甘蓝田四种鳞翅目幼虫的生物学特性及其田间株内分布

作者研究了不同层次甘蓝叶片对四种鳞翅目幼虫(菜粉蝶、小菜蛾、甜菜夜蛾和斜纹夜蛾)生长发育和取食特性的影响。随着叶片成熟度提高(内层→外层),四种幼虫的存活率和生物量积累均逐渐下降,发育历期和总取食量均逐渐增加,但在低、高龄幼虫之间存在一定差异。在田间,低龄幼虫株内分布通常与其卵的株内分布相一致,而高龄幼虫均集中分布在植株中部以内叶片上;甜菜夜蛾和斜纹夜蛾低龄幼虫表现明显的趋边性,高龄幼虫却表现明显的趋中性。作者讨论了叶片营养状况、害虫自身的生物学特性和其它环境因素对四种幼虫田间株内分布的综合影响。

ON THE BIOLOGICAL CHARACTERISTICS AND INTRAPLANT DISTRIBUTION OF FOUR LEPIDOPTEROUS LARVAE DAMAGED ON CABBAGE

The effects of cabbage leaves at different strata on the growth, development and feeding behavior of the larvae of Pieris rapae(L. ) ,Plutella xylostella L. ,Spodoptera ex-igua(Hubner) and Prodenia litura (Fabricius) were comparatively studied in the laboratory. Along with the growing up of cabbage leaves, the larval survivals and pupal weights of all the four species decreased and their developmental durations and totalled feeding amounts increased. There was somewhat differences between the lower and higher instar larvae, the intraplant distribution of lower ones was generally consistent with that of eggs,while all the higher ones mainly aggregated at the middle or inner leaf strata of cabbage plant, and the lower instar larvae of 5. exigua and P. litura obviously approached to the middle and outer leaf strata. The effects of nutrition condition of leaf, bionomic of different species and other enviromental factors on the intraplant distributions of larvae were discussed.