소나무재선충병의 예방을 위하여 실시하는 예방나무주사는 소나무재선충 피해를 예방할 수 있는 매우 효과적인 방제방법이지만 매개충에 대해서는 효과가 밝혀진 바 없다. 본 연구는 살선충제와 살충제가 혼합된 약제를 소나무재선 충병 방제를 위해 나무주사를 실시하면 매개충에 대한 구제와 소나무재선충에 대한 예방효과가 동시에 가능한 방제방법을 개발하기 위하여 실시하였다. Abamectin+Sulfoxaflor DC을 비롯한 3개 약종을 각 2,000배로 희석한 후 솔수염하늘소에 2㎕를 경구투여하여 소화중독에 의한 살충효과를 평가하였다. 살충제 경구 투여 후 신경흥분에 의한 경련반응을 조사한 조사한 결과 Emamectin benzoate+Acetamiprid DC의 경우 경련비율이 가장 높게 나타났으며, 반수치사시간(LT50)도 암컷은 122.18시간, 수컷은 139.55시간으로 나타나 소화중독 효과가 우수한 것으로 나타났다. 따라서 합제를 이용하여 소나무재선충병 매개충 방제와 소나무재선충의 예방효과를 위한 나무주사시에는 Emamectin benzoate+Acetamiprid DC가 매개충에 대한 살충효과가 가장 우수한 것으로 나타났다.

Monochamus alternatus which is major vector for Bursaphelenchus xylophilus is main pest for pine trees. Moreover, their larvae mainly feed on the phloem of the host during the growth period, and this process makes host debilitate. The reason why the epidemiological investigation of that damage caused by Monochamus alternatus is difficult is that the adult and the larva remains very rarely in the host. Even if the larvae remain in the host, it is not easy to distinguish them from other cerambycidae coleopterans without expertise. For the above reason, we introduce the method of field epidemiological investigation for Monochamus alternatus using the remaining larva frass in the host with Recombinase Polymerase Amplification (RPA) method.

Japanese pine sawyer, Monochamus alternatus, is the main pest that mediates pine wilt nematode, Bursaphelenchus xylophilus, that causes serious damage to pine forests. In this study, we studied the strategy to control M. alternatus using entomopathogenic fungi. The fungi were collected from soil by an insect-baiting method and two fungal isolates (Metarhizium anisopliae JEF-197 and JEF-279) showed high virulence against M. alternatus. The Metarhizium isolates were evaluated for insecticidal activity against M. alternatus by spray treatment on live pine trees and wintering trees, and the M. anisopliae JEF-197 showed high insecticidal activity. In addition, the interaction of fungi and M. alternatus were analyzed by RNA-seq. This result can contribute to the development of insect control agents using entomopathogenic fungi.

소나무재선충병의 나무주사는 살선충제를 중심으로 실시되어 왔으며, 매개충인 솔수염하늘소와 북방수염하늘소의 방제는 주로 항공방제나 지상방제를 통하여 이루어졌다. 본 연구에서는 나무주사를 통하여 매개충 (솔수염하늘소)을 방제하기 위한 연구로 Abamectin+Acetamiprid ME, Thiamethoxam DC 약제의 나무주사시 솔수염하늘소의 약효발현농도, 처리 후 기간별 효과(2017년~2018년)를 검토하였다. 실내 발현농도 시험에서는 Acetamiprid, Thiamethoxam LC50 value는 각각 0.102ppm, 0.083ppm 으로 나타 났으며, 야산(포장)에서 Abamectin+Acetamiprid ME, Thiamethoxam DC 처리구의 100.0% 치사 소요일 수는 처리 90일 후 11.0일, 9.4일, 처리 360일 후 11.6일, 10.0일로 나타나서 두 약제 모두 3월 처리시 다음해에 발생하는 매개충 (솔수염하늘소) 방제까지 가능함을 확인 할 수 있었다.

