JP2020068756A - Storage grain insect pest detection method and storage grain insect pest detection device - Google Patents

Abstract

To provide a method and device for detecting the occurrence of stored grain insect pests at the stage of newly hatched larvae.SOLUTION: A storage grain insect pest detection method includes: (1) a step of collecting a gas under an environment of stored grains; and (2) a step of detecting the presence or absence of one or more substance selected from prenol, isoprenol, dimethyl disulfide, and dimethyl trisulfide in the gas. A storage grain insect pest detection device includes: (1) means for collecting a gas under an environment of stored grains; (2) means for detecting the presence or absence of one or more substance selected from prenol, isoprenol, dimethyl disulfide, and dimethyl trisulfide in the gas; and (3) means for making notification about the presence or absence of an insect pest on the basis of the detection result.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a novel method for detecting stored-grain pests and a novel apparatus for detecting stored-grain pests.

Insects account for 30% of the contamination of foods with foreign substances, which is a problem that can occur anywhere from the storage of agricultural products to the table. Among them, grains may be damaged by a large amount of stored-grain insects such as corn borer occurring during storage and distribution. The value of damaged grains is greatly reduced due to deterioration of appearance, deterioration of taste and unpleasant odor.
Up to now, fumigation using methyl bromide has been mainly used as the insecticidal treatment method for grains, but in 2015, some of the substances such as quarantine were used because methyl bromide is an ozone depleting substance. Production and use were abolished except for. Therefore, several developments of insecticidal techniques which are alternatives to fumigation of methyl bromide have been proposed. As a promising alternative technique, there are fumigant hydrogen phosphide and carbon dioxide treatment (see, for example, Non-Patent Documents 1 and 2). However, fumigant hydrogen phosphide has a problem that resistant pests appear, and carbon dioxide treatment requires treatment time. Is long (about 10 days). Further, although an insecticidal method by irradiation with radiation using gamma rays or high-energy electron beams has also been proposed (see, for example, Patent Document 1 and Non-Patent Document 3), there are problems such as the irradiation device being expensive, and in Japan, Practical use has not progressed.

While the use of chemical agents is cheap and provides a stable control effect, it induces residue in foods, environmental damage, and development of resistant pests, so comprehensive pest management that minimizes their use (hereinafter, " IPM ”) is being promoted. To practice IPM, it is necessary to understand the occurrence of stored-grain pests by monitoring. Although visual monitoring is also performed, it is difficult to detect if the number of pests does not increase, so monitoring by traps, which regularly monitors pests at grain warehouses and food factories, is the mainstream. Pheromone traps, sticky traps, bait traps, light traps, etc. are commonly used as traps. The characteristics differ depending on the type of trap, and it is possible to use them properly according to the purpose, but in general, adults with high exercise ability are targeted. Therefore, there is a problem that it is difficult to trap and monitor the pests in the hatched larval stage. When trapped insects (adults) are found by traps, there is a high possibility that approximately 100 times as many larvae are present, and it is slow to eliminate the insects after the occurrence of stored insects by traps, and the use of chemicals is minimized. There was a problem that I could not do it.
For these reasons, there has been a demand for the development of a method and apparatus capable of detecting the occurrence of stored-grain insects during the hatched larval stage.

"Insect protection / fumigation handbook for imported agricultural products", published by Science Forum, 1995 Ministry of Agriculture, Forestry and Fisheries, Production Bureau, Plant Protection Division, "Physical Quarantine Fumigation Work Chief Text, 5th Edition", published by Japan Fumigation Technology Association, 2002 "Research Results Report on Wheat Insecticide by Irradiation (Appendix)", Food Irradiation Research Management Conference, 1983

JP, 10-215765, A

  An object of the present invention is to provide a method for detecting the occurrence of stored grain pests during the hatched larval stage, and a detection device for the same.

  As a result of earnest studies to solve the above problems, the present inventor has found that when larvae of stored-grain insects grow, prenol (3-methyl-2-buten-1-ol) and isoprenol (3-methyl-3). -Buten-1-ol), dimethyl disulfide, and dimethyl trisulfide are newly generated. That is, it was discovered that the occurrence of stored-grain pests during the hatched larval stage can be detected by monitoring prenol, isoprenol, dimethyldisulfide, and dimethyltrisulfide in a stored-grain environment, and completed the present invention.

