This study focuses on developing diagnostic compositions, kits, and information provision methods for identifying species-specific genes in domestically residing Reticulitermes speratus and Reticulitermes kanmonensis, as well as the recently introduced Cryptotermes domesticus. The core innovation of this invention lies in the utilization of species-specific genetic markers to facilitate rapid and accurate species identification using a PCR (polymerase chain reaction)-based diagnostic technique. This approach enables swift identification of termites at quarantine stages, contributing to efficient management of imported goods and minimizing ecological and economic damages caused by termites. Through genome analysis of termites, this research has identified candidate species-specific genetic markers, developed diagnostic compositions and kits based on these markers, and proposed a rapid diagnostic method capable of determining termite species within a day, optimally within three hours. This invention provides a groundbreaking tool for termite management and research, significantly contributing to pest control and biodiversity conservation efforts.
2023년에 국내에서 보고된 적이 없던 외래흰개미 3종이 각각 인천, 서울, 창원에서 발견되었다. 종 동정 결과, 인천에서 출현한 종(Coptotermes gestroi)은 Subterranean termite로 밝혀졌으며, 서울과 창원에서 출현한 종 (Cryptotermes domesticus, Incisitermes minor)은 Drywood termite로 밝혀졌다. 본래 우리나라에는 Subterranean termite 흰개미가 2종이 분포하고 있다고 보고되어 있었으나, 새로운 과 또는 속의 외래흰개미가 발견되면서 국민 들의 우려가 커지고 있다. 국내에서는 일부 외래흰개미를 법적으로 지정(유입주의 생물 2종, 관리병해충 15종)하 여 관리하고 있는데, 해당 흰개미와 그 외의 신규 흰개미의 출현으로 인한 피해가 우려되는 상황이다. 본 연구에서 는 ‘23년 유입된 3종 및 기존 법정관리 외래흰개미, 그리고 국내 유입과 위해가 우려되는 외래흰개미 5과 (Archotermopsidae, Kalotermitidae, Rhinotermitidae, Termitidae, Termopsidae)를 조사하였으며, 이들의 생태적 특 징과 외국의 사례를 통해 외래흰개미 대비 방법에 대하여 고찰하였다.
한국의 목조건축문화유산은 상당수가 산림에 인접하여 흰개미에 의한 피해에 취약하다. 국내 흰개미 방제법은 살충제 접촉을 통한 화학적 방제법이 주로 이용되며, 방제 기간을 단축하기 위해서는 흰개미를 빠르게 약제까지 유인시킬 방법이 필요하다. 본 연구에서는 한국 서식 흰개미 에 대한 유인물질로 이산화탄소를 선정하여 유인여부 및 적절한 유인농도를 탐색하였으며, 지중 환경에서의 유인효력 기초평가를 진행하였다. 평가를 통해 흰개미에 대한 이산화탄소의 유인 효과를 확인하였으며, 이산화탄소 농도 10% 이하의 유효한 범위를 선정하였다. 또한 지중에서의 유인 효과를 확인함으로써 지중 환경에서의 적용 가능성을 파악하였다. 향후 현장에서 이산화탄소의 적용방안을 연구함으로써, 목조건축문화유 산의 흰개미 방제 시 개선된 방제 효과를 가질 수 있을 것으로 사료된다.
Quantitative analysis of termites damage is important in terms of conservation and maintenance of wooden cultural heritage buildings, because termites makes cavities and decreases the section area of wooden structural members. The purpose of this study is to forecast the range and spread of termites damage in the wooden structural members by using ultrasonic pulse velocity method.
Ultrasonic pulse velocity has been used as one of non-destructive test to analysis the internal defect by using difference velocity between medium material and cavity. This method would be effective to analysis termites damages. From the result of the ultrasonic velocity test, the loss rate of area effected by termites damage had a strong correlation with ultrasonic velocity. And it is possible to predict the loss rate of area from by termites damage by using regression equation in the case of structural member of fine tree.
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.
Subterranean termites build extensive underground galleries consisting of elaborate tunnels and channels to forage food resources. Diverse soil conditions surrounding the tunnels, such as soil density, may cause irregularities in the size and shape of the tunnels, and termites are likely to encounter a number of tunnel irregularities while traveling. Considering the tunnel length, how termites respond to an irregularity is likely to affect their movement efficiency, and this in turn is directly correlated to their foraging efficiency. To understand the response of termites, we designed an artificial linear tunnel with rectangular irregularities in a 2-D arena. The tunnel widths, W, were 3 and 4 mm. The rectangular irregularities were 2 mm in width and of varying heights H (2, 1, 0, -1, and -2 mm). The positive and negative sign of H represents a convex and concave structure, respectively. We systematically observed the movement of termites, Coptotermes formosanus Shiraki, at the irregularity and quantified the time needed, τ, for a termite to pass the irregularity. The time τ was shorter for (W, H) = (3, 0) and (3, -1) than for (W, H) = (3, 1), (3, 2), and (3, -2). The time τ was longer for (W, H) = (4, -1), and (4, -2), than for (W, H) = (4, 0), (4, 1) and (4, 2). Four types of behaviors explained the response to the irregularity. The implications of these findings are briefly discussed in relation to termite foraging efficiency.
In the real world, most of biological systems that follow Markov process have internal states which are unobservable, so called hidden states. However, although the states could not be directly observed, events emitted under any hidden states would often be observable. It infers that a lot of biological systems might be simulated by hidden Markov model (HMM). To date, many studies tried to apply the HMM for monitoring and describing of animal behaviors. In this study, we attempted to build a HMM that emulates the traveling behavior of subterranean termites in the artificial tunnels with varying width and curvature, based on the empirical data obtained from our previous study that explored the relationship between subterranean termite's movement efficiency and the geometric pattern of their tunnels.
Subterranean termites construct complicated tunnel network for foraging below the ground. Thus, they often encounter a number of tunnel intersections during their moving from place to place in the network. In order to understand how termites respond to the intersections, we artificially excavated two tunnels intersected with 90° degree in soil-filled arenas. The two tunnels had the width of W1 and W2 (=2, 3, and 4mm), respectively. We systematically observed the response behavior of advancing termites to the intersection with the combination of W1 and W2, (W1, W2). For (W1, W2)=(2, 2) and (3, 3), the advancing termites passed the intersection without directional changes because it was difficult for termites to bend their body to change their moving direction due to the small-sized width. For (W1, W2)=(4, 4), the termites statistically-equally chose the three directions, left, right, and straight, which was due to the fact that the intersection provided enough space for termites to bend. For (W1, W2)=(2, 3), (2, 4), and (3, 4), termites, advancing in narrower tunnels, tended considerably to turn right or left, while termites, advancing in wider tunnels, were favorably inclined to go straight. These results can be understood by considering the relationship between termite body length and tunnel width as explained for the cases of W1=W2. In addition, we briefly discussed our findings in relation to termite foraging efficiency.
Subterranean termites construct underground tunnels, tens to hundreds of meters in length, in order to search for and transport resources. Diverse soil conditions surrounding the tunnels, such as soil pores and differing moisture concentrations, may cause different sized- and shaped-irregularities in the tunnels. To understand how individual termites respond to the irregularities, the present study monitored the movement of termites, Coptotermes formosanus Shiraki, in artificially excavated tunnels with rectangular irregularities of varying sizes in twodimensional sand substrates. Termites tunneled at some of the irregularities and not at the others. The tunneling or non-tunneling behavior resulted from four different responses. The non-tunneling response may result from a behavioral adaptation that allows termites to avoid wasting energy that may be used in foraging.
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.