Pine wilt disease caused by Bursaphelechus xylophilus has continued to expanding in Korea since its first occurrence identified from Busan in 1988. The direction of spread and density of two vector insects, Monochamus saltuarius and M. alternatus, are closely associated with the expansion and occurrence of pine wilt disease being observed in Korea. In 2016, a pheromone trap was installed to investigate the density of each vector. A correlation between the density of two insect vectors and the number of trees infected by pine wilt disease was further investigated in Gyeongnam, Gyeongbuk, Ulsan, and Jeju. To perform a correlation analysis, the number of infected trees was counted within a radius of 50m from which the pheromone traps were installed. In addition, factors that might have an effect on the density of vectors were investigated. This includes the altitude, temperature and forest type from the site where the pheromone traps were installed.

Pine wood nematode (Bursaphelenchus xylophilus), the pathogen of pine wilt disease (PWD), is transmitted to new host trees through Monochamus spp., vector insects. In Korea, aerial application has been allowed conventionally to eliminate the vectors in their flying season. In this study, thiacloprid was applied to four-year-old Pinus densiflora, which were fed to adult M. alternatus emerged from PWD infected logs for 72 h in the condition of 1 DAT (Days after treatment of thiacloprid) and 15 DAT, respectively. We confirmed the presence of nematodes in each beetle applied to experiment by Baermann funnel method and PCR with species-specific ITS primers. After 72 h of 1 DAT and 15 DAT, thiacloprid residues in pine trees were 0.59-16.32 and 0.043-0.131 mg/kg and the mortalities of the beetle were 100 and 99.2%, respectively. Detection rate of B. xylophilus was 51.3%. The incidence rate of PWD in 1 DAT and 15 DAT showed no mortality and 5.55% compared with 55.5% of control, respectively.

Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is considered as a serious pest in pine trees. To develop an eco-friendly strategy to manage this forest insect, we collected entomopathogenic fungi from Korean soil and assessed their virulence against the adults of the insect in laboratory conditions. As a result, two isolates with conidial suspension (1.0×107conidia/ml), showed 87% and 90% mortality 12 days after fungal treatment, respectively. We assessed the potential of the fungi-derived destruxin and protease as additives to the fungal isolates, and they showed insecticidal activity via feeding and spraying treatments. Finally, we produced fungal conidia in massive solid cultures and formulated wettable powders, and now studying optimal conditions of oil-based formulation with two isolates. Based on these results, we are evaluating the control efficacy of the fungal agents against M. alternatus in field conditions.

The nematode Bursaphelenchus xylophilus and its vector insect Monochamus alternatus are major quarantine pests of timber products in Korea. Due to the phaseout of methyl bromide as a fumigant for plant quarantine and pre-shipment treatments, the need for an alternative fumigant is essential. Based on preliminary studies on the efficacy of ethanedinitrile (C2N2) to these two pests, three quarantine trials on logs covered with PVC-tarpaulins were conducted at three dosages and three temperatures potential for inhalation exposure was assessed by monitoring atmospheric levels of C2N2 in relation to the threshold limit value (TLV, 10 ppm, v/v). Concentration × time products (Ct) of 398.6, 547.2 and 595.9 g h m-3 were obtained for each quarantine trial. A 100% mortality of B. xylophilus and M. alternatus larvae at 23±4°C and 10±4°C occurred with a load factor of pine logs of 46% and at 3±1°C with a load factor of 30%. During all fumigant procedures, atmospheric levels of C2N2 20m downwind from the PVC tarpaulin were below the TLV. During aeration, levels 10 m and 5 m downwind were below the TLV after a maximum of 0.4 h and 1 h, respectively. For the purpose of an emergent quarantine or phytosanitary treatment, specific doses of C2N2 at the temperatures that occurred during fumigation could control B. xylophilus and M. alternatus larvae without significant inhalation risk to workers.

