【摘要】 <正> 白背飞虱(Sogatella furcifera Horvath)属远距离迁飞性害虫,河南省各稻区常年普遍发生,局部严重和猖獗年暴发成灾。为了摸清其发生规律,做到适时防治,控制危害,1977—1979年对其地方规律和有关的生物学和生态学进行了研究。兹将结果概述如下。更多还原

【Abstract】 The white back planthopper (W. B. P.), Soggattella furcifera Horvath, is a long-distance migrating insect, and also is one of the important insect pests of rice in the rice growing areas of Henan province.The macropterous adults immigrate into the rice fields from late May to early August every year, but the Maximum immigration occurs in late July to early August. Afterwards, W. B. P. multiplies 3—4 generations in the rice fields and in late August most of the adults migrate out, and the rest may die there at the end of the rice harvesting season.The egg stage lasts for about 8—15 days, the nymphal stage 11—17 days; the preovipositional period averages 3—7 days for the brachypterous and 3—9 days for the macropterous females of the lst-3rd generations. The average number of eggs deposited was 117. 7,70.14 and 36.7 for macropterous adults from the lst generation to the 3rd generation respectively.The average longivity is 13—14 days for the females and 7.5—13 d ays for the males.Under laboratory conditions, the temperature at 25—28℃: was optimal; when the mean temperature raise to 30℃, the survival rate of nymph was low. The effect of the population density of nymph on the developmental rate, survivality of nymph, and adult fecundity have been investigated.Experiments indicated that the close-spacing, excessive fertilizers and standing water field, producing a dense crop stand and thick canopy, always provide a favourable microclimate condition of habitat for the W. B. P.The migration diapause of W. B. P. is closely related to the developmental stage of paddy rice, It was found that the appearance of the adult of the lst generation synchronized with the rice tillering stage at which the females ovaries developed beyond stage 3. When rice crops headed and the lst ovarial developmental stage increased rapidly to 88—100%, immigratory populations would be produced. In order to give further proof of this phenomenon, some lst instar nymphs were caged and reared on rice plants of various growing stages. It also showed that the diapausing individuals at the heading stage of the rice plant are most numerous. When the migratory females were treated with juvenile hormone ZR—777, the diapause is disrupted rapidly. This results indicated clearly that adults migration diapause afte; Heading period was caused by the deficiency of the juvenile hormone.更多还原