The pear pest, Cacopsylla jukyungi (Hemiptera: Psyllidae), is one of the most damaging insect to commercial pears in South Korea. In this study, we developed eight microsatellite markers specific to C. jukyungi and genotyped 132 individuals collected from 11 localities throughout South Korea. Populations showed lower observed heterozygosity than expected heterozygosity and slightly or highly positive values of inbreeding coefficients, suggesting that C. jukyungi is subjected to inbreeding. The nationwide expansion of pear orchards and the replacement with a popular new cultivar during the last 50 years, which may have accompanied the spread of C. jukyungi-bearing pear grafts and scions, are likely sources of such facilitated dispersal. Thus, a management strategy against unintended anthropogenic dispersal of the pear psyllid will be required for better control of C. jukyungi.

배에 피해를 주는 해충 중 하나인 주경배나무이는 2~3월 경 배나무의 거친껍질 밑에서 겨울을 난 후 나무 위로 올라가 산란하는데, 이 때를 월동 후 방제적기로 한다. 월동 후 방제에는 주로 기계유유제를 사용하고 있으나 저온피해가 자주 발생하거나 나무의 세력이 약한 농가는 방제 후에 언피해 발생을 우려하여 살충제를 살포하거 나 방제를 하지 않는다. 월동 후 발생밀도를 조절하지 못할 경우 생육기에 피해가 커지기 때문에 기계유유제를 대체할 수 있는 약제를 확인하고자 하였다. 또한 2023년 2월 EU 수출 대상 농가에는 아바멕틴 성분의 살충제 사용을 제한하는 규제가 발표되어 생육기에 발생하는 주경배나무이 여름형 성충에도 아바멕틴 성분을 대신하 여 적용 가능한 약제를 선정하고자 하였다. 주경배나무이 대상 등록 약제 중 아바멕틴, 아세타미프리드, 이미다 클로프리드, 설폭사플로르를 시험약제로 선정하였으며, 약제검정 결과 겨울형 성충에는 아세타미프리드 > 아 바멕틴 > 이미다클로프리드 > 설폭사플로르, 여름형 성충에는 아바멕틴 > 설폭사플로르 > 이미다클로프리드 > 아세타미프리드 순으로 살충률이 확인되었다. 살충력 추가 검정 및 여름형과 겨울형 성충의 충체 특성을 비교 한 후 기계유유제 및 아바멕틴 성분 대신 사용이 가능한 약제 성분을 권장할 수 있을 것으로 사료 된다.

Insect peptides have been extensively studied due to beneficial effects in the treatment of infectious diseases. Melittin, a fundamental component of honeybee venom produced by European honeybee Apis mellifera, has applied to prevent various inflammatory disease and bacterial infections in human. However, the therapeutic application of melittin is limited due to its low stability, hemolytic activity and expensive manufacturing costs. In this study, we aimed to discovery unknown peptides from the Apis mellifera and evaluate its antibacterial activity against Escherichia coli KACC 10005. A total 15,853 peptide sequences were diciphered using Illumina HiSeq 2500 next-generation sequencing (NGS) platform and analyzed based on the Apis mellifera official Gene Set Version 3.2 (amel_OGSv3.2) and the Collection of Anti-Microbial Peptides (CAMPR3) database. All the peptide sequences and annotation data sets were combined and sorted by physicochemical features of antimicrobial peptides (AMPs), such as short peptide length <=50, positive charge, isoelectric point (8.0<=pl<=12), and aggregation propensity (in-vitro: <=500, in-vivo: –40<= Na4vSS <=60). Among the screened peptides, four unknown peptide candidates, named AMP1-4, were chemically synthesized and tested for antimicrobial activity in comparison with a reference peptide, melittin. Inhibition of bacterial growth was observed in the AMP4 treated group from 6 hours to 48 hours post-treatment against E. coli. These results suggest that honeybee-derived peptide sequences can be applied as natural resources to acquire novel AMPs and the peptide sequences derived parameters are enough to recognize antibacterial peptides. In addition, the selected novel peptide candidate, AMP4, has antibacterial activity.