Specifically, the present invention has the following matters.
1. A stored grain pest detection method comprising the following steps (1) and (2):
(1) A step of collecting a gas under a grain storage environment (2) A step of detecting the presence or absence of at least one selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide in the gas 2. 1. The stored grain pest is one or more species selected from Lepidoptera and Coleoptera (Coleoptera). The method for detecting stored-grain pests according to 1.
3. A stored-grain pest detecting device comprising the following means (1) to (3).
(1) Means for collecting gas under grain storage environment (2) Means for detecting the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide in the gas (3) Based on the detection result Means for reporting the presence or absence of stored-grain pests

According to the stored grain pest detection method or the stored grain pest detection apparatus of the present invention, hatched larvae are monitored by monitoring at least one selected from prenol, isoprenol, dimethyl disulfide, and dimethyl trisulfide in a gas under a grain storage environment. It is possible to early detect the occurrence of stored-grain pests, that is, the occurrence of stored-grain pests.
According to the present invention, since it is possible to detect the occurrence of stored-grain pests earlier than the traps that have been conventionally used, it is possible to implement control measures while the damage to grains is small, and it is effective. It is possible to obtain a good control effect.

FIG. 3 is a diagram showing a trend in the amount of prenol generated from Nostoc commune in Example 1 in Example 1. FIG. 3 is a diagram showing the trend of the amount of isoprenol generated in Nostoc commune in Example 1; FIG. 5 is a diagram showing trends in the amount of prenol generated for each stored grain pest species in Example 2. FIG. 5 is a diagram showing the trends in the amount of isoprenol generated for each stored grain pest species in Example 2. FIG. 5 is a diagram showing a mass chromatogram of molecular ion peaks (m / z = 86) for each of stored grain pest species in Example 2. FIG. 6 is a diagram showing the trend of the amount of isoprenol generated from weevil in Example 3; FIG. 8 is a diagram showing trends in the amount of prenol generated for each stored-grain insect pest species in Example 4. FIG. 8 is a diagram showing trends in the amount of isoprenol generated for each stored grain pest species in Example 4. It is a figure in Example 5 which shows the trend of the amount of production of isoprenol of a weevil and a cornweed. It is a figure in Example 6 which shows the trend of the generation amount of dimethyl disulfide of Welsh beetle and Welsh beetle. It is a figure in Example 6 which shows the trend of the generation amount of dimethyl trisulfide of Welsh beetle and Welsh beetle. FIG. 7 is a diagram showing trends in the amount of dimethyl disulfide generated for each stored grain pest species in Example 7. FIG. 8 is a diagram showing trends in the amount of dimethyl disulfide generated for each stored grain pest species in Example 6.

Hereinafter, the present invention will be described in detail.
The object of protection from stored-grain insects in the present invention is cereals. In the present invention, the grains include rice, wheat, barley, corn, soybeans, adzuki beans, various types of grains such as buckwheat, and powders thereof, as well as pasta, somen noodles, various dried grain processed foods such as dry noodles such as buckwheat noodles. Is also defined as a term including. In addition, the grain storage environment refers to structures such as grain warehouses that store / store these grains, grain transport ships and vehicles that transport grains, food factories that process grains, and the storage or transport of grains. It means a paper, hemp, resin bag or resin container used when doing.

The present invention is based on the new finding that one or more kinds selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide are generated when a larva of a stored grain pest grows. The main constitution of the present invention is to collect the lower gas and detect the presence or absence of at least one selected from prenol, isoprenol, dimethyldisulfide and dimethyltrisulfide in the gas.
<About prenol, isoprenol, dimethyl disulfide, dimethyl trisulfide>
Prenol is an alcohol compound having the following chemical structure, a chemical formula of C ₅ H ₁₀ O, and a chemical name of “3-methyl-2-buten-1-ol”. It has a boiling point of about 142 ° C., is volatile, and has a fruity aroma, so it is also a compound used as a flavoring agent.
Isoprenol is an alcohol compound having the following chemical structure, a chemical formula of C ₅ H ₁₀ O, and a chemical name of “3-methyl-3-buten-1-ol”. It has a boiling point of 130 to 132 ° C., is volatile, and is a compound used as a fragrance as well as prenol.
Dimethyl disulfide is a compound having the following chemical structure, and the chemical formula is also referred to as C ₂ H ₆ S ₂ and methyl disulfide. It has a boiling point of 110 ° C., is volatile, and is also used as a food flavoring.
Dimethyl trisulfide is a compound having the following chemical structure, and the chemical formula is also referred to as C ₂ H ₆ S ₃ and methyl trisulfide. It has a boiling point of 165 to 170 ° C., is volatile, and is a compound that is used as a flavoring agent for foods like dimethyl disulfide.

