Cotton aphid peach aphid serious resistance to alternating drug use is a good solution

Recently, the National Agricultural Technology Center announced the monitoring results of resistance to 13 major diseases and insects in 2015, such as rice planthopper, borer, wheat scab, cotton bollworm, cotton aphid and diamondback moth, and gave countermeasures and suggestions。Brown planthopper

According to the results of 60 resistance monitoring sites in 20 provinces (autonomous regions and municipalities) across the country，Brown planthopper developed different degrees of resistance to various insecticides，So in the brown planthopper control process，Between the migration zone and the migration zone，Between generations in the same area，Insecticides with different mechanisms of action and no cross-resistance should be used alternately，Avoid continuous, single medication。

In view of the high level of resistance of brown planthopper to imidacloprid, thiamethoxam and thiazidone，It is recommended to suspend the use of imidacloprid, thiamethoxam and thiazone to control brown planthopper in rice fields.Strictly limit the use of pyrifolone and chlorpyrifos to control brown planthopper，Rice is best used once per season;New drugs such as endinium, furotestamine and fluridine cyanil should be used alternately，To slow the development of resistance to brown planthopper。

In view of the fact that white-backed and brown planthopper usually occur together, and brown planthopper has developed a high level of resistance to thiazinone, it is recommended to suspend the use of thiazinone to control white-backed planthopper in rice fields to delay the development of resistance。borer

The population resistance to insecticides showed obvious regional status, and the resistance to dicamides and avermectin increased obviously。The results of field trials in Zhejiang and Jiangxi provinces showed that the efficacy of dicamides such as chlorfenamide and flurfenamide was poor, and the efficacy of seedling protection was only 20% ~ 60% after 21 days。In this regard, the use of dicamides, abamectin and other agents should be reduced or limited, so as to avoid successive generations of the moth contact with the same mechanism of action of agents。Wheat scab

Resistance of wheat Scab to carbendazim mainly occurred in Jiangsu Province and its neighboring provinces. Compared with 2014, the resistant bacteria in Jiangsu Province had formed a dominant group, and the frequency of resistant strains increased significantly, and the proportion of resistant bacteria in the pathogen population in the province reached more than 60%。It is suggested that different agents such as cyanobutylate and pentazolol should be used alternately in carbendazim resistant areas to delay the development of resistance to carbendazim in wheat Scab。Cotton bollworm

Compared with the monitoring results in 2014, the resistance ratio of pyrethroid cyfluthrin in most areas was increased。

Expert advice，In the areas where cotton bollworm developed high level of resistance to pyrethroids，In particular, the use of pyrethroids to control cotton bollworm should be prohibited in Shandong Province in North China，To slow the rise of resistance;The use times of organophosphorus and emamectin benzoate should be limited in North China cotton area and Xinjiang cotton area，Other agents with different mechanism of action such as fluvulurea and indacarb can be used alternately。棉蚜

The resistance of cotton aphid to insecticides developed rapidly, and almost all the insecticides used at present developed resistance, especially to pyrethroids, organophosphorus and neonicotinoids。At present, all populations of cotton aphid in monitoring areas are in a high level of resistance to deltamethrin and imidacloprid, and the resistance ratio in some areas reaches tens of thousands of times, and there is still a trend of increase。

Cotton aphid has become one of the pests with serious resistance and difficult to control. The resistance management measures such as suspension of drug use, alternate drug use and rotation drug use should be actively taken to avoid continuous use of the same class of agents (especially pyrethroids and neonicotinoids) to delay the sustainable development of resistance。

Plutella xylostella

In view of the high level of resistance to abamectin and cypermethrin in most areas of China，The use of these two agents against diamondback moth should continue to be suspended in vegetable producing areas;The resistance levels of chlorfenamide, fenacil, indocarb and fluriduron were different from the south to the north，Compared with the monitoring results in 2014，The resistance multiple increased，It is recommended to continue to limit its use in resistant areas，Especially in Hunan, Guangdong, Yunnan, Hainan and other resistant areas, the frequency of vegetable use is not more than 1 times per season，Different agents of action mechanism such as ethyl polycidin can be used alternately。

桃蚜

It is worth noting，At present, the peach aphid population in the monitoring area has a high level of resistance to neonicotinoid imidacloprid and carbamate against aphid，The resistance ratio is more than 100 times.The resistance to pyrethroid bifenthrin was medium to high.Medium to high levels of resistance to the new insecticide fluridifenil。

Peach aphid has become one of the important pests with serious drug resistance and difficult to control on vegetables. The resistance control measures such as suspension of drug use, alternate drug use and rotation drug use should be actively taken to avoid continuous use of the same drug class and delay the sustainable development of its resistance。