Introduction
Tenebrionoidea is a large superfamily in Coleoptera, with over 34,000
known species and 28 families (Lawrence, 1995;
Ślipiński et al ., 2011).
The species in the superfamily have the 5-5-4
tarsal formula in both sexes, with
occasional 4-4-4, 3-3-3 or 3-4-4 in males. Members of the superfamily
demonstrate various types of feeding strategies, the majority of which
are fungivorous, xylophagous, and
saprophagous.
Some Tenebrionoidea species are major agricultural and forest pests,
which attack commercial crops or stored products (Song et al .,
2018). They are widely spread throughout all terrestrial habitats from
the sea shore up to dry desert and steppe habitats in all altitudinal
belts, and in all types of forests, and species in arid environments are
conspicuously diverse. Given these diverse feeding strategies and
habitats, the morphology of the superfamily is complicated (Bouchardet al. , 2009). Taxonomic and phylogenetic studies are essential
for understanding their biodiversity and biological characteristics, and
for further protecting, utilizing and controlling them.
The framework of the classification
system for Coleoptera was firstly established in 1955 and then revised
in 1982, in which the Tenebrionoidea is divided into 5 lineages: 1)
Tetratomidae, Melandryidae,
Mordellidae,
Ripiphoridae; 2) Synchroidae,
Zopheridae, Prostomidae, Perimylopidae, Chalcodryidae, Tenebrionidae; 3)
Oedemeridae, Stenotrachelidae,
Meloidae; 4) Pythidae, Pyrochroidae, Boridae, Mycteridae, Salpingidae;
and 5) Anthicidae, Aderidae,
Scraptiidae (Crowson, 1955; Lawrence
& Newton, 1982). In past years, a number of studies have been reported
to establish the taxonomy system of Tenebrionoidea using comparative
morphology data (Beutel & Friedrich, 2005;
Lawrence et al ., 2011).
Nowadays, 28 families (Mordellidae, Ripiphoridae, Anthicidae, Meloidae,
Pyrochroidae, Oedemeridae, Salpingidae, Scraptiidae, Lagriidae,
Tenebrionidae and so on) are widely recognized for Tenebrionoidea
(Bouchard et al ., 2011). Despite of economic importance, the
monophyletic status of many families and phylogenetic relationships in
Tenebrionoidea need to be elucidated. A comprehensive phylogeny study of
beetles showed the three families Mordellidae, Anthicidae and Meloidae
are monophyletic, the Scraptiidae is paraphyletic based on 18SrRNA, 16S rRNA and COX1 gene sequences (Hunt et
al ., 2007). The phylogenetic
analysis of Coleoptera showed that the families Tenebrionidae,
Oedemeridae, Salpingidae, Mordellidae, Meloidae and
Scraptiidae are monophyletic;
Pyrochroidae is polyphyletic based on four gene (16S rRNA,
COX1, 28S and 18S ) sequences (Bocak et al ., 2014). The
higher-level phylogenetic analysis of beetles indicated that the
Tenebrionidae, Oedemeridae, Salpingidae, Pyrochroidae, Meloidae and
Scraptiidae are monophyletic, whereas Anthicidae is paraphyletic based
on 95 nuclear protein-coding genes from 373 beetle species (Zhanget al. , 2018). Almost all molecular phylogenetic analyses support
the monophyly of Mordellidae and Meloidae, which is inconsistent with
the phylogenetic analyses based on
morphological data (Lawrenceet al ., 2011). Due to incongruent phylogenetic relationships from
different analysis, the phylogenetic relationships and monophyly among
families are still not well settled, and the phylogenetic positions
among some families are contradictory in different molecular studies.
All of these phylogenetic issues urgently need to be elucidated.
With the characteristics of conservative gene content, simple genome
organization, maternal inheritance, small genome size and higher
evolution rate, complete mitochondrial genome (mtgenome) has been widely
used in molecular phylogenetics,
evolution, and population genetics study of insects (Cameron et
al ., 2014). Up to date (October 2021), there have been 71 species of
Tenebrionoidea complete mtgenomes to be reported in GenBank, covering 15
families in Tenebrionoidea. However, there is no complete mtgenome
sequence to be reported from the families Archeocrypticidae,
Stenotrachelidae and Melandryidae, and the characteristics of the
mtgenomes is still little understood in the superfamily. Up to now,
there have been only a few mtgenome-based phylogenetic studies at
high taxa in
Tenebrionoidea. A mtgenome-based
phylogenetic inference of beetles indicated that the families
Tenebrionidae, Oedemeridae, Anthicidae, Mordellidae and Meloidae were
monophyletic, whereas Scarptiidae was polyphyletic based on 245
mitochondrial sequences using Bayesian method (Timmermans et al. ,
2015). The phylogenetic analysis of 37 beetle mitochondrial genes
supported the Mordellidae and Meloidae to be monophyletic groups, and
the Scraptiidae and Melandryidae to be paraphyletic groups using
Bayesian inference (Song et al. , 2018). The mtgenome-based
phylogeny of 51 beetles found that the monophyletic of Meloidae,
Tenebrionidae, and the sister relationship of Meloidae and Tenebrionidae
using Bayesian inference (Tang et al. , 2020). As mentioned above,
previous mtgenome-based phylogenetic studies have not well resolved the
phylogeny of Tenebrionoidea, and phylogenetic analysis of the
superfamily need to be further evaluated.
In this study, we newly sequenced and annotated 19
species of complete mtgenomes, and
comparatively analyzed the mtgenome characteristics of a total of 90
species in Tenebrionoidea. More importantly, we constructed and
discussed the phylogenetic relationships at high taxa level based on
these mtgenome sequences, and inferred the divergence time at main nodes
in the phylogenetics in inference of fossil records. This study lays a
foundation for further understanding of mtgenome characteristics,
phylogenetics and evolution of the Tenebrionoidea.