In Korea, both Sympetrum depressiusculum Sélys, 1841 (Odonata: Libellulidae) and Sympetrum frequens Sélys, 1883 are recorded. However, the identity of Korean populations and the validity of listing the two species have not yet been settled. In this study, we collected 74 individuals from Kroea, Russia, the Netherlands, and Japan. These were sequenced for COI, 16S rRNA, and ITS region. Major morphological characters and phylogenetic, network, and structure analyses all consistently suggest that Korean populations form a single species. Consequently, it could be valid to treat Korean populations as one species, S. depressiusculum, by applying the senior name.

Pantala flavescens is a dominant Odonata species in the rice fields in Korea. To determine the effects of different temperatures on its larval growth and emergence, field and laboratory experiments were conducted. Larval growth was also monitored in mono-cropping and double-cropping rice fields. The growth of larvae was monitored every week by measuring the head width. In the field experiment, no difference was found in larval growth and emergence between the control temperature and +1.9°C of the control temperature. The larval growth was greater at 23°C than at 20°C laboratory temperatures, and no emergence was recorded at either temperature after eight weeks of monitoring. There was a quadratic relationship between larval growth and temperature in an incubator at five temperature regimes of 15, 20, 25, 30, and 35°C. Midseason water drainage caused the extinction of the existing individuals and newly hatched larvae dominated after re-watering in the rice fields. Larval size was greater in double-cropping fields than in mono-cropping fields in late July but the tendency was reversed in early August. The results of this study suggest that temperature warming will directly promote the larval growth of P. flavescens and indirectly influence seasonal growth via changes in water management in rice fields.

The Nannophya species in Korea was thought to consist of only Nannophya pygmaea. Previous studies on the species, including life history and development, conservation and restoration, habitat characteristics, genetic studies, distribution, behavior, and taxonomy have been conducted. However, a new Nannophya species, Nannophya koreana, was recently discovered in Korea. Moreover, this new species was found to inhabit both Korea and Japan. Thus, the previous studies should be reevaluated in relation to the new species, Nannophya koreana, and the latter should be treated as an endangered species worldwide given the current population instability.

In this study, we developed ten microsatellite markers specific to L. angelina using the Illumina NextSeq 500 platform. Forty-three individuals of L. angelina collected from three localities in South Korea were genotyped to validate these markers and to preliminarily assess population genetic characteristics. The observed number of alleles, observed heterozygosity (HO), and expected heterozygosity (HE) at a locus ranged from 4–13, 0.211–0.950, and 0.659–0.871 in the population with the largest sample size (20 individuals), respectively, thereby validating the suitability of the markers for population analyses. Our preliminarily assessment of the population genetic characteristics indicates the presence of inbreeding in all populations, an isolation of the most geographically distant population (Seocheon), and lower HO than HE. The microsatellite markers developed in this study will be useful for studying the population genetics of L. angelina collected from additional sites in South Korea and from other regions. †These authors contributed equally to this paper.

In this study, we developed 12 microsatellite markers specific to N. pygmaea using Illumina paired-end sequencing. Forty individuals of N. pygmaea collected from three currently known localities in South Korea were genotyped to validate these markers and to preliminarily assess population genetic characteristics. No locus showed significant deviation from the Hardy–Weinberg equilibrium (HWE). Our preliminary data indicate an absence of inbreeding in all populations and an absence of obvious genetic difference. The microsatellite markers developed in this study will be useful for studying the population genetics of N. pygmaea collected from other regions, including additional sites in South Korea.

The tiny dragonfly, Nannophya pygmaea (Odonata: Libellulidae) is one the smallest dragonflies in the world and listed as a second-degree endangered wild animal in Korea. We developed microsatellite markers and applied selected markers to South Korean populations to understand population genetic characteristics, along with two mitochondrial DNA (mtDNA) gene sequences (COI and ND5). Two mtDNA-based population genetic analysis indicates substantially reduced genetic diversity in an island population (Muuido) compared to others. On the other hand, population-based FST and RST consistently support that N. pygmaea populations are overall well interconnected with a relatively high gene flow. These results may collectively indicate that N. pygmaea populations in South Korea may have rather larger population size than we previously acknowledged based on a single-locus mtDNA sequence and field observation.

