• 제목/요약/키워드: termite

검색결과 110건 처리시간 0.023초

Radial Variation in Selected Wood Properties of Indonesian Merkusii Pine

  • Darmawan, Wayan;Nandika, Dodi;Afaf, Britty Datin Hasna;Rahayu, Istie;Lumongga, Dumasari
    • Journal of the Korean Wood Science and Technology
    • /
    • 제46권4호
    • /
    • pp.323-337
    • /
    • 2018
  • Merkusii pine wood (Pinus merkusii) was extensively planted throughout Indonesia, where it is only indigenous in northern Sumatera, by the Dutch during colonial times. The demand for this wood species, especially in the domestic market, has increased notably, despite its limited durability regarding decay resistance. The purpose of this study was to investigate the occurrence of juvenile and mature wood on merkusii pine and to analyze its radial features from pith to bark based on density, shrinkage, static bending in modulus of rupture and modulus of elasticity, fiber length, microfibril angle, and durability. A segmented modeling approach was used to find the juvenile-mature transition. The graveyard test was performed to characterize the termite resistance from pith to bark of merkusii pine. The maturations were estimated to start at radial increments of 15 cm from the pith by fiber length and of 12 cm from the pith by microfibril angle. The projected figures for the proportion of juvenile wood at breast height were around 65%. The results also indicate that the pine wood was $0.52g/cm^3$ in density, 1.45 in coefficient of anisotropy, which indicates its good stability, 7597 MPa in modulus of elasticity, and 63 MPa in modulus of rupture. Natural durability against subterranean termite of the merkusii pine wood was rated to be grade 4 to 0 from pith to bark. However, after being treated by Entiblu and Enborer preservatives, its rating increased to grade 10 to 9.

흰개미 테리토리행동 연구를 위한 시뮬레이션 모델 (A Simulation Model for the Study of the Territorial Behavior of Subterranean Termites)

  • 전원주;이상희
    • 한국시뮬레이션학회논문지
    • /
    • 제21권2호
    • /
    • pp.1-9
    • /
    • 2012
  • 흰개미는 땅 아래 서식하면서 네트워크형태의 터널 구조물을 만들어 먹이자원을 획득한다. 종에 따라서는 지하 150m 깊이까지 터널을 형성하기도 하고, 목재의 섬유질을 찾기 위해 종종 지표면까지 이동하기도 하는데, 이로 인해 목재로 지어진 건축물 특히 가옥에 엄청난 피해를 끼친다. 지구 온난화에 의한 온도상승으로 흰개미가 활동하기에 적합한 고온 지역이 넓어지며 이와 같은 피해는 꾸준히 증가하고 있다. 이 피해규모는 흰개미 테리토리영역의 크기 및 그 분포와 밀접한 관련을 가지고 있다. 흰개미 본 연구에서는 흰개미 두 종(Coptotermes formosanus (Shiraki) 와 Reticulitermesflavipes (Kollar))에 대한 테리토리행동을 시뮬레이션 할 수 있는 실험치 기반의 모델을 제안하였다. 모델은 콜로니별로 형성하는 터널네트워크의 성장부분과, 서로 다른 콜로니 사이의 터널교차를 고려한 영역성 부분, 이렇게 두 부분으로 구성된다. 본 모델을 이용하여 터널 성장확률에 따라 테리토리간 경쟁이 어떻게 변하는지에 대한 간단한 결과를 보여 주었다.

호주 Century 아연 광산에서의 MT 탐사 (MT surveys near Century Zinc Mine, NW Queensland, Australia)

  • 이태종;이성곤;송윤호
    • 지구물리와물리탐사
    • /
    • 제10권4호
    • /
    • pp.345-352
    • /
    • 2007
  • 호주 Century 광산 주변에서 2차원 MT 탐사를 수행하였다. 현장으로부터 약 80 km 떨어진 Gregory Downs(RR_GREG)에 원거리 기준점을 설치, 운영하고 이 자료를 이용하여 양질의 탐사자료의 획득이 가능하였다. 이와 동시에 현장으로부터 약 6,400 km 떨어진 일본 Esashi (RR_ESS)에서 측정된 수평 자기장 자료를 이용하여 원거리 기준 자료처리를 수행한 결과 자기장의 coherency가 낮아 원거리 기준점 자료로 사용하기에는 적합하지 않았다. Century 광산의 주변에서 수행된 측선 탐사자료의 2차원 및 3차원 역산 결과 연구지역의 전반적인 심부 지질구조를 잘 나타내었으며, 탐사의 주된 목표인 Termite Range Fault는 측선의 북쪽에 나타나는 저비저항층과 남쪽에 나타나는 고비저항층의 경계면을 이루면서 북동쪽으로 약간 경사진 것으로 해석되었다.

