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.
An ambrosia beetle, Platypus koryoensis, is a vector of Raffaelea quercimongolicae that is known to cause Korean Oak Wilt (KOW), one of the serious threats to forest healthy in Korea. To manage P. koryoensis properly, it is necessary to clarify flight period of the adult. This experiment was conducted to elucidate the relationship between temperature and the flight period based on field observation in three forests consisted of Quercus mongolica from 2007 to 2009 except winter season. Date of flight period for 50% (FP50) was estimated by the cumulative Weibull distribution model based on cumulative proportion of the adult density and air temperature. Relationship between site temperature and the date of FP50 of P. koryoensis was the most significant when temperatures below 6.5℃ were excluded, suggesting lower threshold temperature for the flight period based on the site temperature. The pooling cumulative proportion of flight period against degree days was well described by the degree-day model, which has explanatory power for the 89% of year and site variation in the flight period and predicted accurately the flight pattern in 2011.
This study was conducted to evaluate the attractiveness of the sex pheromone trap of Cnaphalocrocis medinalis Guenée as a forecasting tool from 2006 to 2008 in Suwon, Gyeong-gi province and Seosan, Chung-nam province, Korea. The sex pheromone lure was composed of Z11-18:Ald (55㎍): Z13-18:Ald (500㎍): Z11-18:OH (120㎍): Z13-18:OH (180㎍): Z13-18:Ac (55㎍) per a rubber septum, which set in a cylindrical cone trap. The trap catches of male moths was counted on a weekly basis and the lures were renewed every two weeks. The flight activity of C. medinalis moths monitored by the sex pheromone trap revealed two distinct peaks a year in both experimental areas from 2006 to 2008. Degree-days accumulation was calculated using lower developmental threshold (13.3℃) and degree-days (386.4DD) since adults had been first recorded. Estimated adult peak of the first generation was almost coincident with that observed by sex pheromone trap except in Suwon in 2008.
한국에 자생하는 몇몇 조경용 수목의 만개일과 기온자료를 활용하여 생물계절에 따른 기본온도와 생장도일(Growing Degree Day, GDD)을 추정하였다. 2011~2012년 조경수목의 만개일를 조사하였으며 수원기상대의 온도자료를 사용하여 일평균온도에서 기본온도를 차감한 생장도일을 계산하였다. 기준온도 설정을 위하여 0.1℃ 단위로 생장도일을 계산하여 2011~2012년 생장도일의 표준편차가 적은 온도를 기본온도로 설정하였다. 그 결과 식물의 기본온도는 진달래, 박태기나무, 팥꽃나무는 1.9℃, 공조팝나무 0℃, 장구밥나무 1.2℃로 나타났으며 만개기의 생장도일은 진달래 324.10±96.32℃, 박태기나무와 팥꽃나무 506.90±84.99℃, 공조팝나무 853.65±59.61℃, 장구밥나무 2112.70±11.74℃이다. 계산된 생장도일을 이용하여 홍릉수목원에서의 예측만개일과 실제만개일 비교 시 진달래의 예측만개일의 45%, 박태기나무의 35% 수준으로 일치하였다. 팥꽃나무는 박태기나무와 만개일이 유사하므로 비슷한 예측 정확도를 보일 것이라 생각된다.