Currently, only limited number of mitochondrial genomes (mitogenome) is available from Odonata. In order to extend current mitogenome data for comparative biology and phylogeny we sequenced complete mitogenomes of two endangered dragonfly species, Libellula angelina and Nannophya pygmaea (Ododana: Libellulidae). The whole genomes were 15,233 bp in L. angelina and 15,112 bp in N. pygmaea and included 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. The arrangement of the genomes was identical to typical one found in insects. Phylogenetic reconstruction using concatenated sequences of 13 PCGs and two rRNAs of Odonata (17 species in eight families in three suborders) using both Bayesian Inference (BI) and Maximum Likelihood (ML) methods have shown a strong support for monophyletic Zygoptera (BI, BPP = 1 and ML, 100%). Currently, further scrutinized analysis is under progress.

본 연구는 한국의 멸종위기곤충인 꼬마잠자리 알의 발육과 온도의 관계를 추정하고자 8가지 서로 다른 온도 조건(17, 20, 22, 25, 28, 30, 33 및 36℃)에서 실시하였다. 꼬마잠자리의 알은 2007년 6월 경상북도 문경시 일대의 산간 습지에 서식하는 암컷 성충으로부터 채취하였다. 실험의 결과, 부화율은 17, 20, 22, 25, 28, 30, 33, 그리고 36℃에서 각각 2.86, 17.09, 24.

본 연구는 꼬마잠자리 서식처의 자연환경을 조사하고, 생물종의 복원과 유지를 위한 기초자료로 활용하고자 수행하였다. 꼬마잠자리는 잠자리과에 속하는 초소형 잠자리로서 우리나라에서는 멸종위기 보호야생동식물로 분류되어 보호되고 있다. 국내의 서식처는 중남부 일부 지역에 매우 희소하게 분포되어 있는 것으로 알려졌다. 이러한 멸종위기종인 꼬마잠자리의 서식처 복원을 위한 자료수집을 위해 꼬마잠자리의 서식이 확인된 4개 지역 10개 지점의 경관, 서식처 면적, 식생 유형, 수환경, 수원 등을 조사하였다. 조사는 2006년 6월부터 2007년 8월에 걸쳐 이루어졌다. 꼬마잠자리의 서식처는 대부분 산지의 묵논에 위치하고 있었으며, 서식처 면적은 113.4m2~1,153.1m2로 나타났다. 식생은 골풀과 고마리가 우점종으로 나타났으며, 수심은 2.6~7.3cm 사이였고, 수온은 16~27.8℃이었다. 꼬마잠자리의 서식처는 고산 습지에 위치하는 것으로 보고된 바 있으나, 조사 결과 해발 고도 139~243m 사이의 지역에 서식하고 있는 것으로 확인되었다. 결론적으로 꼬마잠자리의 서식처는 주변이 위요된 육화되기 전의 빈영양화 초기 단계의 묵논과 같은 습지에 복원되어야 하며, 꼬마잠자리는 다른 잠자리보다 환경에 예민한 습성을 가지고 있기 때문에 이러한 사항들을 고려하여 서식처 복원에 접근하는 것이 필요하다.

The hatching rate of the eggs of Nannophya pygmaea Rambur, an endangered dragonfly species in Korea, was experimented in different temperature conditions (10, 15, 20, 25, and 30℃) in laboratory. N. pygmaea eggs were collected from female adults inhabited a small wetland in Mungyong-si, Kyeongsangbuk-do, Korea, in July 2006. The hatching rate was evaluated from the number of hatched nymphs for the period of 100 days. As a result, the hatching rates were 83, 89, and 76% at 20, 25, and 30℃, respectively, however, eggs were not hatched at 10℃ and 15℃ during the experiment period. The derived thermal threshold for egg hatching was 14.3℃, which is relatively higher than the values of other temperate dragonflies.