일본흰개미 (Reticulitermes speratus)의 Odorant-Binding Proteins (OBPs) 발현 양상 (Expression Patterns of Odorant-Binding Proteins (OBPs) in a Termite (Reticulitermes speratus))

  • 나종범;김재경;김규혁
    • Journal of the Korean Wood Science and Technology
    • /
    • 제33권1호통권129호
    • /
    • pp.1-6
    • /
    • 2005
  • 본 연구는 국내에 서식하는 일본흰개미(Reticulitermes speratus)의 생리적 특성에 관한 기초연구로서 흰개미의 커뮤니케이션 수단인 페로몬을 후각수용기로 이동시키는 odorant-binding proteins (OBPs)의 발현 양상을 조사하기 위해서 수행되었다. 경남 진주에서 채집된 일개미와 병정개미로부터 더듬이와 다리를 각각 떼어낸 후 OBP가 존재하는지 확인하기 위하여 RT-PCR을 수행하였다. 일개미의 경우 OBP-1의 발현은 더듬이와 다리에서 모두 관찰되었으며, OBP-2와 OBP-3의 발현은 오직 더듬이에서만 관찰할 수 있었다. 병정개미의 경우 OBP-1의 발현은 일개미에서와 마찬가지로 더듬이와 다리 모두에서 관찰할 수 있었으나, OBP-2가 관찰되지 않았으며, 일개미의 더듬이에서만 관찰되었던 OBP-3의 발현을 병정개미에서는 더듬이와 다리 모두에서 볼 수 있었다. 일개미와 병정개미에서 OBP 발현 양상의 차이는 그들의 역할에 따른 분화적 특이성에 기인한 것으로 생각된다.

Elizabethkingia miricola BM10, a New Symbiotic Bacterium Isolated from the Hindgut of the Termite Reticulitermes speratus KMT001

  • LEE, Dongmin;KIM, Young-Kyoon;KIM, Yeong-Suk;KIM, Tae-Jong
    • Journal of the Korean Wood Science and Technology
    • /
    • 제47권6호
    • /
    • pp.692-699
    • /
    • 2019
  • Elizabethkingia miricola BM10, a symbiotic bacterium, has been isolated from the hindgut of Reticulitermes speratus KMT001, a termite which occurs on Bukhan Mountain in Seoul, Korea. This strain demonstrated a symbiotic characteristic, in that it lacked endo-${\beta}$-1,4-glucanase activity, in a previous study. The major fatty acids of E. miricola BM10 were iso-$C_{15:0}$, iso-$C_{17:0}$ 3-OH, and summed feature 3 (iso-$C_{16:1}{\omega}7c/C_{16:1}{\omega}6c$). The content of iso-$C_{17:0}$ 3-OH was higher, while those of ECL 13.566, iso-$C_{17:11}{\omega}9c$, and summed feature 4 were lower than the other three type-strains of the Elizabethkingia genus. The 16S rRNA phylogenetic analysis confirmed that E. miricola BM10 is a new species. The whole genome of E. miricola BM10 was sequenced. The average nucleotide identity of strain BM10 as evaluated by pairwise comparison with E. anophelis R26, E. meningoseptica ATCC 13253, and E. miricola GTC 862 was shown to be 91.5%, 81.2%, and 94.29%, respectively. Based on our study results, E. miricola BM10 appears to represent a new strain of the genus Elizabethkingia.

