Rhiniidae (Diptera: Oestroidea) diversity in South AfricaTaxonomic review and phylogenetic advances for the Afrotropical region
- Thomas, Arianna
- Anabel Martínez-Sánchez Director
- Santos Rojo Velasco Director
Defence university: Universitat d'Alacant / Universidad de Alicante
Fecha de defensa: 24 November 2020
- Pierfilippo Cerretti Chair
- Celeste Pérez Bañón Secretary
- Daniel Martín Vega Committee member
Type: Thesis
Abstract
The Rhiniidae family (Diptera: Oestroidea) is mainly distributed in the tropic and subtropics of the Afrotropic, Australian, Oriental and Paleartic regions. The family was traditionaly consired to have subfamily rank within the Calliforidae family; however, recent filogenetic studies, based on morphologic and molecular characters, evidence that Calliforidae is not a monophyletic group. This lead to several sistematic rearangements that resulted in rhinids being considered as an independent family. Today, almost 400 Rhiniidae species are recognized, grouped in two subfamilies and 30 genera. The Afrotropical region hosts the largest diversity of rhiniids wordlwide, with aproximatelly 170 species in 5 genera of Rhininae and 11 genera in Cosmininae. There is very little information on the diversity, biology and distribution of the Rhiniidae family. The life cycle and, in particular, the habits and larval morphology are unknown for most of the species. What is known is limited to a few species that are restricted to specific geographic regions. In general, it is known that some species have a strong association to natural environments, that adults are flower visitors and are thought to be important pollinators, and some species seem to have a close relationship with termites. The taxonomy and diversity of the group is outdated, as very few studies after the 1970s have been conducted in the Afrotropical region. Their morphologic identification, in many cases, exclusively depends on male terminalia, and therefore, many females remain unidentified or are wrongly identified. The general goal of this thesis is to contribute and update the knowledge on the Rhiniidae family in the Afrotropical Region by studying its diversity, taxonomy and phylogeny. To do so, we initially developed a taxonomic and diversity study of the family in South Africa, a world biodiversity hot-spot with the greatest diversity of Rhiniidae worldwide. Over 4000 specimens of Rhiniidae were examined in entomological collections from Africa, Europe and USA. We generated an updated checklist of species present in the country, including a thorough revision of their taxonomic status. Additionally, we created historical distribution maps and high-resolution photographs of the habitus of most species. AmongThe Rhiniidae family (Diptera: Oestroidea) is mainly distributed in the tropic and subtropics of the Afrotropic, Australian, Oriental and Paleartic regions. The family was traditionaly consired to have subfamily rank within the Calliforidae family; however, recent filogenetic studies, based on morphologic and molecular characters, evidence that Calliforidae is not a monophyletic group. This lead to several sistematic rearangements that resulted in rhinids being considered as an independent family. Today, almost 400 Rhiniidae species are recognized, grouped in two subfamilies and 30 genera. The Afrotropical region hosts the largest diversity of rhiniids wordlwide, with aproximatelly 170 species in 5 genera of Rhininae and 11 genera in Cosmininae. There is very little information on the diversity, biology and distribution of the Rhiniidae family. The life cycle and, in particular, the habits and larval morphology are unknown for most of the species. What is known is limited to a few species that are restricted to specific geographic regions. In general, it is known that some species have a strong association to natural environments, that adults are flower visitors and are thought to be important pollinators, and some species seem to have a close relationship with termites. The taxonomy and diversity of the group is outdated, as very few studies after the 1970s have been conducted in the Afrotropical region. Their morphologic identification, in many cases, exclusively depends on male terminalia, and therefore, many females remain unidentified or are wrongly identified. The general goal of this thesis is to contribute and update the knowledge on the Rhiniidae family in the Afrotropical Region by studying its diversity, taxonomy and phylogeny. To do so, we initially developed a taxonomic and diversity study of the family in South Africa, a world biodiversity hot-spot with the greatest diversity of Rhiniidae worldwide. Over 4000 specimens of Rhiniidae were examined in entomological collections from Africa, Europe and USA. We generated an updated checklist of species present in the country, including a thorough revision of their taxonomic status. Additionally, we created historical distribution maps and high-resolution photographs of the habitus of most species. Among the most relevant findings are nine new records for South Africa, approximately 15 new species to be described in future studies and the compilation of novel bionomic information for several species (Chapter I). Then, looking deeper into the family, we conducted a taxonomic revision of Fania Zumpt, 1958, an exclusive genus of the Afrotropical region. Fania includes seven described species, however, the taxonomic status of several of them is controversial. After studying the morphology of the male terminalia, together with the revision of the type material, we clarified the taxonomic status of the species. We created identification tools for the genus, including identification keys for both sexes, redescriptions, high-resolution photographs of the male morphology and terminalia, and new synonyms. This study was complemented with the homogenization and update of the morphological nomenclature used for the Rhiniidae family, as well as the proposal of two possible synapomorphies for the diagnosis of the two current subfamilies, Cosmininae and Rhiniinae (Chapter II). Finally, we used molecular tools in order to corroborate morphology-based identifications, associate unidentified female morphotypes to their conspecific males, explore phylogenetic relationships between the different genus and species, and generate the first DNA barcodes library for Rhiniidae. To do so, we generated DNA barcodes (COI) of 138 Rhiniidae specimens. Bayesian inference and maximum likelihood trees were used to infer species limits and their monophyly. Intra-specific and inter-specific genetic variability were reconstructed using the nucleotide substitution model Kimura-2-parameters (K2P) and species delimitation using the ABGD analysis. Most of the species delimited morphologically were recovered as monophyletic. Between 65 and 68 species were determined in our study, and 31 female morphotypes were successfully linked to their conspecific males (Chapter III). Overall, this research highlights the importance of visiting entomological collections for improving the knowledge on diversity and for using valuable information in the specimen’s labels that can provide temporal and spatial occurrence, environmental preferences, and associations to plants and animals, which in turn are relevant for studies on conservation biology, polinization and ecological interactions. Furthermore, DNA barcodes were an efficient tool as a complement for the taxonomic identification of Rhiniidae; however, between very similar species on a morphological level it was not as successful as expected, suggesting a possible recent evolutionary divergence and the need for further molecular studies.