솔수염하늘소는 소나무재선충병을 매개하는 중요한 해충으로 성충의 방제를 위하여 주로 항공살포나 지상살포에 의한 살충제의 접촉독에 의한 방제가 시행되어 왔다. 본 연구는 살충제를 나무주사하여 소나무재선충병의 매개충인 솔수염하늘소를 방제하기 위한 살충제 선발을 위해 Neonicotinoid계 살충제 7종을 각 2,000배로 희석한 후 솔수염하늘소 에 2㎕를 경구투여하여 소화중독에 의한 살충효과를 평가하였다. 살충제 경구 투여 후 신경흥분에 의한 경련반응을 조사한 결과 30분 경과에서는 Clotianidin SL(100%), Thiamethoxam DC(73.3%)이 경련 비율이 높았으며 상대적으로 Dinotefuran SL(46.7%), Imidacloprid DC(0.0%)가 약제에 대한 경련반응이 낮게 나타났다. 반수치사시간(LT50)을 조사한 결과 Clotianidin SL은 수컷에서 54.7시간, 암컷에서는 85.6시간으로 나타났으며, Thiamethoxam DC은 암컷에서 70.1시 간, 수컷에서는 88.7시간으로 나타나 소화중독 효과가 가장 우수한 것으로 나타났다. 따라서 살충제 나무주사를 이용하여 솔수염하늘소의 방제에서는 Clotianidin SL, Thiamethoxam DC가 가장 적합한 약종이라고 판단되었다.

Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae) in forest is considered as a serious forest pest in pine trees. In this study, we collected entomopathogenic fungi from soil and assessed their virulence against the adults of the inset using a spray method in laboratory condition. Two entomopathogeinc fungi isolates showed high virulence against the adults. In the concentration of 1.0 × 107conidia/ml, the mortality rate of the adults were 53% and 60%. In semi-field condition, one isolate showed a virulence of 60% against the adult. Consequently, we confirmed the possibility of the fungal isolates in controlling the beetles. In near the future, we will investigate several factors which is possibly related to the control of the forest insect pest using entomopathogenic fungi in field conditions, given the importance of fungal formulation and practical application methods.

The entomopathogneic fungal colonization has become an interesting issue in ecological pest management. Plant-orientedfungi induce plant growth promotion and act as natural control agents against insect pest. Herein this work, we evaluatedthe ability of fungal colonization on bark, branches and leaves of pine tree (Pinus densiflora) to select optimal candidatesfor controlling Japanese pine sawyer (Monochamus alternatus), which is the pine wilt disease vector in Korea. As a result,some Beauveria and Metarhizium isolates could colonize on the substrates of P. densiflora and showed pathogenicity againstM. alternatus. This result suggests that the selected entomopathogenic fungi are possibly candidates for long-term managementof M. alternatus in pine tree forest.

Japanese pine sawyer, Monochamus alternatus HOPE (Coleoptera: Cerambycidae) are considered as important pine forestinsect pests in several countries which transmits the pine wood nematode, Bursaphelenchus xylophylus. In this study, wetried to control Japanese pine sawyer using entomopathogenic fungi to prevent the spread of pine wilt disease in Korea.Several entomopathogenic fungi were exposed to the adults of Japanese pine sawyer and mycosis was observed in themembranous cuticles after 6 days. In particular, two isolates showed high virulence against the adults. The selected 2isolates were sprayed to the adults at 1×105, 1×106 and 1×107 conidia/ml. In the concentration of 1×107 conidia/ml, thesurvival rates of insects were 40% and 47%, respectively. Based on these results, the possibility of controlling the Japanesepine sawyer was confirmed.

Beetles of the genus Monochamus Dejean (Coleoptera: Cerambycidae) are the most important vectors of the pine woodnematode (PWN), Bursaphelenchus xylophilus (Steiner & Buhrer) (Nematoda: Aphelenchoididae). The most efficient wayto control pine wilt disease is to decrease the population levels of the vector Monochamus beetles. Specific and efficientnatural enemies would be an interesting and environmental-friendly option. From 2016 to 2017, we investigated on thelarval parasitoids associated with M. alternatus Hope and M. saltuarius Gebler using the sentinel logs (Pinus koraiensis)in South Korea. As results of this work, we report two larval ectoparasitoids, Spathius verustus Chao and Cyanopterusflavator (Fabricius) (Hymenoptera: Braconidae) from six survey sites. Each parasitoid was parasitized up to 58.2% and26.3% on 1st and 2nd instar larvae of Monochamus beetles, respectively. These parasitoids are likely to be highly efficientas bio-control agents. Morphological characters with illustration and some biological information of them are provided.

