This study was conducted to investigate the effect of attractant mixture on capture efficacy on Platypus koryoensis, an insect vector of oak wilt disease in Korea. We compared three treatments, such as Citral:EtOH(5:95), EtOH, and no attractant. In order to compare the attractants, Lindgren multi-funnel traps were installed in three oak forests in the Incheon Grand Park. A total of 18 traps was installed, and traps were replaced biweekly. A total of 236, 85, and 25 individuals were collected in Citral:EtOH, EtOH, and control, respectively. Although a mixture of Citral:EtOH seems more effective in attracting P. koryoensis, number of individuals of P. koryoensis caught by attractants was different according to study sites.

많은 산림해충들은 목재검역에서 문제가 되고 있어 포스핀(PH3)을 이용하여 광릉긴나무좀, 왕녹나무좀, 노랑애나무좀의 성충에 대한 살충 활성을 조사하였다. 3종의 나무좀류에 대하여 99% 살충활성을 보이는 LCT값은 각각 3.192 (광릉긴나무좀), 0.994 (왕녹나무좀), 0.501 mg ‧ h/L (노랑애나무좀) 순으로 나타났다. 포스핀을 처리한 3종의 나무좀류는 시간이 지남에 따라 살충활성도 증가하였다. 특히 광릉긴나무좀에서 는 0.4 mg/L 이상의 농도에서 약제처리 7일 후에 100%의 사충률을 보였다. 이러한 결과로 볼 때 포스핀이 3종의 목재해충 성충에 대해 메칠브 로마이드의 대체훈증제로 이용될 수 있을 것으로 판단된다.

Oak wilt disease caused by Raffaelea quercus-mongolicae is one of the serious diseases in Korea. Infected trees showed wilting and discolourations on the cambium when the bark of a tree is peeled, since it deters moisture migration. Raffaelea quercus-mongolicae is vectored by Platypus koryoensis. In this regard, it was assumed that there might be a positive correlation between the number of gallery generated by P. koryoensis and the level of damage on the infected tree by the oak wilt disease. In order to link the occurrence of dead oak trees with the number of galleries produced by P. koryoensis, five regions (Incheon, Anyang, Gwangmyeong, Icheon and Gimhae) were selected in Korea. The number of galleries on Mongolian oaks produced by attack of P. koryoensis was counted in four directions between 50cm and 100cm from the ground level. Furthermore, Vegetation was investigated from the area where the oak wilt disease occurred, and a data logger was set up to collect data including temperature and relative humidity in each region at the elevation between 100~200m. A significant difference was observed in the number of galleries made by the insect vector between dead trees and trees infected with oak wilt disease, while no difference was observed from the vegetation on the area investigated. We will further investigate as to whether climate factors might contribute to the density and the successful invasions of the insect vector to the oak trees.

Korean oak wilt (KOW) caused by Raffaelea quercus-mongolicae and its vector, Platypus koryoensis is one of the most severe forest pests in Korea. In spite of its importance, information about dispersal of P. koryeonsis is very limited. In here, a hypothesis related to long distance dispersal (LDD) of KOW reflecting behavior of P. koryoensis is proposed. When attack density of P. koryoensis increased, location of entry holes in the trunk moved to upward. The individuals which escaped from entry holes in upper trunk had potential to fly upper part of trees and they flew longer distance probably by aid of winds. We suggested that this density dependent dispersal of the beetle explain the spatial dynamics of KOW in large scale.

The environmental friendly control of Platypus koryoensis (Murayama), a vector of oak wilt disease, was investigated using citral. To develop an effective attracted trap was performed in Yeoju (semi-field), Gunpo (field) and Cheongju (field). Using a ratio of four attractant (ethanol 100%, ethanol+citral (90:10, 95:5), ethanol+citral+hexane extract of Quercus mongolica (90:5:5)) was investigated attractive effects for the Platypus koryoensis. Most P. koryoensis were attracted to mixture of ethanol+citral (95:5). As a result, when using a citral in a certain concentration is would be able to develop an effective and environmental friendly control agent.

참나무시들음병 매개충인 광릉긴나무좀(Platypus koryoensis (Murayama))(Coleoptera: Platypodidae)의 에탄올과 신갈나무 수피 추출 물의 유인효과에 대하여 조사하였다. 유인트랩과 유인목 시험에서는 에탄올과 신갈나무 수피 추출물을 사용한 처리구가 대조구(무처리)보다 높 은 유인효과를 나타내었으나, 두 유인제 간의 유의성은 찾지 못하였다. 유인목의 직경별 침입공 수를 비교한 결과, 침입공 수는 직경이 클수록 증 가하였다. 유인목의 횡단면 상부와 하부 침입공 수를 비교한 결과, 상부보다 하부에 침입공이 많았고, 통계적으로 유의한 차이(p<0.05)를 나타내 었는데, 이는 직사광선에 의한 건조가 적은 하부가 매개충의 먹이가 되는 미생물 번식에 유리하기 때문이라고 추정되었다. 결과적으로 신갈나무 수피 추출물보다 비용 면에서 경제적인 에탄올이 광릉긴나무좀 모니터링 및 방제에 효율적으로 활용될 수 있을 것이며, 신갈나무 수피 추출물은 효율을 높일 수 있는 계속적인 연구의 필요성이 있다.

