The Phylogeny Of Genus Bombus (Hymenoptera: Apidae) In North China

Bumblebees belong to the Hymenoptera Apidae genus Bombus. There are about 250 species all over the world (239 species, Paul Williams, conservative number). Bumblebee, Bombus, is social insect about 210 species. Cuckoo bumblebee, Psithyrus, is inquilines about 30 species. There are more than 100 species in our country and it is the richest country in the world. Bumblebee was a group of polyphagous insects. They are widespread in Palaearctic, Oriental, Neotropical.North China was a transition zone of bumblebee distribution from south to north in our country. There are about 16 to 30 species in this region. It was a better place to research the phylogeny of bumblebee in this region. The present thesis studied the phylogeny of genus bombus in the north China, the result are as follows:1. We collected 9 subgenus 15 species of bumblebee from Beijing, Hebei, Shanxi. There are 6 subgenus 9 species, 9 subgenus 13 species, 5 subgenus 8 species in Beijing, Hebei, Shanxi province separately. The arcview visual analyze show the richness of bumblebee in Hebei province was the highest, Beijing province was the second, Shanxi province was the least. The similarity index of bumblebee in Beijing and Hebei was very high. It may be the climate and geographic position that lead to the result.2. The phylogeny of 7 species (4 subgenera) was analyzed by ten morphological characters. Hierarchical Cluster Analysis Statistics method of SPSS 10.0 was employed here. The result shows that all the species in the same subgenus was clustered together. Four subgeneras were all the monophyletic group, Pyrobombus diverged first and Bombus s.str diverged lastly. Melanbombus and Bombus s.str form a sister group. The similar matrix shows that the similarity coefficient of B. lucorum and B. ignitus was the largest. It suggested that the relationship of the two species was the closest. The similarity coefficient of B. lucorum and B. sibiricus was the least. It suggested that the relationship of the two species was the furthest.3. The genetic diversity of 8 species bumblebee was studied by SSCP method. The result show that it was exist genetic diversity obviously in the 8 species. However it does not polymorphy in the intraspecies. Partial COI gene was amplified by COI-04 primer. The length of PCR product was range from 777 to 783 bp. There are 593 conserved sites, 190 singleton polymorphic sites and 106 parsimony informative polymorphic sites in this DNA segment, the similarity coefficient was more than 85% in COI-04 PCR product of the 8 bumblebee species. The substitution rate was not reached the plateau. The phylogenetic relationship of 8 species and apis melliffera as outgroup, including 6 subgenera: Bombus s.str, pyrosoma, subterranebombus, megabombus, melanobombus, sibiricobombus, was analyzed based on the 783bp COI gene sequence. Both NJ and MP tree show that Melanobombus diverged early and belong to the advanced group, Bombus s.str diverged lately. Bombus s.str and Sibiricobombus was become the sister group of other subgenus in the MP tree. Bombus s.str divergedearlier than Pyrobombus^ Melanobombus subgenus. But it diverged later than Subterraneobombus^ Megabombus subgenus in the MP tree. B. ignitus diverged first in the Bombus s.str subgenus. The Subterraneobombus was the earliest species in all the trees. B. sibiricus was clustered in the Bombus s.str in the three analyze methods;it means that Sibiricobombus and Bombus s.str were palaphyletic. It was different in our morphologic research. According to the morphologic character, we consider it reasonable to divided the Sibiricobombus from the Bombus s.str subgenera and form a sister group of Bombus s.str.