What are the control methods for wheat aphids that are resistant to pesticides?
Control of pesticide-resistant wheat aphids
(Agricultural Wealth Network) The control of pesticide-resistant wheat aphids is becoming increasingly difficult. Based on our farming experience, we introduce the control techniques as follows:
1. Choose appropriate insecticides. There are many pesticides for controlling wheat aphids, such as imidacloprid, acetamiprid, pirimicarb, fenvalerate, beta-cypermethrin, omethoate, dichlorvos, phoxim, malathion, and their compound formulations. The use of highly effective, low-toxicity pesticides with systemic action is recommended. In production, the most important thing when choosing an insecticide is to select a pesticide of qualified quality. Some products on the market now have insufficient active ingredient content. If farmers seek cheap prices, the results of use will certainly not be ideal.
2. Emphasize control before wheat flowering. Wheat aphids begin to appear from the wheat greening stage and remain in a slow growth phase until before wheat heading and flowering; after wheat flowering, the population rises sharply. If a careful control application can be made once before flowering, the aphid population will be difficult to restore in a short time, and basically the aphid damage throughout the entire growth period can be controlled. At the same time, it can also control wheat blossom midges. During this period, wheat has not yet grown to its normal plant height, so control is relatively easy and the control effect is good.
3. Increase water volume. Water is the carrier of the pesticide. Through an appropriate amount of water, the pesticide solution can be sprayed onto all parts of the wheat in the field. If the water volume is insufficient, it will leave space for aphids to survive. In the late growth stage of wheat, because the temperature is relatively high, it is very suitable for aphid growth and reproduction, and they can even complete one generation in 5-7 days. If residual insects are left because of insufficient water, their population can be imagined, increasing the difficulty of later control. During the wheat grain-filling stage, the leaf canopy is thick, so water volume must be increased even more during control.
4. Use compound formulations during the wheat grain-filling stage. Under normal circumstances, one control application before flowering can basically ensure that wheat is not harmed by aphids. If for some reason the aphid population is relatively large during the wheat grain-filling stage, some compound formulations can be used. During the wheat grain-filling stage, the plants have already grown to normal plant height and are usually not easy to penetrate thoroughly. Dichlorvos (about 50 ml per mu) can be mixed with other insecticides to give play to the fumigating effect of dichlorvos, which can achieve a relatively good control effect. Alternating the use of other pesticides can also improve the control effect.
5. Adopt different control methods. In the late growth stage of wheat, a common problem in aphid control is that after pesticide application the aphids on the upper part of the plants disappear, while the aphids on the lower part are difficult to kill, and after a few days the aphids again cause damage on the upper part. For this situation, in addition to using compound formulations, fumigation can also be used for control, which has a relatively good control effect on aphids on the lower part of wheat plants. You can use 50-75 ml of 40% dimethoate emulsifiable concentrate, or 75-100 ml of 80% dichlorvos, dilute with 2-3 kg of water, mix with 15-25 kg of fine sandy soil, and spread it into the field in the evening when there is no wind.
6. Reduce the number of pesticide applications. In order to give full play to the control role of natural enemies, to control wheat aphids you must understand the occurrence patterns of wheat aphids and understand the insecticidal properties of pesticides; carry out control at the appropriate time, with suitable pesticides, and by correct methods. Try to use low-toxicity, highly effective pesticides, reduce the number of pesticide applications, protect the various natural enemies in wheat fields, and give full play to the role of natural enemies in controlling aphids.
1. Choose appropriate insecticides. There are many pesticides for controlling wheat aphids, such as imidacloprid, acetamiprid, pirimicarb, fenvalerate, beta-cypermethrin, omethoate, dichlorvos, phoxim, malathion, and their compound formulations. The use of highly effective, low-toxicity pesticides with systemic action is recommended. In production, the most important thing when choosing an insecticide is to select a pesticide of qualified quality. Some products on the market now have insufficient active ingredient content. If farmers seek cheap prices, the results of use will certainly not be ideal.
2. Emphasize control before wheat flowering. Wheat aphids begin to appear from the wheat greening stage and remain in a slow growth phase until before wheat heading and flowering; after wheat flowering, the population rises sharply. If a careful control application can be made once before flowering, the aphid population will be difficult to restore in a short time, and basically the aphid damage throughout the entire growth period can be controlled. At the same time, it can also control wheat blossom midges. During this period, wheat has not yet grown to its normal plant height, so control is relatively easy and the control effect is good.
3. Increase water volume. Water is the carrier of the pesticide. Through an appropriate amount of water, the pesticide solution can be sprayed onto all parts of the wheat in the field. If the water volume is insufficient, it will leave space for aphids to survive. In the late growth stage of wheat, because the temperature is relatively high, it is very suitable for aphid growth and reproduction, and they can even complete one generation in 5-7 days. If residual insects are left because of insufficient water, their population can be imagined, increasing the difficulty of later control. During the wheat grain-filling stage, the leaf canopy is thick, so water volume must be increased even more during control.
4. Use compound formulations during the wheat grain-filling stage. Under normal circumstances, one control application before flowering can basically ensure that wheat is not harmed by aphids. If for some reason the aphid population is relatively large during the wheat grain-filling stage, some compound formulations can be used. During the wheat grain-filling stage, the plants have already grown to normal plant height and are usually not easy to penetrate thoroughly. Dichlorvos (about 50 ml per mu) can be mixed with other insecticides to give play to the fumigating effect of dichlorvos, which can achieve a relatively good control effect. Alternating the use of other pesticides can also improve the control effect.
5. Adopt different control methods. In the late growth stage of wheat, a common problem in aphid control is that after pesticide application the aphids on the upper part of the plants disappear, while the aphids on the lower part are difficult to kill, and after a few days the aphids again cause damage on the upper part. For this situation, in addition to using compound formulations, fumigation can also be used for control, which has a relatively good control effect on aphids on the lower part of wheat plants. You can use 50-75 ml of 40% dimethoate emulsifiable concentrate, or 75-100 ml of 80% dichlorvos, dilute with 2-3 kg of water, mix with 15-25 kg of fine sandy soil, and spread it into the field in the evening when there is no wind.
6. Reduce the number of pesticide applications. In order to give full play to the control role of natural enemies, to control wheat aphids you must understand the occurrence patterns of wheat aphids and understand the insecticidal properties of pesticides; carry out control at the appropriate time, with suitable pesticides, and by correct methods. Try to use low-toxicity, highly effective pesticides, reduce the number of pesticide applications, protect the various natural enemies in wheat fields, and give full play to the role of natural enemies in controlling aphids.