Abstract:Matsucoccus shennongjiaensis Young et Lu, was found in sheng-nong-jia virginal forest area in westen-Hubei in 1986. It is the main factor causing out of larg quantity of Pinus armandi in this area.This pest has one generation a year, it overwinters as first stage nympha and egg (in a few cases). The nymphs suck sap from the trunks, causing rotting of cortex, flowing of resin, decline and death of the trees. The dying process can be acceraleted by the attack of the secondary pests such as bark beetle and so on.The damage in mixed forest is less than in the pure forest. The larvae of a Cecidomyiid eat eggs of this pest. It may be utilized as a biotic controlling agent of the pest.