麦叶灰潜蝇的发生及其影响因素初步研究

系统调查了陕西杨凌地区麦叶灰潜蝇(A g romy za cinerascensM acquart)的发生情况,并对其影响因素进行了初步研究。结果表明,在小麦孕穗抽穗期,麦叶灰潜蝇主要危害小麦旗叶、倒2叶和倒3叶等中、上部叶片,其中以倒2叶受害最重;每个虫斑内有幼虫1~4头不等,其中有1,2,3,4头幼虫的虫斑数分别占总虫斑数的73.81%,20.96%,3.51%和1.72%;不同塬区、不同田块之间,麦叶灰潜蝇的发生情况均有显著差异;不同塬区麦叶灰潜蝇的发生程度,以一道塬最重,二道塬次之,三道塬发生较轻;不同塬区麦叶灰潜蝇发生的严重程度与小麦植株密度有密切的负相关关系,但同一塬区不同田块的发生情况并不完全支持这一结论。相关分析表明,麦叶灰潜蝇的发生情况与小麦株高、旗叶面积、倒3叶面积均无明显的相关关系,但与倒2叶面积呈显著相关。

Preliminary studies on occurrence of the leaf-miner,Agromyza cinerascens Macquart and its affecting factors

This paper deals preliminarily with occurrence of the lea-fminer,Agromyza cinerascens Macquart and its affecting factors in field conditions in Yangling area,Shaanxi province. Results showed that the leaf-miner mainly injured the flag leaf,the second and third leaf on the plant top from booting stage to heading stage of wheat and the third top-leaf was most seriously injured. There were 1-4 larvae in a leaffed spot. Percentage of leaf-fed spot with the larvae of 1,2,3,4 were 73.81%,20.96%,3.51% and 1. 72% respectively. Significant differences in occurrence degrees of the flies were found in various terraces or fields. The most serious injury was seen in the first terrace, next the second terrace and the least in the third terrace. Significant negative effect was assessed between wheat densities of the fields and occurrence degrees of the leaf-miner,i, e. the less plant density of wheat,the more serious occurrence degree. Correlation analysis showed that occurrence degrees of the leaf miner were not significantly related to plant height or areas of the flag leaf and the third top-leaf of wheat ,but significantly related to areas of the second topleaf.