<(1) Collection of gas under grain storage environment>
The stored-grain pest detection method of the present invention comprises (1) a step of collecting gas under a storage environment, and the stored-pest detection apparatus of the present invention includes (1) means for collecting gas under a storage environment, The presence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide in a volatile organic compound (hereinafter referred to as "VOC") contained in the gas under the environment for storage of grains indicates the presence of stored insects. It is something to detect.
The collection of this gas is not particularly limited as long as the gas (air) in the environment where the grains are stored can be collected and the gas can be accumulated for later analysis. A function of concentrating the collected gas may be added if necessary. As a function of concentrating, for example, a gas under a storage environment is sent to a concentrating column by an air pump or the like, VOC in the collected gas is adsorbed to an adsorbent, and the adsorbent is heated to be adsorbed and concentrated. The method of obtaining VOC is mentioned. Examples of the concentration column include a mode in which an adsorbent such as an adsorptive filler or a porous polymer is packed in the column, and a gas under a grain storage environment is continuously passed through to adsorb VOCs on the adsorbent. As the adsorbent, for example, MS3A, MS4A, MS13X, TenaxTA, TenaxGR, PorapakS, PorapakQ, MonoTrap (registered trademark) manufactured by GL Sciences, Twister manufactured by Gestel, and solid phase microextraction (SPME) fiber manufactured by Supelco are used. Etc., and the volume thereof is preferably 0.01 to 5 mL, for example. The conditions for heating the adsorbent may be appropriately set depending on the type of the adsorbent packed in the concentration column. For example, when TenaxTA is used as the adsorbent, the concentration column is heated to 200 to 250 ° C. Good. The heating method may be any method, such as a method of heating by heating a heating material such as a metal wire around the concentrating column, a method of covering the concentrating column with a jacket and flowing a heating medium in the jacket to heat the concentrating column. Examples thereof include a method of heating by blowing hot air.

<(2) Detection of the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide>
The method (1) for analyzing the VOCs obtained by collecting the gas under the grain storage environment is particularly preferable as long as it can detect the presence or absence of one or more selected from prenol, isoprenol, dimethyldisulfide and dimethyltrisulfide. Although not limited, analysis by gas chromatography (hereinafter referred to as “GC”) or gas chromatography mass spectrometry (hereinafter referred to as “GC-MS method”) is preferable. Among them, in order to reliably detect the presence or absence of one or more selected from prenol, isoprenol, dimethyldisulfide, and dimethyltrisulfide in a grain-storage environment where various VOCs are generated, VOCs can be detected by GC before mass spectrometry. The GC-MS method for separating the components is more preferable. In the GC-MS method, the method of introducing the sample into the GC is not particularly limited, and a known method such as a heat desorption method or a solvent extraction method can be used. In particular, in the present invention, the thermal desorption method is more suitable than the solvent extraction method, since a trace amount of highly volatile components is analyzed.
When TenaxTA or TenaxGR is used as the above-mentioned adsorbent, after adsorbing a gas under a grain storage environment, rapid heating is performed while passing an inert gas such as helium through a concentration column containing the adsorbent, thereby increasing the VOC. Can be desorbed in a gaseous state, and then the main VOC can be analyzed by performing analysis by the GC-MS method. In addition to the technique by heating, the components adsorbed by the adsorbent can be back-extracted into the solvent and used. In this case, a method of concentrating the extraction solvent with an evaporator or the like, or a method of injecting a large amount into GC-MS without concentrating (for example, the method of Gestel or Ice Tea Science) can be selected.

