Phylogeny and historical biogeography of the southern African lacewing genus Afroptera (Neuroptera: Nemopteridae: Nemopterinae)

The lacewing genus Afroptera Abdalla & Mansell (Neuroptera: Nemopteridae: Nemopterinae) is endemic to southern Africa, predominantly found in the Fynbos and Succulent Karoo biomes. The taxonomy of the genus has been recently resolved. However, the monophyly and evolutionary history of the genus has never been addressed. This study employs an integrative phylogenetic approach, by incorporating three ribosomal genes (16S, 28S, and 18S) and two protein-coding genes (COI and CAD), and morphological data to examine the monophyly and historical biogeography of Afroptera. We use Bayesian, parsimony and maximum likelihood phylogenetic methods to assess the monophyly and relatedness of Afroptera within the Nemopterinae. We also use ancestral ranges reconstruction and diversification analysis to infer the historical biogeography of the genus. Our analyses reveals the genus as a monophyletic lineage. The genus Afroptera originated during the Pliocene (5.24–3.13 Mya) in a desert environment, experiencing rapid speciation during the Pleistocene, primarily within the Fynbos and Succulent biomes; and secondarily dispersed into the Nama Karoo and Savannah (Kalahari) biomes. The current distribution patterns of Afroptera species likely stem from intensified aridification in the southwest during the Plio-Pleistocene, consistent with the dry-adapted nature of Afroptera's ancestors. Therefore, our findings suggest a climatically driven diversification model for the genus Afroptera.

Methods
Sampling and taxon selection

a)     To test the monophyly and relatedness of the Nemopterinae genera, we included as in-group taxa all known southern African Nemopterinae genera: Barbibucca, Derhynchia, Halterina, Knersvlaktia, Nemeura, Nemia, Palmipenna, Semirhynchia and Sicyoptera, as well as the Australian Chasmoptera Westwood, in addition to the newly proposed Nemopterella Banks sensu stricto, Afroptera Abdalla & Mansell, and Siccanada Abdalla & Mansell. The only genus not included in this study is Nemopistha. A representative of the subfamily Crocinae, Laurhervasia setacea (Klug), was chosen as the out-group taxon, following Sole et al (2013).

b)    To study the biogeography and diversification estimate time of the genus Afroptera, we included 14 species from the genus Afroptera on the basis of availability and suitability of fresh material for DNA extraction. We also include species of two genera, Knersvlaktia (one sp.) and Palmipenna (three spp.), as these taxa were regarded as phylogenetically close to Afroptera (Sole et al. 2013) before the problematic Nemopteralla was split into three genera (Abdalla et al. 2019). Additionally, we sought an outgroup entirely distinct from the problematic Nemopterellla, which Knersvlaktia and Palmipenna fit perfectly. Of these, 12 species of Afroptera were sequenced for the first time, the remainder taxa were retrieved from GenBank (see Table S1). All the sequences are deposited in Genbank (see Table S1).