Clarifying the taxonomy of the Finch Louse Fly Ornithomya fringillina (Curtis) (Diptera: Hippoboscidae) – an analysis of morphotypes

The louse flies in the genus Ornithomya are avian ectoparasites. The patterns of alar microtrichia on the wings of the Ornithomyae are commonly used to help distinguish the various species, with the patterns in most species found to be constant between individuals. The Finch Louse Fly Ornithomya fringillina (Curtis) in the United Kingdom, Ireland and the Isle of Man, is unusual in that the several patterns have been described. Consequently it has a complicated taxonomic history and there is some confusion about species identification. Louse flies were collected by licensed bird ringers and an analysis of the simple morphological features, phenology and geographical distribution of these traits was performed. No significant differences were found between the three main types, and it was concluded that the differences were not due to sexual dimorphism and did not provide evidence that the different forms were separate species. Analysis of COX1 DNA sequences confirmed this result and proved that these are indeed morphotypes and not distinct species. There was no geographical separation between COX1 sequences from the United Kingdom and those from flies sampled in other parts of the world. The molecular analysis also suggested that Ornithomya bequaerti (Maa) and Ornithomya candida (Maa) may not be valid species, but represent morphotypes of O. fringillina.