“Survival of the Fittest” is the everlasting living principle of the nature. Due to pesticides’ directional selection, some pests which have resistance remain alive. But along with the enhancement of the resistance, the application quantity of the pesticides keep increasing accordingly. So it enters into a vicious circle without ending. Many farmers has deep feelings that the pests are more and more difficult to be controlled.
But, how to control the famous resistant pests?
1: Black-head maggot (larvae of the Hylemya antiqua Meigen)
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This maggot cause many places’ Garlic and chinese chive nearly have no harvest. Though, in many areas, Organophosphorus Pesticide were already prohibited to sell and use in the market, but still farmers use them secretly. But the effect is still not satisfied. Kinds of products contain Chlorpyrifos, Phoxim were used in big dosage and still couldn’t controlled well. Only some with Phorate has certain efficiency, but also difficult to kill them thoroughly.
At present, the mainstream recipe are dinotefuran, clothianidin, Abamectin, Chlorpyrifos, Phoxim, Cyromazine, Chlorbenzuron mixed with Beta-cypermethrin, Lambda-cyhalothrin, Alpha-cypermethrin, etc.. Still somebody use Imidacloprid, Acetamiprid, Thiamethoxam with other products.
2: Root-knot nematode
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It is very harmful for many vegetables, field crops and fruits. Till now, mainstream products for root-knot nematode is Abamectin, EC, EW, GR with different kinds of application methods. Because it’s economic, so the application qty is big. Unfortunately, due to this, the resistance is significant now. Another reason is: Abamectin is difficult to move in the soil, so the control effect is decreasing.
The new star products is Fosthiazate which is replacing Abamectin. Except the earlier GR, now the plants are developing different formulations, both single and mixture, like EW, EC, SL, etc. Till now, only few areas have feedback of resistance, but in total the resistance condition is still low because it’s more expensive and has never been used in great range.
Till now, there’s no feedback of resistance for Fluopyram. But we think the reason is its expensive cost and few application.
3: Whitefly
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It’s one of the main medias to transmit the virus and harmful for many vegetables and field broad-leaf crops. In many cases, the virus’ spreading nearly couldn’t be avoided if the prevention is not enough.
Till now, for Single formulations, it seems no products that have special effect. The normal products are Acetamiprid, Imidacloprid, pymetrozine, Thiamethoxam, Deltamethrin, Bifenthrin, etc.. The mixture of Pymetrozine with nitenpyram was ever hot in the market, but now the resistance is already heavy.
So there are no one product can be effective forever. Most of them only work very effective for 2-3 years after wide range usage.
We have a good method for vegetables. Put a little Thiamethoxam WG at the roots and can basicly control the whole growth period’s piercing-sucking insects like whitefly, aphids, thrips, etc.
4: Lepidoptera pests
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It mainly include like Diamond back moth, cabbage caterpillar, beet armyworm, cotton leafworm, cotton bollworm, etc. This series insects has obvious resistance and the chlorantraniliprole and its illegal products is famous due to this reason.
From Chrysanthemum Ester Insecticide to Abamectin, to Emamectin benzoate, to present wide-used chlorantraniliprole, the resistance are all high. We cann’t say that they are not effective. But the application dosage has already been several times or dozens of times than the initial dosage.
At present, Indoxacarb can be used to control the pests that are resistant to the chlorantraniliprole.
5: Flea beetle
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The resistance of this pest is also very high as we know. Many products like DDVP, Trichlorfen, Chlorpyrifos, Thiamethoxam, Deltamethrin, Phoxim all have certain efficiency, but not so good.
Till now, the single formulation only Malathion and Fipronil have good efficiency. Others are all kinds of mixtures. The mixtures containing Pyridafen work well.
What we can do for the resistance?
1: Reasonable applications
It’s the most effective method to decrease the resistance. We can do this through rotational and mixed applications, adding synergist and diversified application methods, etc.
2: Combine chemical control with phisical and biological control.
Phisical control methods mainly include closing the greenhouse in high temperature, clean the fields, clipping the crops, covering field film or insect-proof screen, yellow board, pest-killing lamp, sugar water, etc.
Biological control include pestsVSpests, gern VS harmful pests and other beneficiary pests VS harmful pests.
3: Developing new active ingredients.
The developing is very slow and difficult. So what we should do is to try our best to delay the existed products’ resistance.