摘要
研究表明，土壤湿度在相当大的范围内对棉铃虫的化蛹及羽化影响不大。土壤相对含水量在９０％以下时，棉铃虫化蛹率一般在９０％以上，羽化率在８０％以上，最适为４０％左右。降雨对棉铃虫入土化蛹的不同时段影响有差异，雨水浸湿土壤，对入土后尚未化蛹的幼虫影响很大，其死亡率接近１００％。化蛹后蛹的死亡率则主要取决于浸水时间的长短。浸水１～２ｄ，对蛹的影响较小，羽化率一般在５０％以上；浸水３～４ｄ，羽化率则一般低于２０％。对近年棉铃虫发生的实况分析也表明，棉铃虫入土时降大雨，后期蛾消长曲线上相应的位置将出现一个低谷。灌水灭蛹以幼虫入土高峰期最为经济有效。
The soil moisture in large range of var iation has little effect on pupation and emergence of cotton bollworm, (Helicoverpa armigera). When relative soil moisture percentage below 90%, the pupation rate of cotton bollworm is over 90% and the emergence rate over 80%. The optimum relative soil moisture percentage is about 40%. Rainfall has different effects on cotton bollworm during different stages after its entering the soil. The soil soaked by rainwater has a great effect on the larvea that have not pupated in the soil , and the larvea's mortality is up to 100%. The mortality of pupae is mainly dependent on the length of flooding time. Soil flooded for 1～2 days has not much effect on pupae, so that their emergencerate is generally over 50%. Soil flooded for 3～4 days usualy leads to the emergencerate of pupae lower than 20%. The analysis based on the occurrence of cotton bollworm showed that a valley would occur on the curve of imagines when the larvea entered soil, accompanied by heavy rain. It is most effective and most economical to water soil to kill the pupae during the upsurge of larvea's entering the soil.
出处
《棉花学报》
CSCD
北大核心
1998年第4期210-215,共6页
Cotton Science
基金
江苏省棉铃虫"九五"攻关项目
关键词
棉铃虫
土壤水分
蛹
存活率
下代影响
Helicoverpa armigera soil moisture survivalrate pupae
