Pine wood nematode, Bursaphelenchus xylophilus, is a causative organism to induce pine wilt disease in many varieties of pine trees. Until 2006, Monochamus alternatus had been known as the only insect vector of pine wood nematode in Korea which targeted on Pinus densiflora (Japanese red pine) and P. thunbergii (Japanese black pine). However, pine wilt disease was also reported from Korean pine tree (Pinus koraiensis) in 2006 and we found another insect vector, M. saltuarius, was involved to transmit pine wood nematode. Both Monochamus species were confirmed to transfer pine wood nematode to their hosts but, there is no detail information about other transmitted nematode. Especially Bursaphelenchus mucronatus is common species transmitted by Monochamus species which is morphologically closed to B. xylophilus. Moreover B. mucronatus have two genotypes; one is East Asian type and the other is European type. Both genotypes of B. mucronatus were found in Korea but, the host and vector information related to the genotypes of B. mucronatus was not clear. Monochamus saltuarius was collected from three different geographical locations and nematodes were extracted and identified. For the identification of the juveniles, nematode DNA was extracted and ITS-RFLP analysis was done by PCR and gel electrophoresis. The selected enzymes were Hinf I, Alu I, Msp I, Hae III, Rsa I. Most of Bursaphelenchus species carried by M. saltuarius, which collected from pine wilt disease-free area, was determined as European type of B. mucronatus. We will compare the nematode species and genotypes carried by M. alternatus and M. saltuarius. In addition the rate of nematode carrying insect and the average number of nematode per single insect will be counted and compared.

Pine wood nematode(PWN), Bursaphelenchus xylophilus, is a causal organism to induce pine wilt disease in many varieties of pine trees. PWN is mainly distributed in the East Asia including Japan, China, and Korea, but it was originally imported from the North America of the West. Over 70 species of Bursaphelenchus have been reported, but they are morphologically similar to each other. In Korea, only two species of Bursaphelenchus xylophilus, B. mucronatus (both Asian type and European type) have been reported however, a recent survey showed the distribution of extra species of Bursaphelenchus in dead trees. Three isolates, BSPD-1, BSPD-2, and BSPL-1, were identified as Bursaphelenchus thilandae, B. hylobianum, and B. doui, respectively, which was determined by both morphological and molecular biological characteristics. Both BSPD-1 and BSPD-2 were originally collected from Pinus densiflora in Namyangju and BSPL-1 came from Liriodendron tulipifera in Wanju. The morphology of each species were compared from the original descriptions focusing on male spicule and female tail and reproductive organ. A molecular diagnosis method, ITS-RFLP was applied to confirm morphological identification. Genomic DNA was extracted from a single individual nematode and ITS DNA was amplified by PCR. Amplified ITS was digested by 5 different restriction enzymes (Rsa I, Hae III, Msp I, Hinf I, and Alu I) and provided a discriminatory profile for different species of Bursaphelenchus. The three species, B. thilandae, B. hylobianum, and B. doui, are all unrecorded species in Korea.