Studies on the Occurrence and Control of Gravitdrmata margarotana Heinemann

Gravitarmata margarotana Heinemann is one of the most important insect pests damaging shoots and cones of Pinus massoniana in China.The studies on its bioecology and control were carried out in Yuhang and Kaihua Counties,Zhejiang Province in 1985-1992.G.margarotana has one generation a year.Pupae overwinter in the soil.The habits of adult emergence and larval damage were observed.The relationship of insect occurrence to tree height,crown diameter,crown position and periodic biological phe-nomena are also narrated.Chemical pesticides could be used to control,the insect in masson pine seed orchard.The results showed that the spraying of 20% F'envalerate in mid-April is effective.