각기 다른 화합물들을 성유인제로 이용하는 3종 과수해충인 복숭아순나방(Grapholita molesta), 복숭아심식나방(Carposina sasakii), 복숭아명나방(Conogethes punctiferalis)을 대상으로 단일 성페로몬 미끼 방출제에 2종 혹은 3종의 성페로몬 미끼를 섞어 복숭아원과 사과원에서 유인력을 검정하였다. 복숭아원에서 실시된 복숭아순나방 유인에서 복숭아심식나방이 섞인 혼합미끼 트랩에서 유인력이 감소하였으나, 혼합미끼를 이용한 복숭아원에서의 성충밀도 변이는 단일미끼 트랩과 높은 상관성 보였다. 사과원에서는 복숭아순나방에 대한 혼합미끼의 유인력 감소는 관찰되지 않았다. 복숭아심식나방 유인은 복숭아원과 사과원 모두에서 혼합미끼의 유인력은 단독미끼의 유인력과 유의한 차이가 없었고, 복숭아원에서 단독미끼와 혼합미끼 사이의 성충 밀도 변이 양상도 상관성이 높았다. 복숭아명나방 유인에서는 포획수가 너무 적어 평가가 불가능하였다. 이상의 결과에서 복숭아순나방과 복숭아심식나방 혼합미끼는 예찰에 이용할 수 있을 것으로 추정되었다.

The study was conducted to investigate the spring emergence pattern of G. molesta and to forecast the emerging time of overwintering G. molesta on tree fruit orchards. G. molesta is one of major insect pests on fruit trees in Korea. The host range of G. molesta includes many economically important tree fruit plants such as apple, pear, peach and plum. The overwintering G. molesta emerge from late March as an adult lay eggs on the shoot of peach or fruits of apple, plum and peach. Therefore, it is important to understand the biofix and to forecast the emerging peak period of overwintering G. molesta for establishing the pest management strategy. The pheromone trap of G. molesta has been utilized to monitor the population density in apple orchard. The commercial stick trap (GreenAgroTech) and lure (Z8-12:AC, E8-12:Ac, Z8-12:OH, 95:5:1) was set to monitor the population density of G. molesta on each place (56 different fruit orchards). The record of temperature was received from meteorological center close to monitoring orchards. The parameters for forecasting the emerging time and peak period of overwintering G. molesta were calculated from the results of Yang et al (1997 and 2001). Although the estimated biofix of G. molesta was not fitted well, the peak period of overwintering G. molesta was explained by linear regression model. The spring emergence pattern of G. molesta was presented differently related to host plant and geographical location. The peak period of G. molesta at the same mornitoring county was presented differently according to host plant. The synchronization between host plant and G. molesta may be studied to figure out the spring emerging time of overwintering G. molesta.

Three acetylcholinesterases (AChEs) were identified from the pinewood nematode, Bursaphelenchus xylophilus. Sequence comparison with known AChEs in conjunction with three-dimensional structure analysis suggested that all BxAChEs share typical characteristics of AChE at the major catalytic structures. BgAChE3 was most predominantly transcribed and then followed by AChE1 and AChE2. Immunohistochemistry using anti-BxAChEs antibodies revealed that BxAChE1 is most widely distributed whereas BxAChE2 exhibits more localized distribution in neuronal tissues. BxAChE3 was detected from entire body together with some limited tissues, including mouth parts and alimentary lining, and determined to be the only soluble AChE, suggesting its localization in hemolymph or/and extracellular space. Kinetic analysis of in vitro expressed BxAChEs revealed that BxAChE1 has the highest substrate specificity whereas BxAChE2 has the highest catalytic efficiency with BxAChE3 having the lowest catalytic efficiency. Interestingly, presence of BxAChE3 in the pool of BxAChEs significantly reduced the inhibition of BxAChE1 and BxAChE2 by inhibitors. Knockout of BxAChE3 by RNAi significantly increased the toxicity of nematicides, suggesting the protective role of BxAChE3 against these toxicants. Based on several features, including tissue distribution, expression level, substrate kinetics and inhibition property, it appeared that BxAChE1 is the major AChE with the function of postsynaptic transmission whereas BxAChE3 has been evolved to acquire the function of chemical defense, perhaps intrinsically against secondary toxic compounds from host pine trees, such as α-pinene and limonene. BxAChE2 appears to play a role in post-synaptic transmission in specialized neurons but its detailed physiological function still remains to be elucidated.

Spider mite is the most concerned pest in apple production. This study compared and analyzed the historical changes of two mite pests, Tetranychus urticae koch and Panonychus ulmi (Koch) in 16-30 representative apple orchards in the major apple production area; Gyeongnam, Gyeongbuk, and Jeonbuk province of Korea from 1992 to 2007. Monthly sampling of 100 leaves per orchard provided the basic data of population density of two mite species. Among those orchards, chemical spray history was also analyzed from four orchards, which could be representatives of IPM practitioners. It was found that overall population densities of T. urticae were higher than those of P. ulmi for 16 years. Before 2000, T. urticae was dominant over P. ulmi in most orchards. However since 2000, P. ulmi have occurred more than or as much as T. urticae.. Moreover, although there was large fluctuation of occurrences of two mite species over the years and localities, spider mite pressure appeared to decrease, in general. It seemed to relate the timing of ground cover management with pheromone-based IPM implementation nationwide from late 90s. Panonychus ulmi appeared to rise in April and July in general, fall in August, and go up again in the late season; September-October, while T. urticae appeared to begin to rise in June with July or August peak and sometime with late season second peak in October. Application frequency of acaricide has been dropped from four times in the late 1990s to 2.5 times in the late 2000s.