JP2004033197A

JP2004033197A - Preventive removal of mollusc by intermittently charging voltage

Info

Publication number: JP2004033197A
Application number: JP2002229273A
Authority: JP
Inventors: Hiroshi Kawada; 川田　弘志
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-07-04
Filing date: 2002-07-04
Publication date: 2004-02-05

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and preventively remove mollusc giving vermin damage to crops cultivated in agriculture or horticulture without depending on chemicals. <P>SOLUTION: The mollusc is collectively killed or captured by intermittently charging voltage to a closed electrode having a bait and attracting the mollusc to the electrode. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、農業、もしくは園芸において栽培する作物に対して食害を及ぼす軟体動物を効率的に防除する技術に関する。
【０００２】
【従来の技術】
ウスカワマイマイ、ナメクジ、コウラナメクジなどの陸棲の軟体動物による農作物や花卉の葉、花、幼果、新根等への食害は商品価値を減少させ大きな問題となっている。また、近年海外より侵入したスクミリンゴガイは移植直後の苗や直播水稲の芽だし苗を食害して我が国の西南暖地を中心に問題となっている。これらの陸棲軟体動物の防除には、メタアルデヒド剤が広く使われている。また一部にＸＭＣ剤も使われている。スクミリンゴガイの防除は、メタアルデヒド剤、石灰窒素、ＩＢＰ剤等が検討されているが十分な効果を上げるまでには至っていない。
【０００３】
【発明が解決しようとする課題】
軟体動物の防除には、殺傷能とともに誘因性を有し、また急性毒性も低いメタアルデヒド剤が最も広く利用されている。しかし、その効果は環境や生物種に左右され、湿潤な状態や一部のナメクジには効果が劣る。また、ペットなどが大量に摂食した場合、本質的な解毒方法が未だに見いだされていないため致死に至る０から３０Ｖであった。例えば、５０Ｖを付加した場合、ダンゴムシなどは一部死滅する個体が出現し、必ずしも好ましい結果ではない。付加する電圧によってはこれらの軟体動物を完全に殺滅することが出来ない場合もあったが、運動を停止し、限定された場所に集められていることから、容易に排除することは可能である。
【０００８】
電圧を付加する面積は、対象とする軟体動物の大きさ生息範囲にもよるが数十ｃｍ^２から数千ｃｍ^２である。断続的な通電間隔は、軟体動物の種、その運動速度、索餌時間、配置する餌の量、生息する個体数、生息環境によって変わるが数分から数時間以内である。また通電時間と遮断時間の間隔を同一にせず適宜変更してより効率的な設定も可能である。使用する電流は交流であっても直流であっても良いが交流の方が扱いやすい。
【０００９】
更に、電極の形状、配置が殺滅、捕獲には重要であることが明らかになった。例えば二つの電極を直線上に配置した場合、電極間の中心で且つ通電方向に直交する方向へは容易に脱出した。従って二つの電極は、閉鎖状態に配置させることが不可欠である。
【００１０】
軟体動物を誘引する餌としては各種の野菜や果物を用いることができる。特にキャベツや白菜等のアブラナ科植物の葉は殆どの軟体動物にとって好適である。また誘引を促すため誘引物質を含む酒粕などを併用することもできる。
【００１１】
【発明の実施の形態】
発明の実施の形態を生物効果試験例に基づき説明する。
【００１２】
（試験例１）
電圧の違いによる感受性試験
幅１５ｍｍ、長さ１００ｍｍの銅板２枚をそれぞれ半円形に曲げ、各々の銅板の接点２カ所に厚さ２ｍｍのプラスチック板を挟んで絶縁し、環状の電極を作成した。直径約１２ｃｍ、深さ約２．５ｃｍのプラスチックトレーに前記の電極上部が現れる程度の土壌を詰め軽く散水した。チャコウラナメクジ５匹を環状の電極内に放して、可変トランスを用いて各段階の電圧を電極に付加し、その状態を観察した。その結果を表１に示す。
【００１３】
【表１】

