Influence of Drought in Southwest China on Occurrence of Four Species of Forest Pests from 2002 to 2010

The drought levels from 2002 to 2010 in Yunnan, Guangxi, Guizhou, Sichuan provinces and Chongqing Municipality were classified in purpose to analyze the correlation of the drought extent with the occurrence areas of four major forest pests including Monochamus alternatus, Dendrolimus punctatus, Tomicus piniperda, and Parocneria orienta. The results showed that there was no significant correlation between the drought level and the occurrence area of Monochamus alternatus (P＞0.05); there was negative correlation between the drought level and the occurrence area of Tomicus piniperda (P＜0.05); there was positive correlation between the drought level and the occurrence area of Dendrolimus punctatus in Guizhou, and there was positive correlation between the drought level and the occurrence area of Parocneria orienta in Sichuan and Chongqing（P＜0.01）. The influence of drought on forest pests varied from the drought type, drought extent, and the region that was impacted by the drought.