Investigation on the Population Dynamics of Main Pests and Their Natural Enemies in the Area of double Cropping Rice in Small Watersheds of North Fujian

The effect of natural enemies,such as field spiders etc,on controlling planthopper has been analysed and compared based on the survey results of population dynamics of pests and their natural enemies in double cropping rice fields of small watersheds in north Fujian.It provided a scientific basis for enlarging controlling index,decreasing chemical dosage in field practice.