The developmental time and survival of overwintering larvae of Monochamus saltuarius were studied at 7 constant temperatures (16, 20, 23, 25, 27, 30, 34℃), and a photoperiod of 16 : 8 (L : D) h. The total mortality of overwintering M. saltuarius was lowest at 27℃ (7%) and highest at 34℃ (93%). The total developmental time decreased with increasing temperature between 16℃ (49.48 days) and 34℃ (13.00 days). The relationship between the developmental rate and temperature was fitted by five nonlinear developmental rate models (Logan 6, Lactin 1, 2 and Briere 1, 2). The nonlinear shape of temperature development was best described by the Briere 1 model (r2=0.99). The developmental variation of overwintering larvae was well described by the three-parameter Weibull distribution model (r2=0.98). The temperature-dependent developmental models of M. saltuarius developed in this study could be used to predict emergence period of the adult, or to develop a population dynamics model of M. saltuarius.

Cuticular hydrocarbons (CHCs) of the pine sawyer (Monochamus saltuarius), Japanese pine sawyer (M. alternatus) and oak longicorn beetle (Moechotypa diphysis) were analyzed by GC, GC-MS and compared. Monochamus beetles are typical vectors of pine wilt disease but Moechotypa diphysis, which belongs to the same family, is not. They possess different CHCs in carbon number: 23-25 in M. saltuarius, 25-32 in M. alternatus, and 23-29 in M. diphysis. In comparison to inter-species, these three species of adult beetles have different numbers and chains of constituents of CHCs. In comparison between male and female in intra-species, the quantities of CHCs show the difference but constituents are not. Major constituent of M. saltuarius were analyzed as n-pentacosane ＞ n-nonacosane ＞ n-heptacosane, those of M. alternatus were n-nonacosene ＞ n-pentacosane ＞ n-nonacosane, and those of M. diphysis were n-heptacosane ＞ 13-methylheptacosane ＞ 3-methylheptacosane. From the body surface, most saturated carbohydrates of 3 species beetles are composed of n-alkane (40.2 - 65.7%) and followed by olefines ＞ monomethylalkanes that one or two double bonds in M. saltuarius and M. alternatus. Otherwise, M. diphysis have the difference in order of monomethylalkanes > olefins.

This study was performed to investigate the escape of pine wood nematode (PWN), Bursaphelenchus xylophilus, from two vector species (Monochamus alternatus and M. saltuarius) through oviposition and feeding behavior. First, we checked number of PWNs escaped from M. alternatus emerged from three different cases of pine logs. In case A, healthy pine trees were cut into logs and left in pine forest infected with PWN. In case B, healthy pine trees were cut into logs, left in large screen cage, and let them oviposited by M. alternatus emerged from pine trees infested with PWN. In case C, pine trees which were harboring M. alternatus were cut into logs, and PWN was inoculated artificially. The M. alternatus adults emerged from the above three cases of pine logs were checked in the next year to know how many PWN they were harboring in their bodies. The percentages of M. alternatus harboring PWN (18.3 and 15.6%, respectively) and number of nematodes per vector (5,713.1±9,248.3 and 2,034.1±4,746.8 PWNs, respectively) in case A and B logs are similar to each other. However, the percentage and the number in case C (38.3% and 20,083.1±32,188.3 PWNs) were higher than those of case A and B. Among 52 M. alternatus adults harboring PWN from all the three cases, 20 adults (38.5%) were harboring more than 5,000 PWNs per beetle. And these 20 adults were harboring 97.9% of the total PWNs in 52 adults. Second, we checked the daily escape of PWNs from M. alternatus and M. saltuarius collected at pine forest infested with PWN. The PWN escaped from their vector body for 34.9±12.4 days for M. alternatus, and for 23.9±16.2 days for M. saltuarius, reaching at peak escape during the 2nd week of emergence of the two vector species. A 44.5 and 47.2% to the total PWNs escaped from vector body within 2 weeks of vector emergence for M. alternatus and M. saltuarius, respectively. The number of PWNs escaped from each vector was 3,570.6±5,189.2 and 1,556.2±1,710.3 for M. alternatus and M. saltuarius, respectively.

