浙江省双季稻区稻水象甲致害种群的形成

１９９４－１９９６年对浙江省双季稻水象甲Ｌｉｓｓｏｒｈｏｐｔｒｕｓ ｏｒｙｚｏｐｈｉｌｕｓ Ｋｕｓｃｈｅｌ春季迁飞的系统研究表明，以飞行肌发育起点温度１３．８℃以上的有效积温结合当地，当日起飞时段的天气情况预测越冬代成虫的行入峰期是完全可行的。越冬成虫的第１波下迁一般出现在效积温达７０－９０日度时，主迁峰刚行的。

ON THE FORMATION OF DESTRUCTIVE POPULATION OF RICE WATER WEEVIL IN DOUBLE RICE CROPPING AREA OF ZHEJIANG PROVINCE,CHINA

There are two generations of rice water weevil (RWW) Lissorhoptrus ory-zophilus Kuschel per year in the double rice cropping area of Zhejiang Province, but only the larvae of first generation damage early rice. The results of studies on spring migration of RWW from 1994 to 1996 indicated that the effective temperature constant (ETC, measured by day degrees) over 13. 8 C , the developmental zero of its flight muscle, and local weather conditions at the time it takes off are quite available for predicting the immigration peak time of overwintering generation adult. The first immigration wave will generally occur in the ETC range from 70 to 90 day degrees, and the immigration peak will occur in a wider ETC range from 90 to 140 day degrees, depends on the weather condition. The optimum conditions for spring immigration of RWW are rather high temperature (>20C) and calm or breeze of wind, so its takeoff will generally begin at 16:00 and stop at the time the air temperature drops under 20 C. The precipitation in early spring and early and middle April can reduce the development rate of flight muscle and delay the occurrence of first immigration wave, and the occurrence of immigration peak is usually determined by the rainfall in April and early May.