Sample information, sequencing statistics, hybrid indices, and accession numbers for each sample analyzed in the study.

In the caste column, w: worker and q: young unmated queen. Principal component coordinates (PC1 and PC2) and F. aquilonia admixture proportions (sNMF clustering analysis run with K = 2, sNMF_K2_Faq) are both based on a 5 kbp-thinned dataset of 46,896 SNPs with MAC ≥ 2. HI_loter values are based on 1,490,364 phased SNPs, with non-Finnish species samples used as reference panels. HI_paint values are based on 79,336 ancestry-informative markers displaying allele frequency differences ≥ 80% between non-Finnish species samples. (XLSX)