Xylanolytic and Ethanologenic Potential of Gut Associated Yeasts from Different Species of Termites from India

  • Tiwari, Snigdha;Avchar, Rameshwar;Arora, Riya;Lanjekar, Vikram;Dhakephalkar, Prashant K.;Dagar, Sumit S.;Baghela, Abhishek
    • Mycobiology
    • /
    • 제48권6호
    • /
    • pp.501-511
    • /
    • 2020
  • Xylophagous termites are capable of degrading lignocellulose by symbiotic gut microorganisms along with the host's indigenous enzymes. Therefore, the termite gut might be a potential niche to obtain natural yeasts with celluloytic, xylanolytic and ethanologenic traits required for bioethanol production from lignocellulosic biomass. In this study, we cultured 79 yeasts from three different termites viz. Coptotermes heimi, Odontotermes javanicus and Odontotermes obesus. After suitable screening methods, we identified 53 yeasts, which belonged to 10 genera and 16 different species of both ascomycetous and basidiomycetous yeasts. Most yeasts in the present study represent their first-ever isolation from the termite gut. Representative strains of identified yeasts were evaluated for their cellulolytic, xylanolytic, and ethanologenic abilities. None of the isolates showed cellulase activity; 22 showed xylanolytic activity, while six produced substantial quantities of ethanol. Among xylanolytic cultures, Pseudozyma hubeiensis STAG 1.7 and Hannaella pagnoccae STAG 1.14 produced 1.31 and 1.17 IU of xylanase. Among ethanologenic yeasts, the strains belonging to genera Candida and Kodamaea produced high amount of ethanol. Overall, highest ethanol level of 4.42 g/L was produced by Candida tropicalis TS32 using 1% glucose, which increased up to 22.92 g/L at 35 ℃, pH 4.5 with 5% glucose. Fermentation of rice straw hydrolysate gave 8.95 g/l of ethanol with a yield of 0.42 g/g using the strain TS32. Our study highlights the gut of wood-feeding termites as a potential source of diverse yeasts that would be useful in the production of xylanase and bioethanol.

Resistance of Polystyrene-Impregnated Glued Laminated Lumbers after Exposure to Subterranean Termites in a Field

  • Dede HERMAWAN;Mahdi MUBAROK;Imam Busyra ABDILLAH;Yusuf Sudo HADI;Cossey YOSI;Aujchariya CHOTIKHUN;Rohmah PARI;Gustan PARI
    • Journal of the Korean Wood Science and Technology
    • /
    • 제52권1호
    • /
    • pp.70-86
    • /
    • 2024
  • Termites are a serious threat to wood-based products in Indonesia. This study investigated the termite resistant property of glulam made from polystyrene-modified wood. Three tropical fast-growing wood species, namely mangium (Acacia mangium), manii (Maesopsis eminii), and rubberwood (Hevea brasiliensis), were prepared for flat-sawn laminae. After getting air-dried condition, the laminae were impregnated with polystyrene using potassium peroxydisulphate as a catalyst followed by polymerization at 80℃. Polystyrene-impregnated and control glued-laminated lumbers (glulams) were manufactured, and solid wood was provided. Three wood species and three wood products with six replicates were exposed in a field in Bogor, Indonesia, for four months, and before the tests, their density and moisture content were measured. At the end of the field tests, the weight loss and protection levels of each test sample were determined. A completely randomized factorial design was used for data analysis. The weight percentage gains for mangium, manii, and rubberwood were 22.30%, 18.22%, and 10.44%, respectively. The results showed that manii belonged to low-density wood, whereas the other two woods were medium-density wood, and the moisture content was the ambient moisture content, typical of the Bogor area. Regarding weight loss and protection level, mangium was the most durable against subterranean termite attacks, followed by rubberwood and manii. Among the wood products, the polystyrene-impregnated glulam presented the highest durability, followed by the control glulam and solid wood. Therefore, mangium and rubberwood polystyrene-impregnated glulams are recommended for future product development.

국내 흰개미(Reticulitermes speratus kyushuensis Morimoto)에 의한 토양의 화학적 특성 변화 (Changes in Chemical Property of Soil Affected by Termites (Reticulitermes speratus kyushuensis Morimoto) in Korea)

  • 성세하;김근기;홍창오;박현철
    • 한국환경과학회지
    • /
    • 제26권6호
    • /
    • pp.789-795
    • /
    • 2017
  • 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 $1.11{\pm}0.3gkg^{-1}$, $43.3{\pm}12.4gkg^{-1}$, $27.4{\pm}2.9mgkg^{-1}$, $4.56{\pm}0.2$, $0.82{\pm}0.2cmol_ckg^{-1}$, $3.18{\pm}1.4cmol_ckg^{-1}$, $1.73{\pm}1.1cmol_ckg^{-1}$, respectively. The values of soil property of without termite treatment were $0.56{\pm}0.1gkg^{-1}$, $30.5{\pm}3.1gkg^{-1}$, $24.0{\pm}4.7 mgkg^{-1}$, $4.09{\pm}0.1$, $0.71{\pm}0.2cmol_ckg^{-1}$, $2.88{\pm}1.5cmol_ckg^{-1}$, $1.30{\pm}0.7cmol_ckg^{-1}$, respectively. These results suggest that inhabitation of termites could improve soil chemical properties in an ecosystem.

