婆鳃金龟属幼虫形态和分类学研究

The genus Brahmina Blanchard,1851 (Coleoptera: Scarabaeidae: Melolonthinae) is a small or medium-sized group of scarab beetles, composed of about 110 species, of which 38 species have been recorded in China. As insect pests, the species of Brahmina cause huge economic losses for their larvae damage to potato, beans, peanuts, sugarcane, forest nurseries, and various vegetables. However, the larvae are difficult to identify because our knowledge of the immature Brahmina is limited. On the one hand, previous identifications of larvae normally rely on rearing samples and morphological identification of adults. The traditional identifying method is time-consuming and is often very to fail owing to the high immature mortality. On the other hand, the previous morphological descriptions were merely focused on few morphological characters, which are not enough for larval identification and phylogenetic taxonomy. In this project, we will use DNA barcoding technology for associating the larvae and adults and identifying the samples, use scanning electron microscopy to examine the ultramorphology of all instar larvae, record their biological habits through field observation and rearing, and finally provide valuable information for the larval identification and phylogeny of Brahmina.

婆鳃金龟属Brahmina Blanchard,1851（鞘翅目Coleoptera：金龟科Scarabaeidae：鳃金龟亚科Melolonthinae）是一类重要的农业害虫，以幼虫危害马铃薯、大豆、花生、甘蔗、苗木、以及多种蔬菜作物，常造成严重经济损失。该属已知约110种，我国已记录38种。然而，婆鳃金龟幼虫很难鉴定，幼虫已知的种类非常稀少。长期以来，金龟子幼虫只能通过饲养至成虫才能确定种类，耗时费力，且常因幼虫死亡而失败。另外，以往的金龟子幼虫研究主要采用光学显微镜，缺乏超微形态学研究，很难满足幼虫鉴定和系统发育研究的需要。本项目拟运用DNA条形码技术对婆鳃金龟幼虫和成虫进行快速匹配和准确鉴定；运用光学和扫描电子显微技术，对婆鳃金龟属幼虫开展形态学研究；基于野外观察和人工饲养，研究其生物学习性。本项目的开展，不仅能为婆鳃金龟幼虫的分类鉴定提供依据，而且能为其他类群的相关研究提供借鉴。

婆鳃金龟属Brahmina （鞘翅目Coleoptera：金龟科Scarabaeidae：鳃金龟亚科Melolonthinae）是一类重要的农林害虫，以幼虫危害农林作物地下营养部位而造成重要的经济损失。然而，婆鳃金龟幼虫以往研究很少，能够鉴定的种类不足2%。本项目通过连续3年的野外采集和人工饲养，获得了包括婆鳃金龟幼虫在内的金龟子幼虫标本8亚科43属106种幼虫标本。为鉴定此类幼虫，本项目构建了幼虫形态特征数据库，DNA序列数据库，和生物学特征数据库。其中，本项目运用光学和电子显微技术观察了幼虫头部、口器、胸足和肛腹片形态结构；运用解剖和组织学方法研究了6亚科代表物种消化系统的形态结构；运用分子生物学手段，扩增了33种金龟子的线粒体基因和核基因，并运用二代测序技术拼接注释了12种鳃金龟线粒体基因组；运用生物声学的手段分析了不同种类金龟子幼虫发声行为，揭示了两种不同的发音机制；在人工饲养过程中，运用六臂嗅觉仪比较了不同种类鳃金龟幼虫的取食偏好，并详细记录了鳃金龟科昆虫的生活史。本项目详细比较了包括婆鳃金龟幼虫在内的金龟总科各代表类群幼虫形态特征，以第一注释发表科研论文7篇，为进一步开展金龟子幼虫形态分类和蛴螬类地下害虫综合治理奠定了重要基础。