A morphologically unusual fossil true bug genus, Palaeotanyrhina Poinar, Brown & Kóbor, 2022, placed into Cimicomorpha: Reduvioidea by its authors, is revisited based on an inclusion in mid-Cretaceous Burmese amber. The original description is supplemented with additional details and corrections. It is demonstrated that the placement of Palaeotanyrhina into Cimicomorpha was based on misinterpretations of the morphology of the holotype, and the genus is a member of the infraorder Leptopodomorpha. A phylogenetic analysis is provided for fossil and extant taxa of Leptopodomorpha. Parvilepta Yu, Zhuo & Chen, 2023, Cretaleptus Sun & Chen, 2019, Macrolepta Yu, Zhuo & Chen, 2023 (currently members of Leptopodidae: Leptosaldinae) and Palaeoleptus Poinar, 2009 (the type genus of Palaeoleptidae) are demonstrated to be phylogenetically closely related to Palaeotanyrhina. All the above mentioned genera are recognized to represent stem-group members of Leptopodomorpha: Leptopodidae: Leptopodinae: Leptopodini, and accordingly, they are transferred to the latter tribe. The following new subjective synonyms are proposed: Leptopodidae: Leptopodinae: Leptopodini Brullé, 1836 = Palaeoleptidae Poinar, 2009, syn. nov. = Palaeotanyrhinidae Poinar, Brown & Kóbor, 2022, syn. nov. Based on the analytic results, the subfamilies Leptosaldinae and Leptopodinae of Leptopodidae and the tribes Leotichiini and Leptopodini of Leptopodinae are considered valid, redefined, and a list of their included genera and species are provided. Arguments are provided in support of the placement of Leptosaldinea Popov & Heiss, 2016, formerly placed into Leptosaldinae, into the infraorder Dipsocoromorpha.

The genus Cheguevaria (Kazantsev 2007) is currently comprised of three species which are endemic to the Greater Antilles: Cheguevaria angusta Kazantsev, 2007 (Hispaniola), Cheguevaria taino Kazantsev, 2007 and Cheguevaria montana Kazantsev, 2008 (both from Puerto Rico). Cheguevaria is the sole member of Cheguevariinae, and a previous morphology-based phylogenetic hypotheses suggested a close relationship with the subfamily Amydetinae. Recent collecting trips to Puerto Rico and the survey of other scientific collections allowed us to identify and locate more specimens of the genus, including several color morphs of specimens tentatively identified as C. montana. We used this material to revise the genus, and to describe Cheguevaria cubensis new species, the first record of the genus from Cuba. We also produced DNA barcodes based on partial cytochrome c oxidase subunit 1 (COI), which were used to investigate the species limits within color morph species of C. montana. Our results showed a high level of genetic stability in those color morphs, indicating that all specimens belong to the same species. We present a discussion to explain possible scenarios leading to such variation in color patterns. We also generated amplicons for two specimens of Amydetinae, represented by two Amydetes Illiger, 1807 species, and we tested their relationship with Cheguevaria in a phylogenetic context based on a four gene dataset. Our analyzes indicated a disjoint relationship between Cheguevaria and Amydetes, corroborating previously published morphology-based phylogenies, and we maintained the status of Cheguevaria as an independent lineage within Lampyridae.

The hoverflies are one of the most abundant families in Diptera and an important category of resource insects. They can provide important ecosystem services such as pollination and beneficial biological control agents. In the four-subfamily classification system of the Syrphidae, the monophyly of the Eristalinae within Syrphidae has not been recovered. In this study, we performed new sequencing and analysis of low-coverage whole genomes for 25 species of Syrphidae. Phylogenetic reconstructions were conducted based on different datasets and analytical strategies. Across all our analyses, the monophyly of the Syrphinae is supported but we do not recover the monophyly of the Eristalinae, consistent with previous research findings. Additionally, employing fossil calibrations for divergence time estimation, our results indicate that the origin of the Syrphidae occurred between the Albian and Aptian stages, approximately between 120.5 and 109.3 million years ago, the origin of the subfamily Syrphinae was dated in the Early Eocene, about 50.8–47.8 million years ago, in accordance with the diversification of their prey. This study will help us understand the higher-level phylogenetic and evolutionary relationships within Syrphidae.

Graphical Abstract

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 the superfamily using a fossil-calibrated time tree. We found that filtering out potentially fast-evolving sites altered the family-level tree topology, 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 UpperTriassic (∼225 Ma). A major radiation of families occurred from the UppermostTriassic to the Lowermost Jurassic (190–200 Ma). The ancestral larval feeding mode was inferred to be mycophagy. Most families retained this feature 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 predators 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 sciaroid 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 the group might be correlated with the diversification of mushroom-forming fungi and angiosperms.

The first fossil rust fly (Diptera: Psilidae) from the Insect Bed of the Bembridge Marls of the Isle of Wight is also the first known fossil record of the subfamily Chylizinae. It is late Eocene: Priabonian in age, 34.2 Ma. Chyliza colenutti Ross, Zhou, Hoffeins & Crighton, sp. nov. is compared with 30 extant species of Chyliza and differs from them in having a relatively long 2nd basal cell compared to the discal cell. Some other fossil Acalyptratae records are reviewed and their probable ages updated. The phylogenetic position of the Psilidae is currently uncertain so the family may have appeared anytime from 70–40 million years ago.