Dissertation Research: Phylogeny and Evolution of Subsocial Behavior in the New World Treehopper Subfamily Membracinae (Homoptera: Membracidae)

0104893新世界角蝉亚科 Membracinae（5 个部落，38 属，约 447 种）中的 Danforth 和 Lin 昆虫表现出一系列社会行为，从 (1) 单独个体，到 (2) 若虫或成虫聚集，到 (3) 高度发达的母性护理，通过基质传播的振动进行亲代/子代交流。膜角蝉的行为变异为研究昆虫亚社会行为的进化提供了绝佳的机会。然而，由于对这一群体的系统发育关系的不完整了解，我们目前对该群体亚社会行为进化的了解是有限的。我们不知道孕产妇护理已经进化了多少次，也不知道孕产妇护理是否会引起孤独行为，也不知道涉及沟通和信号传递的复杂形式的孕产妇护理到底是如何演变的。为了更全面地了解膜角蝉社会进化的历史模式，研究生林中平将在康奈尔大学布莱恩·丹福斯博士的指导下，利用形态学和分子（来自核和线粒体基因的DNA序列）数据对该群体进行系统发育研究。新的藏品将从南美洲收集，以增加现有的样品和博物馆藏品。系统发育分析的结果将为重建膜角蝉行为特征变化的可能方向提供一个历史框架。然后，这些信息将用于识别亚社会行为的起源，并追踪亚社会行为在进化过程中的发展。这项研究的结果不仅有助于我们理解这一令人着迷的昆虫群体的亚社会行为，而且有助于了解一般社会性的进化。

0104893Danforth and Lin Insects in the New World treehopper subfamily Membracinae (5 tribes, 38 genera and about 447 species) show a range of social behavior from (1) solitary individuals, to (2) nymphal or adult aggregations, to (3) highly developed maternal care with parent/offspring communication via substrate-borne vibrations. The behavioral variation in membracine treehoppers provides an excellent opportunity to study the evolution of subsocial behavior in insects. However, our current knowledge on the evolution of subsocial behavior in this group is limited because of an incomplete picture of their phylogenetic relationships. We don't know how many times maternal care has evolved, whether maternal care gives rise to solitary behavior, or exactly how complex forms of maternal care involving communication and signalling have evolved. In order to more fully understand the historical patterns of social evolution in membracine treehoppers, a phylogenetic study of this group will be conducted using both morphological and molecular (DNA sequences from nuclear and mitochondrial genes) data by graduate student Chung-Ping Lin under the guidance of Dr. Bryan Danforth at Cornell University. New collections will be made from South America to augment existing samples and museum holdings. The results of phylogenetic analyses will provide a historical framework to reconstruct the likely direction of behavioral character changes among membracine treehoppers. This information will then be used to identify the origins of subsocial behavior and to trace the development of subsocial behavior over evolutionary time. The result of this study will contribute not only to our understanding of subsocial behavior in this fascinating group of insects but to knowledge of evolution of sociality in general.