Jeong Sun Park

Complete mitochondrial genomes of five skippers (Lepidoptera: Hesperiidae) and phylogenetic reconstruction of Lepidoptera

We sequenced mitogenomes of five skippers (family Hesperiidae, Lepidoptera) to obtain further insight into the characteristics of butterfly mitogenomes and performed phylogenetic reconstruction using all available gene sequences (PCGs, rRNAs, and tRNAs) from 85 species (20 families in eight superfamilies). The general genomic features found in the butterflies also were found in the five skippers: a high A+T composition (79.3%-80.9%), dominant usage of TAA stop codon, similar skewness pattern in both strands, consistently length intergenic spacer sequence between tRNA(Gln) and ND2 (64-87 bp), conserved ATACTAA motif between tRNA(Ser (UCN)) and ND1, and characteristic features of the A+T-rich region (the ATAGA motif, varying length of poly-T stretch, and poly-A stretch). The start codon for COI was CGA in four skippers as typical, but Lobocla bifasciatus evidently possessed canonical ATG as start codon. All species had the ancestral arrangement tRNA(Asn)/tRNA(Ser (AGN)), instead of the rearrangement tRNA(Ser (AGN))/tRNA(Asn), found in another skipper species (Erynnis). Phylogenetic analyses using all available genes (PCGs, rRNAS, and tRNAs) yielded the consensus superfamilial relationships ((((((Bombycoidea+Noctuoidea+Geometroidea)+Pyraloidea)+Papilionoidea)+Tortricoidea)+Yponomeutoidea)+Hepialoidea), confirming the validity of Macroheterocera (Bombycoidea, Noctuoidea, and Geometroidea in this study) and its sister relationship to Pyraloidea. Within Rhopalocera (butterflies and skippers) the familial relationships (Papilionidae+(Hesperiidae+(Pieridae+((Lycaenidae+Riodinidae)+Nymphalidae)))) were strongly supported in all analyses (0.98-1 by BI and 96-100 by ML methods), rendering invalid the superfamily status for Hesperioidea. On the other hand, current mitogenome-based phylogeny did not find consistent superfamilial relationships among Noctuoidea, Geometroidea, and Bombycoidea and the familial relationships within Bombycoidea between analyses, requiring further taxon sampling in future studies.

Complete mitochondrial genome of the dwarf honeybee, Apis florea (Hymenoptera: Apidae)

In this study, the 17,694-bp long complete mitochondrial genome (mitogenome) of the dwarf honeybee, Apis florea (Hymenoptera: Apidae), was described, and a noteworthy triplicated tRNAser(AGN) region and an extraordinary long A+T-rich region with repeat regions were identified. The gene arrangement of A. florea mitogenome was identical to that of Apis mellifera, but it contained three tRNASer(AGN), each of which was preceded by a 44-bp-long repeat unit and followed by a 64-bp-long repeat unit plus one complete first repeat adjacent to tRNAMet. A total of 1610-bp long two repeat regions in 1987-bp long A+T-rich region were composed of nearly identical 141–219-bp long 5 tandem repeats and 50–52-bp long 12 tandem repeats that were encompassed by three non-repeat sequences. One potential explanation for this repeat sequence is slipped-strand mispairing and unequal crossing-over events during DNA replication.

Complete mitochondrial genome of an aquatic moth, Elophila interruptalis (Lepidoptera: Crambidae)

Abstract The aquatic moth, Elophila interruptalis (Lepidoptera: Crambidae) belongs to the subfamily Nymphulinae, nearly all of which are aquatic in their entire larval and pupal stages. The 15,351-bp long complete mitogenome consisted of a typical set of genes (13 protein-coding genes, two rRNA genes and 22 tRNA genes) and one major non-coding A+T-rich region, with the typical arrangement found in the majority of Lepidoptera. One of the unusual features of the E. interruptalis mitogenome is the presence of a tRNAPhe-like sequence beyond the A+T-rich region. The sequence is encoded in the minor strand of the genome overlapping with the reversely encoded regular tRNAGlu by 65 bp. The sequence divergence of the tRNAPhe-like sequence to that of regular E. interruptalis tRNAPhe and other within-familial species was as low as 59% ∼ 71%, but has a proper folding structure with well-matched stems and identical anticodon sequences to the regular copy.

