Callipogon Relictus Research Articles

Modelling Distribution of an Endangered Longhorn Beetle, Callipogon relictus (Coleoptera: Cerambycidae), in Northeast Asia

Based on our own field data and using modeling of modern potential ranges (in the MaxEnt program), an assessment of the spatial distribution of the rare representative of the longhorn beetle family, Callipogon (Eoxenus) relictus Semenov 1899, was conducted in northeast Asia (220 geographic locations). The generated maps of the potential range of C. relictus demonstrate a high likelihood of the species’ presence in the upland areas of southern far east Russia, the provinces of northeastern China, and the Korean Peninsula. Field data also indicate the extensive association of the species with undisturbed broadleaf and coniferous–broadleaf forests in northeast Asia. Maps of the potential distribution of C. relictus in northeast Asia have been compiled based on four climate change scenarios from the present time to 2070. Under all of the climate scenarios used, it is shown that suitable habitats for the species will persist in certain areas of Primorsky Krai, as well as neighboring provinces of the People’s Republic of China and a small enclave on the Korean Peninsula in Gangwon-do province. Significant reduction in suitable conditions for the rare longhorn beetle will occur in the rest of its distribution range.

Complete mitochondrial genome of the Chinese Callipogon (Eoxenus) relictus (Cerambycidae: Prioninae) with phylogenetic analyses

The endangered longhorn beetle Callipogon (Eoxenus) relictus, which was designated as a natural monument since 1968 in Korea is still attracting public concern because of its extraordinary body size. Although mitochondrial genome data of this species was reported using Korean individual in 2017, start codon of cox1 is controversial and the secondary structures of transfer RNAs have not been illustrated. To report complete mitochondrial genome of Callipogon (Eoxenus) relictus from Chinese breed. We used dissected muscle tissues from an adult of Callipogon (Eoxenus) relictus. A total of 19,276,266,645bp from 127,657,395 reads were generated. The raw reads were assembled to mitochondrial genome data and annotated. Folded structures of transfer RNAs were drawn. Phylogenetic relationships were estimated by maximum likelihood and Bayesian inference analyses. The mitochondrial genome of C. relictus was 15,745bp in length and composed of 37 genes including 13 protein-coding genes (PCGs), two ribosomal RNAs, and 22 transfer RNAs. The overall base composition was 38.40% for A, 30.98% for T, 11.06% for G, and 19.56% for C. Most transfer RNAs were folded into the typical clover-leaf structure except trnS1. Phylogenetic analyses confirmed the monophyletic status of each subfamily. Mitochondrial genome composition was consistent with previous research, however, we suggest another start codon of cox1 gene and provide illustrated secondary structures of transfer RNAs. Phylogenetic analyses showed that subfamilies Cerambycinae and Prioninae are closely related.

Phylogeographic Investigation of an Endangered Longhorn Beetle, Callipogon relictus (Coleoptera: Cerambycidae), in Northeast Asia: Implications for Future Restoration in Korea.

Simple SummaryThe critically endangered Callipogon relictus is one of the largest longhorn beetle species and also the only remnant species of the genus Callipogon found in the Palearctic region. Knowledge of the phylogeographic history and current conservational status is essential to understand its unique distribution and to establish efficient conservation strategies. We studied the phylogeographical pattern and genetic diversity of C. relictus from almost its entire geographical range. The level of genetic diversity and divergence of C. relictus from the known distributions in four regions in Russia, China, North Korea, and South Korea using two mitochondrial markers (COI and COII) revealed that genetic diversity lies within the range of intraspecific levels. Relatively high genetic diversity with no distinct phylogeographic structures indicates that the wide range of current fragmented populations might be the remnant of genetically diverse populations in the past. The results of our phylogenetic and population genetic analyses suggest that C. relictus populations surveyed in the present study can be used as a “source” for a future restoration and conservation program. The findings of the genetic characteristics and phylogeographic history of C. relictus will help to establish effective conservation strategies for this endangered longhorn beetle species in Northeast Asia.The longhorn beetle, Callipogon (Eoxenus) relictus Semenov, is the only remnant species found in the Palearctic region, while all other Callipogon species are distributed mainly in Central America and partly in South America. This species has been placed in the first category (as ‘critically endangered’) of the Red Data Book in Russia and designated as one of the top-priority target species among all endangered invertebrate species for restoration in South Korea since 2006. Although its restricted distribution in Northeast Asia with a high conservational value has been highlighted, genetic features of C. relictus from different geographic regions remain unexplored. We first investigated the level of genetic diversity and phylogeographic patterns of C. relictus to evaluate the current conservational status and the feasibility of the implementation of a restoration program. The average genetic divergence of mitochondrial gene COI based on Kimura-2-parameter distance among the four regions in Russia, China, North Korea, and South Korea was 2.2%, which lies within the range of intraspecific levels. However, two separate clades with 3.8% divergence were identified, despite no geographical clustering of haplotypes. The linear pattern of the haplotype network with a high level of haplotype and nucleotide diversities suggests that the wide range of currently fragmented populations might be the remnant of genetically diverse populations in the past. This study will provide crucial information on the genetic characteristics and phylogeographic history of C. relictus, which will help to establish conservation strategies for this cherished insect species in Northeast Asia.