Oak wilt disease caused by Raffaelea quercus-mongolicae was firstly reported at Sungnam city, Gyeonggi province, Korea, in 2004, and spread to several area of Korean peninsula. Raffaelea quercus-monglicae was transferred by ambrosia beetle, Platypus koryoensis, and caused oak wilt disease. Because oak wilt disease is mediated by ambrosia beetle, Platypus koryoensis, control of this disease concentrates on managing the ambrosia beetle population. Until now, several control methods such as felling and fumigation of dead oak trees with metham sodium, sticky-roll trap for catching emerged or attacking beetles, and oak tree logs for attraction of ambrosia beetle have been mainly used to control oak wilt disease in Korea. Although effective, current control methods have many side effects. Felling of oak tree is very difficult and dangerous to workers. To reduce the side effects of conventional control methods, new and safe types of control method for managing the ambrosia beetle populations are essential. In this study, we investigated the number of caught beetles, effect of height and direction of collection bottles by using newly developed mass capturing device for P. koryoensis to evaluate the effectiveness of this device as practical use in field.

The dispersal distance and the flight behaviour of adult Platypus koryoensis were examined using mark-release-recapture experiment in central Korea in 2013. Sticky traps were attached to the trunks of oak trees toward release point and opposite direction up to 48.8m from the release point. For each direction, two traps were attached on upper (1.5m from ground) and lower (0.5m from ground) trunk. Platypus koryoensis which emerged within 24 hours were marked with fluorescent powder and released at 11:00 a.m. The number of recaptured beetles was counted after 30 and 90 minutes after release. The experiment was replicated three times on 20, 21, and 26 June. The numbers of beetles released were 299, 810, and 208, respectively. Recapture rates at 90 minutes after release on 20, 21, and 26 June were 0.09, 0.06, and 0.03, respectively. More than 85 percent of recaptured beetles were caught in 30m. The numbers of beetles caught by sticky traps in upper and lower trunk were not significantly different, indicating that P. koryoensis do not hover but just land and move to explore suitable for living site in trunk when they attack oak tree. The valley breeze which drive upward the valleys and mountain slopes in the daytime blew during experiment periods and maximum flight distance of P. koryoensis was 43m, even though the beetles flew against the wind.

Escape pattern of the ambrosia beetle Platypus koryoensis (Murayama) based on individual gallery was investigated. The survey was conducted in four oak forests located in Chuncheon, Hanam, Paju and Seongnam, and escape patterns from individual gallery were surveyed using emergence trap attached at the entrances of galleries formed in 2010. The number of adults caught in each trap was periodically counted from May 2011 to September 2012. The adults ambrosia beetle was caught over two years after infestation. The escape patterns in the first and second year after infestation showed different types; in the first year, escape of adults from gallery was observed one or two times whereas escape from gallery was observed two times in the second year with variation in aspect of escape density and timing. Moreover, variations in escape pattern between trees or between galleries in the same tree was observed. Colonization success rate in living tree was higher than that of dead tree, but the number of progeny per gallery in living tree was lower than that of dead tree. Colonization success rate in the galleries of second year was lower than that of first year, but the number of progeny per gallery of second year was higher than that of first year.

The diurnal flight pattern of Platypus koryoensis (Murayama) was examined using sticky traps attached to the trunks of oak trees in central Korea in 2011. The flight activities of the beetle were estimated on the basis of 2-h interval trap catches from 05:00 to 17:00, between June 9 and July 21 (the peak flight period of the beetle). Peak flight time of the beetle ranged from 09:00 to 13:00, with variations due to the day surveyed and the facing slope. The flights began when the air temperature reached 16.7 °C, and the flights peaked when the air temperature was 23.6 °C. Flights were not observed during rainfall, suggesting that rainfall is one of the factors that influence beetle flight. The time of sunrise was not significantly correlated with the flight initiation time. The direction of flight along with the slope was changed bidirectional to unidirectional (movement from upslope to downslope) between 9:00 and 13:00.