Oviposition and development potential of the spotted-wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), on uninjured Campbell Early grape

The spotted‐wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), originally distributed across a few Asian countries including South Korea, has invaded North America and Europe but is absent from Australia. In order to export the South Korean grape cultivar Campbell Early to Australia, its potential to serve as an oviposition and development medium for SWD must first be determined. In this study, we determined the oviposition and development potential of SWD on Campbell Early, after elucidating the SWD life cycle and establishing an artificial diet‐based mass‐culturing system. An investigation of the life cycle under five temperature regimes (16, 19, 22, 25 and 28°C) showed that the durations of the egg, larval and adult stages were shortened when temperature was increased from 16, 19, 22, 25 and 28°C, but pupal duration was shortest at 25°C and extended again at 28°C. A test of oviposition and development potential of SWD on Campbell Early grape clusters showed oviposition of 30.8 ± 6.8 eggs per cluster of injured grapes and 157.7 ± 16.2 eggs on a culture dish of artificial diet. However, in a similar experiment using uninjured grape clusters, only a single egg was deposited on the grape skin, which soon dried. In light of these results, newly harvested grapes left at vineyards during daily harvests are unlikely to serve as an oviposition and development medium for SWD, as long as the grapes remain uninjured.

Complete mitochondrial genome of Suzuki's Promolactis moth Promalactis suzukiella (Lepidoptera: Oecophoridae).

Abstract Suzuki’s Promolactis moth, Promalactis suzukiella, is in the family Oecophoridae of lepidodpteran Gelechioidea. This species is native to Korea, Japan and Taiwan, but has been recently found in the eastern part of the United States. Sequence information on this genus including P. suzukiella is nearly absent due to its small size and difficulty with identification. Therefore, we sequenced the complete mitochondrial genome (mitogenome) of the species. The 15,507-bp long complete mitogenome consisted of a typical set of genes (13 protein-coding genes, two rRNA genes and 22 tRNA genes) with one major non-coding A + T-rich region, and the typical arrangement found in most Lepidoptera. The controversial start codon for cytochrome oxidase I gene was CGA without any alternatives. The 81 bp P. suzukiella tRNALys was longer than any other tRNAs (e.g. 60–71 bp) due to the presence of a duplicated TTCTAATG sequence located at the 3′ end of tRNALys.

Complete mitochondrial genome of the grass moth Glyphodes quadrimaculalis (Lepidoptera: Crambidae)

Abstract Glyphodes quadrimaculalis (Lepidoptera: Crambidae) feed on a root tuber of Cynanchum wilfordii (Asclepiadaceae), which is one of the most famous traditional medicines in Korea. The genus Glyphodes includes ∼130 species distributed worldwide, so the complete mitochondrial genome (mitogenome) would be helpful for bio-identification, biogeographic studies and multigene-based phylogeny. The 15,255 bp long G. quadrimaculalis genome comprises 37 typical genes and 1 large non-coding region, with the typical arrangement found in Lepidoptera. Of the 13 protein coding genes (PCGs), 12 begin with typical start codons found in insect mitochondrial PCGs, but the COI gene starts with atypical CGA. One of the noteworthy features of the genome includes the presence of a 51-bp long non-coding space sequence located between tRNAGln and ND2 that reveals high-sequence homology (71.4%) to the neighboring ND2 gene, indicating the origin of the region by partial duplication of the ND2 gene.

The complete mitochondrial genome of the moon moth, Actias aliena (Lepidoptera: Saturniidae).

Abstract In this study, we describe the complete mitochondrial genome (mitogenome) sequence of the Actias aliena belonging to the lepidopteran family Saturniidae in terms of general genomic features and composition. The 15,243 bp long genome consisted of a typical set of genes (13 protein-coding genes, 2 rRNA genes and 22 tRNA genes) and 1 major non-coding A+T-rich region. The A. aliena mitogenome harbored the gene order tRNAMet, tRNAIle and tRNAGln between the A+T-rich region and ND2, as shown in most lepidopteran species. The COI gene possessed the CGA initiator, which is found in nearly all lepidopterans lacking a canonical ATN initiator. Twenty-one tRNAs formed the cloverleaf secondary structures but tRNASer(AGN) formed a simple loop in the DHU arm. The 328 bp long A+T-rich region, which was located between the S rRNA and tRNAMet genes, contained several Lepidoptera-specific sequences, such as the ATAGA motif, a poly-T stretch, an AT repeat, and a poly-A stretch, along with an unusual tRNAPhe-like structure.

