Panmictic population of the pollinating moth Tegeticula baja (Lepidoptera: Prodoxidae), across the distribution of its plant hosts

Ecological interactions and demographic history shape the genetic diversity of populations. Tegeticula baja is the specialist pollinator of different Yucca hosts in the Baja California Peninsula, a region that experienced changes in habitat distribution during the Pleistocene. To assess the effects of host specificity and historical changes in habitat configuration, we i) analyzed the genetic structure of moth populations associated with 3 different Yucca plant species, ii) identified signatures of historical demographic changes, and iii) reconstructed the past potential distribution of T. baja at different periods. We genotyped the COI of 128 moths from 39 locations and estimated genetic diversity, population structure, and demographic history. We found an overall haplotype diversity of 0.708 and a nucleotide diversity of 0.0015. Moth populations associated with the 3 hosts exhibited similar diversity levels, with no evidence of genetic structure. These findings suggest that ecological associations with different host plants do not drive T. baja diversification. Instead, its demographic history has played a more significant role in shaping the levels and the distribution of the genetic diversity.