JPH01132501A - Oviposition repellent for cigarette beetle - Google Patents

Abstract

PURPOSE:To obtain an oviposition repellent for cigarette beetle, containing serricorone as an active ingredient, capable of preventing oviposition of cigarette beetle damaging leaf tobacco or stored foods by eating and remarkably inhibiting occurrence by applying to a place readily providing an infestation source of the above-mentioned beetle. CONSTITUTION:An oviposition repellent containing serricorone expressed by the formula [= 2,3-dihydro-3,5-dimethyl-2-ethyl-6-(1-methyl-2oxobutyl)-4H-pyran-4- one] as an active ingredient. Although the compound expressed by the above- mentioned formula has attracting action on male imagoes of cigarette beetle and can be isolated from female imagoes thereof, pyranone obtained by treating 4methylheptane-3,5-dione and propionaldehyde with BF3 can be condensed with propionic anhydride and zinc chloride to readily synthesize the afore-mentioned compound in high yield. The above-mentioned compound, together with a carrier or adjuvant, is prepared in the form of wettable powder, emulsion, dust, etc., and applied to a place readily providing an infestation source. The application amount of the active ingredient is 50-200mug/m<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an egg-laying repellent for the tobacco leaf beetle, which is known as an important pest that damages leaf tobacco and stored foods.

(Prior Art and Problems to be Solved by the Invention) Tobacco beetles are widely distributed throughout the world, and have long been known as pests whose larvae damage leaf tobacco and stored foods. Recently, in response to rapid urbanization and changes in lifestyles, cases of this disease have begun to appear in places never seen before, and this trend is gaining momentum.

For example, damage has been reported to tatami mats in apartment complexes, animal feed, and seafood.

In this way, methods for controlling indoor pests, especially those that target food, are subject to health and safety constraints due to their interaction with humans, making it difficult to take complete control measures such as spraying insecticides. There are many cases.

Traditionally, in tobacco manufacturing factories, smoke control methods have been used to control tobacco beetles using DDVP agents when operations are stopped at night when no one is around, and in conjunction with this, traps equipped with sex attractants have been used to kill tobacco beetles. Implemented. Other measures are being taken, such as cleaning areas that are likely to be breeding grounds for insects and minimizing the number of sources. However, the above chemical control methods are completely ineffective against eggs, mosses, and larvae other than adult insects, and they are also completely effective against narrow gaps in buildings, equipment, and equipment, as well as tobacco debris that is present in these gaps. Currently, it is desired to develop a pest control method that can be used in such places.

First, the present inventors focused on the fact that the chemical substances secreted by tobacco leaf beetles when they lay eggs have the habit of repelling other female adults from laying eggs in that location. We proposed a method to control insect damage by preventing. That is, as a result of searching for compounds that have the property of repelling egg laying against the insects, fatty acids represented by the general formula CH:l(CH2)-COOH (where n in the formula is an integer from 6 to 11) was found to be effective as a repellent (Japanese Patent Publication No. 61-56205). However, since fatty acids have a unique odor, the use of these substances is undesirable in terms of the working environment.

The present inventor carried out this invention with the aim of providing a Fll'J repellent for the tobacco leaf beetle that is not subject to restrictions in use and is effective even in a small amount.

(Means for Solving the Problems) The present inventors extracted an egg-laying repellent component from the body of a female adult tobacco beetle and examined the use of this substance as an egg-laying repellent.

The oviposition-preventing W agent for tobacco beetles of the present invention is a compound represented by the following formula, 2,3-dihydro-3゜5-dimethyl-
2-ethyl-6-(1-methyl-2-oxobutyl)-
4H-bilan-4-one (hereinafter referred to as sericolone)
The active ingredient is

Sericolone was isolated from female adult tobacco beetles, and the present inventors have already reported this compound in Japanese Patent Publication No. 17793/1983 as a substance that has an attractive effect on male adult tobacco beetles. It turned out that there is also a substance that is the same as the one revealed in . However, until now, it has not been known at all that this compound is a substance that has an egg-laying repellent effect on female adult tobacco beetles, and that this substance can be used as an egg-laying repellent.