Since the gas generated during the growth of larvae of stored grain pests has a very complicated composition, it is important but difficult to detect the component of interest as a single peak during analysis.
For example, it is difficult to detect isoprenol, which was focused on in the present invention, by separating it from pentan-1-ol (chemical formula: C ₅ H ₁₂ O), and it is necessary to identify it in a total ion current chromatogram (TICC) of GC-MS. I can't. On the other hand, as a result of examining the mass-to-charge ratio (m / z) of each component of the evolved gas during the entire test period in which the larva of the stored grain pest grows, the molecular ion peaks (m / z = 86) of prenol and isoprenol were found to be mass chromatographies. Although not a base peak (peak with the strongest intensity in the spectrum) in gram (MC), it was found to be a peak that can be used for detecting the occurrence of stored grain pests at the larval stage of hatching, and the present invention was completed. It has come to do. In the future, in the present invention focusing on the molecular ion peaks of prenol and isoprenol, the CI ionization method, which is a softer ionization method than the EI ionization method, may be adopted to reduce fragmentation and facilitate detection. is there.
Moreover, if an ion molecule reaction type mass spectrometer (IMR-MS) utilizing an ion molecule reaction (for example, “Soft ionization mass spectrometer Airsense (trade name)” manufactured by V & F of Austria) is used, gas chromatography No need for graphic separation.
In addition, dimethyl disulfide and dimethyl trisulfide, which were focused on in the present invention, were analyzed by using data analysis software to analyze the mass-to-charge ratio (m / z) of each component of the evolved gas in the entire period of the test in which the larva of the stored grain pest grows. , Was selected as a component that has a large amount of generated gas and is easily detected. The molecular ion peaks of dimethyl disulfide and dimethyl trisulfide are m / z = 94 and m / z = 126, respectively.
The dimethyl disulfide focused on in the present invention is a substance designated as a specific malodorous substance, and many quantitative techniques in the environment have already been developed. As a simple method for detecting dimethyl disulfide, for example, as a detector tube, "Pyrotec detector tube" dimethyl sulfide No. 53 "manufactured by Gastec Co., Ltd. is a gas alarm equipped with a small selective sensor. As a container, there is "Drager X-am 5600" manufactured by Dräger Japan, and these can also be used for dimethyl trisulfide.
By analyzing the gas collected from the grain storage environment and confirming the presence of any of prenol, isoprenol, dimethyldisulfide, and dimethyltrisulfide, and the ratio thereof, it is possible to infer the stored grain pest species. I think.

<(3) Notification of presence / absence of stored-grain pests based on the detection result>
The stored-grain pest detecting device of the present invention has (3) means for reporting the presence or absence of stored-grain pests based on the detection result. When the presence of one or more kinds selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide in the gas under the storage environment is detected, it means that the storage insect pest is detected by, for example, an image, a character, The notification can be performed by a visual method such as color display or light emission, an auditory method such as voice, or a combination thereof. When the notification is performed by a visual method, the notification is performed by displaying an image or a character as a display device, for example. Alternatively, the notification may be given by causing a light emitting element such as an LED to emit light. When the notification is performed by an auditory method, the notification is performed by outputting an alarm sound or a voice guide, for example, as a sound generating device such as a speaker. The notification is not limited to a visual or audible method, and may be any method recognizable by the manager of the grain storage environment. For example, the notification may be given by a vibration pattern or the like.

<Regarding the stored-grain pest detector of the present invention>
The stored-grain pest detection device of the present invention is a detection unit that is a unit that is a unit that collects gas in a storage environment, and is a unit that is a unit that detects the presence or absence of one or more selected from prenol, isoprenol, dimethyldisulfide, and dimethyltrisulfide. Further, it has a notifying unit which is means for notifying the presence or absence of stored-grain insects based on the detection result. It is preferable that the collecting section is composed of an air pump section for sucking gas under the grain storage environment and a concentration column section containing an adsorbent and having a heating section. When only dimethyl disulfide and dimethyl trisulfide are detected, an electrochemical sensor can be used as a detecting means. In this case, it is preferable that the electrochemical sensor is exposed to the gas collected from the grain storage environment or the gas under the grain storage environment is sent to the electrochemical sensor.
The collection part and the detection part are connected, and after collecting the gas under the grain storage environment, the work to automatically detect the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide is automatically performed. Good. Even if the collection unit and the detection unit are not connected, at least one selected from prenol, isoprenol, dimethyldisulfide, and dimethyltrisulfide is collected at the timing according to the purpose after collecting the gas under the grain storage environment. You may artificially perform the work which detects.
When the detection unit detects the presence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide, the notification unit and the notification unit are provided so that the notification unit can promptly notify the presence of the stored-grain insect. The parts are preferably linked.