An ambrosia beetle, Platypus koryoensis, is a vector of Raffaelea quercimongolicae that is known to cause Korean Oak Wilt (KOW), one of the serious threats to forest healthy in Korea. To manage P. koryoensis properly, it is necessary to clarify flight period of the adult. This experiment was conducted to elucidate the relationship between temperature and the flight period based on field observation in three forests consisted of Quercus mongolica from 2007 to 2009 except winter season. Date of flight period for 50% (FP50) was estimated by the cumulative Weibull distribution model based on cumulative proportion of the adult density and air temperature. Relationship between site temperature and the date of FP50 of P. koryoensis was the most significant when temperatures below 6.5℃ were excluded, suggesting lower threshold temperature for the flight period based on the site temperature. The pooling cumulative proportion of flight period against degree days was well described by the degree-day model, which has explanatory power for the 89% of year and site variation in the flight period and predicted accurately the flight pattern in 2011.

Spatio-temporal distribution pattern of an ambrosia beetle, Platypus koryoensis (Murayama) which is vector of Raffaeleaquerci-mongolicae K.H. Kim et al, a causative agent for Korean oak wilt (KOW) was examined in the stand level. Spatial distribution of P. koryoensiswas influenced by their density. Relationship between degree of aggregation and density was positively correlated when the density was extremely low or high whereas the relationship was reverse when the density was intermediate. Patch of P. koryoensis formed around or near dead trees or partial dead trees, suggesting these trees indicated epicenter of P. koryoensis. Fraction of trees attacked by less than 100 individual of P. koryoensis in the stand per year increased abruptly whereas fraction of trees attacked over 1,000 individuals of P. koryoensis increased gradually. Our results showed that the dead trees would be an epicenter of P. koryoensis and the number of trees killed by the ambrosia beetle would be reduced by lowering total population of the ambrosia beetle around the epicenter.

In this study, we examined the spatial dependence and association of Ambrosia beetle, Platypus koryoensis, which is the vector of oak wilt disease caused by Rafaelea sp. using two geostatistical methods. Two adjacent sampling plots were selected and named as "Sector A" and "Sector B". Sector A area was 63 ha and Sector B area was 420 ha, respectively. We arbitrarily separated each sampling plot by 50m×50m grids. Sector A and B were separated by 19×15 and 43×41 grids, respectively. The oak wilt disease damage level of tree was classified by amount of frass of Ambrosia beetle near target oak tree as follows: Lost tree (LT), Severe damage (SD), Intermediate damage (ID), and Light damage (LD). Number of each damage level of oak tree was counted and recorded in each sampling grid. Spatial dependence and association of oak wilt damage was analyzed and compared using mathematical variogram models and spatial analysis by distance indices (SADIE). Variogram model ranges were 179~368m in Sector A and 634~1073m in Sector B, respectively. The damage levels of all trees in each sector were indicated as aggregated distribution by aggregation indices of SADIE (Ia > 1). Each damage level pair had strong association in the consecutive orders than in any random order based on the results of SADIE association test. The spatial dependence and association of oak wilt damage levels presented here provide the baseline information necessary to understand and manage oak wilt disease in Korea.

Differences in the number of Platypus koryoensis (Murayama) (Coleoptera: Platypodidae) trapped in different trap types, colors and positions on the trunk were evaluated to develop a monitoring trap for Platypus koryoensis, a known vector of Korean oak wilt disease. The experiments were conducted in an oak forest located in Gwangtan-myeon, Paju-si, Gyeonggi-do, Korea using two types of trap: sticky trap and multi-funnel trap. Trapping efficiency of the two trap types was not significantly different. Trapping efficiency of the sticky trap was not affected by four trap colors: yellow, black, white and transparent. The number of beetle caught was higher in the traps facing the upper slope than the lower slope regardress of trap type. Our results showed that both traps type are useful for monitoring Platypus koryoensis.

Trapping efficiency by trap types, colors and positions in the trunk was evaluated for monitoring and the integrated pest management of Playtpus koryoensis, known as a vector of Korean oak wilt disease. The experiments were conducted in oak forest located in Gwangtan-myeon, Paju-si, Gyeonggi-do, Korea using two types of trap: sticky trap and multi-funnel trap. Trapping efficiency of two trap types was not significantly different. Trapping efficiency of the sticky trap was not affected by four trap colors: yellow, black, white and transparent. The number of caught by the traps, regardless of trap types, was higher in the traps facing upper slope than lower slope.

