The disadvantage of the current Red imported fire ants (RIFA) diagnostic is that it takes at least two days, because it is subjected to PCR amplification and DNA sequence identification process using an arthropod universal mitochondrial cytochrome oxidase I prime pair after genomic DNA extraction. In order to overcome this drawback, two RIFA specific genes were confirmed and used to develop techniques for identifying the species using various PCR methods. The conventional PCR method can be confirmed by the presence of amplified DNA, but additional time is required to confirm whether the PCR products are present or not. In contrast, SYBR green Real Time (RT) PCR or TaqMan probe RT PCR method has the advantage of confirming the results immediately after the reaction is completed. The new molecular diagnostic method has the advantage of shortening the time of two days, which is the biggest disadvantage of RIFA molecular diagnostic method, to 3 hours or less.

The red imported fire ant (Solenopsis invicta) is categorized into the world’s 100 worst invasive alien species by the International Union for Conservation of Nature. Accordingly, the prediction of potential distribution of the red imported fire ant is demanded in order to provide the possibility of dispersion into new sites, and to identify vulnerable regions to be attacked. In general, species distribution model can predict potential distribution of a specific species, but most of them have used air temperature as the most important variable. However, red imported fire ant has life cycle under ground, requiring soil temperature for more reliable prediction of potential habitats. For this reason, this study was to insert soil temperature into CLIMEX, and to evaluate potential distribution of the red imported fire ant.

Origin of the red imported fire ant (RIFA, Solenopsis invicta) is South America, a tropical climate region. It has settled in the invasive area, causing various problems. In recent, colonies of Solenopsis invicta were discovered in Busan in 2017, and then in Busan, Pyongtaek, Incheon, Daegu and Ansan in 2018. This study aims to validate 31 microsatlite loci referred from previous study for tracing origin of Solenopsis invicta colonies. We tried to test previously developed microsatellite loci so that we establish the protocol for molecular epidemiology of RIFA. We applied 31 microsatellite loci to DNA samples from the RIFA colonies found in Texas and Florida, USA. We will present 31 markers were divided into three injections and the amplification rate for each marker was shown as follows.

The red imported fire ant (RIFA, Solenopsis invicta), an exotic species, detected in Taiwan in 2003 was originally from USA. A program was launched immediately under Bureau of Animal and Plant Health Inspection and Quarantine Council of Agriculture (BAPHIQ) in 2004 for RIFA management. The National Red Imported Fire Ant Control Center (NRIFACC) helps the BAPHIQ to integrate/coordinate the RIFA eradication program which involves every governmental department, however the actual implementation of prevention and control work is the local government. It has made a significant progress in public education, since our general public can recognize RIFA accurately now and succeed to localize RIFA in Northern Taiwan. However, nationwide RIFA eradication is still far from success, the major constraints of the eradication program in Taiwan include (1) RIFA had likely been in Taiwan longer than reported, (2) difficulty to detect incipient infestation, (3) mass reproductive queens that can spread over 10-20 km after nuptial flight, (4) movement control is not easy to perform, (5) man power or company for chemical treatment is not enough, (6) funding is insufficient to allow success, (7) meteorological condition disfavors the control practice. Fortunately, we have developed humidity resistant baits that could enhance the control efficiency of RIFA in humid or wet conditions and resolve the weather constraints of RIFA and other invasive ants control in wet tropical and subtropical habitats. For the success of NRIFACC eradication efforts, participation of all stakeholders would remain a very important strategy in the future. In particular, a centralized team would further facilitate the management of RIFA. Moreover, due to the increasing in international trades and the recent detection of RIFA in Japan and Korea, an international efforts and cooperation on RIFA management is a key issue to control global movements of RIFA.

