A Molecular Phylogeny Of Some Families Of Chalcidoidea (Hymenoptera): Evidence From PCR-RFLP Of 28S RDNA

Chalcidoidea is one of the largest superfamilies of parasitic Hymenoptera and one of the most important natural enemies for biological control. However, owing to the difficulties of taxonomic studies, there are many arguments about the number of families included in and about their relationships. It would seem that the problem with the Chalcioidea is not really with the number of families generally regarded as valid but with what we understand of the phylogeny of the group. Some good character evidence are required to enable us to decide on the phylogenetic relationships of the group as a whole before we can even start to sort out the validity of higher taxa. Recently, insect molecular systematics has undergone a rapid growth and greatly advanced our knowledge of the phylogeny of some groups. In this study, a region of 28s rDNA were examined from specimens of 13 families of Chalcidoidea and 16 genera of Mymaridae. 11 families of Chalcidoidea and 7 genera of 16 of Mymaridae were successfully amplified. Subsequently, 11 samples were selected for restriction fragments length analysis (PCR-RFLP). Patterns obtained were used to construct phylogenetic trees. Congruence and incongruence, simultaneously, are there between molecular data and morphological date on the relationships of 7 families concerned. The drawbacks of this research or possible reasons resulting in this incongruence are discussed in this paper. Owing to these possible reasons, the placement of Mymaridae and its genera leaves much to be desired. Although it is not certain whether the amplified region of 28S is appropriate for the analysis, it seems that the amplified region of 28S is a promising marker for the phylogeny of Chalcidioidea. With the research progressed, the relationships of Chalcidoidea would be well defined.