Labrundinia is a highly recognizable lineage in the Pentaneurini tribe (Diptera, Chironomidae). The distinct predatory free-swimming larvae of this genus are typically present in unpolluted aquatic environments, such as small streams, ponds, lakes, and bays. They can be found on the bottom mud, clinging to rocks and wood, and dwelling among aquatic vegetation. Labrundinia has been extensively studied in ecological research and comprises 39 species, all but one of which has been described from regions outside the Palearctic. Earlier phylogenetic studies have suggested that the initial diversification of the genus likely occurred in the Neotropical Region, with its current presence in the Nearctic Region and southern South America being the result of subsequent dispersal events. Through the integration of molecular and morphological data in a calibrated phylogeny, we reveal a complex and nuanced evolutionary history for Labrundinia, providing insights into its biogeographical and diversification patterns. In this comprehensive study, we analyze a dataset containing 46 Labrundinia species, totaling 10,662 characters, consisting of 10,616 nucleotide sites and 46 morphological characters. The molecular data was generated mainly by anchored enrichment hybrid methods. Using this comprehensive dataset, we inferred the phylogeny of the group based on a total evidence matrix. Subsequently, we employed the generated tree for time calibration and further analysis of biogeography and diversification patterns. Our findings reveal multiple dispersal events out of the Neotropics, where the group originated in the late Cretaceous approximately 72 million years ago (69-78 Ma). We further reveal that the genus experienced an early burst of diversification rates during the Paleocene, which gradually decelerated towards the present-day. We also find that the Neotropics have played a pivotal role in the evolution of Labrundinia by serving as both a cradle and a museum. By "cradle," we mean that the region has been a hotspot for the origin and diversification of new Labrundinia lineages, while "museum" refers to the region's ability to preserve ancestral lineages over extended periods. In summary, our findings indicate that the Neotropics have been a key source of genetic diversity for Labrundinia, resulting in the development of distinctive adaptations and characteristics within the genus. This evidence highlights the crucial role that these regions have played in shaping the evolutionary trajectory of Labrundinia.

We present data on Chironomidae (Insecta: Diptera) collected in South America together with results on the mitochondrial DNA diversity within selected megadiverse genera. This work is part of an on-going project on the ancient origin of South American biodiversity using non-biting midges. Collections were made at 42 localities, in March 2014 and February 2015, in a diverse array of habitats, including small streams, rivers, ponds, lakes and bays. In total, 3196 representatives of six subfamilies were collected. Sixty-one genera were identified, containing at least 211 species. The subfamilies Chironominae and Orthocladiinae predominated in all samples. Tanypodinae were often present, but rarely in large numbers. Except for Podonomus pepinellii, reported from Brazil, Podonominae were collected in a few localities in Argentina (Arroyo Lopez, and Arroyo Gutierrez and Gutierrez Lake) and Chile (Llanquihue Lake). Prodiamesinae were only recorded in Chile. Analysis of DNA barcode sequences using neighbor-joining estimation supported 66 species within the selected genera. The chironomid fauna of South America includes multiple genera with worldwide distributions, with Australian, Nearctic and Neotropical components.