【００１４】
（試験例２）
ウスカワマイマイの感受性試験
試験例１と同じ装置にウスカワマイマイ５匹を放して、２５Ｖの電圧を付加して１５分後、３時間後の状態を観察した。その結果、１５分後全ての個体は頭を伸縮させてその場に留まっていた。３時間後は、殻内に閉じこもった状態であった。この個体を電圧の付加されていない湿潤な環境に３時間おいて給餌した結果、全ての個体が通常の摂食行動をとった。
【００１５】
（試験例３）
直流の軟体動物への影響試験
試験例１と同じ装置にチャコウラナメクジ５匹を放して、１２Ｖの直流を付加して１５分後、３時間後の状態を観察した。その結果、２頭は１５分以内に脱出し、電極に接触した３個体は３時間後に死亡していた。
【００１６】
（試験例４）
自然環境下での試験１
幅１５ｍｍ、長さ１５０ｍｍの銅板２枚をそれぞれ半円形に曲げ、各々の銅板の接点２カ所に厚さ約２ｍｍのプラスチック板を挟んで絶縁した直径約１０ｃｍの環状電極を作成した。直径約１５ｃｍ、深さ約３ｃｍのプラスチックトレーに前記の電極上部が現れる程度の土壌を詰めた。環状の電極内に茹でてみじん切りしたキャベツの葉と魚肉を混ぜたもの２０ｇを土壌表面に平らに置き、落葉のある庭にトレーの最上部が土壌表面になるように埋設した。２５Ｖの電圧を電極に付加し、タイマーを下記間隔にオフ、オンの断続設定して環状電極内に閉じこめられたチャコウラナメクジの数を経時的に観察した。試験は設定時間毎に実施し、設置したトレーは少なくとも１．５ｍ以上離した。試験は午後６時に開始、経時的に観察して翌日午前７時に生存個体数を含めて調査した。その結果を表２に示す。
【００１７】
【表２】

【００１８】
（試験例５）
自然環境下での試験２
試験例３と同様に環状電極内に餌を置いたプラスチックトレーを落葉のある庭に設置し、５０Ｖの電圧を電極に付加して、タイマーを６０分間隔にオフ、オンの断続設定して環状電極内に閉じこめられたチャコウラナメクジ及びダンゴムシの数を試験例４と同様に経時的に観察した。その結果を表３に示す。
【００１９】
【表３】

【００２０】
以上のように、閉鎖状の電極内に軟体動物の餌を置き、人間等が感電しない低電圧を付加することにより集中的に軟体動物を誘引し、殺滅、もしくは捕獲することができる。
【００２１】
【発明の効果】
化学薬品を使用しないで、安全かつ選択的に有害軟体動物を防除する。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for efficiently controlling mollusks that damage food crops grown in agriculture or horticulture.
[0002]
[Prior art]
Feeding damage to agricultural crops and leaves, flowers, young fruits, new roots, and the like by terrestrial molluscs such as the mystical snails, slugs, and the slugs is a serious problem because it reduces the commercial value. In recent years, apple snails that have invaded from abroad have harmed the seedlings immediately after transplantation and the buds and seedlings of direct-seeded rice, and have become a problem mainly in the southwestern warm regions of Japan. For the control of these terrestrial molluscs, methaldehyde agents are widely used. In some cases, XMC agents are also used. For the control of the apple snail, methaldehyde agents, lime nitrogen, IBP agents, and the like have been studied, but they have not yet achieved sufficient effects.
[0003]
[Problems to be solved by the invention]
For the control of molluscs, methaldehyde agents, which are both injurious as well as killing and have low acute toxicity, are most widely used. However, its effects depend on the environment and species, and are less effective on wet conditions and some slugs. In addition, when a pet or the like consumed a large amount, the voltage was 0 to 30 V which was fatal because an essential detoxification method had not yet been found. For example, when 50 V is applied, some individuals that die out of damp bugs and the like appear, which is not always a preferable result. Depending on the applied voltage, these mollusks could not be completely killed, but they could be easily removed because they stopped exercising and were gathered in a limited area. is there.
[0008]
Area for adding a voltage, depending on the size habitat range of mollusks of interest several thousand cm ² several tens cm ^2. The intermittent energization interval is within a few minutes to several hours, depending on the species of mollusk, its movement speed, feeding time, amount of food placed, number of individuals inhabiting, and habitat. Further, the intervals between the energization time and the cutoff time are not made the same, but can be appropriately changed to make more efficient setting. The current used may be AC or DC, but AC is easier to handle.
[0009]
Furthermore, it became clear that the shape and arrangement of the electrodes were important for killing and capturing. For example, when the two electrodes were arranged on a straight line, they easily escaped in the direction between the electrodes and in the direction perpendicular to the direction of current flow. It is therefore essential that the two electrodes are arranged in a closed state.
[0010]
Various vegetables and fruits can be used as bait for attracting mollusks. In particular, the leaves of cruciferous plants such as cabbage and Chinese cabbage are suitable for most molluscs. Also, sake lees containing an attractant can be used in combination to promote the attraction.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described based on biological effect test examples.
[0012]
(Test Example 1)
Sensitivity test depending on voltage difference Two copper plates having a width of 15 mm and a length of 100 mm were each bent into a semicircular shape, and a plastic plate having a thickness of 2 mm was interposed between two contact points of each of the copper plates to form an insulated electrode. A plastic tray having a diameter of about 12 cm and a depth of about 2.5 cm was filled with soil to such an extent that the upper part of the electrode appeared, and lightly watered. Five slugs were released into the ring-shaped electrode, and the voltage of each stage was applied to the electrode using a variable transformer, and the state was observed. Table 1 shows the results.
[0013]
[Table 1]