Effects of gamma radiation on different developmental stages of the oriental tobacco budworm, Helicoverpa assulta (Lepidoptera: Noctuidae)

Ionizing radiation is increasingly used as an alternative to post‐harvest crop fumigation by methyl bromide. We studied the effects of gamma irradiation on Helicoverpa assulta (Lepidoptera: Noctuidae) at different stages of development to determine the minimal dose for the prevention of normal emergence of adults. We selected five doses of gamma rays (100, 200, 300, 400 and 500 Gy) based on preliminary experiments and irradiated eggs, larvae, pupae and adults. A dose of 100 Gy to eggs allowed 21.83% of larvae to pupate, but these all died during the pupal stage. A dose of 100 Gy to last‐instar larvae caused larval or pupal death, or the emergence of abnormal adults; no normal adults developed. Irradiation of pupae with doses of 300 Gy and above resulted either in their death or emergence of abnormal adults; however, after 100 or 200 Gy, normal adults emerged and F1 eggs were produced, but no eggs hatched. Following irradiation of adults, eggs were produced at all doses, although the numbers were significantly decreased compared to untreated controls (P < 0.05; 69.45–125.50 vs. 475.05 eggs per female); however, none of the eggs hatched. As prevention of normal emergence is a key outcome for measuring the effectiveness of radiation, then the 100 Gy dose was effective for irradiation of eggs and larvae, and 300 Gy for pupae.

Complete mitochondrial genome of the gelechioid Hieromantis kurokoi (Lepidoptera: Stathmopodidae)

Abstract Although the Gelechioidea is the second most species-rich group of Lepidoptera, comparatively few mitochondrial genomes (mitogenomes) have been sequenced in this superfamily. Here, we determined the complete mitogenomic sequence of the gelechioid Hieromantis kurokoi (Lepidoptera: Stathmopodidae) as the basis for a future study of the phylogeny of butterflies and moths (clade Ditrysia). The H. kurokoi genome was 15,208 bp with a typical set of genes (13 protein-coding genes [PCGs], two rRNA genes and 22 tRNA genes) and one major non-coding A + T-rich region. The cytochrome c oxidase subunit 1 (COI) gene had a CGA start codon, which is the start codon for this gene in the majority of lepidopteran species, whereas other PCGs began with an ATN codon. A 360 bp-long A + T-rich region harbored the blocks of conserved sequences that are typically found in lepidopteran insects. Phylogenetic analysis using the 13 PCGs and Bayesian inference (BI) and maximum-likelihood (ML) methods indicated that H. kurokoi belonged to the family Stathmopodidae and grouped together with the within-familial species Atrijuglans hetaohei with the highest nodal support (BI, 1.0; ML, 100%).

Geographic variation in the spotted-wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), based on mitochondrial DNA sequences

Abstract The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is an economically damaging pest that feeds on most thin-skinned fruits. It was originally native to a few Asian countries, including Korea, but is now found in North America and Europe. In this study, we sequenced portions of the mitochondrial (mt) COI and ND4 genes from a total of 195 individuals collected mainly from Korea. We then combined GenBank-registered COI sequences from all ancestral-range and introduced-range populations with our own COI data to assess the worldwide diversity, divergence, and relatedness of SWD haplotypes. A total of 139 haplotypes were obtained from the concatenated COI and ND4 sequences. Most haplotypes were confined to single localities, but 12 of them were found in more than two localities, and one haplotype (SWDCN61) was found from Korea to Canada. A dataset combining GenBank sequences with our own data identified a total of 94 worldwide COI haplotypes with a maximum sequence divergence (MSD) of 5.433% (32 bp). Although most haplotypes were found in only a single country, a few haplotypes were found commonly in China, Korea, and Japan; these occurred at a higher frequency and were often involved in introductions. A rough estimate of genetic diversity in each country showed higher diversity in ancestral distributional ranges, but the invasion over Asian countries seems to have been substantial because haplotype diversity was only 2.35 to 3.97-fold lower in the U.S.A, Canada, and Italy than that in the populations’ ancestral ranges.