精準農業試驗田區水稻主要蟲害之監測

Abstract

為配合精準農業遙測分析之需求，進行地面實際之蟲害發生種類與數量消長調查，期能與遙測資料相呼應。除89 年度外，其餘年度之調查採樣點採均可定位之設計，每次調查結果皆以MS Excel 檔記錄，可供其他遙測結果分析時參考，計畫期間各期作調查的害蟲皆以鱗翅目之瘤野螟蛾（Cnophalocrocis medinalis (Guenéé) ）與二化螟蛾（Chilos suppressalis ( Walker ) ）危害較明顯，大螟（Sesamia inferens walker ）僅在89 年第一期作有發生，往後即未再發現。褐飛蝨（Nilararvata lugens ( stål )）, 斑飛蝨(Laodelphax striatellus (Fallen)）, 黑尾浮塵子(Nephotettix spp.）等同翅目及綠樁象(Nezara viridula L.）、稻細蟎（Steneotarsonemus spinki Smiley）等皆為零星發現，密度在經濟危害水準以下。瘤野螟與二化螟通常於第二期作為害較嚴重，且前者較早出現為害徵狀，族群起伏在89 至91 年度都較大。92 年第一期作此二種害蟲發生情形與往昔不同，自第5 次調查5 月21 日開始直至採收不見危害，而二化螟之為害蘗數卻開始增加，至採收前平均每25 叢仍有3.7蘗被害，此可能影響第二期作之族群密度。 The Lepidopterian pests, rice leaffolder (Cnaphalocrocis medinalis (Guenéé)) and rice stem borer (Chilo suppressalis (Walker)), were the major targets surveyed during the cropping seasons in this study. The occurrence of other minor pests was also recorded. The pink borer (Sesamia inferens (Walker)) occurred in the First Crop of 2000 but was not found in later the following crops. The Homopterian pests, brown planthopper (Nilaparvata lugens (Stål)), smaller brown planthopper (Laodelphax striatellus (Fallen)) and green rice leathopper (Nephotettix spp.), southern green stink bug (Nezara viridula L.), and rice tarsonemid mite (Steneotarsonemus spinki Smiley) were found scarcely, their population densities were bellow the Economic Injured Level. Rice leaffolder and rice stem borer usually presented more in the second cropping seasons. Generally the injured symptoms induced by rice leaffolder appeared more earlier than that induced by rice stem borer, and the population density of rice leaffolder fluctuated much more stronger than the rice stem borer. In the first cropping season of 2003, the occurrence of these two major insects was different than the normal years. Rice leaffolder disappeared suddenly from the 5th collection on 2lth of May until harvest, while injury caused by rice stem borer increased gradually; there were 3.7 plants injured by this pest per 25 rice tussocks before harvest. Such phenomenon is expected to influence the population density of these two insect pests in the second cropping season.