A report on monitoring stem borers in burned areas in Daxinganling Mountain.
The ecological equilibrium of forests in Daxinganling Mountain was disturbed by a fire in May, 1987, resulting in a regionwide outbreak of stem borers. A survey was conducted from April to Sep., 1988, in Tuqiang, Xilinji, Tahe and Amur. Results showed that more than 20 species were found on Pinus sylvestris var. mongolica and Larix olgensis. The dominant species were Monochamus sutor and Ips subelongatus, and the populations of M. urussovii and I. sexdentatus tended to increase. Hylobius albosparsus and H. abietis were important pests attacking young stands newly established. All burned stands, timber depots and dumps were severely infested by these insects. Later, insects in badly burned stands moved to medium and lightly burned stands. It was predicted that the population of Monochamus sutor in timber depots in 1989 would be 7× that of 1988, and stem borer populations in medium and lightly burned stands would increase considerably. This forms a severe threat to the green standing trees in adjacent areas.