Mitogenomic Phylogeny, Divergence Times, and Ancestral Range Reconstruction of the Rolled-Winged Stonefly Family Leuctridae (Plecoptera: Nemouroidea)

The family Leuctridae is a species-rich group of Holarctic stoneflies whose phylogenetic relationships, diversification timeline, and biogeographic history remain poorly resolved. We assembled a mitochondrial dataset comprising 30 species representing nine of the twelve currently recognized genera, combining complete and nearly complete mitogenomes with mitochondrial genes extracted from transcriptomes, and nine outgroups, to reconstruct the phylogeny, divergence times, and ancestral ranges of the family. Analyses strongly supported the monophyly of Leuctridae and recovered Megaleuctra as the earliest-diverging lineage, followed by two major Leuctrinae clades: (Despaxia + Leuctra) + Moselia and (Paraleuctra + Pomoleuctra) + (Perlomyia + Rhopalopsole + Zealeuctra). Molecular dating placed the crown origin of the family in the Late Triassic at 205.9 Ma (95% HPD: 178.1–237.0 Ma), with extant genera diversifying from the Late Cretaceous to the Late Eocene. Ancestral-range reconstruction under the DIVALIKE + J model favors western North America as the ancestral area at the crown node (relative probability 0.59) and at most deep nodes, although with substantial uncertainty. The present disjunct distributions between East Asia and North America are most consistent with deep-time range persistence and repeated founder-event colonization, possibly combined with ancient vicariance. Our results provide a novel mitogenome-based framework for further studies of leuctrid diversification.