Study on biological and ecological characteristics ofIps subelongatus Motsch

Ips subelongatus Motschulsky were raised indoors and in the field using fresh baits for study of biological and ecological characteristics during 1992–1994. The life cycle of the pest in Lishu County, Jilin Province was described. The study results indicated that temperature was a main factor affecting the development ofIps subelongatus. The initial temperature for development of egg, larva, pupa and adult was 6.1, 8.0, 10.3 and 9.8°C, respectively. To complete one-generation needs, respectively, 48 d at temperature of 18°C, 39 d at 20°C and 33 d at 22°C. The pest has different number of generations in different area as a result of temperature change. In Jilin Province, it generally has three generations, except that some individuals have 2 generations. The nature enemies for this pest areThanasinus substriatus, Tomimicobia seitneri Ruschk,Coeliodes sp. etc. Foundation item: This paper is part of key subject of the Ministry of Forestry (formerly)—The Systematic Control Technique ofIps subelongatus Motschulsky. Biography: G{upao} Chang-qi (1952-), male, research fellow in Jilin Forestry Academy. Responsibe editor: Chai Ruihai