Abstract: Sinna extrema(Walker) is the most important insect pest of Cyclocarya paliurus(Batal) Ilkinsk. In South China it infests leaves only. The paper deals with its bionomics and control measures conducted during 1994～1999 in Fujian Province. Laboratory rearing and field observation showed that this insect had six generations per year in Nanping city and SanMing city, Fujian Province. There are six larval instars, Overwintering takes place as pupa in cocoon at weeds and shrubbery and on the fallen leaves. The control methods of the pest are as follows: (1) Spraying with 50% Phoxim E.C 1000～1500× or 40% Isofenphos-methyl E.C 1000～1200× or Beauveria bassiana powder to eliminate mature larvae of the 1st and 6th generation before cocoonning. (2) Spraying with 80% Dichlorvos E.C 1000～1200×, to eliminate larvae of the 3rd～4th instar. (3) Dichlorvos used as smokes “741” was found to be effective against adults of the 6th generation.

Key words: Sinna extrema(Walker), Biology, Control