The study was conducted to investigate the phenology of G. molesta adult, and to develop and validate the degree-day model of G. molesta in apple orchards. It was known that G. molesta is a multi-voltine insect depending on temperature and geographic location. G. molesta damage to many economically important fruit trees such as apple and pear. Data collection was carried out in five apple-growing location (Chungju, Bonghwa, Andong, Uiseong, and Geochang) and at least three commercial orchards of each location was selected for collecting data in 2011 and 2012. The commercial pheromone monitoring trap (GreenAgroTech) was used to investigate the flight phenology of G. molesta. The relationships between degree-day accumulated above the low temperature threshold and cumulative proportion of accumulated G. molesta caught per generation were used to predict the phenology of G. molesta. The phenology of G. molesta per generation was analyzed by Weibull 2-parameter function. The generation of G. molesta was depending on local environmental conditions, specially temperature. The first flight of G. molesta adult in Chungju was later than other places. The average number of G. molesta caught in Uiseong was significanlty decreased from 2011 to 2012. The occurrence of G. molesta adult was explained well by degree-day model using Weibull 2 parameter function. The developed model system could be applied to manage G. molesta population in apple orchards.

Grapholita molesta is one of economically important pests in pear orchards and has four to five generations per year depending on food resources, geographic location, and temperature. The overwintering larvae of G. molesta pupate early in the spring and new adults start to flight for several reasons such as mating, seeking resources and oviposition. The study was conducted to develop the full seasonal phenology model of G. molesta and to investigate the phenology of G. molesta adult in pear orchards. Data collection was carried out in five pear-growing location (Anseong, Icheon, Sangju, Ulju and Naju). Three commercial orchards of each location was selected for collecting data in 2011 and 2012. The flight phenology of G. molesta was investigated by the commercial pheromone monitoring trap (GreenAgroTech) once per week. The phenology of G. molesta per generation was predicted by the relationships between degree-day accumulation above the low temperature threshold and cumulative proportion of accumulated moth caught per generation. The phenology of G. molesta per generation was calculated by Weibull 2-parameter function. Although the latitude of Sangju was higher than that of Naju, the first flight of G. molesta adult from two orchards was similar. The average number of G. molesta adult caught in every pear orchards was increased from 2011 to 2012. The occurrence of G. molesta adult was explained well by degree-day model using Weibull 2-parameter function.

경북의 자두 주요 생산지인 경산시와 의성군내 8개의 자두과원을 선정하여, 2010년과 2011년에 주요 심식나방류인 복숭아순나방, 복숭아순나방붙이, 복숭아심식나방의 발생상을 성페로몬 트랩을 이용하여 조사하였다. 또한 경산지역에서는 과수원 내부와 외부에서 포획된 개체수 자료를 이용하여 내외부 발생량을 비교하였다. 경산에서 복숭아순나방과 복숭아순나방붙이 발생은 의성보다 약 1주일 정도 빠르게 나타났다. 복숭아순나방은 3월 하순에 발생을 시작하여, 4월 하순 최성기를 이루었으며, 이후 세대는 6월 중순, 7월 중순, 8월 중순에 성충 최성기를 보였다. 반면 복숭아심식나방은 두 지역간의 차이가 없었으며, 6월 상순에 발생을 시작하여 9월 중순까지 2-3회의 발생 최성기를 보였다. 복숭아심식나방의 경우 2010년은 전형적인 2회 최성기를 보였으나 2011년에는 3회 최성기를 보였다. 연간 복숭아순나방, 복숭아순나방붙이, 복숭아심식나방의 발생량비는 경산지역에서 63-47:16-35:20-18%였고, 의성지역은 51-46:18-13:31-36%로 나타났다. 복숭아순나방과 복숭아순나방붙이의 경우 과수원 내부와 외부에서 포획량의 차이는 없었다.

Insects in temperate climate zones are challenged to endure harsh temperature regimes and the absence of food resources during winter. Many insects overwinter in diapause at different sites. The overwintering sites differ according to the insect species. The study was conducted to investigate the overwintering sites between the two orchard systems for the Grapholita molesta larvae. Overwintering sites of Grapholita molesta were found different between apple grafting systems. More individuals favored the side branches and main bottom trunk as overwintering sites in big tree system (M26) and in dwarf grafting high density system (M9) respectively. There was no significant different between M9 and M26 cultivars in the relative proportion of larvae. However, significant differences were found in the interaction between the overwintering sites and the two M9 and M26 cultivar orchard systems. The natural mortality from the field was estimated as 22.1% and 18.3% from dwarfing, high density orchards and the big tree orchard systems respectively. This study provides valuable information and guidelines to understand the major overwintering sites within different orchard systems for scheduling management actions against spring adult moths population emergence.

