Systematics of the genus Dilta Strand, 1911 (Machilidae) in the Canary Islands (NW Africa, Spain) with comments on the phylogeny of Microcoryphia (Insecta)

Phylogenetic inferences based on morphological and genetic data often exhibit discrepancies due to evolutionary convergences, complicating the accurate determination of evolutionary relationships. In Microcoryphia, the lack of comprehensive genetic studies has left significant gaps some of which we try to address in this work. We conducted molecular analyses using mitochondrial and nuclear markers on specimens from Morocco, the Iberian Peninsula, and the Canary and Balearic Islands, representing the two known families and 10 genera within the order. During our study, we revised the nomenclature of the studied taxa, and established three new synonymies (Machilis fastuosa Lucas, 1846 = Machilis bimaculata Lucas, 1846 n. syn. = Machilis crassicornis Lucas, 1846 n. syn. = Machilis italicus Grassi, 1887 n. syn.) and a new combination, Dilta fastuosa (Lucas, 1846) comb. nov. In the Canary Islands, our sampling led to the discovery of three new species of the genus Dilta Strand, 1911 with morphological and molecular distinctive traits that differentiate them from other congeneric species (Dilta (Budilta) tilosina Palacios-Martínez & García-París sp. nov.; Dilta (Budilta) benahoarense Palacios-Martínez & García-París sp. nov.; and Dilta (Budilta) islabonita Palacios-Martínez & García-París sp. nov.). The phylogenetic analyses herein suggest that a hidden rapid evolutionary radiation of Dilta took place in the Canary Islands archipelago. Ours findings show the necessity for a comprehensive taxonomic review of the family Machilidae, integrating molecular and morphological data to resolve existing inconsistencies and provide a clearer understanding of their evolutionary history.