next highest activity in the silica gel-hexane fraction Components contained in the -5% ether / hexane fraction were analyzed as follows. The same analytical equipment as above was used.

7-1. HPLC analysis As a result of HPLC analysis of the silica gel-5% ether / hexane fraction, the chromatogram shown in FIG. 10 was obtained. Detailed analysis conditions for HPLC are also shown in FIG.

7-2. Activity of HPLC fraction Next, in the above chromatogram, a biological test was performed on a compound (named as Compound C) contained in the fraction having a retention time Rt = 30 to 35 min. From these results shown in FIG. 11 and Table 3, the compound C showed a strong egg-laying inhibitory activity (p = 0.0006).

7-3. Structural analysis of compound C The structural analysis of compound C, which was a single peak and recognized activity, was performed. ¹³ C-NMR and ¹ H-NMR of Compound C are shown in FIG. 12 and FIG. The measured values of ¹³ C-NMR and ¹ H-NMR chemical shifts of Compound C are shown in Tables 4 and 5 in comparison with the literature values of α-tocopherol. From these analysis results, Compound C was identified as α-tocopherol.

Example 2
In this example, it was examined that squalene and vitamin E exhibited strong egg-laying inhibitory activity against leguminous insects (Riptortus clavatus).

Specifically, squalene (squalene manufactured by Wako Pure Chemical Industries) and vitamin E (α-tocopherol manufactured by Nacalai Tesque) were diluted with hexane, and each was adjusted to a concentration of 100 ppm. Each solution containing 0.2 mL each of about 1 cm ³ of absorbent cotton and sufficiently dried was used as an egg-laying substrate for stink bugs. For comparison, 0.2 mL absorbent cotton containing only hexane as a solvent was also prepared.

  Next, in the acrylic insect breeding container (30 cm × 30 cm × 25 cm) shown in FIG. After 12 hours, the number of eggs laid on each absorbent cotton was counted, and the average number of eggs laid was calculated. The result is shown in FIG.

  As shown in FIG. 15, the average number of eggs laid in the control group using only the solvent was 36, whereas the average number of eggs laid in the group to which squalene and vitamin E were applied was 6 and 5, respectively. The average egg production was significantly suppressed. Therefore, it was confirmed that squalene and vitamin E have a strong egg-laying inhibitory activity against hemipod pests other than whitefly.

Example 3 (field experiment 1)
In this example, the pest control effect of house horticultural crops (eggplants) by squalene and vitamin E was examined. Specifically, as in Example 2 described above, squalene (manufactured by Wako Pure Chemical Industries) and vitamin E (α-tocopherol manufactured by Nacalai Tesque) were diluted with hexane, and each was adjusted to a concentration of 100 ppm (test substance). And the above test substance was sprayed periodically on eggplants grown in a greenhouse. Among the following target pests, tobacco whitefly, southern blue thrips, and cotton aphid were counted for the number of parasitic infestation that occurred naturally on five leaves per eggplant. On the other hand, for dust mites, 30 leaf disks (diameter 8 mm) were prepared per test section, and the number of dust mite parasites was measured under a microscope. The detailed test method is as follows.

Target crop: Eggplant cultivation method: Greenhouse cultivation (Kochi University)
Variety: Thousand No. 2 Test substance spraying time: Plant height of about 60 cm ・ Growth test substance spraying concentration / amount: 100 ppm, 100 mL / strain Number of spraying: 5 times in total every five days Target pest: Tobacco whitefly (Bemisia tabaci)
Southern thrips (Thrips palmi)
Dust mite (Polyphagotarsononemus latus)
Cotton aphid (Aphis gossypii)

  These results are shown in FIGS. In each figure, component A represents squalene and component B represents vitamin E. For comparison, the results of the untreated group in which no test substance was sprayed are also shown.

  FIG. 16 is a graph showing the transition of the number of parasitic whitefly adults parasitic on eggplants. In the untreated group, the number of adult whiteflies increased to 10/5 leaves about 2 weeks after the start of the test, whereas all the groups sprayed with squalene (component A) and vitamin E (component B) were tested. The parasitic state was almost the same as that at the start, and the number of parasitic whitefly was suppressed to 5/5 leaves or less. Since these compounds have strong egg-laying inhibitory activity against whiteflies, adult whiteflies are likely to move from the test substance-treated group to the untreated group, which cannot lay eggs, and as a result, repellent effects are observed. . The same tendency was observed in the investigation of the number of parasites of whitefly eggs and larvae conducted simultaneously with the above experiment.

  FIG. 17 is a graph showing the change in the number of parasitic thrips parasitic on eggplants. In the untreated group, the occurrence of southern blue thrips gradually increased, whereas in the group sprayed with squalene (component A) and vitamin E (component B), all of the groups after spraying the test substance three times, The number of infestations could be kept as low as 2/5 leaves or less.

