Phylogeny and ecological diversity of Palaearctic Coleophoridae (Lepidoptera: Gelechioidea)

Abstract The family Coleophoridae exhibits remarkable diversity, with over 1450 species known worldwide. Although the group is supported by well‐documented ecological data, evolutionary pathways derived from these traits have not yet been thoroughly investigated. This study explored phylogenetic relationships within the family using molecular data. A phylogenetic analysis was conducted on 139 coleophorid species and four outgroup species (a total of 143 species) based on a four‐gene dataset totalling 631–3571 bp, including two mitochondrial protein‐coding genes (COI and CYTB) and two nuclear protein‐coding genes (EF‐1α and CAD). Among the 143 species, sequence data for 76 ingroup species and four outgroup species were generated in this study (2718–3571 bp), and COI data (631–1467 bp) for the remaining 63 species were obtained from GenBank to incorporate key species. The combined dataset was analysed using maximum likelihood (ML) phylogenetic frameworks. In addition, to investigate ecological trait evolution, an evolutionary approach was applied, focusing on host plant type (growth form), larval feeding sites and larval case types, based on the maximum likelihood tree reconstructed in this study. Ancestral state reconstruction was conducted using parsimony in Mesquite and Bayesian inference in BayesTraits. The resulting phylogeny was compared with previously published molecular phylogenies to examine overall congruence and evaluate the consistency of inferred relationships within the family. The analysis showed the following: (1) among the eight recently proposed species‐groups within the genus Coleophora (s.l.), seven species‐groups were recovered as monophyletic, except that the C. albella species‐group was paraphyletic due to the inclusion of the genus Ischnophanes , and the C . saturatella and C . frischella species‐groups were recovered as sister groups; (2) in contrast, under a different framework of seven clusters and a multi‐level classification system, only clusters I and VII were recovered as monophyletic, whereas several tribes (Agapalsini, Coleophorini, Razowskiini and Systrophoecini) and some genera were non‐monophyletic, indicating questionable assignments at multiple taxonomic levels; (3) Coleophora (s.l.) was recovered as non‐monophyletic under three‐genera classification system and, correspondingly, under the multi‐level classification system, the subfamily Coleophorinae was also recovered as non‐monophyletic due to the nested placement of Ischnophanes . Furthermore, the results suggest that ancestral coleophorids likely fed within plant tissues without constructing larval cases and primarily targeted the reproductive organs of herbs. Across the phylogeny, transitions from herbaceous–subshrub flora to woody flora and shifts from reproductive organ feeding to leaf feeding occurred repeatedly, with multiple reversals. Larval case evolution showed repeated, independent origins of similar case types, indicating substantial homoplasy in larval case architectures. Taken together, this study provides a framework for understanding the phylogenetic relationships of the family Coleophoridae, re‐evaluates the boundaries of certain taxonomic groups and presents preliminary insights into the evolutionary history of ecological traits.