玉米螟和桃蛀螟在夏玉米上的生态位及其种间竞争

Niche and Inter-specific Competition Between Ostrinia furnacalis(Guenée) and Dichocrocis punctiferalis (Guenée) in Summer Corn Plants

摘要:

研究了玉米螟和桃蛀螟在夏玉米茎秆和雌穗上的生态位差异及其种间竞争。结果表明，在玉米茎秆上，玉米螟和桃蛀螟的虫口数量接近；在雌穗上，桃蛀螟的数量明显多于玉米螟。两个种群在不同部位的分布显示，玉米螟在茎秆下部和雌穗基部的分布比例较大，桃蛀螟则较多地分布在茎秆下部和雌穗端部。在茎秆上玉米螟的生态位宽度大于桃蛀螟；在雌穗上后者的生态位宽度大于前者。对其空间生态位相似性比例和种间竞争系数进行分析，两者在茎秆和雌穗上的相似性比例分别为0.934 9和0.742 6，竞争系数分别为0.990 9和 0.873 1，玉米螟和桃蛀螟在玉米雌穗上的竞争程度小于茎秆。

Abstract:

This paper studied the difference of niche, as well as inter-specific competition between Ostrinia furnacalis(Guenée) and Dichocrocis punctiferalis(Guenée) in stem and female ear of summer corn. The results showed that the proportion of Ostrinia furnacalis on the stem was approximately equal to Dichocrocis punctiferalis, the number of Dichocrocis punctiferalis was significantly more than Ostrinia furnacali on female ear. The distributions of two species on different parts showed that the proportions of Ostrinia furnacali in the lower part of stem and the basal of female ear were more than that in the other places, and the proportions of Dichocrocis punctiferalis in the lower part of stem and the top of female ear were more than other places. The research showed that Ostrinia furnacalis’s niche breadth in the stem was wider than Dichocrocis punctiferalis, it was contrary in the female ear. The niche analogy in the stem and in the female ear was 0.934 9 and 0.742 6, respectively. The coefficient of inter-specific competition was 0.990 9 and 0.873 1 in the stem and female ear respectively, this result suggested that the competition level of Ostrinia furnacalis and Dichocrocis punctiferalis in the female ear was lower than in the stem.