First mitochondrial genomes of the crane fly tribe Elephantomyiini (Diptera, Tipuloidea, Limoniidae): comparative analysis and phylogenetic implications

Abstract

Limoniidae, the most speciose family in the superfamily Tipuloidea, consists of four subfamilies and more than 11,000 species. However, mitochondrial (mt) genome sequences, which have been widely used for phylogenetic study, are available for only 11 species across three subfamilies. Thus, a larger variety of mt genome sequences in Limoniidae are required to improve our understanding of tipuloid phylogeny and genomic evolution. Here we present mt genomes of Elephantomyia (Elephantomyia) inulta Alexander, 1938 and Helius (Helius) pluto Alexander, 1932, representing the first mt genomes of the tribe Elephantomyiini (Limoniidae). The two mt genomes are typical circular DNA molecules and show similar gene order, nucleotide composition and codon usage. Standard ATN start and TAR stop codons are present in most protein-coding genes. All transfer RNA (tRNA) genes exhibited the cloverleaf secondary structure typical for metazoans except in tRNASer(AGN), which lacks the dihydrouridine arm. Phylogenetic analyses were performed based on four nucleotide matrixes for the currently sequenced species of Tipuloidea using Bayesian inference and maximum likelihood methods. Four-cluster likelihood mapping was used to study incongruent signals between different topologies. Pediciidae is supported as the earliest lineage in Tipuloidea, and the sister-group relationship between Cylindrotomidae and Tipulidae is also supported, but the monophyly of Limoniidae is not supported. Our study also supports the monophyly of Elephantomyiini (Elephantomyia + Helius), as one of origins of flower-visiting in Limoniidae. Although Elephantomyiini is sister to Limoniinae + Epiphragma (Limnophilinae) in our study, a more precise understanding of its phylogenetic position in Tipuloidea will require additional studies that include a broader species sample.

New records for the Helius Lepeletier & Serville fauna (Diptera, Limoniidae) of China

“…For descriptions and illustrations of this species, also see Alexander (1938) and Podenas and Byun (2014). The species is closely related to H. ( H.) subfasciatus Alexander, 1924 in the key by Xu et al (2023) and can be distinguished by the brownish-yellow pleuron and the yellow coxae (Fig. 5A).…”

“…Helius Lepeletier & Serville, 1828(Latreille et al 1828) is a species-rich genus in the family Limoniidae consisting of extant 232 species and subspecies from nine subgenera around the world (Oosterbroek 2023). This genus and another limoniid genus Elephantomyia Osten Sacken, 1860 (Osten Sacken 1860), both with elongated rostrum, are often considered as a sister group (such as Ribeiro (2008), Petersen et al (2010), Kang et al (2023)). It is worth mentioning that there are many records of Elephantomyia feeding on flowers (such as Alexander (1924a), Savchenko (1983), Savchenko (1986), Zhang et al (2015), Kato (2017)), but there seems to be no published record of Helius feeding on flowers or of feeding in any other way (Oosterbroek and Lukashevich 2021).…”

“…Xu Y, Zhang S, Chen Y, Wang G,Yang D, Zhang X (2023) First records of the crane fly genus Helius Lepeletier & Serville (Diptera, Limoniidae) in Guangxi, China with description of one new species. ZooKeys 1168: 131-149. https://doi.org/10.3897/ zookeys.1168.104106 • Zhang X, Li Y, Yang D (2015) A review of the genus Elephantomyia Osten Sacken from China, with descriptions of two new species (Diptera, Limoniidae).…”

An updated review of the genus Toxorhina Loew, 1850 (Diptera, Limoniidae) from Yunnan, China with a description of a new species

“…Members of Toxorhina differ from most limoniid crane flies in their particularly elongate rostrum and are often recorded as feeding on flowers (e.g., Alexander and McAtee 1920 ; Alexander 1937 ; Lehnebach and Robertson 2004 ; Oosterbroek and Lukashevich 2021 ). The genera Elephantomyia Osten Sacken, 1860 and Helius Lepeletier & Serville, 1828 (in Latreille et al 1828 ) have a similar elongate rostrum to Toxorhina , and these three genera, together with another limoniid genus without an elongate rostrum (i.e., Protohelius Alexander, 1928), form the tribe Elephantomyiini ( Alexander 1920 ; Savchenko et al 1992 ; Hynes 1997 ; Podenas and Gelhaus 2007 ; Kang et al 2023 ).…”