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.

Two infamous ant species, red imported fire ant (RIFA, Solenopsis invicta) and tropical fire ant (TFA, S. geminata), originated from South America are invading and harming many countries around the world. Among them, RIFA, known as one of the 100 world’s worst invasive alien species, has been discovered in South Korea; in Busan (Gamman CT) in 2017, and subsequently in Busan (Hutchison CT), Pyongtaek, Incheon and Daegu in 2018. With these relentless introduction of RIFA, South Korea is not safe no more from these ants and faces a risk of settlement. Our research goal is tracing the country origin of invasive populations of RIFA and TFA based on molecular epidemiological approach. We are conducting both microsatellite and genome-wide SNP analyses in order to derive a complementary interpretation. These two methodologies are expected to result in improved resolution in population genetics analysis. Nevertheless, this work needs collaboration of many countries belonging to the range of origin and invasion of RIFA and TFA. We will briefly introduce our research project and progress of collaboration research.

This study is about determination of fire origin by using analysis of shadow that was recorded CCTV data at the fire scene. This analysis is based on straight and radiate nature of light. At fire experiment with about 1m flame, we conformed that 2-dimensional extension line is focused at the bottom of the fire. If the fire is burning at the same level with shadow, it indicate the point of origin exactly. In 3-dimensional analysis that connect extensional line between distinctive points the shadow and the objet, the line focused in the Ø 50cm-circle. We estimate the reason of that is because of the character of combustion of gases. The line indicate not the point of origin but the flame that is over the point of origin. thus, you have to consider the line indicate the flame when you do 3-dimensional analysis.