Morphological and molecular revision of the subfamily Heterolepismatinae (Zygentoma, Lepismatidae), with descriptions of two new genera from the Atacama Desert, Chile

This work aims to update the systematics of silverfish of the subfamily Heterolepismatinae (Zygentoma, Lepismatidae) based on morphological and molecular data of new taxa from the Atacama Desert (Chile) with a comparison with specimens from Argentina, from where species originally described as belonging to the genus Heterolepisma Escherich, 1905 come. This comparison also includes COI gene sequences of Argentine specimens attributed to H. andinum (Silvestri, 1902), and of Australian Heterolepismatinae previously classified as Heterolepisma or Visma Smith et al., 2021.

As a result, the genera Lapidisma gen. nov. and Cactisma gen. nov. are described from Chile, and new morphological characters diagnostic of H. andinum are provided. The species Lapidisma paposanum sp. nov. and Cactisma camanchaca sp. nov. are associated with different habitats. The species Heterolepisma annectens (Silvestri, 1924) is tentatively attributed to the first genus (Lapidisma annectens comb. nov.).

The molecular data place the three South American genera in separate lineages, but cluster them as a sister group to the Australian Heterolepisma + Visma. This supports the proposal of the genus Silvestrisma gen. nov. to include Australian species previously assigned to Heterolepisma. Additionally, the new name Vistrolepisma nom. nov. is proposed for silverfish species previously assigned to the genus Visma, since this generic name is pre-occupied.

With this re-arrangement, the subfamily Heterolepismatinae consists of six genera, pending further studies in other geographic regions where poorly studied species occur that were (and are provisionally) assigned to Heterolepisma.