Abstract:

Massicus raddei was a new outbreak pest in the northeast of China. To analyze the distribution pattern of the pest, some oaks (Quercus liaotungensis) in 5 plots were anatomized. The results showed that in the tree with all tops dieback, the larvae mainly lived in oak trunks below 4m and the pupae distributed in 1-4 m of the trunk, and in the tree with partial dieback the larvae mainly lived in the trunk below 6 m and the pupae were 3-7 m. The amount of larvae was positively correlated with the bark thickness, as well as with the trunk diameter. The pests were only found in the trees until the bark thickness was more than 0.47 cm and the trunk diameter was more than 9.02 cm,. Larvae of low instar mainly lived on sunny part of trunk phloem, while most of pupae lived in xylem. In the current year, when the eggs were hatched, and until next June, the larvae fed in phloem, larvae begun to bore into xylem in June, the boring reached to a in July and August, and most of them entered xylem in September. The relationship between Number of the wormhole below 2m of the trunk was positively correlated with trunk diameter at breast height, and was negatively correlated with the highest height of living branches. The larvae occurred the most between 4 to 7 m of the height of the highest living branch.

Key words: Massicus raddei, Quercus liaotungensis, spatial distribution, mathematical model