棉铃虫自然种群生命表的研究及其应用

A STUDY ON THE NATURAL POPULATION LIFE TABLEOF COTTON BOLLWORM AND ITS APPLICATIONIN THE PEST PREDICTION

本文通过跟踪观察24593个有效样本,归纳为24个消亡因子,组建了18个世代生命表和3个平均生命麦。剖析了长江下游棉区棉铃虫自然种群数量变动规律,K-值分析和组分(M(si)值)分析说明种群数量变动最大的阶段是在生命前期(即卵至2龄期)。b,r^2值综合分析法表明影响第2、3、4代种群数量消亡的关键虫期分别为4龄、6龄和蛹期。b值分析和K-值图解表明影响种群数量消亡的关键因子:2代为齿唇姬蜂和土壤含水量、风雨冲刮,3代为胡蜂和三突花蛛、小花蝽,4代为滞育和随蕾花脱落、三突花蛛。参考Morris(1963)关键因子逼近法探索了棉铃虫数量预测式。

In this paper, 18 generation life tables and 3 average life tables of cotton bollworm (Heliothis armigera Hubner) were established in Nantong county, Jiangsu province, by continuous observation of 24593 effective samples. The results showed that there were 24 main factors to fluctuate natural population of this pest insect on the lower reaches region of Changjiang River. The results of lvalue analysis and composition analysis showed that the most fluctuating dynamics in population density occured in the early stage of the insect life cyale, namely, the egg stage and the 1st-2nd instar of larvae. The results from the 6-value and r-value comprehensive analysis showed that the key developmental stages within the first generation to fluctuate the 2nd, 3rd and 4th generation populations were the 4th and 6th instar, and pupal stages, respectively. The results of 6-value analysis and k-value curves analysis showed that the key factors for the 2nd generation were Campoletis chlorideae Uchida, and moisture content of soil, and weather (such as wind and rain); those for the 3rd generation were Vespoidea spp., Misumenops tricuspidatus (Fabricius) and Orius similis Zheng, those for the 4th generation were diapause, and drop of flower and bud, and Misumenops tricuspidatus (Fabricius). Based on the key factors approach analysis (Morris 1963), the equation using data of the 2nd generation to predict the 3rd generation was expressed as.lg Nn+1 = l.2616 + 0.588 lg N+ 0.9831 lgp±0.0931 and that for the 4th generation relying on the 3rd generation was expressed as.lg Nn +1 = 2.2026 + 1.7023 lgnNM3 - 0.2679 lgw±0.0862.