Figure legends
Figure 1. Geographic location and host species of theCactoblastis cactorum populations sampled in this study (A). Regions represent biogeographic provinces according to Morrone et al. (2014). Panels (B) and (C) represent the maps of habitat suitability forC. cactorum during the present (B) and during the Last Glacial Maximum (LGM, ca. 21ky) (C) as inferred by the most-supported ENM model in MAXENT. For visual representation, we only displayed ENM results based on the model constructed with the climate-based habitat suitability maps for host species (CurrentHOST), which resulted with the lowest AIC score in model comparison. Inferences from alternative models are shown in Figure S5.
Figure 2 . Population genetic structure and phylogenetic relationships of the C. cactorum populations sampled in this study, using nuclear and mitochondrial genetic data. Each genetic group is represented by the same color across panels. (A) Pie charts represent the average ancestry coefficient of individuals belonging to each of 28 sampling sites distributed along three biogeographic regions according to Morrone (2014). (B) Species tree reconstructed by the coalescent method SNAPP using a matrix of 2,086 unlinked SNPs; numbers in nodes denote posterior probability for the most supported topology based on the maximum credibility tree. (C) Results of individual assignment in genetic clusters using sNMF method. Vertical bars represent the ancestry coefficient of each individual to the corresponding genetic cluster. (D) Principal component analysis (PCAs) using the two major axes of genomic variation. (E) Median-joining network obtained with mtDNA data. The mitochondrial network consisted of 66 haplotypes grouped in at least six haplogroups.
Figure 3. Visual representation of the most supported demographic model (Model 8) estimated using Fastsimcoal2. Parameter estimates included timing of population divergence (TDIV1 and TDIV2), historical and contemporary effective population sizes (NEANC1 and NEANC2), and asymmetric rates of gene flow (MSC, MCS; MES, MSE; MCE, and MEC).
Figure 4. Spatial pattern of population genetic diversity forCactoblastis cactorum . The map shows the projection of climatic and habitat stability through time, from LGM (~21 Kya) to the present, for the three ENM models based on (i) only climatic variables (StabilityENV) (A), (ii) climate-based habitat suitability maps for host species (StabilityHOST) (B), and (iii) combining climatic variables climate-based habitat suitability maps for host species (StabilityENV-HOST) (C). Circle sizes denote varying levels of population genetic diversity as indicated by nuclear [(A). H E, expected heterozygosity; (B). π, nucleotide diversity) and mitochondrial (C). HD, haplotype diversity)]. Bottom panels show the significantly positive relationships between a given genetic diversity index and latitude.