The investigation of summer migration of rice water weevil lissorhoptrus oryzophilus kuschel in double cropping rice area of zhejiang province in 1994 and 1995 indicated that the main cause of its always low population density in second generation is that most of the adults of first generation emigrated from early rice fields for summer and winter hibernation 研究表明，浙江省双季稻区稻水象甲二代虫量低的首要原因是绝大部分一代成虫迁出早稻田夏蛰并越冬，构成二代虫源的比例极微。
Three methods , namely , community species composition similarity analysis , community composition similarity analysis , and community characteristic similarity analysis , were employed to study the similarity of insect pest - natural enemy communities of three rice types ( early rice , middle - season rice and late rice ) and their three development stages ( tilling stage , boot stage and milk stage ) in the yangtze - huaihe region of anhui province 摘要采用群落种组成相似性分析、群落组成相似性分析和群落特征相似性分析3种方法，研究了安徽江淮地区早稻、中稻、晚稻3种稻型及分蘖、孕穗、乳熟3个生育期害虫天敌群落的相似性。
As has been demonstrated by the data in tables 1 , 3 , 5 and 6 , the total average yields of two rice crops have reached 15 , 482 kg / ha ( 7 , 937 kg / ha on early rice and 7 , 545 kg / ha on late rice ) at shaoxing and 14 , 876 kg / ha ( 5 , 943 and 8 , 942 kg / ha on early and late rice respectively at fuyang , the yields have touched or almost close to the yield target required for triple cropping of - " project of 15 ton grain yield per hectare " which is carrying out in the province 表1 、 3 、 5 、 6中数据显示，两季水稻总平均产量在绍兴已达到15 , 482公斤/公顷（早稻7939 ，晚稻7545公斤/公顷） ，在富阳已达到14 , 876公斤/公顷（早稻5943 ，晚稻8942公斤/公顷） ，该产量已达到或接近浙江省推行的吨粮田计划中三季稻的产量目标。