<Regarding the stored-grain pest detection method of the present invention>
As an aspect of the stored-grain insect detection method of the present invention, (1) only the step of collecting gas under the stored-environment is performed under the stored-grain environment, and (2) selected from prenol, isoprenol, dimethyldisulfide and dimethyltrisulfide in the gas. The step of detecting the presence / absence of one or more types includes the step performed at a place remote from the grain storage environment. For example, in a plurality of grain warehouses, food factories, etc., gas under a storage environment is collected, and the collected gas sample can be detected for the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide. It is also possible to carry out the step of collectively detecting the presence of stored-product insect pests by concentrating on a center or the like. The form of the collected gas sample is, for example, a form in which the collected gas is simply filled in an aluminum bag without any treatment, or a form in which the adsorbent collects the gas in the storage environment for a certain period of time under the storage environment. In addition to the above, a form in which a gas under a grain storage environment is collected in a collecting tube filled with an adsorbent can be mentioned. This embodiment is useful because it is not necessary to provide an analyzer or the like capable of detecting the presence or absence of one or more kinds selected from prenol, isoprenol, dimethyldisulfide and dimethyltrisulfide for each grain storage environment.
On the other hand, in a huge grain warehouse such as a country elevator, the gas under the grain storage environment is collected at multiple locations and the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide is detected to detect silos. It is possible to grasp the location of the stored-product insects in such a huge tank. By limiting the place where the stored grain pests are generated, the damaged grain can be minimized, and the labor and cost of the control measures can be reduced, which is useful from the viewpoint of IPM.
In addition, by collecting the gas in the packaged bags and detecting the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide, it is possible to confirm the presence or absence of the stored grain pests in each bag. It is possible. It is possible to find a bag in which stored-grain pests are occurring from a large number of bags, and it is possible to minimize the loss of cereals, which is effective.

<About stored-pest insects>
The stored grain pest targeted by the present invention means a pest that harms cereals. Specifically, for example, Nosima Medaragai, Aedes aegypti, Aedes aegypti, Chamadara maiga, Bakuga, Gaimaitsuduriga, Ittenkoga, Koguga, Kasinoshimagaiga, Koumenosimagaiga, Koga, Kokumaruhabiga moth, corn leafworm, etc. , Weevil, Weevil, Weevil, Granaria Weevil, Pleurotus vulgare, Pleurotus esculentum, Saw beetle, Beetle, Beetle, Beetle, Beetle, Beetle, Beetle, Beetle , Aphididae beetle, Guimai beetle bug beetle, Pleurotus spp., Pseudococcidae symbiont, Pleurotus spp., Pleurotus sp. Ginkgo, Azuki bean weevils, Bean weevil, Lepidoptera weevil, Acalyca weevil, Pleurotus speciosus, Haukakumunehiratamushi, Turkish Kakunemirahirataushi, Kashimirakukusumotokioki, Otsunokokokuchikudoku, Himekokukusuto, Himekokukusuto, Himekokukusuto, Himekokokusutoshi Symphonia lucidum, Pleurotus chinensis, Kurohiratacokunusutomodoki, Komenokeshikisu, Kuriyakeshikisuui, Semale leopard beetle, Naga beetle beetle, Brazilian bean weevil, Stinkbill beetle, Kadokobushihogoshi, beetle squirrel, beetle, beetle, beetle, beetle. Coleoptera (Coleoptera) pests such as Tenebrionidae, Tenebrionidae, Hirata-Chatate, Katsubushi-Chatate, Tsuyako-Chatate, Kocha-Tate, Saw Nchatate, mention may be made of 囓虫 Lepidoptera such as mouse Gros Chatate, Yamatoshimi, firebrat, the adults and larvae, such as Thysanura pests such as silverfish.
INDUSTRIAL APPLICABILITY The present invention exerts an excellent effect on early detection of the occurrence of stored grain pests including the pests exemplified above. Among them, the present invention is, Noshimemadaragaiga, Aedes aegypti, Aedes aegypti, Chamadara mayga, Bakuga, Gaimatsutsurigiga, Ittenkoga, Koga, Kashinoshimagaiga, Koumenoshimagaiga, Koga moth, corn scales, corn leafworm , Weevil, granaria weevil, stag beetle, stag beetle, sawtooth leaf beetle, stag beetle, stag beetle, stag beetle, beetle bug, beetle bug, beetle bug, beetle bug, beetle bug, beetle bug Tenebrion beetle, Tail beetle beetle, Beetle beetle, Beetle scarlet beetle, Beetle beetle, Beetle beetle beetle, Beetle beetle, Beetle Azuki bean weevils, bean weevils, leaf weevil, white-beetle weevil, scutellaria japonicum, stag beetle, stag beetle, turkey stag beetle, beetle stag beetle, beetle stag beetle, beetle stag beetle, beetle stag beetle, beetle stag beetle, beetle stag beetle, beetle stag beetle, beetle beetle. Coleoptera (Coleoptera) pests of Hosochibikokunusuto, Kurohiratakunokusutomodoki (Coleoptera), Hiratachata, Katabushichata, Tsuyakochata, Kochata, Pteridophyta of Saomenchata, Usugurochata, total insect pests of Yamatosimi, Madaramidami, Tadashi It is effective against lepidopteran pests of Nomemedarameiga, Susimamadarameiga, Sudikonamidamaiga, Chamadaramaiga, Bakuga, Gaimatsuduriga, Ittenkogaga Weevil, Weevil Weevil, Granaria Weevil, Weevil Beetle, Hemlock Weevil, Sawtooth Beetle, Beetle Beetle, Beetle Beetle, Beetle Beetle, Beetle Beetle, Beetle Beetle, Beetle, Beetle, Beetle Pteridophyta (Coleoptera), Pleurotus sp. It exhibits a more excellent effect in early detection of the development of pests of the common eye, Yamatosimi and Madarasimi.

