The Research Of Flower-visiting Dipterans From Burmese Amber

Diptera is one of four major orders of insects.To date,over 150,000 species of dipterans have been described.Dipterans with extremely high species and ecological diversity.Flies,especially flower-visiting flies,play an important role in driving evolution of ecosystem.Diptera is one of the insect groups that transfer the most amount of pollens in the ecosystem and also a relatively ancient pollinator with developed the specialized long proboscis in the Jurassic.The terrestrial ecosystem underwent a dramatic restruction and diversification during 125-88 Mya.Angiosperms began to rise as the dominator in terrestrial vegetation.The co-evolution of insect pollinators and flowering plants is considered to be one of the most important reasons for the angiosperms radiation.The Burmese amber was deposited during the Albian to Cenomanian when the vegetation transformation comes to the crucial part.Many flower-visiting insect fossils were discovered from Burmese amber,which provides important evidence for the evolution of flower-visiting insects.This dissertation studied the taxonomy and palaeoecology of flower-visiting dipterans in Burmese amber.Three new species are established based on the material of Stratiomyidae and Nemestrinidae.This thesis described a species of Stratiomyidae,Lysistrata burmensis Liu,Cai and Huang,2016;reported two forms of larvae of Stratiomyomorpha;established a new nemestrinid Hirmoneura burmanica Liu and Huang,2019;redescribed the species Hirmoneura aff.richterae Grimaldi,2016 as a new species Hirmoneura mostovskii Liu and Huang,2019;discussed the venation variation of Hirmoneura caudiprima Grimaldi,2016.Besides,This thesis collected morphological data from fossil and extant species of Nemestrinidae to compare their flight ability,and concluded that nemestrinids in the mid-Cretaceous have developed a high-level flight ability close to extant groups.The fossil evidence of flower-visiting insects summarized herein indicates a lag between the vegetation transformation and the feeding transition of insects.