Trunk injection of nematicides is applied to prevent pine wilt disease(PWD). Although the trunk injection of nematicides is effective to PWD prevention, it is not effective to vector insects such as adults of M. alternatus and M. saltuarius. Thus, This study was investigated for the insecticidal activity and the effect of feeding deterrence by injecting to pine trees with acetamiprid. For screening effective nematicides, some insecticides were injected to pines on December 30th, 2008 and their insecticidal activities and feeding areas of M. alternatus and M. saltuarius were investigated in the insects breeding dishes (100× 40mm) where put on 1 to 2-year-old twig which was selected from injected pine trees in early June. As a result, insecticidal activity and feeding deterrence of acetamicprid were most effective. Feeding areas of M. alterantus adults, when tested with 1-year-old twig and 2-year-old twig of healthy pine trees, were 170.3±107.0 mm2 and 258.0±123.2 mm2 respectively. And Feeding areas of M. alterantus adults, when tested with 1-year-old twig and 2-year-old twig of pines injected at a dose of 0.3 ml per cm dbh of a pine tree with acetamiprid, were 57.7±72.3 mm2 and 65.7±51.2 mm2 respectively and their mortalities also were 0%, 28.6%. The feeding areas of M. alterantus adults tested with 1-year-old twig and 2-year-old twig of pine trees injected at a dose of 0.6 ml per cm dbh of a pine tree with acetamiprid, were not fed on it and the mortalities were 28.0%, 57.1% respectively. In case of the feeding areas of M. saltuarius adults, when tested with 1-year-old twig and 2-year-old twig of healthy pine trees, it was 112.±35.1 mm2 and 159.2±65.2 mm2 respectively. And the feeding areas of M. saltuarius adults, when tested with 1-year-old twig and 2-year-old twig of injected pine trees at a dose of 0.3 ml per cm dbh of a pine tree with acetamiprid were 0.61±0.0 mm2 and 8.1±12.4 mm2 and both mortalities were 23.1%. Although M. saltuarius adults, when tested with 1-year-old twig of a pine tree injected at a dose of 0.6 ml per cm dbh of a pine tree with acetamiprid, were not fed on it but M. saltuarius adults tested with 2-year-old twig of the same pine tree were 2.0±3.7 mm2 and their mortalities were 53.8%, 61.5% respectively. We investigated insecticidal activities, the effects of feeding deterrence of acetamiprid for vector insects where fed twigs of injected pines by stop up hole with a cork or not, and the trunk injection to pine trees at a dose of 0.5, 1 ㎖ per ㎝ dbh of a pine tree with acetamiprid on the early June. As a result, all of the vector insects were not fed and the feeding area was within 11 ㎟ and the mortality of M. alternatus was 70%.

Entomopathogenic fungi were isolated directly from a cadaver of adult M. saltuarius (infected with white fungi) supporting fungal sporulation, to develop biological control of pine wilt disease vector, M. saltuarius which was the most abundant in the middle to northern part of Korea and caused enormous damage to native pine tree in Korea, Japan and other regions of Asia. Pathogenicity of each fungus was tested using oak longicorn beetle, Moechotypa diphysis, as substitutive insect. As the result, only one of them showed pathogenic to adults of M. diphysis, with up to 100% mortality within 13 days of inoculation. Selected fungus was named as MsW1 and identified by Beauveria bassiana using microscopic examination, B. bassiana-specific PCR primers and genetic sequencing of the ITS region analysis. Pathogenicity test were conducted with various concentration of conidial suspensions of this isolate on M. saltuarius (3rd instar larvae and adults). Mortality rates varied from 57.1% to 100.0% and from 16.7% to 100.0% of M. saltuarius (3rd instar larvae and adults), respectively at 30 days. This is the first report of natural infection of M. saltuarius by B. bassiana.

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.

Monochamus alternatus and M. saltuarius were reported as the vectors of Bursaphelenchus xylophilus, pine wood nematode in Korea. According to Kwon et al. (2006), each of 2 species has occupied their own regional distribution : M. saltuarius in southern part including Jeju island and M. alternatus in mid-northern part of Korean peninsula. We measured the supercooling point (SCP) of 2 species (laboratory-reared populations) by each of developmental stages. The SCPs of 2nd, 3rd and 5th instar larvae of M. saltuarius were -7.68±0.19℃, -7.02±0.69℃, -4.93±1.34℃ each of stages. On the other hand, the SCPs of 3rd, 4th, 5th instar larvae and pupae of M. alternatus. were -4.46±1.12℃, -5.94±1.33℃, -7.83±1.44℃, -9.53±1.78℃ each of stages. The SCPs of M. saltuarius larvae generally was lower than that of M. alternatus. The pupae of M. alternatus and 2nd instar larvae of M. saltuarius had the lowest SCP among measured samples. On the other hand, the highest SCP were recorded in 2nd and 5th instar larvae, each. This result shows that regional distribution of 2 beetles may be associated with the adaptation capacity to low temperature represented by the SCP as well as the developmental temperature. However, beetles experimented were not collected from pine forest fields. In further study, we are planning experiments with field populations and all developmental stages.