Hereinafter, the present invention will be described with reference to examples, but the technical scope of the present invention is not limited thereto.
The method / means for detecting the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide is as follows.
<Analyzer>
GC-MS: Agilent 5973 (manufactured by Agilent Technologies)
GC column: DB-Wax (60 m length, 0.25 mm i.d., 0.25 μm df) was connected to the tip of a hollow (unmodified) fused silica capillary column (0.57 m length, 0.10 mm id). used.
<Analysis conditions>
The analysis temperature was maintained at 40 ° C. for 1 minute, then the temperature was raised to 240 ° C. at 4 ° C./minute and maintained for 8 minutes.
Carrier gas flow rate: 1.0 mL / min (constant flow)
Mass spectrometer: m / z scans the range of 20 to 400 Ionization voltage: 70 eV

<Example 1> Investigation of trends in the amount of prenoles and isoprenol generated from Nosima Medalla lava (1) Collection of volatile components (VOC) Brown rice (100 g) and Nomemedara Mayaga in a glass container (iwaki NEW clear pack, capacity: 1 L) The eggs (about 200 pieces) were put into a lid, the lid was placed in a laboratory at 25 ° C., and volatile components were analyzed with time.
The lid of the container was provided with two openings provided with an inlet septum (manufactured by Shimadzu Corporation), and each opening was filled with an adsorbent (Tenax TA) using a needle and a luer lock joint. A collection tube (TDU tube, manufactured by Gestel) was connected. One collection tube was connected to an atmospheric suction pump (SP208-100Dual II, manufactured by GL Sciences Inc.) and sucked at a rate of 100 ml / min to collect volatile components (VOC) in the test glass container. It was collected by introducing it into a collecting tube and adsorbing the components to an adsorbent. The amount of gas sucked was 5L. The other collecting tube was opened, and air sucked from the inside of the test glass container was replenished. At that time, in order to prevent the volatile component (VOC) in the laboratory from being mixed in the supplemented air, the volatile component (VOC) in the laboratory was captured by the adsorbent in the collection tube.

(2) Analysis The volatile component (VOC) collected in the adsorbent was thermally desorbed using a thermal desorption unit (TDU, manufactured by Gestel). The heating and desorption conditions were such that the temperature was maintained at 40 ° C. for 30 seconds, then the temperature was raised to 240 ° C. at 12 ° C./second, the temperature was maintained for 5 minutes, and a carrier gas (helium) was flown in splitless mode. The transfer line of the thermal desorption unit and the cooled injection system was 300 ° C. The temperature rising vaporization type injection port was cooled to -40 ° C in advance, and the volatile component (VOC) was cryofocused in the solvent vent mode at a flow rate of 60 ml / min during the thermal desorption time.
Upon completion of thermal desorption, simultaneously with the start of GC analysis, the inlet was rapidly heated to 240 ° C. at 12 ° C./sec and held for 5 minutes to introduce a volatile component (VOC) into the GC / MS system.

(3) Test progress In order to detect the occurrence of stored-product pests by volatile components (VOC), pay attention to different components compared to headspace gas (HSG) of cereals in which stored-product pests are not generated. .. Although it may be statistically processed by using metabolomics for comprehensive analysis, this time visual difference analysis was performed.
No significant difference was observed in the total ion current chromatogram (TICC), but due to the difference in odor, when the spectra of the peaks with the same retention time (RT) were compared one by one, RT was 20. At the peak of 9 minutes, although there was no peak of m / z = 86 in the test plot (control) where no stored grain pests were generated, in the test plot where Nosed Medallion was released, m / z = 86 It was confirmed that a peak was present.
When the peak at m / z = 86 was monitored, it was revealed that the peak occurred immediately after the start of the test and that it increased with time. When the time further passed, a peak of m / z = 86 appeared even at RT of 23.2 minutes. As a result of detailed examination of the two peaks at m / z = 86, the peak at m / z = 86 existing in the peak at RT of 20.9 minutes is isoprenol, and the peak at RT of 23.2 minutes. It was a prenol and 86 was found to be the respective molecular weight.

