Chemical distances based on CHC analyses
The cluster analysis carried out on the CHCs yielded two main clusters (Figure 2A). One belonged to the hydrocarbon profiles of E. ruidum sp. 1 and is clearly separated from the second, which contained two subclusters, one with the E. ruidum sp. 2 samples and the second with specimens assigned to E. ruidum spp. 3 and 4. TheE. ruidum sp. 2 cluster showed that the CHC profiles of the populations from Colombia and Puerto Morelos, in southeast Mexico, were more similar to each other than those of the population from Coyula, Oaxaca, Mexico (Figure 2A). We also found that the CHC profiles of E. ruidum sp. 3 were different from those of the populations ofE. ruidum sp. 4.
Chemical distances were significantly correlated with the genetic distances obtained for the 3RAD (Mantel test, r = 0.855, P = 0.001), UCE (r = 0.876, P = 0.016), and cox1 (r = 0.847, P = 0.004) data sets (Table S6; Figure 4). In contrast, there was no significant correlation between geographic and chemical distances (r = -0.022, P = 0.354), nor between geographic and genetic distances (Table S6) calculated from 3RAD (r = 0.322, P = 0.141), UCEs (r = 0.052, P = 0.225), cox1 primary haplotypes (r = 0.217, P = 0.205) and cox1 secondary haplotypes (r = -0.258, P = 0.826).