[0014]
(Test Example 2)
5. Sensitivity test of Usukawa maimai Five Usukawa maimai were released to the same apparatus as in Test Example 1, a voltage of 25 V was applied, and a state was observed 15 minutes and 3 hours later. As a result, after 15 minutes, all individuals had their heads stretched and stayed there. Three hours later, it was trapped in the shell. The animals were fed for 3 hours in a humid environment in which no voltage was applied, and as a result, all the animals took normal eating behavior.
[0015]
(Test Example 3)
Influence test of direct current on mollusks Five slugs of slugs were released to the same apparatus as in Test Example 1, 15 minutes after applying 12 V direct current, and 3 hours later, the state was observed. As a result, two animals escaped within 15 minutes, and three animals that had come into contact with the electrodes died three hours later.
[0016]
(Test Example 4)
Test 1 under natural environment
Two copper plates having a width of 15 mm and a length of 150 mm were each bent into a semicircular shape, and a ring-shaped electrode having a diameter of about 10 cm was insulated with a plastic plate having a thickness of about 2 mm interposed between two contact points of each copper plate. A plastic tray having a diameter of about 15 cm and a depth of about 3 cm was filled with soil so that the upper portion of the electrode appeared. 20 g of a mixture of boiled and cut cabbage leaves and fish meat was placed in an annular electrode flat on the soil surface, and buried in a garden with deciduous leaves such that the top of the tray was on the soil surface. A voltage of 25 V was applied to the electrode, and the timer was turned off and on at the following intervals, and the number of slugs trapped in the ring electrode was observed over time. The test was performed every set time, and the installed tray was separated at least 1.5 m or more. The test started at 6 pm and was monitored over time and investigated at 7 am the following day, including the number of surviving individuals. Table 2 shows the results.
[0017]
[Table 2]

[0018]
(Test Example 5)
Test 2 under natural environment
In the same manner as in Test Example 3, a plastic tray with food placed in the ring electrode was placed in a garden with defoliation, a voltage of 50 V was applied to the electrode, and the timer was turned off and on at intervals of 60 minutes, and the ring was turned on and off. The numbers of the slugs and damselflies trapped in the electrode were observed over time as in Test Example 4. Table 3 shows the results.
[0019]
[Table 3]

[0020]
As described above, mollusk food can be intensively attracted, killed, or captured by placing mollusk food in the closed electrode and applying a low voltage that does not cause electric shock to humans or the like.
[0021]
【The invention's effect】
Safe and selective control of harmful mollusks without the use of chemicals.

Claims

A method for controlling mollusks by intermittently applying AC or DC voltage to a local area where a feed-inducing substance is arranged.

The control device according to claim 1, wherein the terminal to which the voltage is applied is closed.