Monitoring the masson pine moth, Dendrolimus punctatus (Walker) (Lepidoptera

The masson pine moth, Dendrolimus punctatus (Walker) (Lepidoptera: Lasiocampidae) was monitored at 102 trapping locations distributed in Qianshan County, China, with a synthetic sex pheromone during the 1998-2000 field seasons. Traps baited with a 25:10:28 three-component blend of Z5,E7-12:Ac; Z5,E7-12:Pr, and Z5,E7-12:OH (>97% pure) were used to attract male moths. The mean numbers of adult male D. punctatus captured in pheromone-baited traps during the overwintering generation flight periods in 1999 and 2000 increased sharply by 6.25 and 112.43, respectively, compared with those of male D. punctatus in 1998. The mean numbers of male D. punctatus captured during the first generation flight periods in 1999 and 2000 increased by 0.2256 and 5.92, respectively, compared with those in 1998. Traps placed at lower than 5.5 m in a masson pine forest canopy caught significantly more males of D. punctatus than did those placed higher in the forest canopy during the overwintering generation of 1998 and the first generation of 1999 flight periods. No significant differences were found among catches in traps placed on different slopes. A theoretical simulation method was used to estimate the suitable number of trapping locations needed in this study for acceptable precision. We estimated that 33-72 trapping locations are needed to monitor with statistical significance the dynamics of D. punctatus in Qianshan County during different field seasons.