The hypopharyngeal gland (HPG) of the honeybee worker produces royal jelly (RJ) and has a developmental cycle closely related to the division of labor. In this study, we investigated to compare the HPG acini diameter of differently aged worker bees with high royal jelly producing colony (HRC) or less producing colony (LRC). Additionally, we also evaluated whether the fresh weight of the head is a reliable indicator of the developmental status of HPG. The HRC showed a significantly higher RJ production about two-times as compared with those of the LRC. We measured the HG-diameters on days 1, 3, 6, 9, 12, 15. The microscopic analysis revealed that the acini size of the HRC was significantly larger than the LRC. In addition, the acini diameter of HRC was 15% longer than the LRC on the first day after emerging. It was shown that the fastest development during 3 days which is preparing for nurse the brood. The HPG acini diameters increased in both colonies in a similar fashion until day 12 and then decreased. We also compared the fresh head weight of the experimental colonies, differences were similar to the development of HPG. Therefore, high royal jelly production may have a positive correlation between HPG acini size and the fresh head weight.

The ectoparasitic honey bee mites was originally confined to the Asian honey bee(Apis cerana etc.), mites had become widely established in the world and have continued to cause extensive bee colony deaths. Mites attach to adults and developing brood, where they feed on their blood. If left untreated, mites can deform bees and eventually kill the colony. Varroa destructor and Tropilaelaps clareae has plagued European honey bees, Apis mellifera. Differences in mite tolerance are reported between two honey bee species A. mellifera and A. cerana. We were counted number of mites(V. destructor and T. clareae) form 20 colonies. V. destructor and T. clareae has very similar behavior in honeybee colony. When behaviorally close, two competing species may populational interfere, and thereby affect their population dynamics. We tested for populational interference (PI) between two populational competing honeybee mites, V. destructor and T. clareae, by investigating their population dynamics when they competed on the same colony.

A partial sequence of the mitochondrial cytochrome oxidase subunit I (COI) gene is widely used as a molecular marker for species identification in animals, also termed a DNA barcode. However, the presence of more than one sequence type in a single individual, also known as heteroplasmy, is one of the shortcomings of barcode identification. In this study, we examined the extent and divergence of COI heteroplasmy, including nuclear-encoded mitochondrial pseudogenes (NUMTs), at the genomic-DNA level from 13 insect species, including four individuals of orthopteran Anapodisma miramae. Furthermore, a long fragment of mitochondrial DNA (~13.5 kb) and cDNA from A. miramae were used as a template for COI PCR to compare the patterns of heteroplasmy between DNA sources and to investigate a possible way to avoid ambiguity in DNA barcoding. When multiple numbers of clones originated from genomic DNA were sequenced, heteroplasmy was prevalent in all species (3~16 heteroplasmic copies), with a varying degree of maximum sequence divergence (<1% in 7 species, <4% in 3 species, <6% in 2 species and 2.15-8.03% in four A. miramae individuals). In five species, NUMTs also were observed when genomic DNA was used as a template. Long fragment DNA also is a source of heteroplasmic amplification, but the divergent haplotypes and NUMTs obtained in the genomic DNA-based PCR were not detected in A. miramae. On the other hand, cDNA was heteroplasmy-free, without NUMTs when multiple numbers of clones were sequenced. Consistently, one dominant haplotype was always obtained from the genomic DNA-origin clones in all species and also from the long fragment- and cDNA-origin clones of A. miramae. Furthermore, the dominant haplotype was identical in sequence, regardless of the DNA source. Thus, one possible solution to avoid the barcoding problem in relationship to heteroplasmy could be the acquisition of multiple numbers of barcoding sequences to determine a dominant haplotype that can be assigned as barcoding sequence for a given species.

