蝎蛉科幼虫比较形态学及其系统学意义

Larva is an important developmental stage of holometabolous insects and plays an important role in species identification and phylogenetic research. However, most of the current classification system is based on adult characters, with the larval features being largely ignored. Panorpidae is the largest family of Mecoptera. Their larvae are of eruciform type with eight pairs of abdominal prolegs and possess a pair of prominent compound eyes on the head. Previous studies have indicated that there are obvious paraphyletic problems during phylogenetic reconstruction of Panorpidae based on adult characters. The introduction of larval features is expected to resolve the paraphyletic problem. This project investigates the morphological diagnosis, character evolution, ultrastructure, functional morphology of larvae using comparative morphology and phylogenetic methods and establishes a natural classification system conforming to the evolutionary history of Panorpidae, with the larval features as the main basis combined with adult characters, using the Bittacidae and Panorpodidae as outgroups. This research will provide reference for the taxonomical studies of other holometabolous insect larvae.

幼虫是全变态类昆虫重要的发育阶段，幼虫特征在昆虫种类识别和系统发育研究中均起着重要作用。但当前分类体系的建立多基于成虫特征，幼虫特征在很大程度上被忽视。蝎蛉科Panorpidae是长翅目Mecoptera第一大科，幼虫蠋式，有8对腹足，头部具一对发达的复眼。前期研究表明，仅基于成虫形态特征的蝎蛉科系统发育重建中存在明显的并系问题，引入幼虫特征可望解决并系问题。本项目拟采用比较形态学和系统发育分析方法，研究蝎蛉科幼虫的形态识别、特征演化、超微结构、功能形态等，并以蚊蝎蛉科和拟蝎蛉科为外群，以幼虫特征为主，结合成虫特征，建立符合蝎蛉科进化历史的自然分类系统，并为其他全变态类昆虫幼虫的分类学研究提供借鉴。

幼虫是全变态昆虫生活史的重要阶段。幼虫的形态学研究可为全变态昆虫的分类和系统发育分析提供更多、更重要的依据。我们通过人工饲养，共获得了蝎蛉科7属36种幼虫，其中蝎蛉属Panorpa 11种、双角蝎蛉属Dicerapanorpa 3种、广翅蝎蛉属Megapanorpa 2种、单角蝎蛉属Cerapanorpa 7种，叉蝎蛉属Furcatopanorpa 1种，华蝎蛉属Sinopanorpa 2种，新蝎蛉属Neopanorpa 10种。形态学特征分析表明，蝎蛉属幼虫缺乏共有衍征，种间形态存在变异；新蝎蛉属头壳具浅沟，唇基边缘锯齿状，复眼较为平滑，环纹毛突较短；双角蝎蛉属幼虫腹足粗壮，头部刚毛针状；广翅蝎蛉属幼虫下唇须顶端具11个锥形感器。蝎蛉科幼虫形态在属间和种间的变异，尤其是口器感器数量和排列以及头部刚毛毛序，可为蝎蛉属和新蝎蛉属的进一步划分以及蝎蛉科昆虫系统发育分析提供更多依据。.通过对蝎蛉科7属32种幼虫进行特征编码，分别基于幼虫（91个特征）、成虫（132个特征）、以及成、幼虫联合特征，采用最大简约法，对蝎蛉科昆虫系统进行了发育分析。结果表明，蝎蛉科由新蝎蛉亚科和蝎蛉亚科两大支系组成；支持蝎蛉属为并系群；支持单角蝎蛉属、双角蝎蛉属、广翅蝎蛉属和华蝎蛉属的单系性。成、幼虫联合特征分析有助于建立更为可靠的蝎蛉科系统发育关系。