Systematics Of Subfamily Limoniinae From China (Diptera:Limoniidae)

The family Limoniidae(Diptera:Tipuloidea)is one of the largest groups of Diptera and widely distributed all over the world.As the largest subfamily of Limoniidae,Limoniinae is rich in the diversity of species.For Limoniinae,there are more than 3800 species in 34 genera are recorded in the world,of which nearly 300 species in 24 genera are known from China.Members of Limoniinae are bioindicators of water quality.Limoniinae is an important decomposition of organic matter,which is of great significance to the maintenance of ecological balance.Some species of Limoniinae can cause harm to the crops.In addition,some species have the habit of visiting flowers.Therefore,it is of great significance to study Limoniinae.However,the study of Limoniinae from China is far from enough.The early research was mainly made by foreign scholars,and the collection of specimens was also limited.Phylogenetic relationships between Limoniidae are also controversial.Systematics of Limoniinae from China is carried out in the present dissertation.In this study,the morphological characters and biology of Limoniinae were introduced,and the phylogeny,classification and geographical distribution of Limoniinae were studied.The results are shown as follows:(1)Seven Mitochondrial(Mt)genomes of Limoniinae are sequenced and analysed.The result shows that the lengths of those genomes are about 1.5kb.All the Mt genomes contain 37 genes and have no gene rearrangement.(2)Phylogenetic analysis based on Mt genome data support the monophyly of Limoniinae,and both tribe Dicranoptychini and tribe Elephantomyiini belonging to Limoniinae.The phylogenetic relationships among tribes of Limoniinae are(Dicranoptychini + Elephantomyiini)+(Antochini +Limoniini).(3)In the taxonomic section,334 species in 24 genera are included,of which 104 species in 20 genera are described and illustrated.29 species are described as new to science,of which 12 species are from Rhipidia,seven species from Geranomyia,five species from Toxorhina,two species from Elephantomyia,two species from Thrypticomyia,and one species from Dicranoptycha.Six species are recorded from China for the first time,of which three species are from Rhipidia,two species from Toxorhina,and one species from Elephantomyia.In total,35 species are added,raising the species number of Chinese Limoniinae from 299 to 334.Keys to the subfamilies of Limoniidae,and the genera and the species of Limoniinae are also given.(4)The distribution patterns of Limoniinae are studied.Based on the distribution patterns in the world,the Oriental region is the richest in the diversity of genera,followed by the Palaearctic region and the Australian region.The Nearctic region is the least.According to the distribution patterns in China,the South China is the richest in the diversity of species and genera,followed by the Central China and the Southwest China.The Northeast China is the least.In addition,the number of the endemic genera in the Australian region and the South China are the most,respectively.