솔수염하늘소는 소나무에 시들음 증상을 유발하여 괴사시키는 소나무재선충을 매개하는 대표적 매개충이다. 소나무재선충병 고사목 방제 살충처리 방법으로 훈증방법을 대체할 수 있는 그물망을 이용한 방제법이 도입되고 있다. 본 연구는 솔수염하늘소의 쏠기와 탈출 행동을 유발시 키는 조건을 구명하기 위하여 구속 공간 및 온도를 달리 처리하고 탈출여부를 조사하였다. 솔수염하늘소는 직경 30 mm 이하의 공간에 구속되었 을 때 장애물을 뚫고 탈출이 가능하였다. 온도 15°C에서는 탈출에 성공하지 못하였으며, 20~30°C 범위에서 탈출 성공률이 높았다. 먹이를 이용 한 솔수염하늘소의 유인은 탈출 성공률에 영향을 미치지 않았다. 좁은 공간에 구속되지 않는 경우는 갉는 부위가 집중되지 않아 탈출공을 형성하 지 못하였다. 구속된 공간에서 솔수염하늘소는 가운데와 뒷다리 부절을 이용해 좁은 공간에서 몸을 이동시키며 큰턱으로 정면에 있는 장애물을 집중적으로 갉아서 탈출공을 만들고 앞다리를 뻗어 몸을 지탱하면서 빠져나오는 행동을 보였다. 본 연구의 결과는 훈증 대체기술로 제시되고 있 는 구속 그물망의 성능을 평가하는데 중요한 기초자료로 활용될 수 있을 것이다.

Monochamus alternatus (M. alternatus) and Monochamus saltuarius (M. saltuarius) are major vectors for Bursaphelenchus xylophilus in South Korea. When an adult, they are easily distinguishable by several morphological classification. However, it is difficult to identification between M. alternatus and M. saltuarius when they are larvae as they have very similar morphological characters. Thus, they are not easily distinguishable without expertise about Cerambycidae taxonomy. Furthermore, during epidemiological investigation, sometimes, adults or larvae would not be founded in death pine trees. For these reasons, in this experiment, we are able to identified between M. alternatus and M. saltuarius by mitochondrial 12S rRNA gene primers that are specific to 12S rRNA gene fragment of M. alternatus using larvae tissue and frass. Moreover, we had examined whether vectors that were already escaped from dead pine tree have Bursaphelenchus xylophilus or not by multiplex PCR using larva frass that was remained in dead pine tree.

The adult activity of M. alternatus caught in a pheromone trap showed a bimodal form consisted of the first peak in mid to late June and the second peak in mid to late September in Jeju area, Korea. The two peaks were separated apparently between mid and late August, showing a valley. The pine trees without oleoresin flow were abundant during early July to early August, and declined thereafter, which did not match with the valley of adult activity curve. Thus, the hypothesis that dying pine trees attract much strongly M. alternatus adults than that of pheromone lures may not fully explain the bimodal pattern, because the first adult activity peak occurred during the peak period of dying pine trees and it declined with decreasing dying pine trees. The accumulated degree-days showed that the emergence of the 2nd generation adults could occur before the second peak when the diapause ecology of M. alternatus was not considered. The voltinism of M. alternatus can affect basically the control strategy of this pest. Consequently, further studies are required to find out clearly the voltinism of M. alternatus in Korea.

Monochamus alternatus (M. alternatus) and Monochamus saltuarius (M. saltuarius) are major vectors for Bursaphelenchus xylophilus in South Korea. When an adult, they are easily distinguishable by several morphological classification. However, it is difficult to identification between M. alternatus and M. saltuarius when they are larvae as they have very similar morphological characters. Thus, they are not easily distinguishable without expertise about Cerambycidae taxonomy. Furthermore, during epidemiological investigation, sometimes, adults or larvae would not be founded in death pine trees. For these reasons, in this experiment, we are able to identified between M. alternatus and M. saltuarius by mitochondrial 12S rRNA gene primers that are specific to 12S rRNA gene fragment of M. alternatus using larvae tissue and frass. Moreover, we had examined whether vectors that were already escaped from dead pine tree have Bursaphelenchus xylophilus or not by multiplex PCR using larva frass that was remained in dead pine tree.