Designation of a new family group name, Tonzidae fam. nov., for the genus Tonza (Lepidoptera, Yponomeutoidea), based on immature stages of Tonza citrorrhoa

The systematic position of Tonza Walker, 1864 is re-evaluated, based on the characteristics of immature stages and DNA barcodes. Larvae and pupae of Tonza citrorrhoa Meyrick, 1905 are described and illustrated for the first time. Larvae of this species form a loose web among the leaves and branches of the host plant, Putranjiva matsumurae Koidz. (Putranjivaceae Endl.). The immature stages of Tonza exhibit four unique apomorphies including: in the larva, the prolegs on A5 and A6 absent, and the seta L2 on the A1–A8 very small; in the pupa, four minute knobs are positioned in the middle portion on abdominal segments V and VI; while its caudal processes possess a W-shaped spine with numerous minute spines. These characteristics clearly distinguish Tonza from other yponomeutoid families and hence, we propose a new family group name, Tonzidae Kobayashi & Sohn fam. nov., for the genus Tonza. Existing DNA barcode data suggest a relationship with Glyphipterigidae Stainton, 1854. The family level status of Tonzidae fam. nov. provides a hypothesis that needs to be tested with larger molecular data.