Grapholita dimorpha is a new pest of apple, pear and plum in Japan and Korea as well. Although G. dimorpha was reported as a multi-voltine insect with four generations per year, the phenology is not fully known in Korea. We present a model to predict the spring occurrence of G. dimorpha adults based on the relationship between the cumulative proportion of G. dimorpha adult catches and accumulated degree-days. Five different distribution models were applied and the selection was made based on the statistical information criteria (AICC and BIC). Model validation was performed with the field data of the male moth catches in sex pheromone-baited traps of two apple production regions (Chungju and Geochang) of Korea in 2011. Model predictions of the dates for the cumulative 50% male moth catches were within five days variation. Because G. dimorpha has a feeding habit of boring inside the fruit the management practice of G. dimorpha should apply on egg and neonate larval stage. The management strategy of G. dimorpha in spring might be improved by the model.

The study was conducted to develop the full seasonal phenology model of G. molesta in pear orchard. G. molesta is a multi-voltine insect with four to five generations per year depending on temperature, food resources and geographic location. For precise model construction, information on temperature-dependent development and the distribution of developmental completion of overwinteirng and summer G. molesta population was used. The performance of model was based on single cohort population of G. molesta. The validation of model system was performed with the male moth catches in sex pheromone-baited traps of pear orchards in four pear production regions (Anseong, Icheon, Naju and Ulju), three apple production regions (Andong, Chungju and Geochang), and four plum orchards (Uiseong) of Korea in 2010 and 2011, respectively. The observed phenology of seasonal population of G. molesta was explained by our model system. The predicted dates for the cumulative 50% male moth catches per each generation were within seven days variation per each generation. The precise predictive model of G. molesta adult occurrence could help decision making and enhancing control efficacy.

Many insects overwinter in diapause in the temperate region. Winter diapause often terminates far yearly than our thought, eg. Many in December. After diapause termination, insect becomes in quiescence. The lower developmental threshold of overwintering Oriental fruit moth larvae is in the range of 7.5-8.4℃ depending on the geographic location. We have determined the developmental period of overwintering OFM larvae from the time series interval collection. Collections were made from mid Jan to late March at 10d interval. Collected larvae were held in a cold chamber at 6°C for 5 days, and then subjected at 20°C with 75% R.H., 16:8(L:D).hr. The developmental period from overwintering cocooned larvae to adults was longest in mid. January collections, became shorter after 31 Jan. collection, then gradually decreased until mid March. Cocooned larvae developmental period became shorter after 31 Jan. while that of pupae became shorter after 20 Feb. During this study, female ratio was not different to 0.5. Mortality of winter collected larvae to adults was 45% including 30% parasitism. Partial explanation of the insect development under the lower developmental threshold was discussed; limitation of linear model estimation, temperature data quality and physiological metabolism after diapause termination. From January to February, daily average temperature fluctuated but under the lower developmental threshold. However, daily maximum temperature became noticeably higher than the lower developmental threshold after 20 Jan. However, this result indicates that after late Jan, physiological state of OFM is altered.

Understanding the spatial pattern of G. molesta and the temporal variation of their patterns are important to develop and maintain pest management programs in fruit orchards. The overwintering larvae of G. molesta pupate early in the spring and new adults begin a flight for several reasons such as mating, seeking resources (food or shelter) and oviposition. It was known that G. molesta presented “low movement activity” and male G. molesta flight behavior was closely related to the proximity of its host crops. Unmated males remain near the site of emergence in order to find and copulate with unmated females. The fruit-bearing status of orchards are important factors for G. molesta movement. To elucidate the spatial distribution and temporal variation of G. molesta within and among orchards, pheromone traps targeting male G. molesta were used because the trap represent a reliable and economic tool for monitoring adult G. molesta populations. The study was conducted in two apple orchards (one is isolated from other fruit orchards and another is surrounded by apple orchards), Andong and in seven plum orchards, Uiseong, 2010. Using spatial analysis by distance indices, the spatial pattern of G. molesta in each sampling date was presented. In the study of the spatial pattern within apple orchard, the index of aggregation (Ia) of isolated orchard were presented >1, indicating an aggregated distribution pattern, from monitoring results. The spatial association between successive monitoring using X (the index of spatial association) was negative during spring season and after then the value was changed to positive. In the experiment of the spatial pattern among orchards, the index of aggregation was >1 in most monitoring date and the index of spatial association was negative during early and late growing season. Factors influencing the spatial-temporal dynamics of G. molesta are discussed.

