Effects of different pesticides on populations of main pest insects and natural enemies at the seedling stage in soyabean fields.
The important pest insects at the seedling stage in soyabean fields in Shandong, China, were Aphis glycines and Melanagromyza sojae. In 1988-89, field trials were made on the control effects of 4 insecticides (35% phosalone, 50% pirimicarb, 40% omethoate and 20% fenvalerate). Results showed that they resulted in significant control of A. glycines. The mortality of natural enemies (bugs and parasitic wasps) caused by 35% phosaline was not significant. It is recommended that it is applied alternately with fenvalerate.