본 연구에서는 소나무재선충을 매개하는 매개충 솔수염하늘소와 북방수염하늘소에 대하여 무인항공기(무인헬리콥터)를 이용하여 유인항 공용 방제 약제의 약효 및 약해를 조사하였다. 약효는 소나무와 잣나무의 수간을 3등분한 곳에 대상 곤충을 케이지에 넣어 매달아 두어 살충효과 를 조사하였다. 시험약제로는 티아클로프리드 액상수화제, 아세타미프리드 미탁제, 플루피라디퓨론 액제를 각각 33배로 희석하여 살포하였고, 감수지를 이용하여 살포 약제의 낙하입자를 측정하고 피복도를 조사하였다. 약제 살포에 의한 주변 비산거리 및 비산량을 조사하였다. 세 약제 모 두 솔수염하늘소, 북방수염하늘소에 대하여 96%이상의 우수한 살충 효과를 보였다. 낙하입자 분석 결과 낙하입자는 균일한 양상을 보였다. 주변 비산 현상 분석 결과, 약제 살포시 무인헬리콥터 진행방향으로 20 m의 비산을 보였고, 좌우, 후방으로 10 m의 비산이 확인되었다. 낙하입자수에 의한 비산량 조사 결과, 모든 방향에서 5 m내에서 낙하입자지수 6-7이였고, 10 m지점에서는 낙하입자지수 2를 기록하였다.

Monochamus saltuarius Gebler are the insect vector of the pine wood nematode (PWN), Bursaphelenchus xylophilus (Steiner & Buhrer) mostly in the mid-northern areas of South Korea. In 2017, we installed sentinel logs to lure efficient parasitic wasps of the vector and to evaluate ecological characteristics of parasitoids in prior to the development of biological control strategy for the PWN transmitting insect vector. As a result of the survey, we found Spathius verustus Chao (Hymenoptera: Braconidae) as a predominant parasitoid with the highest parasitism rate among six species of larval parasitoids. The parasitism rate was higher along the edge (0m of the forest depth) of the survey sites than the inner sides (20m and 40m of the forest depth). Also, the parasitoid showed highest parasitism rate in late-May at one of Gapyeong_sites, where was supposed to be the oldest infected areas. Lastly, the parasitism rate along the trap heights was higher at height of 0m than the 1.8m above the ground.

소나무재선충의 매개충인 솔수염하늘소(Monochamus alternatus Hope)와 북방수염하늘소(Monochamus saltuarius Gebler) 암수 성충의 더듬이 감각기를 주사전자현미경로 관찰하여 형태적 특성과 분포를 조사하였다. 두 매개충의 암수 성충 더듬이는 자루마디(scape), 팔굽마디(pedicel)와 9개의 채찍마디(flagellum)으로 이루어져 있었다. 더듬이 표면에 있는 감각기의 종류에는 종 간, 암수 간에 차이가 나지 않았으며 Chaetica 3 종류, Trichodea 2 종류, Basiconica 3 종류, Coeloconica 1 종류로 구분되었다. 이 중 Basiconica 3 종류는 모두 후각 수용체, Trichodea는 미각 수용체, 나머지는 기계적 감각기로 추정되었다. 감각기의 더듬이 내 분포를 보면 전체적으로 Chaetica 감각기가 가장 많았다. Basiconica 감각기는 채찍마디에만 존재하였으며 끝으로 갈수록 수가 많아졌다. Trichodea 감각기와 Coeloconica 감각기는 각 마디별로 밀도가 일정하였다.

In order to identify the specific antigens for pine wood nematode (PWN), we confirmed that one of the genes commonly found in the transcriptome, proteome and secretory proteins of PWN belonged to the Aldose Reductase (AR) family protein. 36.5 kDa PWN-AR1 was expressed and purified using Baculovirus Expression System. Total 1,546 hybridoma fusion library was generated and screened for specificity to PWN-AR1 by Enzyme Linked Immunosorbent assay (ELISA). Nine clones showed strong immunoreactivity to PWN-AR1 were limited-diluted. Total 864 limited-diluted clones were further screened using PWN-AR1 by ELISA and 34 monoclonal antibody (Mab) clones were selected. 34 Mab clones were further screened using PWN extracts and a standard PWN-infected pine tree extract by ELISA. Finally nine clones were selected and their immunoreactivities to 4 different nematodes were examined by ELISA. Seven clones pecifically recognized PWN while two clones recognized 4 nematodes. Our data suggested that PWN-AR1 is a PWN secretory enzyme while PWN is invading pine trees, Thus, PWN-AR1-Mabs could be used to develop diagnosis tools for PWN and its infected pine trees. (This work was supported by National Institute of Forest Science)

Two species in Monochamus (Coleoptera: Cerambycidae) are wellknown vector species of the pine wood nematode (PWN) in South Korea. In 2018, the surveys using sentinel logs with two Monochamus species larvae were made from early June to last September in Pinus densiflora forests of Pohang city, South Korea. The experiments were repeated 10 times in order to investigate parasitism patterns of the larval parasitoids of M. saltuarius and M. alternatus. Three plots were chose at interval distance of 20 m (0 m, 20 m, 40 m) from the edge to the center of the forests (i.e. forest depths) in one damage area of the pine wilt disease for each of three different locations. For each time of the exposure ten sentinel logs were hung along the tree heights (i.e. sentinel logs positions) (height: 0 m, 1.8 m, 3.6 m, 5.4 m, 7.2 m). As the results of the surveys six larval parasitoids in total were identified, and most abundant parasitoids were Spathius verustus and Cynopterus flavator. Analyses showed that the parasitism rate on larvae of two Monochamus species was not affected according to forest depth, but the parasitism rate was the highest in the third plot. Also the parasitism rate was the highest at 5.4 m height of a tree. Lastly, parasitisms rate on M. alternatus was higher than that of M. saltuarius.

Pine tree, a dominant species in the flora of Korea is the most beloved tree in Korea. However, recent outbreak of pine wilt disease caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus threatens the vegetation of Pinus species seriously. Furthermore, Pinus densiflora and P. thunbergii, the predominant species in Korea forest are highly susceptible to PWN. Therefore, there has been an urgent demand for the development of a new nematocidal compounds to control PWN, which spurred the national research for the development of new compounds. To find novel sources for nematocidal agents, we used various plant resources for the development. In addition to the foreign plant extracts themselves, we also used the extracts of endophytes composed of over 300 endophytic fungi and 1,000 endophytic bacteria from plants which was reported to contain nematocidal activity. Several extracts of endophytes and plant extracts contained strong nematocidal activity, and the resources are analyzed to identify the active nematocidal compounds. These integrated approach of finding effective nematocidal compounds from plants could be a novel way to elucidate the sources for brand-new nematocidal agents.