Studies On The Occurrence Rules And Control Technique Of Apocheima Cinerarius

Apocheima cinerarius is widely distributed in 21 prefectures of Lhasa, Xigaze and Shannan in Tibet. It severely damages the leaves of poplar, willow and sea buckthorn plant, etc. The morphology, damage characteristics, distribution area, biological behaviors, occurrence rules and control methods of Apocheima cinerarius were studied by laboratory tests and field investigation. Two kinds of insectticides which had better control effect on Apocheima cinerarius were screened out. A set of integrated control technique was proposed. A demonstration forest for control was set up. The main results were as follows:1.The morphological characteristics of four stages of Apocheima cinerarius were observed in Tibet Zhanang. The harmful levels of damage on the trees was investigated, it is 56.24% and 32.39% respectively in the years of 2010 and 2011. Apocheima cinerarius was mainly distributed in Tibet Lhasa, xigaze and shannaneven including 21 counties(districts).2. The life cycle and occurrence regularity of Apocheima cinerarius were found out in Tibet. It had 1 generation a year in the Tibetan region. It overwintered and oversummered by the pupa in the soil under canopy. Apocheima cinerarius emerged In midddle March every year, adult began to lay eggs in early April, eggs hatched into larvae in midddle April. It caused severely damage in mid to late May. The grown larvae pupated in the soil after mid June for oversummer and overwinter.3. The occurrence degree and biological behaviors of the egg, larva, pupa and adult in Apocheima cinerarius were studied. The lifetime of adult was 14~21 days, a female laid 285 eggs, egg period was 15~24 days, egg hatching rate was 97.19%. The duration of larval stage was about 32 days, the first instar larva period was 7~9 days, the second larva period was 7~8 days, the third, fourth and fifth instar larva period was 6~7 days. The trees which were damaged was 72.90% in early May, the rate of damage was 56~82% by the second and third instar larvae. The forests which were severely damaged were 70%. The ratio of male pupa and female pupa was 291: 295, the forest that had pupae was 80%. It overwintered and oversummered by the pupa from middle June to the next year of late March, It last for 9 months.4. Three kinds of insecticides, such as chlorbenzuron Ⅲ(25%) 、 fenoxycarb(3%) and thiacloprid(4.5%), were selected from 6 kinds of insecticides through virulence determinationin vitro, chlorbenzuron Ⅲ(25%) and fenoxycarb(3%) should be extended in the field by further screening tests.5. The time of controlling Apocheima cinerarius was found out. Monitoring and predicting of Apocheima cinerarius was based on the investigation of pupae and larvae stage, the optimum time of chemical control was in early and mid May, the 2~3 instar larvae reached around 60%. It should be controlled 2~3 times in the forest which were severely damaged, the time of interval was 7~10 days.6. A set of integrated technique of controlling Apocheima cinerarius was proposed and demonstrated. The demonstration forest of 133 hm2 for control was set up. It had effectively controlled the damage of Apocheima cinerarius.