목조문화재의 원형보존을 위한 충해 방제방안 (Pest control managements for preservation of wooden cultural properties)

  • 이규식;정소영;정용재
    • 보존과학연구
    • /
    • 통권21호
    • /
    • pp.5-55
    • /
    • 2000
  • The cultural properties are damaged by various causes according to the characteristics of material, the condition of preservation, and the period of time. Especially, biodeterioration makes lots of damages in organic properties than inorganic ones. The damages of wooden cultural properties by insects usually are caused by the three orders; Isoptera, Coleoptera, and Hymenoptera. As the result of investigation on the state of 141 buildings of wooden cultural properties in 1999, some of them were damaged by many kinds off actors; wasp, powder post beetle, cigarette beetle, termite, decay, and physical cracking. And it was found that the patterns of damages were related to species-specific habits of insects. There are several methods of pest control for the prevention of wooden cultural properties from damages caused by insects. Those are as follows; physical control, chemical control, biological control, and integrated pest management. When insects and fungi were detected at the wooden buildings, the fumigation is best treatment to stop biodeterioration. And then, wood materials also need to be treated with insecticidal and antiseptic chemicals to avoid a reinfestation, because the fumigant is volatile. The six commercial chemicals which are applied to the insecticidal and antiseptic treatment of wooden cultural properties were purchased to test their abilities. According to the comparative results of efficacy of them in laboratory, chemical D showed excellent efficacy in all items, including antiseptic and termiticidal items. The goal of these pest controls is to protect wooden buildings from insects and microorganisms. The most effective method used currently is chemical control(fumigation, insecticidal and anticeptic chemical treatment), but it has to be treated periodically to control pest effectively. Recently environmentally-friendly control methods such as bait system or biological treatments are replacing traditional barrier treatments using large amounts of chemicals. Especially, termite is a social insect which makes a colony. Although a building with fumigation treatment is safe for a while, once attacked building has a risk of damage by reinfestation of termite. Therefore, to control termites from damaged building, the entire colony including reproductives(queen and king) and larvae around buildings must beeliminated. Bait system can be used as a preventive measure in early detection of them through termites colony monitoring and baiting. It would be the most effective for termite control if bait system would be used together with the chemical controls.

  • PDF

열처리 조건이 목재의 색상 변화 및 흰개미 저항성에 미치는 영향 (Effect of Heat Treatment Conditions on Color Change and Termite Resistance of Heat-Treated Wood)

  • 나종범;김기범;임경훈
    • Journal of the Korean Wood Science and Technology
    • /
    • 제40권6호
    • /
    • pp.370-377
    • /
    • 2012
  • 잣나무(Pinus koraiensis S. et Z.)와 로지폴소나무(Pinus contorta Dougl)를 이용하여 열처리 목재를 제조한 후 처리조건에 따른 재색변화를 조사하였다. 반응표면분석법에 따라 설정된 9가지 처리조건(처리온도 : 170, 180, 200, 220, $230^{\circ}C$, 처리시간: 90, 120, 180, 240, 270 min.)에서 열처리 시편들을 제조하였으며, 색차계를 이용하여 재색을 측정한 후 흰개미 저항성을 평가하기 위하여 진주에 설치된 흰개미 시험장에서 6개월 동안 야외노출시험을 실시하였다. 처리온도와 처리시간이 증가함에 따라 명도가 감소하였으며 감소폭은 시간보다 온도에 의한 영향이 더 큰 것으로 나타났다. 미국국립표준국(National Bureau of Standards : NBS)에서 제시된 방식에 의해 평가된 색차를 처리온도와 처리시간의 함수로 표현한 반응표면분석모델은 잣나무의 경우 $R^2$의 값이 0.92, 로지폴파인의 경우 0.88로 열처리조건에 따른 색채의 예측가능성을 보여주었다. 6개월의 야외시험결과 열처리 조건에 상관없이 흰개미 가해가 심하게 발생된 것으로 나타났는데, 이는 제조된 열처리 목재의 흰개미 저항성이 야외에 사용하기에 적합하지 않다는 것을 보여준다.