Red imported fire ant Solenopsis invicta is one of the 100 most threatening alien species in the world. Originally distributed in parts of South America, it has invaded 24 other countries and regions now. Because of its ferocious habits, rapid reproduction and strong competitiveness, it is easy to outbreaks and cause disaster in a short period of time after the invasion, and will endanger agriculture and forestry, human health, biodiversity and public safety. The fire ant had been found in Taoyuan, Taiwan in September 2003, and Guangdong, mainland China on September 23, 2004. As a new invasive species in south China, although it was paid serious attention by the governments and the scientists, but the fire ant has kept spreading fast after its invasion. In order to delay its expansion and control its infestation, the following research on the fire ant has been carried out and completed 14 years after its invasion in China. To discover the fire ant invasion in mainland China, and reveal its spreading and expanding law, including 1) the genetic diversity, invasive sources, ways, routes, migration and expansion of the fire ant in China at different spatial scales; 2) a system of methods for estimating invasion and expansion; 3) monitor continuously for 14 years to clarify its diffusion dynamics in mainland China. Clarify the catastrophic law and mechanism of the fire ant invasion in mainland China, and include 1) The laws and mechanisms of invasive biology, behavior, population dynamics, ecological adaptation, social immunity, interspecific competition/reciprocity; 2) The disturbance of the fire ant invasion to crops, species relationship, community structure, control pest function, pollination function and soil environment in southern six ecosystems; 3) The laws and mechanisms of inhibiting invasion and restoring diversity in the diverse habitats; 4) New functions of chemosensing related genes and the regulation mechanism of light avoidance behavior. Reveal the basic theory of chemical control of the fire ant, and establish a safe and efficient technical system for emergency control and eradication, such as 1) the transmission toxicity, behavioral toxicity, reproductive disturbance, repellent activity, control effect and environmental effect of 46 insecticides; 2) pesticide-induced killing-queen behavior and its mechanism; 3) standard methods for evaluation of control effect for insecticides. Reveal the basic theory of chemical control of the fire ant, and establish a safe and efficient technical system for emergency control and eradication, such as 1) Five safe and efficient formations and their application technologies, and breakthroughs in high attractiveness, waterproofing formations and application methods, and the control effect of single use with 89% - 97%; 2) emergency prevention and control in 8 types of ecological areas eradication mode and technology system, with the breakthrough of inefficient or ineffective products and technology in rainy and low temperature seasons, and the control effect with 96% - 100%, and local eradication of 19 areas. Put forward risk management strategies, and build up an accurate, efficient and safe monitoring and quarantine technology system, and include 1) the suitability and risk management strategies and techniques based on more extensive research; 2) new monitoring technologies with the accuracy of 98% - 100%; 3) relationship among the three methods, and a monitoring and index system; 4) efficient quarantine technology for entry-exit, occurrence regions and transportation; 5) near infrared reflection ant nest detection system, and information management system; 6) construct the management, technical standards and promotion system, and apply them widely; 7) more than 40 national standards and schemes in a management/technical standard system.

The red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), is an invasive pest affecting urban and rural communities, agricultural production and wildlife. Its complex biology and genetics is reflected in the existence of two different colony forms: monogyne and polygyne. We focus our studies on the polygyne form more abundant in Texas, characterized by the presence of multiple queens that co-operate for colony success. Our conceptual framework resides in the hypothesis that understanding gene networks linking nutrition and reproduction may reveal critical signaling pathways that could be disrupted to manage fire ants. In the pre-omics era we began by systematically cloning and characterizing the expression of genes and proteins important for reproduction and signaling and that we believe participate in the fire ant ‘genetic tool kit’. Our earlier studies focused on the vitellogenin receptor (VgR) and in the application of RNAi to reduce VgR gene expression as proof of principle that gene silencing in queens could lead to impaired egg production. Signaling systems related to reproduction and nutrition were also studied, such as the insulin receptors and the sNPF receptor, a G protein-coupled receptor. We have immunolocalized the sNPF receptor in the brain of queens and workers and found correlations in its neuronal gene expression in both castes with respect to the presence or absence of brood in the colony. We have generated and compared transcriptomes of mated and virgin queen brains and ovaries and identified a few differentially expressed genes. Most recently, with the release of the new fire ant genome in the Fall of 2018, we mined the genome to compile and curate the annotation of G protein-coupled receptors. The lecture will summarize key aspects of the biology of fire ants and morphological and functional differences among colony members. Experimental approaches utilized to begin to understand regulation of colony growth at the molecular level will be presented. It is our goal to unravel the endocrinological control of the fire ant colony with the hope of identifying novel targets to impair queen maturation, ovarian development, colony nutrition and brood production.

