Figure 1. Median haplotype network of Ornithomya avicularia specimens from different regions based on the mtDNA COI gene sequence. Yellow circles represent individual haplotypes; diameters correspond to the number of specimens. Red circles represent ancestral haplotypes. Lines on branches represent mutations. Green clouds represent genetic groups.
Parasites are useful model objects for studying how broad ecological niches influence evolutionary patterns. The bird louse fly Ornithomya avicularia (Diptera: Hippoboscidae) is a widespread ectoparasite of birds, parasitizing a wide host range across Eurasia, Australia, and Africa. However, the relationship between the geographic location of populations and morphological and genetic diversity within this species remains poorly understood.
The morphological and molecular variability of Ornithomya avicularia was investigated using samples from seven populations spanning Europe, Western Siberia, and the Russian Far East.
Scientists from the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) found that morphological variation was largely continuous across most of the studied range, but populations from Siberia and the Russian Far East exhibited consistent differences in the pattern of microtrichia on the wings and the length ratios of some wing veins.
Genetic analysis revealed three main haplotype groups, including a widespread European-West Siberian cluster (Fig. 1, Group 1) and two deeply divergent lineages (Fig. 1, Groups 2 and 3) restricted to the Russian Far East. One of the Far Eastern lineages demonstrated genetic distances approaching interspecific levels (Group 3) and was highly distinct, consistent with its recognition as a separate species described elsewhere.
A significant association was found between geographic distance and morphological differences, whereas genetic differences showed weaker geographic structure.
Using molecular clock analysis, the estimated formation time of Groups 1 and 2 was analyzed. The groups diverged approximately 2.2 million years ago (MYA). From a paleoecological perspective, this corresponds to the late Miocene and Pliocene.
Related materials:
RAS: "Morphological and Genetic Variability of Bloodsucker Fly Populations in Northeastern Eurasia"