The Reason for the Rapid Development of Abamectin
Abamectin also known as avermectin, has been well developed in recent years; experts say that avermectin will have a good development potential and prospect in the future. Well, why avermectin can get such a good development? Based on what?
Avermectin is a mixture of natural fermentation, occupying an important position in China pest control system. Currently there are more than 10 enterprises producing avermectins. The commercially available avermectin series on market are abamectin insecticide, ivermectin, eprinomectin and emamectin benzoate salt, etc. The fine avermectin is a kind of white crystalline powder, mp 155-157℃, due to no acidic or basic functional groups on its structure, which is stable under normal conditions, do not decompose in the PH = 5-9(it will decompose if there is light).
Avermectin is a nerve poison, acting on the mechanism of insect neuromuscular synapse or synaptic GABAA receptors, to interference messaging insect nerve endings that stimulate nerves to release neurotransmitter inhibitors γ-amino butyric acid (GA-BA), prompting GABA-gated chloride channel to extend the opening of the chloride channel with activation, resulting in a large influx of chloride ions nerve membrane potential hyperpolarization, resulting in the inhibition of the nerve membrane, thereby blocking the contact between nerve not tips and muscles; as a result, insects become paralyzed, food refused, then dead. Because of its unique mechanism, there is no cross-resistance with commonly used pharmaceuticals.
It is reported that, in addition to the GABA receptor chloride channel control, avermectin can also affect other ligand-controlled chloride channels. At the same time, avermectin has good layer shift activity which means that avermectin can penetrate the leaf tissue after crop spraying, forming a thin-walled sac in the epidermal cells for long-term storage, so avermectin can have a long-lasting effect. Because of its good level shift activity, making avermectin more effective than conventional drugs on pests difficult to control such as pest mites, leaf miner, leaf miner and borer pests or sucking pests. What is more, avermectin biodegrades easily in soil and water, then absorbed by the soil without leaching or residue, having no harmful effects on the environment; nor accumulating persistence of residues in bodies, hence it’s supposed to be pollution-free pesticides.
Avermectin can also be decomposed into derivatives with higher activity by the soil microorganism, like the insecticidal effect on plant nematodes. Now China has more than a dozen manufacturers of avermectin, the annual production capacity being 200-800 t/Y, but their skill levels are different, that the gaps mainly focus on the fermentation contamination rate and potency. Chinese abamectin suppliers titers are generally around 3500μg/ml, individual manufacturers reaching more than 4000μg/ml; the contamination rate is generally below 10% while one or two can keep it under 3%. It’s lately reported that the newly breed bacteria with higher activity cultivated by a institute can achieve 8000μg/ml in potency, which is highly concerned by various manufacturers that if this technology gets industrialized, China’s overall technological level of production of avermectin will be greatly improved, expected to reach the international advanced level.
50% of avermectin produced in China is used for its downstream products, 30% for export and 20% for a variety of preparations. As the major existing bio-pesticide varieties, avermectin is short of supply, which directly led to the constantly rising price. So far the development of new formulations avermectin has become an international hot spot, which has many types of formulations, such as cream, microemulsion, soluble granules, microcapsules, etc. With the huge increase in its preparations usage, avermectin has been recognized by the international market, especially in developing countries, such as Thailand, Pakistan, India, where the imports has increased year by year. As you see, avermectin really has extremely broad prospects for development.