小地老虎与粘虫发蛾期同步现象的探讨

小地老虎(Agrotis ypsilon)在江苏一带,每年春季都有很大的蛾量出现,与为数极少的越冬虫量很不相符。这批虫源是哪里来的?有人推测是外地迁飞来的,有人则认为是本地越冬的。富有启发性的问题是:小地老虎在我国不但有种种迁飞的迹象,而且越冬代蛾常与粘虫、(Mythimna separata)同期发生,有明显的同步关系。粘虫具有远距离迁飞习性,在国内已为研究所证实,因此深入探讨它们之间的同步现象,就能为小地老虎的迁飞提供旁证,有利于搞清越冬代蛾的虫源性质。

A STUDY ON THE SYNCHRONIZATION OF THE OCCURRENCE OF TWO NOCTUIDS THE BLACK CUTWORM AND THE ARMYWORM

The black cutworm(Agrotis ypsilon)cannot overwinter in Jiangsu.Comparing it with the armyworm(Mythimna separata),We have observed that,there exists synchronization between these two noctuids.The moths of these two noctuids appear almost simultaneously in the spring.The peaks of moth appearance are similar.They both show sudden outbreak within a relatively large area.The development of the ovary,the fluctuation of the sex ratio of the moth and the mating habit of these two pests are all alike.The long-distance migration of the armyworm has been recognized by many entomologists.The synchronization of occurrence of the armyworm and the black cutworm in spring may be cosidered as an indirect evidence of the migration of the latter.