The dung beetle, Copris tripartitus, (Coleoptera: Scarabaeidae), is one of the insect species listed as endangered wildlife in Korea. In order to establish conservation strategy an investigation on nation-wide genetic magnitude and nature of genetic diversity would be required. In this study, we sequenced each partial sequences of mitochondrial COI (658 bp) and CytB (433 bop) genes and complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA (411~420 bp) from 70 individuals of C. tripartitus collected from five Korean localities. The sequence divergence of mitochondrial genes was unexpectedly substantial as 5.0% (33 bp) for COI and 4.6% (20 bp) for CytB, whereas that of ITS2 was only 1.9% (6 bp), revealing much higher variability in mitochondrial DNA. In phylogenetic analysis, each 57 and 47 haplotypes obtained from COI and CytB gene sequences was subdivided into two groups (groups A and B), but the node supports for each group was not strong enough to consider each group as independent monophyletic groups in both genes. This interpretation was further supported by the same analysis with ITS2, showing no subdivision at all. These findings reinforce importance for the inference of phylogenetic result using both mitochondrial and nuclear encoded sequences. The C. tripartitus occurring in Korean peninsula was genetically well connected to each other and no obvious population genetic structure was detectable.

The pear psylla, Cacopsylla pyricola Foerster (Homoptera: Psyllidae), is a serious insect pest of commercial pear crops. The species, which resides on pear trees throughout its life cycle, is rapidly spreading in some regions of the world. Given the life cycle, it is unclear how such a rapid spread has been facilitated. Presently, the population genetic structure of the species including genetic diversity and gene flow was studied to understand the nature of dispersal and field ecology of the species. Pear psylla was collected from several pear orchards in Korea. The 658-bp region of mitochondrial COI gene and the 716-bp long complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA were sequenced. Unlikely other previously studied insect pests, the COI-based genetic diversity of the pear psylla was extremely low (maximum sequence divergence of 0.15%). This finding allowed us to conclude that the species may have been introduced in Korea relatively recently, possibly with the phenomenon of genetic bottlenecks. ITS2 sequence-based analyses of phylogeny, population differentiation, gene flow, and hierarchical population structure all concordantly suggested that the pear psylla populations in Korea are neither genetically isolated nor hampered for gene flow. These genetic data are concordant with the dispersal of an overwintering winterform morph outside the non-pear habitat in the fall and the possibility of subsequently longer distant dispersal.

The perilla leaf pyralid moth, Pyrausta panopealis Walker (Lepidoptera: Pyralidae), is a serious pest damaging to leaf perilla. In order to establish the life parameters of P. panopealis for eventual purpose of control, the developmental span of each stage were investigated under five temperature regimes (20℃ ~ 3 0℃). In addition, the larvicial efficacy of several on-the-market environment-friendly agricultural materials (EFAMs) was tested. The width of head capsule at each larval stage measured to be the mean of 0.21, 0.32, 0.47, 0.64, and 0.98 mm, respectively. The larval period of P. panopealis was longest at 20ºC as 27.0 days and shortened as temperature goes up to 30ºC as 11.3 days. Survivorship of the larval P. panopealis was the highest at 30ºC as 80%, whereas that of other temperatures ranged from 40% (20ºC) to 62.5% (27.5ºC), indicating that the P. panopealis appears to favor higher temperature. In addition to larval period, the duration of egg, prepupa, and pupa stages also shortened as temperature goes up, whereas the duration of adult stage increased as temperature goes up: from 4.1 days at 20 ºC to 6.1 days at 30ºC. After the perilla leaf pyralid moths were successfully stabilized in indoor environment the larvicidal efficacy of the ten EFAMs that were previously selected from the result of other moth species was tested aimed at 4th instar larvae for 48 hrs. Seven of the ten tested showed more than 90% of mortality within 12 hrs and reached nearly up to 100% within 24 hrs, but the remaining three showed less than ~70%.

