论文部分内容阅读
本文是报道1977～1980年棉花红铃虫Pectinophora gossypiella(Saun-ders)田间种群消长及杀虫剂对其影响。研究结果表明红铃虫成虫数及卵量在上海郊区除1977年外,基本表现为逐代递增的第三代多发型;1977～1980年蛾量与卵量发生不一致,这与成虫产卵期的气侯因子有关。红铃虫第二、三两代的卵量和棉铃被害关系密切。第二、三两代产卵盛期这一批的卵孵化后为害棉铃的程度,在8月上中旬和10月中旬前后吐絮花中的单铃幼虫数中得到反映。由于每年红铃虫发生量不同,杀虫剂对其影响也有差异。在发生轻的年份7～9月用药2～4次其单铃幼虫数与对照比较,其差异不显著。但中等发生年与大发生年,在第二代、第三代成虫产卵高峰前各用药一次可以减少虫50％以上。这表明可以减少田间用药次数。作者另对红铃虫第一代是否要进行防治,第二、三代的防治指标以及早期用药对棉田天敌影响等问题进行了讨论。
This article is to report the effects of insecticides on the population decline and the population of Pectinophora gossypiella (Saun-ders) from 1977 to 1980 in cotton fields. The results showed that the number and number of eggs of pink bollworm in Shanghai suburbs in 1977, except for 1977, the basic performance of the third generation of multiple generations from generation to generation; 1977 to 1980, the amount of moray and the occurrence of inconsistent egg, and adult spawning period Of the climate factor. The second and third two generations of red bollworm eggs and cotton bolls were closely related. In the second, third and second generation of spawning period, the number of eggs that hatched after the hatching of the eggs was reflected in the numbers of single bell-bee larvae in the mid-August and mid-October. As the annual occurrence of pink bollworm insecticides have different effects on them. In light of the years from July to September medication 2 to 4 times the number of single bell bells compared with the control, the difference was not significant. However, in the middle of the year and the year of big occurrence, the second generation and the third generation adults use the medicine once before the spawning peak can reduce the insects by more than 50%. This shows that we can reduce the frequency of field use. The author also discussed whether the first generation of red bollworm should be controlled, the second and third generations of prevention and control indicators and the impact of early use of drugs on natural enemies in cotton fields.