Historical review and occurrence records of Callipogon relictus Semenov, 1899 (Coleoptera, Cerambycidae) in Gwangneung Forest, South Korea with suggestions for species conservation.

Biodiversity has been declining and extinction rates have been exponentially increasing because of land use changes, invasion of exotic species, nutrient enrichment and climate change. In this scenario, many international networks such as the International Union for the Conservation of Nature have been making efforts to raise conservation awareness and preserve species and their habitats in many countries. The relict longhorn beetle Callipogon relictus Semenov, 1899 (Coleoptera: Cerambycidae) is the largest coleopteran species in the Palearctic region and has a unique distribution compared to its congeneric species. Callipogon relictus has been protected by two Korean laws since it was designated as a Korean Natural Monument and an Endangered Species in 1968 and 2012, respectively. To improve the conservation of this species, ecological and biological data were obtained from studies performed during the last 12 years on its populations in Gwangneung Forest, the fourth UNESCO biosphere reserve in South Korea. Previously scattered distribution records of C. relictus from South Korea from 1932 to 2007 are therefore summarized and ecological features of adults observed during fields studies performed from 2008 to 2019 are presented. Based on the summarized data, we suggest different management measures and conservation efforts to maintain the size of C. relictus populations in South Korea, which can also be further used in the restoration of other endangered insects.

Genome Size Estimation of Callipogon relictus Semenov (Coleoptera: Cerambycidae), an Endangered Species and a Korea Natural Monument.

Simple SummaryThe longhorned beetle Calipogon relictus has been considered as a class I endangered species since 2012 in Korea. In an attempt towards beetle conservation, we estimated its genome size at 1.8 ± 0.2 Gb, representing one of the largest cerambycid genomes. This study provides useful insight at the genome level and facilitates the development of an effective conservation strategy.We estimated the genome size of a relict longhorn beetle, Callipogon relictus Semenov (Cerambycidae: Prioninae)—the Korean natural monument no. 218 and a Class I endangered species—using a combination of flow cytometry and k-mer analysis. The two independent methods enabled accurate estimation of the genome size in Cerambycidae for the first time. The genome size of C. relictus was 1.8 ± 0.2 Gb, representing one of the largest cerambycid genomes studied to date. An accurate estimation of genome size of a critically endangered longhorned beetle is a major milestone in our understanding and characterization of the C. relictus genome. Ultimately, the findings provide useful insight into insect genomics and genome size evolution, particularly among beetles.