This study was performed to investigate the emergence timing and daily emergence from the different tree species logs (Korean white pine, Pine, and Japanese larch) at Cheongwon, Chungcheongbuk-do from 2006 to 2008. Pine sawyer adults began to emerge on early May (2~10th day) and finished on mid-June (4~20th day) in the Korean white pine and pine logs. However, pine sawyer adults began to emerge on mid-May (13th day) and finished late May (27th day) in Japanese larch logs. Japanese larch logs shows shorter emergence timing of pine sawyer adult compare to those of other two tree species. Emergence timing shows no difference between males and females. Sex ratios of emerged adult in 2007 were 0.55 from Korean white pine, 0.46 from Pine, and 0.59 from Japanese larch, it shows no difference among tree species. Female and male adults emerged throughout 24 hrs, 22.8% of the total adults emerged from 12~14:00 (22.8%) and adults emerged lowest from 06~08:00. Of the adults emerged from the logs, 98.9% was univoltine and the rest was biennial which emerged next year.

To investigate the ecological emergence of pine sawyer beetle adult, it was examined the escape time and period and daily escape according to the tree species at Cheongwon, Chungbuk from 2006 to 2008. In the emergence chamber with non-shading treatment, the adults began to escape on May 6 in Pine and Korean white pine, May 13 in Japanese larch, and the last day of emergence was examined the beginning to Middle of June in Pine tree, middle to last of June in Korean white pine, last of May in Japanese larch, it showed the difference among tree species. In the emergence chamber with shade treatment, the first day of emergence of adult was delayed the eleven to sixteen days and showed lower 2.22℃ in temperature compare to the emergence chamber with non-shading treatment. Escape period did not show the difference between males and females. Daily emergence was escaped throughout 24 hrs. Number of emergence adult in daily hours was highest emerged with 22.8% in 12-14:00 and lowest in 06-08:00. Among escaped adults from shaded chamber in 2007, ratio of the adults of one generation per year was showed 98.8% and ratio of one generation in two year was observed 1.1 % in 2008. From 2006 to 2008, sex ratio of emerged adult from Korean white pine was showed 0.53-0.58 and its average was 0.54.

Larvae of Monochamus saltuarius showed normal growth and development on conifers of Pinus koraiensis, P. densiflora, Abies holophylla, Larix leptolepsis, P. bungeana, and P. rigida, respectively, but the conifers influenced significantly the body weight and the survival rate of larvae. Though the larval body weights were in a wide spectrum among treatments, growth curves of them were very similar from each other, showing continuous increase from the early larval stage to about 3 months old. The body weight was decreased slightly after the feeding period of the early 3 months. The size of larvae and adults became the largest from P. bungeana fed larvae. The mid-sized ones were from P. koraiensis, P. densiflora and A. holophylla. Small ones came from L. leptolepsis and P. rigida. The larval growth was retarded without water supply. Overall survival rates from the early stage of a larva to a fertile adult were 53.6% from P. koraiensis, 51.8%, P. densiflora, 34.7%, A. holophylla, 17.8%, P. bungeana, 16.7%, L. leptolepsis, and 12.3%, P. rigida. Adults from larvae fed the 6 species of conifers, respectively, were grown into the reproductively potent adults, which laid viable eggs. A few of overwintered larvae did not pupate and remained still as a larva until the late October of the year. Data from the field survey, the head width emerged from P. koraiensis was larger than that of L. leptolepsis. The adult emergence hole in P. koraiensis was larger also. While, the size of the emergence hole was larger in the artificially innoculated log of P. koraiensis, which was kept for a larva to be with a minimized food competition and sufficient water supply, than that of the field.

