荔枝葉蟎（Oligonychus litchii）在番石榴之分布、最適取樣數估測及族群動態

"Distribution, Estimates of the Optimal Sample Size and Population fluctuation of Oligonychus litchii on Guava"

"在番石榴（Psidium guagava L.）上的荔枝葉蟎（Oligonychus litchi Lo et Ho）為番石榴上最主要之害蟎物種，其危害有日趨嚴重之趨勢。自2014年3月24日至5月27日止於屏東縣長治鄉的番石榴園內進行荔枝葉蟎之田間分布類型研究，應用分散係數、Green`s之Cx指數、Lloyd之平均擁擠度指數（m*）、Lloyd's patchiness index（m*/m）指數、Taylor power law（TPL）之b值、及Iwao's patchiness regression（IPR）之β值等學說評估其空間分布型式，結果顯示番石榴園荔枝葉蟎呈聚集型分布。當採樣精密度（D）設為0.2依Taylor's power law（TPR）及Iwao's patchiness regression（IPR）估算出之最適取樣數，在每葉密度2隻荔枝葉蟎時，田間最適取樣數低於322，當每葉密度達10隻時，其最適取樣數均低於66。自2014年1月至12月於高雄市大社區番石榴園進行田間週年族群動態調查，結果顯示荔枝葉蟎於番石榴園內有2次密度高峰期,分別為3月及11月，6月以後因連續降雨影響致使葉蟎族群密度下降，顯示其田間族群動態受降雨影響。"

"The litchi spider mite, Oligonychus litchii is the most important of spider mites in guava, causes tremendous damages. The spatial distribution of O. litchii in guava orchard in Pingtung County, Taiwan was observed from March 24 to May 27, 2014. The entire indicators as indices of dispersion, Cx of Green, mean crowding (m*) of Lloyd, patchiness index (m*/m) of Lloyd's, b value of Taylor power law (TPL), and the β value of Iwao's patchiness regression (IPR); indicated a clumped dispersion of O. litchii on guava in the study areas. The precision (D) of 0.2, estimated of optimal sample size, based on the assumption of either TPL or IPR both were less than 322 when the density exceeded two spider mites per leaf. The optimal sample size estimated based on the assumption of either TPL or IPR both were less than 66, when the density exceeded 10 spider mites per leaf. While observing the population dynamics of O. litchii in guava orchard in Kaohsiung City, Taiwan from January to December 2014, two peaks of O. litchii was observed, one on March and another on November. This study also observed that population dynamics of O. litchii were highly affected by rainfall."