Effects of temperature on instar number and larval development in the endangered longhorn beetle Callipogon relictus (Coleoptera: Cerambycidae) raised on an artificial diet

Abstract Callipogon relictus Semenov (Coleoptera: Cerambycidae) is currently listed in the Red Data Books (Category I) of Russia and South Korea and, in 2006, was designated by the South Korean government as the first invertebrate priority target species in a restoration project. However, the species is also classified as an invasive quarantine pest by the Canadian Food Inspection Agency. Due to the five-year to seven-year life cycle of the species, experimental information about instar numbers has been poorly documented. Therefore, the goal of the present study was to document the instar numbers of non-diapause Callipogon relictus larvae reared on an artificial diet. Under conditions of 30 °C, 60% relative humidity, and constant dark (0:24 hour light-dark photoperiod), developmental pathways of 8, 10, and 12 instars were observed. The effect of temperature (20, 25, and 30 °C) on the duration of larval development was also examined to identify the optimum temperature for producing Callipogon relictus for conservational purposes. Larvae reared at 30 °C and 60% relative humidity, without a chill period, developed in seven to eight months, which is about one-tenth the duration of C. relictus development under natural conditions and the most rapid development of C. relictus observed to date.

A review of host plants of Callipogon (Eoxenus) relictus Semenov (Coleoptera: Cerambycidae: Prioninae), a Korea natural monument, with a new host, Quercus aliena Blume

Abstract A comprehensive checklist identifying host plants of phytophagous insects are essential in protecting forest ecosystems from major insect pests. We investigated host plants of Callipogon (Eoxenus) relictus Semenov (Coleoptera: Cerambycidae: Prioninae), an insect categorized as a natural monument in South Korea. Field surveys in Gwangneung forest led us to newly recognize the oriental white oak, Quercus aliena Blume (Fagaceae), as a host plant of C. (E.) relictus. Based on this result and a literature search, we provide an updated list of host plants of C. (E.) relictus in the present study. In addition, we also discussed about microorganisms (mushrooms) and habitats in Gwangneung forest (South Korea) and Ussurisky Nature Reserve (Russia) that are relevant to C. (E.) relictus.

West meets East: How do rainforest beetles become circum-Pacific? Evolutionary origin of Callipogon relictus and allied species (Cerambycidae: Prioninae) in the New and Old Worlds

The longhorn beetle genus Callipogon Audinet-Serville represents a small group of large wood-boring beetles whose distribution pattern exhibits a unique trans-Pacific disjunction between the East Asian temperate rainforest and the tropical rainforest of the Neotropics. To understand the biogeographic history underlying this circum-Pacific disjunct distribution, we reconstructed a molecular phylogeny of the subfamily Prioninae with extensive sampling of Callipogon using multilocus sequence data of 99 prionine and four parandrine samples (ingroups), together with two distant outgroup species. Our sampling of Callipogon includes 18 of the 24 currently accepted species, with complete representation of all species in our focal subgenera. Our phylogenetic analyses confirmed the purported affinity between the Palearctic Callipogon relictus and its Neotropical congeners. Furthermore, based on molecular dating under the fossilized birth–death (FBD) model with comprehensive fossil records and probabilistic ancestral range reconstructions, we estimated the crown group Callipogon to have originated in the Paleocene circa 60 million years ago (Ma) across the Neotropics and Eastern Palearctics. The divergence between the Palearctic C. relictus and its Neotropical congeners is explained as the result of a vicariance event following the demise of boreotropical forest across Beringia at the Eocene-Oligocene boundary. As C. relictus represents the unique relictual species that evidentiates the lineage’s expansive ancient distribution, we evaluated its conservation importance through species distribution modelling. Though we estimated a range expansion for C. relictus by 2050, we emphasize a careful implementation of conservation programs towards the protection of primary forest across its current habitats, as the species remains highly vulnerable to habitat disturbance.

Distribution of the longhorned beetle Callipogon relictus (Coleoptera: Cerambycidae) in Northeast Asia

The distribution of the longhorned beetle Callipogon (Eoxenus) relictus Semenov, 1899 (Coleoptera: Cerambycidae) in Northeast Asia was summarized for the first time, based on the examination of comprehensive material. Callipogon relictus is the only representative of the genus Callipogon in the Palearctic region. Its distribution ranges from Shanxi province (China) in the south, northward through the Korean Peninsula to Amur Oblast (Russia), and from Inner Mongolia (China) in the west to the coastal area of the Russian Far East.

Morphological anomalies of endangered Korean relict long-horned beetle Callipogon relictus (Cerambycidae, Coleoptera) during ontogenesis and possible causes of their occurrence.

