The nonbiting midges are tiny insects with a wide distribution around West Lake, China. In this study, the seasonal dynamics of the local dominant midge species was investigated. Phylogenetic trees of this species also were analyzed to discover its evolutionary history. Ultraviolet (UV) light traps were used for surveillance around West Lake in the period from April 2017 to November 2018. External morphological identification was performed using a stereomicroscope. Two genes of adult female midges that encoded the cytochrome oxidase subunit I (COI) and internal transcribed spacer 1 (ITS-1) were sequenced and aligned online using GenBank nucleotide database and the Molecular Evolutionary Genetics Analysis (MEGA) software 10.1.7. According to the field surveillance in 2017–2018, Forcipomyia bikanni Chan and LeRoux (Diptera: Ceratopogonidae) is the representative dominant species of West Lake, with its activity peaking in August and October. The COI and ITS-1 gene sequences of F. bikanni (XH01-5) were 523 bp and 315 bp, respectively. The final phylogenetic tree of the COI implied that F. bikanni (XH01-5) has 97.9% significant similarity with conspecific F. bikanni (LC015045) from the adjacent Fujian Province, China (E-value ≤ 0.1%). Furthermore, the ITS-1 sequences with 98% likelihood showed the highest linkage between F. bikanni (XH01-5) and F. townsvillensis (Taylor) (HM775502-HM775504) with different branches. Thus, the final unrooted phylogenetic trees of COI and ITS-1 are essential tools for reconstructing the evolutionary histories of nonbiting midges.