  FIG. 18 is a graph showing changes in the number of adult dust mite parasites infesting eggplants. In the untreated group, the occurrence of dust mites gradually increased, but in the group sprayed with vitamin E (component B), the number of parasites can be suppressed to 1 head / 5 leaves or less after spraying 3 times. It was. Moreover, the control effect of squalene (component A) was more remarkable than that of vitamin E (component B), and could be suppressed to 1 head / 5 leaves or less during the whole period.

  FIG. 19 is a graph showing the transition of the number of parasites of adult cotton aphids parasitic on eggplants. In the latter half of the test, the number of cotton aphid parasites increased rapidly in the untreated group, whereas the increase in the group sprayed with vitamin E (component B) and squalene (component A) could be suppressed. Since the squalene inhibitory effect was higher than that of vitamin E, it was found that the squalene control effect was high.

Example 4 (field experiment 2)
In this example, the pest control effect of house horticultural crops (Chrysanthemum) by squalene and vitamin E was examined. Specifically, an aqueous solution (test substance) of squalene and vitamin E is prepared in the same manner as in Example 3 described above, and the above test substance is periodically sprayed on chrysanthemum grown in a greenhouse. Pests that were parasitic on naturally occurring on 5 stems per tree were measured. A similar test was performed on 6 chrysanthemum (30 stems in total), and the average of pests parasitic on 5 chrysanthemum stems was calculated. The detailed test method is as follows.

Target crop: Chrysanthemum cultivation method: Greenhouse cultivation (Kochi University)
Variety: Kogiku test substance spraying time: plant height approx. 30 cm ・ Growth test substance spraying concentration / amount: 100 ppm, 24 mL / strain spraying frequency: approx. 3 times every 7 days Target drug: commercially available starch raw material solution (Air Gate) Blocker)
Target pest: Kikuhime Higenaga Aphid
(Macrosifoniella samboni)

  These results are shown in FIG. In each figure, component A represents squalene and component B represents vitamin E. For comparison, the results of an untreated group in which no test substance was sprayed and a control group using a commercially available starch raw material liquid (air gate blocking agent) are also shown.

  From FIG. 20, in the untreated group, the number of adults of Kakuhihigenaga aphid increased after the start of the test, whereas the group sprayed with squalene (component A) and vitamin E (component B) As in the control group, all remained in the same parasitic state as at the start of the test, and the number of parasitic aphids was about 5 or less (squalene: component A) and about 20 or less (component B: vitamins). E) It was suppressed to 5 stems or less. In particular, when squalene was used as compared with vitamin E, a high control effect was obtained.

Example 5 (field experiment 3)
In this example, the pest control effect of squalene on house horticultural crops (cucumber) was examined. Specifically, an aqueous solution (test substance) of squalene is prepared in the same manner as in Example 3 described above, and the above-mentioned test substance is periodically sprayed on cucumbers grown in a greenhouse, and each cucumber is Pests that parasitize naturally on 2 leaves were measured. The same test was performed on 6 cucumbers (12 leaves in total), and the average of pests parasitic on 6 cucumber leaves was calculated. The detailed test method is as follows.

Target crop: Cucumber cultivation method: Greenhouse cultivation (Kochi University)
Variety: Aoyama cucumber test substance spraying time: Plant height of about 20 cm ・ Growth test substance spraying concentration / amount: 100 ppm, 50 mL / strain number of sprays: 2 times in total at intervals of about 7 days

  For comparison, the same experiment was performed for the untreated group in which no test substance was sprayed. These results are shown in FIG. FIG. 21 shows the ratio of the treated group (vs. the untreated ratio) when the result of the untreated group is 100 at each spraying time of the test substance (0 day, 7 days, and 14 days later).

  From FIG. 21, it was found that squalene has a control effect against female adult spider mites.

  From the results of Examples 3 to 5 above, squalene and vitamin E are both mite, such as whitefly, cotton aphid, Hemiptera aphid, and thrips pests such as Thrips thrips, and mites such as dust mite, It was confirmed that it exhibits a high control effect against both eye pests. Squalene and vitamin E are essential components of the living body and are not considered to be toxic. From these structural features, it is presumed that the control action against insect pests other than whiteflies is due to airway blockade.

Claims (3)

  An egg-laying inhibitor for hemiptera pests, thrips pests, or mite pests, comprising squalene as an active ingredient.   The egg-laying inhibitor according to claim 1, wherein the Hemiptera pest is a whitefly, stink bug, or aphid.   The egg-laying inhibitor composition containing the egg-laying inhibitor of Claim 1 or 2, and a base material.