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 wilt disease (PWD) is one of the most serious forest tree diseases and now the damaged area covers 7,877 ha and more than 60 cities in Korea. The causal agent of PWD, Bursaphelenchus xylophilus is transmitted by the insect vectors, pine sawyers (Monochamus spp.). Spread of PWD damage and control effect for PWD are directly related to dispersal potential of Monochamus spp. vectors. Recently, harmonic radar technology has been applied as a means for tracking individual dispersal of tagged insects. Tracking insects with harmonic radar system is similar to a mark-and-recapture technique, in which an organism is tagged, released, and recaptured. Our objective is to develop a harmonic radar tracking system by using lightweight tags to investigate dispersal of Monochamus spp., insect vectors. The harmonic radar system consists of two parts: a commercially available, light-weight (1.6 kg), handheld transceiver (RECCO Rescue System) and a small tag that reflects the transceiver signal (917 ㎒) at harmonic frequencies (1,834 ㎒). A tag consists of a miniature diode (Toshiba ISS350) with wires (36-gauge tinned copper) soldered using conductive epoxy on each side to produce a dipole antenna. These tags were evaluated in an open field to assess their maximum detection range, and at tag length of 13 ㎝, the tag was detected at >100 m.
전북지방의 씨감자 생산적지를 선정하기 위한 기초자료로서 고랭지대인 전북 무주군 무풍면 상오정 1대(700-800m)와 평야지인 전주에서 대관령 고랭지 시험장산 원종 남작(Solanum tuberosum Var. Irish Cobbler, Shimabara)과 무주산 재래종 씨감자(품종미상)를 재배하면서 씨감자의 바이러스 이병율 및 재배기간중의 지역별 감염율등을 혈청학적으로 검정하여 다음과 같은 결과를 얻었다. 1. 우리나라에서 현재 유통되고 있는 씨감자의 감자 바이러스 혼합감염율은 이며 바이러스별로는 Potato virus Y(PVY)< Potato Virus(PVX)로서 PVX가 가장 높은 이병율을 나타내고 있었다. 2. 감자바이러스의 1년차 감염율은 무주지방이 , 전주지방이 로서 무주지방이 낮고 특히 곤충매개가 심한 PVY의 감염율은 밖에 안되어 이는 씨감자 생산지로서 적합함을 인정할 수 있었다. 3. 씨감자 자체의 바이러스 이병율은 대관령산이 , 무주 재래종이 로서 대관령산과 비슷하였고 작황은 대관령 산이 좋았다.