Abstract:Hegesidemus harbus Darke (Hemiptera: Tingidae) is one of the most dangerous pests, it is increasingly injuring "I-45", "I-72", "I-69", and "I-214" new Poplar clone.Both the adult and the nymphs feed on the back of leaves, causing the appearance of small whitish bleached areas on upper surfaces of the leaves. The Tingids produce a large quantity of excrements which become the medium of black sooty molds. While infested seriouly, all the leaves begin to turn yellow, resulting in the damaging effect to the growth of poplar.The Tingid has 4 generation a year in Shandong, China. The adults overwinter preferably in bark crevices and under leaves which fall down on the ground of poplar stands. They also overwinter in the crack of land.The adults emerge in late April to early May of the next year, when the mean daily temperature is at 11-12℃. The eggs are laid on the underside of the leaves adjacent to the veins. The adult and the nymphs feed gregariouly on leaves. The symptoms of infestation appear from the lower part of the tree to the upper part of it.It is promising to use 80% Dichlorvos, 40% Omethoate, and 50% Monocrophos to control the pest. Silvicultural method is effective for controlling the pest. Use and protect natural enemies is also recommended.