Phylogeny and evolution of larval feeding mode in the megadiverse superfamily Sciaroidea (Diptera)

The superfamily Sciaroidea is a megadiverse clade within Diptera that
exhibits diverse larval feeding modes. In this study, we explored the
phylogenetic relationships and evolution of larval feeding modes within
Sciaroidea using a fossil-calibrated time tree. We found that filtering
out potentially fast-evolving sites altered the family-level tree topology
of Sciaroidea and that species within Sciaroidea incertae sedis might be
crucial in determining the general tree topology. The most recent common
ancestor of Sciaroidea was inferred to have originated in the Upper
Triassic (~230 Ma). A major radiation of families occurred from the
Uppermost Triassic to the Lowermost Jurassic (190–200 Ma). The
plesiomorphic larval feeding mode was inferred to be mycophagy. Most
families retained this feeding mode with only minor transitions occurring
in some clades; however, Cecidomyiidae and Keroplatidae went through
notable shifts in larval feeding mode. Cecidomyiidae underwent a
transition from mycophagy to phytophagy in the Lower Cretaceous, in line
with angiosperm radiation as suggested in previous studies. The larvae of
stem Keroplatidae were inferred to be predatory since the Jurassic. A
transition back to mycophagy occurred within the subfamily Keroplatinae
during the Paleogene to Uppermost Cretaceous, coinciding with the origin
and radiation of species-rich mycophagous clades of other Sciaroidea
families. Our study highlights the importance of taxon sampling and
sequence filtering in phylogenetic analyses of Sciaroidea. We suggest,
based on temporal patterns of lineage diversification, that the evolution
of larval feeding modes within Sciaroidea might be correlated with the
diversification of mushroom-forming fungi and angiosperms.