Two complete mitochondrial genomes (mitogenomes) of the endangered, lycaenid butterflies, Spindasis takanonis and Protantigius superans (Lepidoptera: Lycaenidae), were sequenced. Each 15,349 bp and 15,248 bp-long genome contained both the lepidopteran specific gene arrangement that differ from the most common arrangement of insects by the movement of tRNAMet to a position 5’-upstream of tRNAIle. Neither of the species have typical COI start codon. Instead, the CGA (arginine) sequence that is commonly present in all other lepidopterans was also found in both lycaenids. The possible binding site for the transcription termination peptide, TACTA sequence, also was well retained in both species. The high A+T-content, which is a characteristic of insect mitogenomes was well reflected in the genomes in the form of higher frequency of codons with A/T nucleotides, severe A/T bias in 3rd codon position, and extremely high A/T content in the A+T-rich region. The 19 bp-long poly-T stretch and the downstream conserved motif ATAG, which were suggested previously to function as a structural signal for minor-strand mtDNA replication, was also well conserved in the A+T-rich region of both lycaenids. Phylogenetic analysis among lepidopteran superfamilies supported the relationships of either (((((Bombycoidea + Geometroidea) + Noctuoidea) + Papilionoidea) + Pyraloidea) + Tortricoidea) by concatenated amino acid sequence or (((((Bombycoidea + Geometroidea) + Noctuoidea) + Pyraloidea) + Papilionoidea) + Tortricoidea) by concatenated nucleotide sequences of 1st and 2nd codon positions of 13 protein-coding genes, two rRNA genes, and 22 tRNA genes, revealing fluctuating positions of Papilionoidea and Pyraloidea between the two data sets.

Eumenis autonoe belonging to a lepidopteran family Nymphalidae (superfamily Papilionoidea) is an endangered species in Korea. Historically, the species was distributed in Europe and Asian region including a wide region in Korean peninsula. However, in Korean peninsula, the species is found only in two isolate dregions: South in a remote island Jeju, where altitude is higher than1, 400 meter on Halla Mt. and North in far northern Korean peninsula around Mt. Bekdu. In this study, we report the complete mitochondrial genome of the endangered E. autonoe collected from Mt. Halla. The 15,489-bp long E. autonoe genome has a typical gene content found in animal mitochondrial genomes and contains the gene arrangement identical to all other sequenced lepidopteran insects, which differs from the most common type found in insects, as the result of the movement of tRNAMet to a position 5’-upstream of tRNAIle. As seen in many other lepidopteran insects, no typical ATN codon for COI gene is available. Thus, we tentatively designated the CGA (arginine) found at the beginning of the COI gene, as has been suggested for lepidopteran COI starter. The intergenic spacer sequence located between tRNASer (UCN) and ND1 of E. autonoe mitogenome also contains the ATACTAA motif which is conserved in all sequenced lepidopteran species. The 678-bp long A+T-rich region, which is longest in sequenced lepidopteran insects contains ten identical tandem repeats composed of 27 bp plus one 13-bp long identical incomplete final repeat. Such repeat sequence is rare in the lepidopteran mitogenomes known so far. The E. autonoe A+T-rich region also contains a poly-T stretch located at the end of the region as 19 bp and also contains the downstream conserved motif ATAGA that were previously suggested to serve as a structural signal for minor-strand mtDNA replication. Phylogenetic analysis using the concatenated 13 amino acid sequences of PCGs among available six lepidopteran superfamilies (Tortricoidea, Pyraloidea, Papilionoidea, Bombycoidea, Geometroidea, and Noctuoidea) rooted with three dipteran species with BI and ML analyses supported the following topology: ((((Bombycoidea + Geometroidea +Noctuoidea) + Papilionoidea) + Pyraloidea) + Tortricoidea). Within Papilionoidea, a closer relationship between Lycaenidae and Pieridae, excluding Nymphalidae was observed. Further fruitful information will be available after more analysis is done.