Understanding molting process in subterranean termites is a critical step to implement successful control program as chitin synthesis inhibitor baits interfere molting process of termites. In the present study, we report detailed molting process in Reticulitermes speratus kyushuensis Morimoto, 1968 that foraging workers start fasting period 5 days after they were collected and finished their entire molting process for the next 5 to 6 days. Ecdysis took less than an hour, specifically 9.2 ± 4.9 minutes from jack-knife posture to separation of the antenna and 36.6 ± 8.5 minutes from separation of the antenna to regain mobility. We believed relatively short time window of molting process in R. speratus kyushuensis may affect lengthy colony elimination time.

We have determined the mitochondrial genome of Reticulitermes speratus kyushuensis Morimoto, 1968. The total length of the R. speratus kyushuensis is 15,898 bp with 65.3% A + T content. It consists of 13 protein–coding, 22 tRNA, 2 rRNA genes and an A+T–rich control region. All the protein–coding genes used ATN as start codon. But the stop codons were TAA, TAG, and an incomplete termination codon (T) abutting an adjacent tRNA gene. The A+T–rich control region was 1,105 bp in length with 67.8% A + T content

Field surveys for the genus Reticulitermes were conducted from 2013 to 2014 in Korea, and the results were compared with published data of the genus Reticulitermes. Totally, two species, R. speratus kyushuensis and R. kanmonensis were collected from several provinces, and R.kanmonensis is newly confirmed as an unrecorded species in Korea. The R. speratus kyushuensis was mainly collected in various trees, showing 0-2% genetic divergences; whereas, the R. kanmonensis was collected in pine woods of western regions, Gunsan, Wanju, Iksan (Jeollabuk-do), and Seocheon (Chungcheonnam-do). In the morphological comparison, R. kanmonensis is distinguished from R. speratus kyushuensis by more than 15 setae on pronotum and reveals 7.0% genetic difference (in a mitochondrial COII gene) from R. speratus kyushuensis in the molecular comparison.

Subterranean termites bring enormous damages on wooden buildings and cultural properties (e.g., ancient temple, historical documents). Due to temperature increase in climate, there is a strong potential for termites to disperse in temperate zone widely. Since subterranean termites construct complex nests, diverging vertically from the horizontal network, we measured “movement efficiency” to address how fast termites pass through the tunnels in different slopes. Artificial tunnels were constructed on observation arena (curvature of 3cm) across different slopes (20o, 40o and 60o between the plate and ground). The passing time of the tunnel by single individual was subsequently measured. When the angle was 20o, there was no significant difference in movement efficiency (7.37 ± 1.07sec) compared with the case without slope (7.84 ± 1.35sec). As the angle was further increased, however, passing time increased. The mean time was approximately 8.79 ± 2.45sec and 14.83 ± 2.479sec at angles 40o and 60o respectively. It was also noteworthy that the termites showed the tendency to avoid entering into the tunnel. Optimization in nesting was further discussed between cost (i.e., energy requirement) and benefit (i.e., foraging efficiency) in tunnel construction.

Part of a field survey to assess the extent of damage by termite (Reticulitermes speratus kyushuensis Morimoto), termite samples were collected from various locations of Korea from 2009 to 2011. During the study period, we firstly discovered Reticulitermes species on Jeju island, and partial sequences of mitochondrial COII gene, which is proved useful to study phylogenetic relationships of termites were investigated. Also, morphological characteristics of the collected samples were compared with previous reports. According to the result of taxonomic study and comparative sequence analysis, it was identified as Reticulitermes speratus kyushuensis Morimoto, and this is first report of R. s. kyushuensis from Jeju island in Korea which can be used as estimation of population structure and tool of control strategy.

Termites are a major problem for home and business owners around the world. Termites gnaw through wood and burrow under the foundations of buildings causing a great deal of damage to the structure of the building. Phosphine (PH3) is very effective fumigant and is widely used to control pests. PH3 rapidly penetrate through treated material, so it replaced many conventional fumigants for treatment of durable materials. In this study, we have investigated the effectiveness of PH3 fumigation on wood pests, Reticulitermes speratus kyushuensis. We evaluated two bioassay methods; wooden cube (10×10×10 cm) and insect breeding dish in comparison with effectiveness of PH3 penetrations into the timber block. Fumigation to adults of R. speratus was carried in a desiccator system for 24 h at 5 and 15℃. As a result, LC99 of PH3 to R. speratus in wooden cubes and insect breeding dish at 5℃ was 0.183 and 0.177 mg L-1, respectively. LC99 of PH3 in wooden cubes and insect breeding dish at 15℃ was 0.077 and 0.078 mg L-1, respectively. There were no significant differences between the two bioassay methods. Thess results indicate that PH3 described herein merit further study as potential fumigants for termite control.

Field survey to estimate extent of damage to Reticulitermes species were conducted from 2009 through 2011 in the various locations of Korea. We discovered Reticulitermes species from three different locations of Jeju island. Partial COII sequences of mt DNA and morphological characters were collected and compared with previous reports. As result of comparative sequence analysis and taxonomic study, it was identified as Reticulitermes speratus kyushuensis Morimoto 1968 and this is first report of Reticulitermes speratus kyushuensis from Jeju island in Korea which can be used as estimation of population structure and tool of control strategy.

Termites (Isoptera) are classified into approximately 3,106 species. In Korea, only one species has been identified, which is Reticulitermes speratus kyushuensis Morimoto. The termite, a social insect, is known to play an important role in nutrient cycling of the ecosystem, although some species of termites are well-known pests attacking wooden structures or any plant materials. However, there is a lack of research about termites in Korea, including aspects such the taxonomy, physiology, and ecology of termites. This study was carried out to provide valuable basic data on the ecological role of termites in an ecosystem in Korea for the future studies. For the experiments, soil and termite samples were randomly collected from Mt. Hwajang located in Jikdong-ri, Eonyang-eup, Ulju-gun, Korea between October 5 and 30, 2015. Analysis results showed that there were no significant differences in soil chemical properties between the soil samples just after air-drying and one year elapsed without any treatment. The treated soil with termites showed significantly higher than the soil without termite treatment. Chemical properties of total nitrogen, organic matter, available phosphate, pH, Calcium(Ca), Potassium(K) and Magnesium(Mg) in soil treated with termites were 1.11 ± 0.3 g kg-1, 43.3 ± 12.4 g kg-1, 27.4 ± 2.9 mg kg-1, 4.56 ± 0.2, 0.82 ± 0.2 cmolc kg-1, 3.18 ± 1.4 cmolc kg-1, 1.73 ± 1.1 cmolc kg-1, respectively. The values of soil property of without termite treatment were 0.56 ± 0.1 g kg-1, 30.5 ± 3.1 g kg-1, 24.0 ± 4.7 mg kg-1, 4.09 ± 0.1, 0.71 ± 0.2 cmolc kg-1, 2.88 ± 1.5 cmolc kg-1, 1.30 ± 0.7 cmolc kg-1, respectively. These results suggest that inhabitation of termites could improve soil chemical properties in an ecosystem.