FIG. 1 shows the amount of prenol generated from Nostoc commune, and the amount of isoprenol generated in FIG. 2 measured over time. The vertical axis of FIGS. 1 and 2 is the logarithmic value of the peak area of the mass chromatogram at m / z = 86.
Eggs of Nostidae larvae hatch within a few days and become larvae, and become adults over 1-2 months. As shown in FIGS. 1 and 2, isoprenol was detected 3 days after the start of the test, and although the reason was unknown, prenol was also detected 30 days after the start of the test, and the gas under the grain storage environment was collected, and the prenol in the gas was collected. By detecting and / or isoprenol, it has become clear that stored grain pests can be detected.

In addition to the method described in "(1) Collection of volatile components (VOC) of Example 1" described above, MonoTrap (registered trademark) RGPS-TD (manufactured by GL Sciences Inc.) was placed in a test glass container for 24 hours. I let it stand. It was confirmed that the stored-grain pests could be detected by heating and desorbing and analyzing this.
It was confirmed that the method of placing a plurality of MonoTrap (registered trademark) depending on the size of the grain storage environment is also useful in the practice of the present invention.
In addition, as a result of analysis of gas components generated during growth of larvae hatched from eggs for stored-grain pests other than Nostoc commune, the occurrence of prenol and / or isoprenol was confirmed in all investigated species.
Next, the production amounts of prenols and isoprenol of the stored grain pest species are verified in Example 2.

<Example 2> Investigation of trends in the amounts of prenoles and isoprenol generated according to stored-product insect pests 1-1
The same test as in Example 1 was carried out using, as the stored-grain pests, white-spotted moths, white-spotted moths, chamadal-moths, and red-spotted moths.
FIG. 3 shows the amount of prenol generated and the amount of isoprenol generated for each stored grain pest species measured with time. Moreover, the mass chromatogram of the molecular ion peak (m / z = 86) for each of the stored grain pest species on the 15th and 65th days from the start of the test is shown in FIG.
As shown in FIGS. 3 and 4, although there was a difference in the amount generated depending on the stored grain pest species, the generation of prenol and / or isoprenol was confirmed in all.
Note that the data on the first day of control in FIG. 4 is considered to be due to contamination in which isoprenol was detected because regeneration of the used adsorbent was insufficient. By retesting at a later date, it was confirmed from the first day that no isoprenol was generated in the test plot (control) where no stored grain pests were generated, and it was concluded that contamination was the cause.

<Example 3> Trend study on the amount of isoprenol generated by stored-pest insects 2-1
The same test as in Example 1 was carried out using weevil and Welsh beetle as storage grain pests.
FIG. 6 shows the amount of isoprenol generation in the weevil, which was measured with time.
Elephant weevil eggs hatch and become larvae within a few days and become adults within about one month. As shown in FIG. 6, 14 days after the start of the test, isoprenol was detected, and it was revealed that the stored insect pest can be detected by collecting the gas under the grain storage environment and detecting the isoprenol in the gas.
Probably due to its preference for cereal flour, the growth rate was slow in this test system using brown rice, and isoprenol was detected 26 days after the start of the test.
By this test, it was confirmed that the occurrence of stored grain pests belonging to the order Coleoptera (Coleoptera) can be detected in addition to stored grain pests belonging to Lepidoptera pests.

<Example 4> Trend study of generation amounts of prenol and isoprenol of stored-pest insect types 1-2
As described above, in Example 2, the measured data value was considered to be derived from the insufficient regeneration of the adsorbent used, and therefore the retest was performed.
As storage grain pests, using Noshimemadaraiga, Susimamadarameiga, Sudikonamidamaiga, Chamadaramaiga, Gaimaitsutsurigiga, the volume of the glass container of Example 2 was changed to 500mL, except that the test was carried out in 2 repetitions. The same test was conducted.
FIG. 7 shows the average value of the amount of prenol generated for each stored-grain insect pest, and FIG. 8 shows the average value of the amount of isoprenol measured over time.
As shown in FIGS. 7 and 8, although there was a difference in the generated amount depending on the stored grain pest species, the generation of prenol and / or isoprenol was confirmed in all. Also, this time, normal test results were obtained without problems such as contamination.

