JP2619683B2 - How to reduce mosquitoes in the area - Google Patents

Description

The present invention relates to a method for reducing the number of mosquitoes in an area in which a large number of egg-laying containers for killing mosquito larvae (bow fowl) are dispersed and arranged in the area.

(Prior art) According to research reports, etc., which applied insecticides such as fenitrothion to 15 g per 1 m ² according to the enforcement order of the Infectious Disease Prevention Law, the effect on water containers etc., which are mosquito spawning sites, It is claimed to be within one week. Today, it is not possible to use a highly persistent insecticide from the viewpoint of pollution, and it is said that the effect of the insecticide in a very short time is not effective for driving mosquitoes in the area.

(Problems to be Solved by the Invention) As an exterminating means that does not use an insecticide, only a method of removing all the small water areas, such as bamboo stumps, tree canals, empty cans, florets, and cups, which are mosquito spawning sites, remains. Although it is not, it is not realistic to remove all water containers and the like in the area. Rather, it is effective to reduce the number of mosquitoes by actively dispersing a large number of mosquito spawning containers in the area, letting most of the eggs lay in this container, and killing hatched bow hula in this container. The present invention has been devised based on the findings described above.

(Means for solving the problem) Copper or tin, which kills or suppresses the growth of mosquito larvae (bow hula), is thrown into an egg-laying container filled with water, and metal ions are dissolved in the egg-laying container. Since Aedes albopictus lays eggs not on water but on the wall surface of the container, the container is not filled with water, and the wall surface is preferably not smooth like plastic but has a fine uneven surface like ceramics, wood or carbon. As the dissolving ion, a copper ion or a copper compound (Rokusho) ion is particularly preferable, but a tin or silver ion source having a strong insecticidal action may be used.

A large number of these spawning containers are dispersed and arranged in the area, and empty cans, etc. suitable for spawning in the area are arranged so that only the adult mosquitoes (females) in the area spawn only in the spawning container. Either remove the small container in advance, or throw a copper or tin piece into the small container or the puddle in advance, so that these small containers are also unsuitable for larval growth.

(Effect) Eggs such as Aedes albopictus laid on the inner wall surface or water surface of the egg-laying container hatch into larvae (bowgrass),
Grow in water in containers. Larvae molt three times to become pupae (adults). The young larvae of the first and second instars suppress overgrowth by emitting overdensity-controlling hydrocarbons, and the hydrocarbons are metabolized by bacteria in water to produce highly toxic 3-methylalkanone. It is said that it becomes acid and increases the mortality of young larvae. In the present invention, copper ions and tin ions dissolved in water act as growth inhibitory factors for young larvae, and significantly increase the mortality of young larvae. Young larvae hatched in the spawning container die entirely.

Assuming that the suitable place for laying eggs in the region is the egg-laying container, all the eggs laid by the adults in the region are performed in the egg-laying container. The anniversary generation of Aedes albopictus is
The overwintering eggs hatch in early April to produce the first generation, the first-generation adults appear in mid-May, six generations by early and mid-September, and part of the seventh-generation eggs and the eighth generation It is estimated that the majority of eggs will overwinter. Depending on the mosquito's radius of activity, the spread of spawning vessels over a large area will result in a rapid decline in adult numbers and eventually extinction.

(Example) Water is poured into a black spawning container (1) having a diameter of about 16 cm,
A piece of copper (2) is placed in this water (FIG. 1). A plurality of the spawning containers (1) are arranged around the house (3) as shown in FIG. Fill each spawning container (1) with water early in the morning on August 19.
The solid line (a) in FIG. 3 shows the number of larvae in the container (1) containing only water, and the number of young larvae increased after 3 days and kept at a high level thereafter. The dashed line (b) indicates the number of larvae in the container (1) in which the copper ion was completely removed after the copper ion water was charged and copper ion was attached to the inner wall surface in which only water was newly added. Instar larva appears. At first, growth of the larva is suppressed or killed by the insecticidal action of the attached copper ions (copper compound ions), but the larva begins to grow from day 7 due to disappearance of the activated copper ions. The dotted lines (c) and (d) show the case of the container (1) containing the copper piece (2), and the container (1) of the dotted line (c) throws the copper piece () on August 22, The dotted line (d) shows the copper piece (2) thrown on August 25, and the young larvae rapidly decrease due to the dissolution of copper ions. Larvae that have become larger, such as the third and fourth instars, become pupae and emerge and fly out rather than decrease in this case. Since the insecticidal action of the copper ion of the present invention is extremely weak, the effect is remarkable only on the first and second instar young larvae.

(Effect) In short, the present invention provides an egg-laying container (1) for producing copper ions or tin ions that kill or inhibit the growth of mosquito larvae.
In order to allow eggs such as Aedes albopictus to be laid in this container, all of the hatched larvae die and the mosquitoes in the area are scattered. Alternation of generations will be suppressed and mosquito growth will decrease significantly.
In particular, in an area where the environment is maintained and where there are many greens such as trees, an artificial micro-water area is created, and the occurrence of Aedes albopictus due to an increase in the number of humans serving as a blood-sucking source is remarkable, and it works effectively in such an environment.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a cross-sectional view of an egg-laying container, FIG. 2 is a layout diagram of the egg-laying container, and FIG. 3 is the number and measurement of larvae generated in the placed egg-laying container. It is a graph which shows the relationship with a day. 1 ... Egg laying container, 2 ... Copper pieces

Claims (3)

(57) [Claims] 1. A substance for killing or inhibiting the growth of mosquito larvae is dissolved in an egg-laying container filled with water, and a large number of such egg-laying containers are arranged and dispersed in a region, and eggs such as Aedes albopictus are laid in this container. A method of diminishing hatching larvae and killing hatched larvae. 2. The method according to claim 1, wherein copper or tin is placed in the spawning container. 3. Preliminarily removing micro-water areas suitable for spawning of mosquitoes in the area, or throwing copper or tin into these micro-water areas, and then killing or growing mosquito larvae A method for gradually reducing mosquitoes in a region, comprising dissolving a substance to be suppressed in an egg-laying container filled with water and arranging a large number of such egg-laying containers in the region.