Abstract
Ophraella communa LeSage is native to North America and a biological control agent of the invasive weed Ambrosia artemisiifolia L. Since A. artemisiifolia plants grow old and die after September annually, O. communa suffers from food shortage. To understand the effect of food shortage or deprivation on population fitness of O. communa, the development and fecundity and hatchability of its progeny eggs were observed when larvae were offered A. artemisiifolia plants for either 3, 6, 12 or 24 hours daily. The results showed that larval food deprivation significantly influenced survival and developmental durations of larvae and pupae. Survival rates and developmental durations of larvae and pupae decreased and were prolonged significantly with decreasing time of larval daily food intake. Longevity and fecundity of adults shortened and decreased significantly with decreasing time of larval daily food intake. In addition, the hatch rates of progeny eggs decreased significantly with decreasing time of larval daily food intake. The present study suggests that food shortage is one of the most critical factors that suppresses O. communa populations. This can explain why field populations of the beetle decrease significantly with ageing and death of A. artemisiifolia plants after late September.
Acknowledgements
We are very grateful to Prof. Mark S. Goettel, Editor-in-Chief of Biocontrol Science and Technology for editing the English of this manuscript, and thank two anonymous reviewers whose appropriate commentary strengthened the manuscript. We also thank Ms Min Li (Fujian Agricultural and Forestry University) and Ms Wei Guo (Hunan Agricultural University), Mr Xing-Wen Zheng, Mr Yong-Xiang Fang and Ms Hai-Yan Zheng (Jiangxi Agricultural University), and Prof. Yuan-Hua Luo (Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China) for their help during the experiment.
Funding
This work was supported by the National Natural Science Foundation for Excellent Young Scholars [grant number 31322046] and the National Natural Science Foundation of China [grant number 31171908].