Conclusions
Here we according to the morphological characteristics and the
phylogenetic tree constructed based on the 6 genes, phylogenetic
relationship of the genus Diestramima is shown. At present, the
interspecies morphological characteristics and molecular phylogeny
relationships of all the samples have maintained extremely high
consistency. However, at the subgenus level, it is difficult to give a
reasonable explanation on the phylogenetic tree although we found that
some groups share some common characteristics. In phylogenetic clades ofDiestramima , similarity in geographic distribution is as
important as similarity in morphological characteristics. This
phenomenon may be related to their lack of wings and weak mobility.
Combined with the results of biogeographic analysis, the ancestors of
the genus Diestramima had already arrived in Guangxi and Yunnan
provinces in China before the Miocene. The two temperature rises in the
Palacocene and Miocene may have intensified the dispersal of the
ancestors of the genus Diestramima in the Oriental realm. The
temperature drop and the uplift of the Qinghai-Tibet Plateau were the
main reasons for the divergence within the genus Diestramima . In
addition, changes in humidity and changes in surface plant communities
are also important factors affecting their divergence. The low
mountainous hilly region of Guangxi, Guizhou and Hunan is the area where
the insects of this genus are most differentiated. At the early
Pliocene, they may have reached most of the areas where they are now.
The arrival of the Quaternary Ice Age has caused these species to
undergo violent and complex evolution in inland China.