The red imported fire ants, Solenopsis invicta Buren are one of the serious pests in the world. Recently, S. invicta and S. germinata were found at Gamman pier, Pusan port in Korea by Animal and Plant Quarantine Agency. It is difficult to discriminate between S. invicta and S. germinata because of their morphology. Although DNA barcoding is an efficient method for species identification based on partial sequence of the mitochondrial cytochrome oxidase I gene(COI), amplification of non-target sequences or heteroplasmic COI sequences may result in the failure of Sanger sequencing. To overcome these limitations, application of next generation sequencing platforms is an alternative method. Here, we developed SNP markers using NGS technologies to distinguish two fire ants accurately and easily. For read mapping from high-throughput sequencing data, we used S. invicta reference genome version Si_gnG downloaded from NCBI database. Samtools were used for genotypes calling after mapping read to reference genome by BWA. After coding sequence SNPs that clearly distinguish S. invicta and S. geminata from one candidate gene were selected, the SNPs were validated additional Sanger sequencing using various accessions, including S. invicta and S. geminata. Our results demonstrated that detection of S. invicta from Solenopsis genus group could be accurately and quickly detected by these markers.

Incursions of red imported fire ant (RIFA), Solenopsis invicta into Korea have been increasing. After a first interception of a colony of S. invicta on Gamman pier, Pusan port while intensive surveillance by Animal & Plant Quarantine Agency (APQA) in September 2017, three more RIFA colonies have been found in sea port piers of Pyeongtek, Incheon and Pusan cities. The social forms and mitochondrial DNA haplotypes of the intercepted RIFA colonies were analysed by allelic discrimination assay (peptide nucleic acid probe based RT-PCR) of Gp-9 gene and mt-DNA fragment of 768 bp, which is part of the Cytochrome oxidaseⅠ gene. The colony on Gamman pier, intercepted in Sep. 2017 was previously reported as a haplotype 5 (H5) of mitochondrial DNA and a social form of polygyne. The colony on Hutchison pier of Pusan port, intercepted in June 2018 were confirmed as a H22 haplotype and a monogyne. Those different social forms show different origins of each colonies. Those on piers of Pyeongtek and Incheon ports, also found in 2018 were confirmed samely as H22 and monogyne. However, it could be putatively assumed that those two colonies were differently introduced via different container cargoes, considering those colonies were found in container yards of distantly located different sea ports. More genetic variation analyses using diverse sets of molecular markers such as microsatellites, genome-wide single nucleotide polymorphisms, etc. in nuclear gens are being proceeded for more exact introduction routes (origins).

Origin of Red imported fire ant (RIFA : Solenopsis invicta) is Central America, a tropical climate region. It has settled in the invasive area, causing various problems. In recent, Solenopsis invicta were discovered in Busan in 2017 and then in 2018 at a construction site in Busan, Pyongtaek, Incheon and in Daegu. This study aims to confirm the origin of invasive colonies of Solenopsis invicta. We tried to test previously developed microsatellite markers so that we establish the tracing protocol for molecular epidemiology of RIFA. We justified 66 microsatellite markers already developed using DNA from the RIFA found in Incheon Harbor. As results, 30 markers were selected to facilitate amplification and fragment analysis.

The red imported fire ant (Solenopsis invicta) is a species of ant native to South America. The fire ant was inadvertently introduced into USA, Australia, New Zealand, and other Asian countries including China and Taiwan. Since the first report of the fire ant in port city of Busan, Korea in 2017, it was found in many other cities of Korea in following year. To obtain the molecular information of this invasive species, total RNA was extracted from the abdominal segment of the ants collected in Incheon, and subjected to transcriptome sequencing. By using Illumina sequencer platform, 101 base pared-end sequencing generated 2 × 50,064,081 of raw reads to obtain 2 × 45.95 Gbase of quality filtered nucleotide sequences. The in silico cDNA library was constructed by Trinity de novo assembler followed by TransDecoder ORF finder and CD-HIT clustering program to streamline the library. The final version of cDNA library contains 20,442 contigs with protein coding capability. To survey the virome of this ant, these contigs were searched against the viral reference sequences from NCBI RefSeq database with BLASTN program. As a result, contigs which showed high sequence identities with several RNA viruses including previously reported SINV-2 were found from the fire ant. This virome information might give an idea of a shift of virological environment of this newly found ant isolate or population in Korea.

