Mutualism between Epicephala sp. and Phyllanthus microcarpus — Biology and mutualistic stability
Author of the article:YANG Xiao-Fei** LI Hou-Hun ***
Author's Workplace：College of Life Science, Nankai University, Tianjin 300071, China
Key Words：Phyllanthaceae, Phyllanthus, Lepidoptera, Epicephala, biology, mutualistic stability
Abstract： [Objectives] To determine whether the mutualistic relationship between Phyllanthus microcarpus and Epicephala sp. involves one partner avoiding overexploitation of the other. [Methods] Based on studies of morphology and biology of Epicephala sp. that pollinate P. microcarpus exclusively, we clarified the behavioral traits of Epicephala sp. that have developed in response to their specific host and the benefits that each species has obtained from their mutualistic relationship. [Results] The results show that the lifespan of Epicephala sp. is six months with two generations per year. Changes in the number of adults synchronize with changes in the total number of the female and male flowers. The parasitism rate was 96%, and the number of larvae per fruit was above 1. However, only 56.9% of seeds were consumed per fruit and a high death rate of young instar larvae limited seeds from being overexploited. Moderate seed predation and the high death rate of young instar larvae appear to be the key factors maintaining the mutualistic relationship between these species. [Conclusion] P. microcarpus includes two phenotypic populations, both of which are mutualistic hosts of Epicephala sp. Thus, further morphological and biological studies of Epicephala sp. can contribute to understanding the evolutionary mechanisms underlying Epicephala sp.-P. microcarpus mutualism. This research provides a reference for further investigation of the mutualistic biodiversity between Epicephala and plants of the Phyllantheae (Euphorbiaceae).