饲料喂养方法评估草地贪夜蛾对玉米田多种植物的适应性

Evaluating the Adaptation of Spodoptera frugiperda to Various Plants in Corn Field via Artificial Diet Method

了解不同植物对植食性昆虫生物学特性的影响是昆虫-植物互作研究的基础,对制定有效的害虫防控策略具有重要意义。入侵害虫草地贪夜蛾(Spodoptera frugiperda)可能危害的植物多达353种,但大多数寄主植物对其生物学特性的影响尚不清楚。采集植物新鲜叶片饲喂植食性昆虫幼虫是研究的通用方法,而此方法受气候、地理位置、植物生长周期等条件的限制。以玉米(Zeamays)为参照,选取玉米农田及其周边的6种作物和杂草为试验材料,包括大豆(Glycine max)、豇豆(Vigna unguiculata)、番薯(Ipomoea batatas)、艾草(Artemisia argyi)、油麦菜(Lactuca sativa)和黄瓜(Cucumis sativus)。将上述植物的新鲜叶片统一采集、磨成粉末,按1%比例掺入人工饲料中,分别用这些饲料喂养草地贪夜蛾幼虫,观测其存活(幼虫存活率、化蛹率、羽化率)、生长(幼虫增重、蛹重、相对生长率)、发育历期(幼虫期、预蛹期、蛹期)和食物利用情况(相对消耗率、近似消化率、食物转化率、消化转化率)等,探究草地贪夜蛾取食这7种植物后的生物学特性。为验证植物叶片粉末饲料喂养方法的可行性,同时采集上述植物的新鲜叶片分别喂养草地贪夜蛾幼虫。结果显示大豆、豇豆是草地贪夜蛾适宜的寄主植物;而番薯、艾草、油麦菜对草地贪夜蛾的生长发育具有抑制作用,若将其运用于玉米间作系统中,可减轻草地贪夜蛾的为害。运用层次分析法建立指标评价体系进行量化评分,结果表明,植物粉末饲料和新鲜叶片喂养的效应一致,且前者限制条件少、操作简便,可较好地评估农田植物对草地贪夜蛾生物学特性的影响。

Understanding the effects of different host plants on the biological characteristics of herbivorous insects is the basis for the study of insect-plant interactions, and is of great significance for effective pest management strategies. The invasive pest, fall armyworm Spodoptera frugiperda, may damage plants as many as 353 species, but the effects of most host plants on its biological characteristics are still not clear. Feeding the fresh plant leaves to the larvae of herbivorous insects is the common method, but it is limited by climate, geographical location, plant growth cycle and so on. In this study, Zea mays was used as a reference, and 6 crops and weeds in and around corn fields were collected as experimental materials, including Glycine max, Vigna unguiculata, Ipomoea batatas, Artemisia argyi, Lactuca sativa and Cucumis sativus. The fresh leaves of the above plants were uniformly collected and then ground to powder. The powder of different plants was added to the artificial diets at a ratio of 1%, then was used to feed the larvae of S. frugiperda respectively. The survival(i.e., larval survival rate, pupation rate, eclosion rate), growth(i.e., larval gain weight, pupal weight, relative growth rate), development period(i.e., larval period, prepupal period, pupal period), food utilization(i.e., relative consumption rate, approximate digestibility, efficiency of conversion of ingested food, efficiency of conversion of digested food) were investigated to explore the biological characteristics of S. frugiperda after feeding the above diets. In order to verify the feasibility of the plant leaves powder feed method, the fresh leaves of the above plants were also collected uniformly and fed to the larvae of S. frugiperda respectively. The results showed that G. max and V. unguiculata were the suitable host plants for S. frugiperda. While I. batatas, A. argyi and L. sativa presented negative effects on S. frugiperda, which may reduce the harm to corn when the plants were intercropped with corn. With the help of analytic hierarchy process(AHP),a quantitative grading index evaluation system was established to compare the two methods quantitatively. As a result, the effects of diets and fresh leaf feeding were consistent, and the plant leaves powder diet method has few restrictions and easy operation, which is better evaluating the effects of farmland plants on the biological characteristics of S. frugiperda.