The mitochondrial genome of a giant water bug Lethocerus deyrollei (Hemiptera: Belostomatidae) from South Korea

Abstract

A giant water bug Lethocerus deyrollei (Hemiptera: Belostomatidae) is a large, predatory, and nocturnal hemipteran insect, which has been considered threatened and thus enrolled as an endangered species in South Korea and Japan. Here, we characterized the complete mitochondrial genome of L. deyrollei, which has a circular form with 19,295 bp in length, which is the longest when compared to those of the 111 hemipteran species reported so far. Its longest genome size is due to the extremely extended CR (4686 bp), which is much longer than those of China and Japan. It consisted of a total of 37 genes (13 PCGs, 22 tRNA genes, and two rRNA genes) and one control region (CR). The genome composition and gene order were identical to those previously reported from the same species of China and Japan with over 99.7% sequence similarities except for CR and trnI. The nucleotide composition was highly A + T biased, accounting for 71% of the whole mitochondrial genome, as in other species of Nepoidea. Based on the aa sequences of 13 PCGs, we reconstructed a maximum likelihood tree, which indicated that the three mitochondrial genomes of L. deyrollei from South Korea, China, and Japan are grouped, and also Lethocerus, Belostomatidae, Nepoidea, Nepomorpha, Heteroptra are strong monophyletic groups, respectively.

Keywords: A giant water bug; Lethocerus deyrolli; South Korea; an endangered species; mitochondrial genome.

Figure 1.

Phylogeny of Heteroptera based on the 13 PCG amino acid sequences of mitochondrial genomes under the mtART + F + I + G4 model inferred from IQTREE analyses. The mitochondrial genome of L. deyrollei obtained in this study is highlighted with a black box. Numbers at nodes indicate bootstrap support values (BP). A silver leaf whitefly Bemisia tabaci was employed as an outgroup.