Schematic representation of mitochondrial gene arrangements and the A + T-rich regions in three Thitarodes species. All the currently determined Thitarodes species have the ancestral gene order. Previously sequenced lepidopteran species have the trnM (M) translocated upstream of trnI (I), trnQ (Q), and an intergenic spacer (IS). There are 4.9 repeat units (I–IV with 107 bp per unit) in T. yunnanensis and 8.5 repeat units (i–viii with 113 bp per unit) in T. renzhiensis. Similar repetitive sequence is absent in Thitarodes sp.