JPH0778001B2 - Communication disruption method - Google Patents

Description

The present invention relates to a method for controlling pests by a pheromone communication disruption method.

(Prior Art) A method for controlling pests using pheromones as a communication disrupting agent is widely considered to be a method for reducing the use of pesticides, and its potential is expected.

(Problems to be solved by the invention) However, in this control method, the effect is not sufficiently exerted unless the density of the target pest is low at the initial stage of using the pheromone, and it is difficult to maintain an effective concentration in a windy area. It is known to have two drawbacks:

As a countermeasure, in order to maintain the concentration of pheromones and prevent the invasion of pests from the outside, a method of covering the entire field initially was considered, but it is economically difficult to cover the entire large area. Not implemented.

As a result of various tests conducted by the present inventor, the inventors have found that a sufficient effect can be obtained by using a net having air permeability with a certain opening only around the target crop, and arrived at the present invention. did.

(Means for Solving the Problem) The method of communication confusion using a pheromone according to the present invention is to arrange a net having air permeability of a height corresponding to the flight height of a target pest around a crop, in which the pheromone is placed. It aims to control pests by diffusing.

The air-permeable net used in the present invention may be made of any material such as vinylon, polyester, and polypropylene as long as it has excellent weather resistance. Not only fine nets are expensive and uneconomical, but they also have poor ventilation and, in some cases, can hinder the growth of crops. On the other hand, too coarse particles cause invasion of target pests and increase air movement, making it difficult to efficiently disrupt communication by pheromones. Therefore,
The mesh size of this net is usually 0.01 to 5 mm.

As a more preferable mode of use of the net, the upper and lower openings of the net are changed so that the lower opening at a height of 10 to 60 cm above the ground has a relatively poor air permeability of 0.01 to 2 mm. The upper part of the opening from ~ 40 cm to about 60 to 200 cm should have a coarse opening of 0.1 to 5 mm to prevent insects from invading, or the opening should be gradually expanded from the bottom to the top. By doing so, the pheromone concentration in the area can be maintained at a predetermined value to achieve effective control of pests, and at the same time, sufficient air permeability required for crops can be secured.

The height of the net can be arbitrarily selected and adopted according to the size of the crop, the flying height of the target pest, and the like. As an example, a fine net with a height of 30 cm, a coarse net of 1.2 m at the top for Chahamaki and Kokakumon Hamaki, a fine net of 20 cm at the bottom and a coarse net of 90 cm at the top can be used for Konaga. it can.

The net is also preferably used around the entire circumference of the crop, but in consideration of economic efficiency, the net can be used only on the side of the crop hosting the target pest, and the upper and lower sides in the wind direction.

One of the advantages of the method of the present invention is that by arranging the net around the crop before using the pheromone, even if the density of the target pest in the adjacent field at the start of the use of the pheromone is high, the pheromone can be used. Is the point where the effect of is demonstrated. In other words, in areas such as Gunma and Nagano prefectures where the density of diamondback moths decreases due to low temperatures in winter, the effect of using pheromones can be increased without the use of nets, but in Southeast Asia and parts of Kyushu, the growth of each species can be improved. Since there is a stage crop and the temperature is also sufficiently high, the density of diamondback moth is already high around the pheromone when the pheromone is used, and the effect of using the pheromone cannot be enhanced by the conventional methods. However, even under such conditions, the field is left unused for 1 to 2 weeks after harvesting to reduce the density of diamondback moth, and then a pheromone is used after the net is stretched around the field according to the method of the present invention. If so, the effect of using the pheromone can be fully exerted.

As the type of pheromone used in the present invention, the pheromone of the target pest may be used, but the amount of the pheromone can be more effective than when the net is not used.

Pests suitable for applying this method include those of the genus Spodoptera, such as the diamondback moth, chachamaki, teaspot beetle described above, as well as Hasmonyoto, Shiroiimonjitoto, and Egyptian Cotton Leaf Worm.

(Examples) Hereinafter, specific embodiments of the present invention will be described with reference to Examples and Comparative Examples, but the scope of the present invention is not limited to the types and heights of the nets described in these Examples.

Example 1. A vinylon net with an opening of 0.2 mm and a height of 1.2 m was stretched all around the tea plantation, and Hamakicon (Shin-Etsu Chemical Co., Ltd., pheromone formulation) was provided with 300/10 are and 250 / Ten
Treated with Earl. Also, for comparison, the above nets were not processed and processed with 300 pieces / 10 ares. In each field, the mating rate of the females was measured. The results are shown in Table 1.

Example 2. A cabbage was planted by connecting a net having a mesh of 0.1 mm and a net of 30 cm and a net having a mesh of 1 mm of 90 cm to each other, with the former facing downward, around the field. Ten days after planting, a tubular pheromone preparation (AIZ-11-HDA: Z-11-HDAL = 1:
1, 0.25 g / m) was processed at 100 m / 10 are. After 1 month, the density of diamondback moth larvae was measured. For comparison, the larval densities of the group using the pheromone formulation without the net, the group using the net without using the pheromone, and the group using neither the net nor the pheromone were also measured.

The results are shown in Table 2.

Example 3. Various fences shown in the table below were placed in a field of scallions immediately after planting of scallions, and after 5 days, 100 pheromone formulations for Shiroiemon swordfish were treated per 10 ares. After 45 days, the density of larvae per 10 strains of Allium edodes was measured. The results are shown in Table 3.

(Effects of the Invention) According to the method of the present invention, effective control of pests by pheromones can be carried out even when the density of target pests is high at the initial stage of use of pheromones, or even when wind is strong and it is difficult to maintain the effective concentration. You can

Claims (2)

[Claims] 1. When controlling a pest using a pheromone, a net having air permeability of a height corresponding to the flying height of the pest is placed around the target crop, and the pheromone is diffused therein. Communication disruption method. 2. The communication disruption method according to claim 1, wherein the nets have different openings in the upper and lower sides, the upper openings are 0.1 to 5 mm and the lower openings are 0.01 to 2 mm.