果蝇因其模式物种在遗传、进化及生态学等研究中的广泛应用而备受瞩目。凤仙花访花果蝇是直到最近才被我们认识到的一个果蝇类群，其所有已知成员均具访花习性。现有证据表明凤仙花果蝇是果蝇科较早分化的进化枝之一，对探讨果蝇科起源和多样化历史具有重要意义。本项目将结合形态学和DNA条形码数据，对我们所收集的凤仙花果蝇标本进行物种鉴定，基于多个线粒体及核基因分子标记的DNA序列数据构建凤仙花果蝇的系统发育关系，基于形态特征对凤仙花果蝇进行支序系统学分析，基于系统发育分析和支序系统学分析结果建立与凤仙花果蝇相对应的新分类单元，描述所发现的所有凤仙花果蝇新种，并对已描述物种的分类地位进行修订；我们还将基于系统发育分析结果，估计凤仙花果蝇的起源及物种分歧时间，重建其祖先物种分布地，探讨地质历史及古气候变化对凤仙花果蝇进化的影响，讨论凤仙花果蝇寄主选择的进化。

The drosophilid flies have drawn and are still drawing attentions owing to the wide using of the model species among them in genetics, evolutionary and developmental biology, and ecology, etc. The balsamine-visiting drosophilids (BVDs) form a species-assemblage which has not been recognized until recently, with all of known and putative species visit flowers, and are morphologically distinct from other drosophilid groups. This group was proved to represent one of the early-diverged clades in the family Drosophilidae, thus be important for investigation of the origin and history of diversification of the family. This project is proposed to reconstruct the phylogeny of the BVDs based on not only morphological data but also DNA sequence data of multiple mitochondrial and nuclear loci, establish new taxon (or taxa) for the BVDs, describe all the new species, and revise the classification of the previously described BVDs. We will estimate the divergence times based on the resulting BVD phylogeny, reconstruct the ancestral distributions, so as to assess the impacts exerted by the palaeogeographical and palaeoclimatological factors on the evolution of the BVDs. We will also discuss the evolution of the host-selection in the BVDs.