冀中南地区二点委夜蛾主害代幼虫田间消长与暴发为害规律

Population dynamics of larvae of the moth Athetis lepigone and crop damage caused by this pest in central and southern Hebei province

【目的】二点委夜蛾Athetis lepigone(M?schler)主害代幼虫在麦秸下隐蔽危害玉米幼苗,早期难以发现。本文研究其在田间的消长动态和暴发危害规律。【方法】2014-2016年间,在河北省中南部进行广泛监测,选择在二点委夜蛾的重灾区开展调查。从玉米播种后进行系统监测,一旦发现有幼虫的田块,每天进行调查,其中在邯郸的馆陶县和沧州的南大港得到了完整数据。【结果】玉米田二点委夜蛾主害代幼虫消长规律呈现Peal-Reed曲线,具体表现为在田间发现幼虫后,虫量迅速增加,维持高水平后开始化蛹,而后开始迅速下降。玉米苗被害株率随时间呈现S曲线,玉米苗出现被危害后,被害株率迅速增加,4 d后被害株率达到最高值,然后趋于稳定。【结论】本研究证实了二点委夜蛾属于生态型气候性害虫,具有暴发性强、危害迅速的特点,其结果为二点委夜蛾科学防治提供了理论依据。

[Objectives] Larvae of Athetis lepigone （M6schler） damage maize seedlings when these are under wheat straw making this damage difficult to detect at an early stage. This study aims to clarify the relationship between the population dynamics of these larvae and crop damage caused by them. [Methods[ Extensive monitoring was conducted in central and southern Hebei Province between 2014 and 2016. Study plots were situated where A. lepigone damage was serious and monitoring began after corn sowing. Plots were investigated daily once larvae were found and complete datasets were obtained in Guantao county and Nandagang district. [Resultsl Population growth and crop damage approximated the Peal-Reed curve. Larvae increased rapidly in abundance after they were first detected, but declined rapidly after they began to pupate. The proportion of damaged plants also increased rapidly after damage was first detected and approximated an ＂S＂-shaped curve over time. The peak proportion of damaged plants was recorded in only 4 days. [Conclusion] Under particular ecological and climatic conditions A. lepigone has the capacity for explosive population growth and can rapidly damage a high proportion of maize crops. This study provides a theoretical basis for the scientific control of A. lepigone.