农药瓶盖是农民在农药稀释当中习惯用的“量具”,但多数农民对其容积大小不清楚,致使药液有时对得过浓(即不经济、甚至会伤害天敌,或使作物产生药害)。有时对得偏稀(效果差、劳而无功)。药液浓度对得适当与否,是治虫防病中的关键环节,为帮助农民把药液对得准确,笔者特别 Pesticide bottle caps are peasants’ “measuring tools” that are customary in the dilution of pesticides. However, most peasants are not aware of their volume so that they sometimes get overly concentrated (that is, they are uneconomical and may even hurt natural enemies or cause crop injury ). Sometimes too thin (poor effect, labor ineffective). Proper concentration of liquid or not, is a key step in pest control, in order to help farmers to liquid correct, I especially