Abstract:Eupterote sapivora Yang is a new forest insect pest injuring 22 tree species belonging to 15 families. It mainly attacks Panlownia tomentosa, Toona sinensis, and Sapium sebiferum. There is one generation a year in Guizhou Province. It overwinters in the pupal scage. There 7 instars in the larval stage 1-3 instar larvae feed on leaves on the upper part of the tree, while 4-7 instar ones are distributed on the middle and lower part of the trees. At daytime, the larvae remain still gregariously and form a ball. While at night, they feed on the leaves. The larvae appears in the middle of June. The peak period of infestation is from August to September. The larvae pupate in middle October. The outbreak of the pest is related with temperature, humtdity, altitude, slope, slope inclination, tree species and age of the tree.