Chemical control ofZethenia rufescentaria Motsch

Zethenia rufescentaria Motsch. has outbroken successively in the larch plantation of Jixi region and seriously damaged stands since 1990. Chemical control was studied for controlling the occurrence of the pest. The results showed as follows: When the third or the forth instar larvae was controlled with smoke agent of 5% Lindane. the most suitable time was July 10–13. The area controlled was 2000 hm². The dosage was 7.5 kg/hm² and the mortality of the pest reached 93.5%. 25% dimilin III (flowable formulation) was used to prevent the third instar larvae. The best time was about July 5. The dosage was 150g/hm². The mortality of the pest reached 89.85%. 3% Hexyclan dusting was also used to control adults of the pest. The best time was before the peak of their emergence (June 3). the dosage was 11.3 kg/hm². The mortality of the pests reached 89.6%.