桉树新害虫——曲线纷夜蛾的生物学和生态特性研究

曲线纷夜蛾Polydesma boarmoides Guenée是我国桉树食叶害虫,已在部分桉树种植区造成严重危害。国内外仅在区域昆虫种类调查中发现并提及该虫,而未见其生物学特性、生态学特性和发生规律等方面的相关研究报道,因此,有必要对该虫进行更系统、深入的研究,为防控该虫提供依据。笔者2013年5月首次发现该虫在广东省紫金县危害桉树林,2016年5月再次发现该虫在茂名市危害桉树林。调查、研究结果表明:(1)曲线纷夜蛾起始取食灌木叶片直至叶片被取食殆尽后,逐步转移至桉树林继续取食桉树叶片;(2)曲线纷夜蛾在广东地区1年发生4代;(3)曲线纷夜蛾3-5龄幼虫在桉树林间呈现聚集分布,且聚集密度呈现随种群密度增大而增大的规律,而在桉树树冠上则呈均匀分布。

Preliminary report on biological characteristics and ecological characteristics of Polydesma boarmoides Guenée,a new defoliator on Eucalyptus in China

Polydesma boarmoides Guenée was a new defoliator on Eucalyptus in China, which had seriously harmed part of eucalyptus in the eucalyptus planting area. The insect were only found and mentioned in the survey of regional insect species at home and abroad, but no morphological, biological, ecological characteristics and occurrence regularity were reported. Therefore, it was necessary to carry out a more in-depth systematic study of this pest to provide basis for the prevention and control of it. In May 2013 , it was first found to endanger eucalyptus forest in Zijin County, Guangdong Province. In May 2016, it was once again found to endanger eucalyptus forest in Maoming city, Guangdong Province. The results of investigation and research showed that, the initial feeding of it was shrub leaves until the food exhausting, and then gradually transferred to eucalyptus forest to continue feeding to supplement nutrition; It occurred about 4 generations in one year in the Guangdong area; 3 -5 instar larvae of it showed aggregation distribution in Eucalyptus forest, and the aggregation density increased with the increase of population density, while uniform distribution in the eucalyptus crown.