The Evolution and Maintenance of Mutualism Between Lycaenid Butterflies and Ants

普林斯顿大学的内奥米·皮尔斯博士提出了一种有趣的方法来量化推动生物体内共生进化的各种选择力。本研究将确定影响食杂蚁幼虫与蚂蚁共生进化的选择力量，以及维持这种关联的行为和生化机制。该项目的第一部分将衡量蚂蚁（Iridomyremes aneps和I. rufoniger）从照料紫斑Jalmenus evagoras幼虫中获得的收益，包括群体增长率和对繁殖后代的投资。本研究还将探讨聚类生活的紫斑蛾幼虫对蚂蚁吸引力的个体差异的重要性。该项目的第二部分将考虑维持这种联系的一些因果机制，首先测试雌性evagoras在不同氮含量的寄主植物上的产卵行为。然而，这方面研究的主要重点将是使用蚂蚁生物测定和生化分析来了解更多关于lycaenid幼虫分泌物的性质。特别感兴趣的将是确定幼虫和伴随蚂蚁之间物种特异性识别所涉及的化学线索。为了做到这一点，皮尔斯博士将比较与特定种类蚂蚁相关的每一种蚂蚁的分泌物。她还将确定不同种类的Jalmenus分泌的氨基酸谱是否反映了其伴随蚂蚁的饮食偏好。最后，她将研究lycaenid幼虫的表皮分泌物是否以任何方式模仿其伴随蚂蚁的一窝表面分泌物。这些研究将大大增加我们对相互依赖的生物体联系的理解和我们对一般进化的看法。

Dr. Naomi Pierce of Princeton University proposes an intriguing approach to quantifying various selection forces that drive the evolution of mutalisms in living organisms. This research will identify selective forces shaping the evolution of mutualism between lycaenid larvae and ants, and behavioral and biochemical mechanisms maintaining the association. The first part of the project will measure the benefits that ants (Iridomyremes anceps and I. rufoniger) receive from tending larvae of Jalmenus evagoras in terms of colony growth rate and investment into reproductive brood. It will also investigate the importance of individual variation in attractiveness to ants of larvae of J. evagoras that live in aggregations. The second part of the project will consider some of the causal mechanisms maintaining the association by first testing the oviposition behavior of females of J. evagoras on host plants that vary in their nitrogen content. The main emphasis of this side of the research, however, will be in using ant bioassays and biochemical analyses to learn more about the nature of the secretions of lycaenid larvae. Of particular interest will be identifying the chemical cues involved in species specific recognition between larvae and their attendant ants. To do this, Dr. Pierce will compare the secretions of each species in the genus that associates with a particular species of ant. She will also determine whether the amino acid profiles secreted by different species of Jalmenus reflect the dietary preferences of their attendant ants. And finally, she will examine whether the epidermal secretions of lycaenid larvae mimic in any way the surface secretions of the brood of their attendant ants. These studies should add significantly to our understanding of interdependent organism associations and to our perspective on general evolution.