Cryptic diversity of the jewel beetles Agrilus viridis (Coleoptera: Buprestidae) hosted on hazelnut

The larval, pupal and mitogenomic characteristics of Agrilusadelphinus Kerremans, 1895 (Coleoptera, Buprestidae) from China

In this study, the larva and pupa of Agrilusadelphinus are described and illustrated. DNA barcoding (COI gene) was used to associate the larval and pupal stages with adults based on the maximum-likelihood method. In the resulting phylogenetic tree, species from the same species-group were found to be clustered on a branch with high support value. To better understand A.adelphinus, the complete mitochondrial genome of this species was also sequenced and annotated. Comparing this genome to the known mitogenomes of Agrilus species, the newly sequenced genome is shorter, with 15,732 bp. However, its whole mitogenome composition and gene orientation were consistent with that of most species of Buprestidae. In the mitogenome of A.adelphinus, the ATGATAG sequence was observed between ATP8 and ATP6, which is ATGATAA in other insect mitogenomes. Leu2, Phe, Ile, Gly, and Ser2 were the five most frequently encoded amino acids. The results further prove that DNA barcoding can remove the limitation of traditional taxonomy which cannot identify to species all developmental stages. This study also provides valuable molecular and morphological data for species identification and phylogenetic analyses of the genus Agrilus.

First Report of Complete Mitochondrial Genome in the Tribes Coomaniellini and Dicercini (Coleoptera: Buprestidae) and Phylogenetic Implications

The complete mitochondrial genomes (mitogenomes) of the tribes Coomaniellini and Dicercini were sequenced and described in this study, including Coomaniella copipes (16,196 bp), Coomaniella dentata (16,179 bp), and Dicerca corrugata (16,276 bp). These complete mitogenomes are very similar in length and encoded 37 typical mitochondrial genes, including 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs) and 13 protein-coding genes (PCGs). Most of PCGs had typical ATN start codons and terminated with TAR. Among these mitogenomes, Leu2 (L2), Ile (I), Ser2 (S2), and Phe (F) were the four most frequently encoded amino acids. Moreover, phylogenetic analyses were performed based on three kinds of nucleotide matrixes (13 PCGs, 2 rRNAs, and 13 PCGs + 2 rRNAs) among the available sequenced species of the family Buprestidae using Bayesian inference and Maximum-likelihood methods. The results showed that a Chrysochroninae species interspersed in Buprestinae, and Coomaniellini is more closely related to Dicercini than Melanophilini. Moreover, the clade of Buprestidae was well separated from outgroups and the monophyly of Agrilinae is confirmed again. Our whole mitogenome phylogenetic results support that the genus Dicerca can be transferred from Chrysochroinae to Buprestinae; whether Dicercini can be completely transferred remains to be further verified after enriching samples. Our results have produced new complete mitogenomic data, which will provide information for future phylogenetic and taxonomic research.

The complete mitochondrial genomes of five Agrilinae (Coleoptera, Buprestidae) species and phylogenetic implications

Five complete mitochondrial genomes of five species from the subfamily Agrilinae were sequenced and annotated, including Coraebusdiminutus Gebhardt, 1928 (15,499 bp), Coraebuscloueti Théry, 1893 (15,514 bp), Meliboeussinae Obenberger, 1935 (16,108 bp), Agrilussichuanus Jendek, 2011 (16,521 bp), and Sambusfemoralis Kerremans, 1892 (15,367 bp). These mitogenomes ranged from 15,367 to 16,521 bp in length and encoded 37 typical mitochondrial genes: 13 protein-coding genes (13 PCGs), 2 ribosomal RNA genes (2 rRNAs), 22 transfer RNA genes (22 tRNAs), and a control region (CR). Most of PCGs had typical ATN start codons and terminated with TAR or an incomplete stop codon T–. Among these five mitogenomes, Leu2, Ile, Phe, Ser2, Gly, Met, and Val were the seven most frequently encoded amino acids. Interestingly, in A.sichuanus, a 774 bp insertion was present at trnW and trnC junction, which is unusual in Buprestidae. Additionally, phylogenetic analyses were performed based on three kinds of nucleotide matrixes (13 PCGs, 2 rRNAs, and 13 PCGs + 2 rRNAs) using Bayesian inference and maximum-likelihood methods. The results showed that the clade of Buprestidae was well separated from outgroups and all Agrilinae species formed to a single highly supported clade. The tribe Coraebini was polyphyletic, as the genus Meliboeus (Coraebini) clustered with the genus Trachys (Tracheini). The rRNA genes had important impact for the tree topology of Agrilinae. Compared to the tribes Tracheini and Agrilini, the tribe Coraebini is a younger group.