【摘要】 1973～1981年进行了一系列试验来研究处于低纬度的广东翁城(24°22＇N)、始兴县(24°57＇N)和广州(23°N)第四代三化螟幼虫光周期诱发滞育的效应。结果表明,光周期是诱发滞育的主导因子。在自然光温条件下,光周期短于13小时显著地诱发三化螟滞育,长于14小时则促进化蛹,属典型的长日长反应型。在25℃条件下,始兴县和广州种群的临界日长分别为13小时20分和13小时18分。幼虫对光周期反应起累积效应。在25℃,LD13.5:10.5、LD14:10、LD15:9和LD24:0条件下,其临界日数依次为18、14、13和10天。幼虫对光周期反应具后效作用,短光周期不能使接受过长光周期的非滞育幼虫倒逆。广东4～5世代区第4代三化螟发育分化而形成局部世代的原因得到科学的解释。更多还原

【Abstract】 A series of experiments was carried out from 1973 to 1981 to investigate the effects of photoperiod on larval diapause of the paddy borer in the 4th generation in Shi Xing County (24°57′N) , Weng Cheng (24°22′N) and Guang Zhou(23°N) in South China.It was shown that a short photoperiod is a major factor for larval diapause induction of the paddy borer. The day-length shorter than 13 hr. caused the larval diapause induction while the day-length longer than 14 hr. accelerated greatly the larvae to pupate whithout diapause in natural temperature in laboratory. The critical day-length estimated for the borer population in Shi Xing County at 25℃ is 13 hr. 20 min. and 13 hr. 18 min. in Guang Zhou. The cumulative effect of long day-length was shown in the borer to photoperiodic response. The critical day number (CDN)required to produce 50 per cent pupation in the condition of 25℃ and photoperiod of LD 13.5:10.5, LD 14:10, LD 15:9 and LD 24: 0 was 18, 14, 13 and 10 days respectively. And the after-effect of photoperiodic response was shown in the borer. All the larvae of the 4th generation treated previously in 25℃ and long day-length (above LD 13:11) pupated in natural condition in October and November.Although South China is in lower latitude, the photoperiodic response in the borer is very obvious. The cause that a part of the 4th generation of the borer in South China could develop into the 5th generation and other major part of the 4th generation occurred diapause, has been evidently explained. A part of the 4th generation of the borer, that developped early and became the 3th instar larvae before the date (September 15th) of the critical day-length, could continue to develop and became the 5th generation. Other major part of larvae of the 4th generation, that developped late and still were younger than 3rd instar before the critical day-length, occurred diapause. Surviving larvae of the 5th generation also occurred diapuse later.更多还原