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粘虫是吉林省粮食作物的大害虫。本文为作者于1953—1962年研究粘虫的一部分工作,目的在于分析吉林省粘虫发生猖獗世代的虫源问题。我们怀疑春季出现的大量成虫有两种可能来源:(1)本地越冬的成虫、蛹或幼虫;(2)由外地迁入。通过研究分析,所得结果如下: 1.粘虫在吉林省一年完成两个世代。春季发生的第一代是猖獗世代,幼虫为害盛期在6月下旬至7月上旬,其繁殖虫源主要来自5月下旬到6月上半月出现的成虫。 2.粘虫在当地的入冬虫态,有幼虫、蛹及成虫。经过发生地的越冬调查及野外试验,证明粘虫在东北和内蒙地区的自然条件下不论何种虫态,均不能越冬。 3.据粘虫抗寒力测定,在-8℃恒温下,幼虫、蛹、成虫均迅速死亡,在-5℃下最长只能存活3—7小时,在1±1℃下全部死亡的理论时间为成虫19.95天、幼虫44.67天、蛹25.70天。查当地1、2两月旬平均气温最高-9.4℃,最低-16.5℃,田间5厘米深的土温为-12.4—-9.4℃,均超过虫体的死亡低温。 因此,粘虫不可能在吉林省越冬,从而可以推断猖獗世代的虫源,是由外地迁入的。
Army worm is a large pest of food crops in Jilin Province. This article is part of an effort by the author to study armyworm in 1953-1962 with the aim of analyzing the source of the worm in rampant generations of armyworms in Jilin Province. We suspect that there are two possible sources of large numbers of adults in spring: (1) native wintering adults, pupae or larvae; (2) migrating from the field. Through research and analysis, the results obtained are as follows: 1. Mythimna separata in Jilin Province one year to complete two generations. The first generation occurred in spring is rampant generation, larvae peak in late June to early July, the main source of its breeding insects from late May to the first half of June adult. 2. Mythimna separata in the local state into the winter, larvae, pupae and adults. After the occurrence of overwintering surveys and field experiments, it was demonstrated that armyworms can not winters no matter what their natural state is under the natural conditions in the northeast and Inner Mongolia. According to cold-resistant armyworms measured at -8 ℃ constant temperature, larvae, pupae, adults died rapidly, at -5 ℃ maximum survival only 3-7 hours, at 1 ± 1 ℃ all died The theoretical time is 19.95 days for adults, 44.67 days for larvae, and 25.70 days for pupae. Check the local 1,2 month ten-day average maximum temperature of -9.4 ℃, the lowest -16.5 ℃, field 5 cm deep soil temperature of -12.4 - 9.4 ℃, are more than the dead body temperature. Therefore, it is impossible for the armyworm to win the winter in Jilin Province, so that it can be concluded that the source of the rampant generation is migrated from other places.