Phylogeny of the Limnophilinae (Limoniidae) and early evolution of the Tipulomorpha (Diptera)

Abstract

Tipulomorpha (craneflies) comprise one of the largest subgroups of Diptera, but its phylogeny at different levels has been poorly explored. This study presents the most comprehensive cladistic analysis of the group ever made, with emphasis on the genera and subgenera of the subfamily Limnophilinae (Limoniidae), assumed to include some of the earliest lineages of Tipulomorpha sensu stricto and therefore important for the understanding of the early patterns in the evolution of the craneflies. Eighty-eight characters of the male imago were scored for 104 exemplar species. The most parsimonious trees were searched using implied weighting, in the framework of a sensitivity analysis with different values of k (2 to 6). The dataset based on the characters of adult male morphology showed high levels of homoplasy and yielded very incongruent and unstable phylogenetic results, which are very sensitive to changes in analytical parameters. In the preferred and most parsimonious phylogenetic hypothesis, the Pediciidae is the sister-group of all other Tipulomorpha sensu stricto. The results indicate the paraphyly of the Limoniidae with respect to the Cylindrotomidae and Tipulidae, which are considered sister-groups. The Limoniidae subfamilies Limnophilinae, Limoniinae and Chioneinae are considered non-monophyletic. The study allowed a reconstruction of the possible ground plan condition of selected features of the adult male morphology of craneflies. The genera/subgenera Epiphragma (Epiphragma), Acantholimnophila, Shannonomyia, Limnophila (Arctolimnophila), Eloeophila, Conosia, Polymera, Polymera (Polymerodes), Prionolabis, Eutonia, Phylidorea (Phylidorea), Metalimnophila, Gynoplistia (Cerozodia), Gynoplistia (Dirhipis), Nothophila, Pseudolimnophila (Pseudolimnophila), Pilaria and Ulomorpha are considered monophyletic, but in general are defined by combinations of very homoplastic character states. Two Temperate Gondwanan clades, (Tonnoirella + (Edwardsomyia + (Tinemyia + (Rhamphophila + (Nothophila))))) and ((Notholimnophila + Bergrothomyia) + (Mesolimnophila + (Chilelimnophila + Ctenolimnophila))) are recovered. The genera Limnophila, Neolimnomyia, Gynoplistia (sensu lato) and Hexatoma (sensu lato) are considered non-monophyletic. The systematic position and some morphological characters of `problematic` taxa, such as Dactylolabis, Elephantomyia, Helius and Atarba are discussed on the light of the proposed phylogeny and the analysis of the characters. Character states are richly illustrated. A detailed study of the morphology of the male genitalia is made, and several genera and species have the morphology of the male genitalia illustrated for the first time.