<Example 5> Investigation of trends in the amount of isoprenol generated by stored-grain insects 2-2
In Example 3, although it was possible to detect the generation of isoprenol in Pleurotus cornucopia, it was not possible to clearly indicate it as the logarithmic value of the peak area of the mass chromatogram at m / z = 86 because the amount generated was small. Therefore, the test was repeated in the same manner except that the capacity of the glass container of Example 3 was changed to 500 mL and the test period was lengthened to perform the test in two repetitions.
The average value of the isoprenol generation amount of the weevil and the peanut beetle measured over time is shown in FIG. 9.
As shown in FIG. 9, isoprenol was detected in the weevil on the 22nd day of the test and on 53rd day of the test for the corn stinkweed.
By this test, for stored grain pests belonging to the order Coleoptera (Coleoptera) as well as stored grain pests belonging to Lepidoptera pests, gas under the grain storage environment is collected, and isoprenol in the gas is detected to detect stored pests. It became clear that it could be detected.

<Example 6> Trend study of generation amount of dimethyl disulfide and dimethyl trisulfide of stored insect pests 3-1
The generation transition of dimethyl disulfide and dimethyl trisulfide was investigated in the experiment of Example 5 in which weevil and cornweed were used as stored grain pests. The monitor peak is a peak at m / z = 94 for dimethyldisulfide and a peak at m / z = 126 for dimethyltrisulfide.
The dimethyl disulfide generation amount and the dimethyl trisulfide generation amount measured with time are shown in FIG. 10 and FIG. 11, respectively.
As shown in FIGS. 10 and 11, the generation of dimethyldisulfide and / or dimethyltrisulfide was confirmed in the weevils and the Japanese weevil, although there was a difference in the generation amount.
It should be noted that, since 20 days after the start of the test, a large number of kinds of gases are generated, so that the peaks of dimethyl disulfide and dimethyl trisulfide have other M / z = 94 and m / z = 126 ions. It is not possible to clearly distinguish from the components, and there is a “fluctuation” in the data that the amount of gas generated increases and decreases on the drawing, but it can be confirmed that dimethyl disulfide and dimethyl trisulfide are both generated during this period. It was
By this test, it was revealed that even for stored grain pests belonging to the order Coleoptera (Coleoptera), the stored grain pests can be detected by collecting gas under the storage environment and detecting dimethyldisulfide or dimethyltrisulfide in the gas. became.

<Example 7> Investigation of trends in the amount of dimethyl disulfide and dimethyl trisulfide generated by stored-pest insects 3-2
In the experiment of Example 4 in which Nosume Medara-gaiga, Suspicillus latipera, Chamadala-gaiga, Sugimadara-gaiga and Gaimaitsuduriga were used as stored-grain pests, the occurrence transition of dimethyldisulfide and dimethyltrisulfide was investigated.
FIG. 12 shows the amount of dimethyl disulfide generated for each stored grain pest species, and FIG. 13 shows the amount of dimethyl trisulfide generated, measured over time.
As shown in FIGS. 12 and 13, the generation of dimethyl disulfide and / or dimethyl trisulfide was confirmed in Noshimemadaraiga, Sudikonomadaimaiga, Chamadarameiga, Sujimamadaraiga, Geimatsutsurigiga, although there is a difference in the amount generated. ..
By this test, even for stored grain pests belonging to the stored grain pests belonging to Lepidoptera pests, it is clear that the stored grain pests can be detected by collecting gas under the grain storage environment and detecting dimethyldisulfide or dimethyltrisulfide in the gas. Became.

According to the stored grain pest detection method or the stored grain pest detection apparatus of the present invention, hatched larvae are monitored by monitoring one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide in a gas under a grain storage environment. It is possible to early detect not only the lepidopteran pests of the time period but also the beetle (Coleoptera) pests in various grain storage environments, that is, the occurrence of the grain storage pests.
Furthermore, according to the present invention, it is possible to detect the occurrence of stored-grain pests earlier than the traps that have been conventionally used, and therefore it is possible to implement the control measures while the damage to the grains is small. It is possible to obtain an effective control effect.

Claims (3)

A stored grain pest detection method comprising the following steps (1) and (2):
(1) A step of collecting a gas under a grain storage environment (2) A step of detecting the presence or absence of one or more kinds selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide in the gas   The stored-grain pest detection method according to claim 1, wherein the stored-grain pest is one or more species selected from Lepidoptera and Coleoptera (Coleoptera). A stored-grain pest detecting device comprising the following means (1) to (3).
(1) Means for collecting gas under grain storage environment (2) Means for detecting the presence or absence of one or more selected from prenol, isoprenol, dimethyl disulfide and dimethyl trisulfide in the gas (3) Based on the detection result Means for reporting the presence or absence of stored-grain pests