A new target capture phylogeny elucidates the systematics and evolution of wing coupling in sack‐bearer moths

The frenulum is a wing coupling structure that is found on the wings of
most families of Lepidoptera. It is a single bristle or set of bristles
that originate from the base of the hindwing that often interlocks with
the forewing during flight. This wing coupling mechanism is thought to
have been a major evolutionary innovation that allowed for enhanced flight
in Lepidoptera. The sack-bearer moths (Mimallonidae) are unusual among
Lepidoptera in that not all species within the family have a frenulum. We
test the hypothesis that the frenulum is not necessary and is therefore
lost in mimallonids that have longer male forewings because such wings are
perhaps better suited to be coupled by other means. To understand the
evolution of the frenulum, we inferred the most taxonomically and
genetically sampled anchored hybrid enrichment-based phylogeny of
Mimallonidae, including 604 loci from all 41 genera and from 120 species,
covering about 40% of the described species in the family. The maximum
likelihood tree robustly supports major relationships within the family,
and ancestral state reconstruction clearly recovers the frenulum as the
plesiomorphic condition in Mimallonidae. Our results show that the
frenulum is more often observed in species that have shorter, rather than
longer, male forewings. The frenulum has historically been used as an
important character for intrafamilial classification in Mimallonidae, but
our results conclusively show that this character system is more variable
than previously thought. Based on our results, we erect two new
subfamilies, Roelofinae St Laurent & Kawahara, subfam. n. and
Meneviinae St Laurent, Herbin, & Kawahara, subfam. n., for four
genera previously considered incertae sedis. In the predominantly
frenulum-lacking clade Cicinninae, we describe a new genus, Cerradocinnus
St Laurent, Mielke, & Kawahara, gen. n., and the genus Gonogramma
stat. rev. is revalidated to include many species previously placed in
Cicinnus sensu lato. With these changes, Cicinnus can now be considered
monophyletic. Thirty-three species are transferred to Gonogramma from
Cicinnus sensu lato.