붉은불개미는 남미가 원산인 외래해충으로써 기후변화로 인한 기온 상승과 국가간 교역량의 증가를 통해 전세계적으로 서식범위를 확장해 나가고 있다. 국내에서는 붉은불개미가 2017년 9월 부산 감만항에서 처음 발견된 이후 올해까지 4차례 추가로 발견되어 국내 침입 및 정착 가능성이 점차 증가하고 있다. 곤충에서 인슐린 신호체계는 일반적으로 산란, 생장 및 발육, 대사계, 스트레스 저항성에 관여하는 것으로 널리 알려져 있다. 본 연구에서는 붉은불개미의 인슐린에 대한 생물학적인 기능을 이해하기 위해 인슐린 수용체(insulin receptor)의 발현을 억제한 후 나타나는 생리적 변화를 관찰하였다. 그 결과 체내빙결점(supercooling point)에 영향을 미쳐 붉은불개미의 저온생리에 영향을 준다는 것을 확인할 수 있었다.

Red imported fire ant (Solenopsis invicta) is a notorious pest which has caused damage of human life. Recent expansion of its habitat due to climate change has threatened where it cannot live before. South Korea has been exposed to its invasion, alerting early assessment of potential distribution of Solenopsis invicta. The objective is, hence, to predict potential distribution of Solenopsis invicta in South Korea based on climatic suitability. CLIMEX software was used for predicting Solenopsis invicta distribution in 2020 under RCP 8.5 climatic change scenario. Result showed that climates in coastal areas, Daegu, and Jeju island would be suitable for inhabitation of Solenopsis invicta. This results suggested that the risk of Solenopsis invicta invasion might be increased with the current climate change.

Climatic similarity between a native region and a target area is the first step to be considered for judging an invasive risk of alien species. In this study, we compared climate of the origin of Solenopsis invicta with that of South Korea. Match Climate application in CLIMEX software was used to simulate Composite Match Index (CMI) which quantitatively evaluated climatic similarity between two locations. We selected a native city (Cordoba in Argentina) of Solenopsis invicta and compared its climate with the current climate in South Korea. Result showed that climatic similarity is higher in Gyeongsangbuk-do area including Andong and Pohang, When only comparing climate during April to October, CMI was generally increased, but areas with the highest CMI was decreased.

A colony of Solenopsis invicta was first intercepted on Gamman pier, Pusan port in Korea at September, 2017 by Animal and Plant Quarantine Agency. The mitochondrial DNA (mt-DNA) of workers was analyzed and compared with vary libraries of mt-DNA haplotypes to elucidate the origin of the introduced colony with the trade pattern of the Gamman pier. The mt-DNA fragment of 768 bp, which is part of the Cytochrome oxidae I gene, was amplified and sequenced. The results showed that the mt-DNA was in the clade of haplotype 5, which is endemic in southern USA, China, Taiwan, and Australia. More than 60% of containers are imported from China into Gamman pier, it may be possible to assume that the colony was inadvertently invaded through containers from China.

Recently a colony of Solenopsis invicta, the red imported fire ant (RIFA), was intercepted on Gamman pier, Pusan port in Korea by Animal and Plant Quarantine Agency. It has been generally known that RIFA has two social forms as monogyne and polygyne, which showing the behavioral differences between the two forms and dictated by a pheromone binding protein, Gp-9. The social forms of the RIFA colony was revealed as polygyne form, when the GP-9 gene was analyzed by three allelic discrimination assays including Real-Time PCR (RT-PCR), rh-Amp SNP Genotyping, and peptide nucleic acid probe-based RT-PCR in this study.

벌목 개미과 두마디개미아과(Hymenoptera: Formicidae: Myrmicinae)의 Solenopsis invicta Buren, 1972가 국내 부산항에서 처음 발견되 어 농림축산검역본부에 의해 신속하게 제거되었다.