The vertical distribution characteristics of Monochamus alternatus on the trucks of infested Pinus yunnanensis were investigated both in field and laboratory.The results showed that the quantity distribution of oviposition scar in trunk was lower part > middle part > upper part;and the density distribution of oviposition scar had not significant difference(P>0.05).The quantity distribution of entrance hole in trunk was middle part > lower part > upper part;and the density distribution of entrance hole was upper part > middle part > lower part.The quantity distribution of exit hole in trunk was middle part > upper part > lower part;and the density distribution of exit hole was upper part > middle part > lower part.There were positive correlations between the quantities of oviposition scar or entrance hole in lower part of trunk and the entrance hole or exit hole in whole trunk,respectively.The linear regression equations of the quantity of oviposition scar in lower part(x1),the entrance hole in lower part(x2) and the quantity of oviposition scar in whole trunk(y1),the entrance hole in whole trunk(y2),the exit hole in whole trunk(y3) are y1=7.117+2.283 x1,y2=24.220+0.701 x1,y3=8.794+0.434 x1,y2=28.805+2.211 x2,y3=20.367+0.778 x2.All partial correlations had reached the very signiticant level.
