The mode of action and features of the avermectin

But its leaves have a strong osmosis effect, can kill pests under the skin, and long residual activity. Its mechanism of action is different from the general insecticide, it interferes with the insect’s neurophysiological activity, stimulates the release of r- aminobutyric acid, and r- aminobutyric acid inhibit arthropod’s nerve conduction, after mites and insect larvae contact this drug will show up the paralysis symptoms, not activity, not feeding, death after 2-4 days. Because they do not cause the insects rapidly dehydrating, so its lethal effect is slower. Although it has direct killing effect on the predatory and parasitoid, but due to it remains lower in plants surface, so that it less damage on beneficial insects.

Avermectin after spraying can penetrate into the crop leaf tissue, form a sachet in the epidermis thin layer of parietal cells, storage for a long time, so the avermectin has better lasting period. Because of its good layer shift activity, the avermectin have high efficient on spider mites, leaf miner and other borer pests or sucking pests and other pests that conventional agents hard to control. Avermectin easily biodegradable in soil and water, and adsorpted by soil in the soil, no residue, not pollute the environment; also not accumulation and persistence residues in vivo, so avermectin is pollution-free pesticides. Abamectin can also be decomposed into higher activity derivatives by soil microbial.

Different manufacturers’ avermectin have different effect. We know that there is a big drawback of avermectin, that it is very easily to be decomposed in the presence of light and oxygen, trials show that after abamectin formed sensitive layer, its half-life is only 4-6 hours, that is to say, abamectin spraying in rice fields was decomposed after eight hours or so. A most important method to slow down the decomposition is adding UV absorbers or antioxidants (BHA or BHT), and the effect of adding antioxidants is better than adding UV absorbers. Some abamectin suppliers may be added this thing, which leads to the avermectin is not easy to be decomposed, so that showed higher control efficiency.

Some abamectin manufacturers are likely to add silicone or something like in avermectin. Foliage spreading agent can not be used in the avermectin pesticide, because after use the spreaders, abamectin(including emamectin benzoate ) spreads out in the surface of the crop, so that form a thin membrane, immediately break down and lose their effect under the action of sunlight. But it can add penetrant. The organosilicon both have the role of spreading and penetration. Avermectin has bad absorption and general tag toxicity, mainly through the stomachtoxicity to play a role. When the Fipronil or Yasuhiro spray to the blade, the crop will be able to absorb the drug in and make the whole rice plant has drug liquid. The effect of avermectin direct spray to the leaf borer body to make it death is not good. Avermectin best role is sprayed onto the rice leaves, leaf borer eat leaves will be poisoning, this is the stomach poisoning. So that avermectin spraying is necessary to very carefully, it is best to spray every leaf. Of course, this can not be done. Organic silicon have a strong spreader and infiltration effect, only sprayed a small part of blade, the entire blade will be filled with the drug solution, the leafroller eating a full liquid blade will be immediately poisoning, and dying slowly. So that silicone on avermectin controls leaf borer have a lot of synergies.

Source:http://www.cospcn.com