This paper describes for the first time cases of exogenous morphological anomalies that occur during rearing of Callipogon relictus Semenov, 1899 in a laboratory setting. The highest frequency of the anomalies has been observed during pupation. It can be assumed that in beetles of this group, at final stages of ontogenesis, some abiotic factors such as humidity and temperature play an important role.

Newly developed fungal diet for artificial rearing of the endangered long‐horned beetle Callipogon relictus (Coleoptera: Cerambycidae)

AbstractIn this study, we attempted to develop an artificial diet to effectively rear the endangered long‐horned beetle Callipogon relictus Semenov to facilitate restoration efforts for this species. Fungal mycelia of the white‐rot fungus Pleurotus florida (Eager) were, for the first time, provided as an artificial diet for the larvae of C. relictus. The experiment started on August 11, 2015 with 53 larvae being provisioned with the fungal diet under laboratory conditions (25°C, 60 % RH, L:D 0:24) without diapause. During the first year, 11 adults (4 males and 7 females, 20.8 % of the 53 larvae) emerged between September 10 and October 1, 2016. The body length of the largest male was 106.8 mm, and three of the four males exceeded 100 mm in length. These results show that a fungal diet for rearing C. relictus is useful not only for reducing the larval period to approximately 1/6 of the normal larval period in nature, but also for producing large adults. These results support the notion that fungus may provide nutritional benefits during the larval development of C. relictus, and also indicate that this species is fungivorous.

Developmental biology and ecological peculiarities of the relict longhorn beetle Callipogon relictus Semenov, 1899 (Coleoptera, Cerambycidae)

The developmental biology of the relict longhorn beetle Callipogon relictus Semenov, 1899 was studied from egg to adult in the laboratory for the first time. The molting dynamics and morphometric characteristics of all the larval instars were determined. The location of larvae within the tree trunk was investigated by nondestructive modern methods. The reproductive behavior and the process of oviposition are described. Individual development of the species under laboratory conditions, at constant temperature and humidity, took 44 months, suggesting that in the nature it extends over at least four years.

Molecular identification and larval description of Callipogon relictus Semenov (Coleoptera: Cerambycidae), a natural monument of South Korea

An unknown larva of enormous size was found from Carpinus laxiflora in the Gwangneung forest and identified by using a barcode gene. It was a larva of Callipogon relictus Semenov, a natural monument of Korea, at an undetermined instar. Based on the result, we provide the larval morphological description of this particular instar, with the illustrations and biometric measurement data of diagnostic characters.

Areal of Callipogon relictus Semenov, 1899 (Coleoptera, Cerambycidae) in the Russian Far East

Data on the distribution of Callipogon relictus Semenov, 1899 over the Russian Far East were generalized. The distribution map for C. relictus is based upon long-term observations and collection materials by the leading institutions. The chronology was studied within the Russian geographic range of the species.

광릉숲에서의 장수하늘소(딱정벌레목; 하늘소과) 서식실태 조사결과 및 보전을 위한 제언

본 연구는 광릉숲에서의 장수하늘소의 실제 서식현황을 재확인하고, 서식밀도를 추정하기 위해 수행하였다. 2006년 성충 발생기를 전후하여 조사한 결과 암컷 1개체가 발견되었으며, 발견된 암컷의 방사과정에서 산란행동이 관찰되었는데, 나무 상부로 이동하면서 서어나무의 수피 틈에 낱개로 산란하였으며 산란회수는 20회 이상임이 확인되었다. 금번연구를 통해 현재까지 알려진 정보들을 종합하고 이들의 보전을 위한 방안을 제시하였다. A survey to investigate the inhabitation of Callipogon relictus Semenov and evaluate the population of the species in the Gwangneung Forest was conducted during last seven years. During the study, a female was observed in the forest in 2006 which confirmed a possibility of the inhabitation with a small population. Fortunately, a ovipositing female was observed in the forest during this study period in 2006. The female laid more than 20 eggs singly in the crack of bark of the Carpinus laxiflora Blume. We collated the all available data for the species with the present study including the previous reports to provide the information far the conservation plan. It will be needed the long term monitoring and various efforts for the conservation of the species will be need hereafter.