Factors limiting Osmia excavata Alfken populations in apple orchards in Shandong Province
Author of the article:CAO Yan-Bin1, 2** ZHOU Xian-Hong1 YE Bao-Hua2 LI Li-Li1 LU Zeng-Bin1 XU Heng1 LI Wen-Qiang1
Author's Workplace：1. Institute of Plant Protection,Shandong Academy of Agricultural Sciences/Shandong Provincial Key Laboratory of Plant Virology，Jinan 250100, China; 2. Shandong Agricultural University, College of Plant Protection, Tai’an 271000, China
Key Words：apple, Osmia excavata Alfken, population, life table, lethal factors
Abstract：
[Objectives] To clarify the factors that limit Osmia excavata Alfken, one of the most important insect pollinators of apples in Shandong Province, and therefore maintain this important ecological service. [Methods] Demographic trends of O. excavata populations from 6 locations in Shandong Province were compared using life tables. [Results] There were significant differences in pupation rates (7.64%-73.84%) and numbers of pupae per tube（0.80-5.56）among the 6 locations. All population trend indices were > 1, varying from 1.80 to 11.80. The exclusive index of population control (EIPC) of eggs; un-hatched, parasitized, predation and natural death, were 1.07、1.10、1.03、and 2.53, respectively. Total EIPC of the 6 locations varied from 1.19 to 5.50, which indicates that O. excavata populations could potentially increase by 19% to 450% without those lethal factors. [Conclusion] Natural death of O. excavata is the main limiting factor in Shandong orchards, and improving their breeding management can decrease the natural mortality rate..