Surprisingly, the strength of Sericolone in repelling spawning is greater than the 10,000% fatty acid described in Japanese Patent Publication No. 61-56205.
Effective at one-fold lower concentration.

Sericolone can be easily synthesized in high yield by condensing pyranone obtained by treating 4-methylhebutane-3,5-dione and propionaldehyde with boron trifluoride with propionic anhydride and zinc chloride. Can be done.

The egg-laying and bow-preventing agent of the present invention can be used by formulating it into a wettable powder, emulsion, powder, granule, etc. with a suitable carrier or auxiliary agent according to a conventional formulation method, and then using it according to a conventional application method. Furthermore, by applying this egg-laying repellent to packaging materials, it is also possible to prevent egg-laying on products.

The amount of active ingredient in the egg-laying repellent of this invention is 50 to 200 μg per square meter, which is a much smaller amount than conventional insecticides.

Hereinafter, this invention will be explained in more detail with reference to Examples.

(Example-1) A hexane solution of Sericolone was prepared, and the treatment group was 2 sheets of muslin cloth with a diameter of 611 to which the addition amount was 0.15 and 1.5.15 ng, respectively, and the control group was unadded. Two pieces of muslin cloth were placed radially in a petri dish with a diameter of 5 cm. A mated female adult is in this petri dish.
The heads were released and allowed to lay eggs in a dark place at a temperature of 28° C. and a humidity of 60% overnight, and the effect of preventing spawning was tested. Table 1 shows the results of comparing the effects on the number of eggs laid on each muslin cloth. The experiment was repeated five times and the average value is shown.

Table-1 (Example-2) 40g of corn flour is evenly packed and has a diameter of 13cm
Two petri dishes were placed 1 m apart in a screened room with an internal volume of 8 m3. An acetone solution was sprayed onto one side of the petri dish so that the amount of Sericolone added was 1 μg to provide a treated group, and the other portion was used as an untreated control group. Approximately 100 tobacco beetles of mixed sexes (Hll) are inside this screen room.
The head was released and left overnight in a dark place at a temperature of 28°C and a humidity of 60% to allow spawning. Each of these corn flours was transferred to a rearing medium (260 g) consisting of a mixture of 92 parts corn flour to 8 parts Ebios (trade name, Tanabe Pharmaceutical Co., Ltd.) at a temperature of 2.
The cells were cultured for 50 days at 8°C and 60% humidity. The egg-laying prevention effect of Sericolon was compared by the number of adults emerging from a medium containing treated corn flour and an untreated control medium.

The experiment was repeated four times and the average value was taken, Table 2
The results shown are obtained.

Table 2 (Example 3) Two 40×40c+++ plastic bags containing 100 g of chopped tobacco were placed in a screened room with an internal volume of 2 m3, and an acetone solution containing 10 μg of Sericolone was poured into the opening of one of the bags. A strip of cloth with a width of 10 cm was applied to each area to serve as a treated area, and the other area was an untreated control area.

Approximately 100 tobacco beetles of male and female mixture (1:1 ratio) were released into this screened room, and after keeping them for one week at a temperature of 28°C and a humidity of 60%, the shredded tobacco in each bag was placed in a rearing container (diameter 13cm, height 7 cm), cultured for 50 days, and counted the number of emerging adults. The experiment was repeated four times and the results are shown in Table 3.

Table 3 (Actions and Effects of the Invention) As is clear from the above examples, the egg-laying repellent of the present invention has the effect of inhibiting the egg-laying of tobacco beetles even in extremely small amounts. By applying this in an appropriate manner to locations that are likely to be the source of tobacco beetle outbreaks, the outbreak can be significantly suppressed.

Applicant: Japan Tobacco Inc.

Claims (1)

[Claims] A tobacco beetle egg-laying repellent characterized by containing the compound sericolone as an active ingredient.