Grapholita molesta, G. dimorpha and C. sasakii as “internal feeders” are important apple pests in Korea. Three species overwinters around and in apple orchards. New young larvae of three species bore into new shoots or fruits and then feed inside apple. When mature larvae escape from fruits they make holes that reduces the commercial value of fruit. Therefore, understanding the phenological distribution of three species is critical to establish the precise management system for reducing three species population. The study was conducted to investigate the adult emergence of G. molesta, G. dimorpha and C. sasakii using pheromone traps and to forecast the cumulative proportion of each population. This study is second part of consecutive experiment. Data collection was carried out on three commercial apple orchards and one experimental orchard of Giran in 2010 and 2011. The experimental process was same in the study of plum. More than 50% of G. molesta male was occurred in spring season (within 500 degree-days), 2010 and 2011. The adult emergence of G. dimorpha and C. sasakii was linear and sigmoidal pattern in each year. The phenology of C. sasakii was explained well by nonlinear functions and the equation 3, 6, 8 and 11 were selected based on AICc and BIC. The selected equations were validated by the data of present year (2011) in each region. The performance of G. molesta and G. dimorpha was analyzed well by bimodal functions. The importance of phenological model is discussed to develop and maintain a more precise system for multiple pest management on apple orchard.

The study was conducted to investigate the phenological distribution of G. molesta, G. dimorpha and C. sasakii and to estimate the emergence timing of three species in plum orchards. It was known that G. molesta and G. dimorpha are a multi-voltine insect and C. sasakii has one to two generations depending on temperature and geographic location. Three species damage to many economically important fruit tree such as plum, pear, peach and apple. The main emergence time of each species is different depending on host plant and environmental conditions, specially temperature. Therefore, if we have the information of population density and low temperature threshold of a species and air mean temperature of a region in previous year we can predict the phenology of a species in present year. This is one part of consecutive research. Data collection was carried out in seven plum-growing commercial orchards of Uiseong in 2010 and 2011. The commercial pheromone monitoring traps (GreenAgroTech) were used to investigate the flight phenology of three speices. The record of temperature was received from meteorological center close to monitoring orchards. The relationships between degree-day accumulated above the low temperature threshold and cumulative proportion of accumulated moth caught of previous year was used to predict the phenology of three species in present year. The results of G. molesta and G. dimorpha estimated by bimodal functions were better than those analyzed by nonlinear functions. The phenology of C. sasakii was analyzed well by nonlinear function and the equation 3, 6, 8 and 11 were selected based on AICc and BIC. The selected equations were validated in each orchard.

The study investigated the chemical treatment effects on apple borers (Lepidoptera: Totricidae, Carposinidae) when the larvae already bored inside the apple fruits. Infested apple fruits were harvested from the insecticide-free orchards in Giran, Andong on 17 July, 2010. Twenty chemical pesticides registered for the apple borers were treated on recommendation dose with dipping methods. Each treatment consisted of 20 infested apples with average 6.2 larva per apple. Mortality was relatively low, mostly 10% and a few with 30~40%. No larva died inside the apple. But dying larva escaped from apple much earlier than live ones. However there was significant sublethal effect.. Escaping time (d) from chemical treatments was longer than that from control where no chemical was treated. After escaping from the apple, in took ap. 2days to become pupae. Pupal periods were ap. 12 days without any difference among treatments. However adult emergence rate was higher in control (10.7%) than in treatments (18.5%). Among survived adults, one third was Carposina sasakii and remaining was Grapholita molesta. On conclusion, timing of insecticide spray is critical in the apple borer management.

Apple borers such as oriental fruit moth (OFM) Grapholita molesta (Busck) (Lepidoptera: Totricidae), and peach fruit moth Carposina sasakii Matsumura (Lepidoptera: Carposinidae) can reduce the yield and its quality if not managed properly. Even peach fruit moth infestation in harvested apple could produce quarantine problem in exportation. We investigated the temporal distribution of apple borers infestation in an apple orchard where the infestation level of fruit was around 95% from September to early December, 2010. Every week, 150 apples were harvested from the apple orchard in Giran, Andong, Korea and 50 apples were cut to monitor the number of larval infestation. At the same time another 100 apples were kept in plastic container inside and outside the laboratory 50 each to check the escape of the infested larvae for overwintering cocoon formation. All larvae collected were identified based on the morphology and also verified by DNA sequence. The study indicates that the numbers of the infested larvae increased from September to October second week and then slightly decreased until early December with similar number of holes per apple. The holes produced by the escaping larvae were mostly found on dorsal side of the apple, but less on basal portion. Most of the infested larvae escaped from apple during late October to early November. Based on morphological characters such as anal comb, crocket and pupation shelter, the collected larvae were identified. 42.31% of larvae were G.molesta, 52.59% of larvae were C.sasakii and 5.10% were other species not identified.