Spatial and host related genomic variation in partially sympatric
cactophagous moth species
AbstractSurveys of patterns of genetic variation in natural sympatric and
allopatric populations of recently diverged species are necessary to
understand the processes driving intra and interspecific
diversification. The South American moths Cactoblastis cactorum,
Cactoblastis doddi and Cactoblastis bucyrus are specialized in the use
of cacti as host plants. These species have different distribution
ranges and differ in patterns of host plant use. However, there are
areas in which their ranges overlap, as in northwestern Argentina, where
they are largely sympatric. Using a combination of genome-wide SNPs and
mitochondrial data we investigated the phylogeographic patterns of these
cactophilic moths and searched for footprints of hybridization.
Additionally, we evaluated a moth population feeding on Cleistocactus
baumannii, a plant never reported as a host for the genus. We identified
three well delimited species and detected signs of historical gene flow.
Our survey also revealed intraspecific geographic structure in both C.
doddi and C. cactorum and showed that the moth population feeding on C.
baumannii may be considered as conspecific to C. bucyrus. Overall, our
results indicated historical events of genetic interchange occurred in
Cactoblastis cactophagous moths, but host plants likely played an
important role during divergence limiting gene flow across species.