Characteristics of Melanagromyza sojae occurrence and hazard and its non-hazard control techniques.
M. sojae is a newly founded pest on Pisum sativum in Xianyou county of Putian, Fujian, China, and had caused serious hazard during 2001-05. A field survey was performed in Xianyou county from 2001, to study the characteristics of its occurrence and hazard. The larvae completed 6 generations annually. They overwintered as pupae in roots and stems of host and the adults appeared in March and April in the next year. The adults showed phototaxis and were active at 25-30°C. The adults laid eggs on the base of axillary bud and below the epidermis near the main vein of dorsal leaves. The hazard of M. sojae was dominated by larvae. The incubated larvae fed on mesophyll firstly, and then entered stems along petioles. The larvae seriously damaged stems of M. sojae, resulting in plant stunting, leaf yellowing and even plant death. The 4th-generation larvae appeared in late August and early September, and they were the generation causing most serious damage in a year. Furthermore, some non-hazard control techniques are presented. They included selecting cultivars with high resistance to plant diseases and pests, rotation with gramineous crops and application of biological pesticides and physical control.