This study was performed to investigate the toxicity of 39 registered insecticides to the susceptibility, systemic effect, and residual effect and control effect against Pine sawyer beetle, Monochamus saltuarius. Eleven kinds of chemicals such as fenitrothion, fenthion, phenthoate, phosphamidon, dinotefuran, actamiprid, clothianidin, thiacloprid, thiamethoxam, esfenvalerate + fenitrothion, and fipronil were showed 100% insecticidal activity both in body spray and twig dipping bioassay. Among these chemicals, fenitrothion and fenthion were showed 100 % insecticidal activity when sprayed at 4000 times diluted solutions, and phenthoate, thiacloprid, thiamethoxam and fipronil were showed 100% insecticidal activity when sprayed at 2000 times diluted solution. Root systemic effect was showed 100% mortality in phosphamidon, clothianidin, thiamethoxam, and 77.7% in thiacloprid. In residual effect, fenitrothion and thiamethoxam were showed 80% mortality fifteen days after treatment (DAT), and fenthion, phosphamidon, clothianidin were showed 80% mortality ten DAT, fenitrothion, thiamethoxam, fipronil showed 100% mortality in seven DAT, thiacloprid was showed 100% mortality in three DAT. Fenthion and phenthoate were showed 100% mortality one DAT. In the control effect, 6 kinds of chemicals were showed 100% mortality one DAT and all chemicals showed 100% mortality three DAT.

Pine sawyer beetle, Monochamus saltuarius preferred the feed on fresh twig of Korean white pine trees (Pinus koraiensis) than one-year old and two-year twig. It means that the current twig is appropriate to increase the lifespan and reproduction of this insect. In a bioassay after fractionated the hexane layer from the water layer, the hexane layer did not show feeding response; however, the water layer was preferred in the order of fresh twig>one-year twig>two-year old twig. By HPLC analysis, we identified three kinds of sugar, namely, fructose, sucrose, glucose. The quantity of fructose was the highest in fresh twig followed by one-year and two-year old twig. In the preference test using each standard sample, the order was fructose>sucrose>glucose at 10, 30 μg/filterpaper, and fructose>sucrose >glucose at 50μg/filterpaper. From the above result, fructose plays an important role as a feeding stimulant for pine sawyer adult.

Pine wilt is the most important disease of pine trees in Korea, Japan and China. The pathogen causing this disease, the pinewood nematode (Bursaphelenchus xylophylus), is transmitted vectored by adults of some cerambycid beetle species and the Japanese pine sawyer, Monochamus alternatus, is the major vector species in Korea. Although chemical insecticides have been used to kill vector insect and thus prevent transmission of the pathogen, the efficacy is not good. In Japan, to control this insect, an entomopathogenic fungus was studied and developed as an insecticide. This is thought to be the convenient and effective method to control M. alternatus. Recently, there are several reports about the pinewood nematode is vectored by also the pine sawyer, M. saltuarius, in Korea. The objective of this study, therefore, was to isolate and identify entomopathogenic fungi from M. saltuarius cadaver to control it. We collected the cadaver of M. saltuarius and then screened several fungi colonies. The pathogenicity of each fungus was tested using oak longicorn beetle, Moechotypa diphysis, as substitutive insect. M. diphysis is also serious pest to various trees in forest. As the result, only one of them showed high pathogenicity against M. diphysis. Selected fungus was identified by microscopic examination and DNA analysis. Pathogenicity was also evaluated to M. saltuarius.

As a major component of cuticle wax, cuticular hydrocarbon plays key roles as a chemical cue among inter- and intra-species in some beetles like as pheromone and alleolochemicals in addition to the physical function. In this study, cuticular hydrocarbon was analyzed and compared with three species of beetles adult, Monochamus alternatus, M. saltuarius belong to the Monochamus sp., and belong to the same class, Moechophyta diphysis, a typical vector of pine wilt disease. The composition of cuticular hydrocarbon of three species of beetles adult did not show the difference between male and female in intra-species, however, showed the difference in inter-species. They also differed from carbon numbers in inter species as 25-32 in M. saltuarius, 25-35 in M. alternatus, and 23-31 in M. diphysis. Major constituent of M. saltuarius was analyzed as n-C25, 2 or 4 MeC26, 9-C25:1, n-C27, 4-MeC28, n-C29, (9,x)-,and/or (11,x)-diMeC29; those of M. alternatus were n-C25, n-C27, 4-MeC28, n-C29, (9,x)-, and/or (11,x)-diMeC29, 9-C29:1, n-C29, (9,x)-,and/or (11,x)-diMeC29; and those of M. diphysis were n-C25, n-C26, n-C27, 3-MeC27,9-C29:1, 11-MeC29. The contents of n-alkanes were as follows: M. saltuarius ≒ M. alternatus > M. diphysis. The contents of monomethylalkanes were as follows: M. diphysis > M. saltuarius ≒ M. alternatus. The contents of dimethylalkanes were as follows: M. saltuarius ≒ M. alternatus > M. diphysis. And the content of olefine in female were analyzed as follows: M. saltuarius > M. alternatus ≒ M. diphysis, and the male's contents were similar in three kinds of beetles.