An ambrosia beetle, Platypus koryoensis, is known as a major vector of Korean oak wilt disease (KOW) to Mongolian oak and it is considered as the one of the major threat to forest ecosystem health. This study was conducted to assess damage on Mongolian oak inflicted by the ambrosia beetle on the basis of entry hole density and location within the trunk. Two hundred forty Momgolian oak trees from Mt. Uam (Gyonggi-Do, Korea) and 60 from Mt. Gyebang (Gangwon-Do, Korea) were randomly selected. Initially, the damage degree on an individual tree and the diameter at breast height (DBH) were measured, and followed by the measurement of entry hole density per 148 X 210 mm2 on lower trunk (above the surface of the earth) and upper (100 cm above the surface) on each upslope and downslope. The damage degrees were divided into three classes: Ⅰ indicating healthy tree, Ⅱ tree damaged by the ambrosia beetles and Ⅲ dead tree by the KOW. As the damage class of the Mongolian oaks increased, the number of the entry holes increased regardless of locations of entry holes. The density of entry hole lower trunk was higher than that in upper trunk, showing that the ambrosia beetle preferred to attack the lower trunk on downslope. In addition, the results showed a tendency that the average DBH of the oak trees increased as the damage class increased from Ⅰ to Ⅲ. This suggests that the ambrosia beetle prefers to attack older trees. The entry hole densities on each lower and upper trunk on downslope were principal components to assess the damage degrees of the Mongolian oak.

광릉긴나무좀은 참나무시들음병을 일으키는 한 요인으로 작용하는 매개충 이다. 광릉긴나무좀의 생활사는 봄에 수세가 쇠약한 참나무류(주로, 신갈나무) 를 성충 수컷이 집단 공격하여, 수목에 침입공를 형성한 후, 교미하여, 갱도를 형성하고 그 속에서 번식하며, 이듬해 봄 갱도 내에서 우화한 새로운 성충들 이 새로운 기주를 찾아 다시 집단 공격을 가한다. 참나무시들음병의 방제 방 법으로는, 광릉긴나무좀의 공격을 받은 감염목 및 고사목을 벌채하여 훈증 방 법으로 광릉긴나무좀의 증가(밀도)를 억제하여 참나무시들음병의 확산을 억제 하고 있다. 광릉긴나무좀에 의한 참나무시들음병의 친환경적 방제방법을 개발 하고자, 본 발표자들은 광릉긴나무좀의 유인제(기주의 유인 물질, 페로몬 등) 를 탐색해 왔다. 그 결과, 광릉긴나무좀 암수 성충이 생성하는 물질의 비교 및 광릉긴나무좀 미교미 수컷이 배출한 프라스(톱밥+광릉긴나무좀 분비물)의 추출물과 교미 후 암수 성충이 배출한 프라스의 추출물의 비교를 통하여, 페 로몬 후보물질을 선정하였고, 이 물질들이 전기생리활성실험(EAG)에서 활성 을 가지고 있으며, 야외유인실험을 통하여 암수 성충을 유인하는 결과로부터 집합페로몬 활성을 가지고 있음을 밝혔다. 본 발표에서는 광릉긴나무좀의 수 컷이 생산 분비하는 집합페로몬의 동정 과정 및 구조, 전기생리활성, 야외유 인 검정실험 결과와 페로몬의 천연물농약으로서의 가능성에 관하여 보고하고 자 한다.

The first occurrence of oak wilt disease(OWD) in Korea was reported in 2004 and a Platypodid beetle, Platypus koryoensis, was known to contribute significantly the occurrence of the disease. To reduce the oak wilt disease, it is necessary to control density of P. koryoensis under injury level. This experiment conducted to clarify the flying period of adult P. koryoensis. Four forests containing dead trees by OWD were selected and the location of the experimental sites were Mt. Surak in Seoul, Goyang-si, Paju-si in Gyeonggi-do, Hongcheon-gun in Gangwon-do. Sticky trap or vertical multi-funnel trap was settled on Quercus mongolica trees located in infested forest. Density of P. koryoensis was survey with one or two week interval from May to October in 2007 and 2008. The number of the beetle collected by the vertical trap and sticky trap was positively correlated (r2=0.69). The optimum flying period of the beetle was ranged from late June to late July with geographical variations.

Ambrosia beetle, Platypus koryoensis, is a vector of oak wilt disease caused by Raffaelea sp. in Korea. The degree of damage by oak wilt disease was dependent on the density of the beetles in the oak trunk, a relationship between the degree of damage by oak wilt disease and the density of beetle on the basis of the number of entry hole was studied. Entry hole distribution within tree trunk was analyzed by the nearest neighbor method. Thirty four oak trees (Quercus mongolica) located in survey area were selected and then degree of damage, the number of attack hole/623 ㎠ in upper (50 ㎝ from the surface) and lower (surface) trunk and the nearest neighbor distance between the holes were measured. The number of hole and the nearest neighbor distance in upper and lower part were positively correlated with each other. As the degree of damage was severer, the number of the holes increased, whereas the nearest neighbor distance decreased. The distribution pattern of the hole was changed from clumped one to uniform as the severity of damage increased. These results suggested that Platypus koryoensis attacked the oak tree in concentrative manner at initial stage of attack but at final stage, it distributed uniformly to reduce intraspecific competition between the beetles.