水稻水象鼻蟲族群變動及防治

Population Fluctuation and Control of Rice Water Weevil

施錫彬(Hsi-Pin Shih)

《桃園區農業改良場研究報告》 11期 (1992/12) Pp. 33-46

https://doi.org/10.29567/ZHWHGX.199212.0003

摘要

水稻水象鼻蟲（Lissorhoptrus oryzophilus Kuschel）於1990年3月首於桃園縣新屋鄉發現，經兩年之蔓延，被害地區已擴及桃竹苗地區之34鄉鎮，被害稻田達壹萬五千餘公頃，目前仍在繼續蔓延擴散中。據調查本蟲為孤雌繁殖在台灣每年發生兩世代，幼蟲分別為害期間在第一、二期作之秧苗至分蘗期。第一世代成蟲於五月中旬至六月中旬出現後即遷往田埂或防風林、山邊雜草上取食，待第二期作插秧即再遷入稻田產卵為害稻根；第二世代成蟲於十月中旬至十一月上旬出現後再度外遷，並於防風林，田埂雜草地面淺土中或枯葉下越冬，於二月中旬至三月上旬再遷入稻田為害。一期作水稻被害較二期作嚴重，擴散速率也以第一世代成蟲較第二世代為大。高溫與晒田對水稻水象鼻蟲有明顯抑制作用。越冬期間成蟲亦受白殭菌感染，感染率平均為23.5%。水稻水象鼻蟲之成蟲為害稻葉造成白色斑痕，而幼蟲為害水稻根部，阻害稻株生長，株高及分蘗數顯著減少，甚至全株死亡。接蟲試驗結果顯示每叢接成蟲1隻產卵為害，即可導致稻穀產量18.5 %之損失，其經濟為害基準估算為每叢0.25隻。為防治水稻水象鼻蟲，多種使用於秧苗箱處理，水面撒佈或葉面噴佈之藥劑業經篩選，其中以插秧前24小時每秧苗箱使用3% Carbofuran G. 50g之防治效果最為經濟有效。

關鍵字

水象鼻蟲 ； 族群變動 ； 防治

並列摘要

The rice water weevil (RWW) Lissorhoptrns oryzophilus Kuschel, was found firstly at the farm of Taoyuan DATS, Hsin-Wu, Taoyuan Hsien in northern part of Taiwan in March 1990. Since then the pest has spreaded quickly and distributed to cover 34 townships in the prefectures of Taoyuan, Hsinchu and Miaoli during past two years. More than 15,000 ha. of paddy fields per crop season has been recorded to be infested by the pest. RWW has two generations per year. The occurrence of each insect stage in the first and second generation were well synchronized with development of the first and second crop rice. The infestation of RWW in the first crop season was severer than that in the second rice crop, while the pest spreaded its distribution in the second crop seaseon wider than that in the first crop season. High temperatures, drainage of paddy field in the early stage of rice and infection of Beauveria bassiana to the hibernated adults were the important limiting factors to inhibit population of the pest. Assessing the damage caused by RWW indicated that the yield loss exceeded 15% when more than one adult per hill was released. In order to control RWW, many insecticides were used for seedling-box treatment. Broadcast of grarules or liquid foliar application has been screened to evaluate their effectiveness. Use of 3% carbofuran G. at rate of 50 grams per box at 24 hours before transplanting showed the most economic and effectiveness.