中臺灣水稻水象鼻蟲族群動態與危害評估

Population Fluctuation of Rice Water Weevil (Lissorhoptrus oryzophilus Kuschel) (Coleoptera: Curcuilonidae) and Assessment of Rice Yield Loss in Central Taiwan

廖君達(Chung-Ta Liao) ； 陳慶忠(Ching-Chung Chen) ； 林正賢(Cheng-Hsien Lin) ； 方敏男(Min-Nan Fang)

《臺中區農業改良場特刊》 60號 (2003/06) Pp. 133-144

https://doi.org/10.29563/ZHWHGX.200306.0039

摘要

水稻水象鼻蟲（Lissorhoptrus oryzophilus Kuschel）於2000年二期稻作在中臺灣水稻栽培區立足，2001年一期稻作普遍發生於臺中縣沿海鄉鎮，2002年一期稻作更擴展至彰化縣西北部鄉鎮，顯示水稻水象鼻蟲正緩慢地向南擴展。水稻水象鼻蟲年發生兩個世代。成蟲於三月中旬達到高峰。三月下旬即可在根部檢出幼蟲；四月下旬幼蟲進入高峰期；五月上旬可檢視到蛹，第一世代成蟲則於五月下旬起陸續羽化。二期稻作插秧後，第一世代成蟲再遷入產卵危害；幼蟲於八月中旬即可檢出，八月下旬至九月上旬為發生盛期；第二世代成蟲則於九月中旬起陸續羽化。水稻水象鼻蟲可在田間殘留之稻椿根際越冬，稻田第一次翻耕後即潛伏於較潮濕之表層土壤。1月中旬，成蟲即遷出越冬棲所，開始取食湛水田區之落粒稻苗。插秧前耕犁耙平作業時，成蟲藉由漂浮或游泳至田埂之土壤縫隙或雜草根際。俟水稻插秧後，遷入田區取食及產卵於田埂兩側的秧苗。一期稻作收割後，水稻水象鼻蟲成蟲並無明顯的越夏蟄伏情形，田埂禾本科食草及再生稻苗葉片持續有受害情況。湛水整地前，稻樁及田埂均可檢視到成蟲。湛水整地後，41.7～100%田埂表土檢視到水稻水象鼻蟲成蟲。試驗結果顯示，當每叢水稻有2隻水稻水象鼻蟲成蟲，可造成正值分蘗期之稻作分蘗數顯著地減少；然而，水稻收割時分蘗數並未達到顯著性差異，可能因水稻旺盛的分蘗補償能力大於受害程度所致。二期稻作調查顯示，當每叢水稻達1.68隻成蟲，才會對水稻產量造成5%以上的顯著損失。

關鍵字

水稻水象鼻蟲 ； 擴展 ； 遷移 ； 危害評估

並列摘要

The rice water weevil (Lissorhoptrus oryzophilus Kuschel) based itself on Taichung Hsien in the 2nd-crop rice, 2000 and soon spread to the coastal townships of Taichung Hsien in the 1st-crop rice, 2001 in central Taiwan. Furthermore, rice water weevil was further invaded to northwest townships of Changhu Hsien, but the trend of southern forward of rice water weevil was slowly. The rice water weevil had two generations all the year round. The adult reached the peak in mid-March and larvae was to be observed on root portion in late-March. The maximum larval density occurred in late-April. The pupa was primarily found on root portion in early-May. The first generation adults were pupated from late-May. After transplanted of 2-nd crop rice, the first generation adult moved to the field and oviposition. The larvae were primary observed in mid-August, and reached the maximum density from late August to early-September. The 2-nd generation adults were pupated from mid-September. The hibernation sites of rice water weevil during unplanted periods were investigated to understand their migrated characteristics. Those results suggested that the adults could be hibernated in the base of rice stubble during unplanted periods of winter season, then hibernated in more moisture surface soil after dry plowed. The adults moved from the hibernation sites to damage the drop-seedling of rice on flooded field in mid-Janarury. Before the transplanted work, the rice water weevil adults were swimming or floating by climbed on the other floated materials to the levees of paddy fields after flood plowed. As rice transplanted, the adults moved to field and damaged the adjacent seedlings from levees. The newly generated adults didn't have an obvious dormant behavior during unplanted period of summer season. Furthermore, grass of Gramineae on levees and the re-born seedlings of rice were damaged lasting resulted from adults feeding. Before flood plowed, the adults were founded both on rice stubble and levees, then the adults moved to the surface soil of levees. When 2 adults were released to each rice plant, the tiller numbers were suppressed during the tiller periods, but not significantly different in the harvest. The compensation capacity of rice tillers could be overcome the damaged caused by larval feeding effects. These results revealed that 1.68 adults per plant would cause 5% rice yield loss in the 2nd crop rice.

並列關鍵字

rice water weevil ； Lissorhoptrus oryzophilus ； spread ； migration ； yield loss assessment