Cerurinae

St Laurent, Ryan A., Goldstein, Paul Z., Miller, James S., Markee, Amanda, Staude, Hermann S., Kawahara, Akito Y., Miller, Scott E. & Robbins, Robert K., 2023, Phylogenetic systematics, diversification, and biogeography of Cerurinae (Lepidoptera: Notodontidae) and a description of a new genus, Insect Systematics and Diversity 7 (2), pp. 1-25 : 20

Biogeography of Cerurinae

An African origin for Cerurinae makes sense because all extant species of the sequentially sister lineages of Cerurinae until Clades (B+C) are Afrotropical. There is no evidence of secondary dispersal back into Africa south of the Saharan desert from any of the biogeographic analyses. The Mediterranean African Cerura delavoiei ( Gaschet, 1876) is the only taxon believed to have recolonized Africa, but only north of the Sahara in Morocco, Algeria, Tunisia, and the Canary Islands ( Schintlmeister 2008), a region we treat biogeographically as part of the West Palearctic.

Outside of Africa, the biogeography of Cerurinae is more complicated, with several major dispersal events. However, the most likely scenario is that Cerurinae invaded the Palearctic from Africa via the Balkans or Asia Minor, from whence they spread throughout the East and West Palearctic and spawned all subsequent radiations of Cerurinae . Two major lineages evolved in the Palearctic, the first (Clade B) leading to the sister genera Neoharpyia and Furcula , which spread from the Palearctic to the Americas; and the more speciose Clade C which independently colonized the Americas ( Americerura ), Indomalaya and Australasia ( Neocerura and Kamalia ), and radiated in situ within the Palearctic ( Cerura ).

The dispersal events that led to the colonization of the Americas by Americerura and Furcula occurred during the Miocene. Americerura are found from Canada to Uruguay and have radiated in the Neotropical realm, whereas Furcula are found exclusively in the Northern Hemisphere. The ancestor of Americerura arrived in the Americas via North America some 15 Ma, requiring either long distance dispersal from the Old World or shorter dispersal routes in the Bering region. The ancestor of Furcula , on the other hand, spread from an exclusively East Palearctic range to a more widespread East Palearctic and Nearctic range during the Miocene, potentially overlapping the period when Americerura is inferred to have arrived in the Nearctic. The ancestor of Furcula eventually led to two major lineages in the late Miocene to early Pliocene, one each in the Old World and New World. Within the Old World Furcula clade, at the beginning of the Pleistocene, the ancestor of F. furcula , F. gigans , and F. occidentalis likely spread again to a semi-Holarctic distribution (Nearctic and East Palearctic) and in less than 2 My, split into F. furcula in the East and West Palearctic and the ancestor of F. gigans and F. occidentalis in the Nearctic. These two extant species occur in boreal/subarctic habitats ranging into temperate deciduous forests, and the sister to the clade of these two species, Eurasian F. furcula , is found throughout the northern Palearctic. Thus, the biogeography of these high-latitude Furcula species was likely impacted by glacial cycles and sporadic Beringian land bridges rather than long distance dispersal (the latter being a more likely scenario in Americerura , for example). Previous research suggested possible affinities between American ‘ F. furcula ’ and Old World F. furcula subspecies found in Siberia and the Russian Far East ( Miller et al. 2018), but further research is needed to contextualize the biogeography of each lineage in this clade because we lack other F. furcula subspecies and topotypical F. gigans , which may be more closely related to Old World F. furcula than Colorado populations (e.g., deorum ) based on COI barcodes ( Miller et al. 2018). Ongoing work with nuclear AHE phylogenomics, including both Alberta and Colorado F. gigans populations, however, seems to contradict the mitochondrial data (St Laurent unpubl. data).

Concurrent with the invasion of the Americas in Clade C, the predominantly Indomalayan and Australasian genus Kamalia and the principally Palearctic genus Cerura evolved from an East Palearctic ancestor. While we only sampled one species of the Australasian contingent of Kamalia ( K. amoa [ Holloway, 1979] from New Caledonia), it is worth noting that it was found to be sister to the remainder of the genus. This makes determining the ancestral range of Kamalia , and thereby the ancestral range of the most recent common ancestor of Kamalia and Cerura , more complicated because the majority of Kamalia species are Indomalayan and not Australasian. To further complicate matters, K. malaysiana jakli ( Schintlmeister, 2002) occurs on both sides of Wallace’s Line in Bali and Sumbawa, suggesting a second invasion of Australasia by the relatively widespread K. malaysiana ( Holloway, 1982) . Kamalia and Cerura were considered a single genus until Schintlmeister (2002) split them on morphological grounds. Due to the estimated 15 My divergence and the pronounced morphological differences between them, treating these as separate genera is warranted and conveys historical biogeography and morphological information.