蔬菜花期蓟马的种群动态与空间分布研究

西花蓟马是近年来在我国局部地区暴发成灾的重要外来入侵害虫,有关西花蓟马入侵对本地蓟马种群动态、空间分布及优势种影响的报道较少。对云南省昆明市近郊蔬菜花期的蓟马种群动态和空间分布研究表明,蔬菜上的蓟马种类主要是西花蓟马Frankliniella occidentalis(Pergande)、花蓟马F.intonsa(Trybom)、棕榈蓟马T.palmi(Karny)和端大蓟马Megalurothrips distalis(Karny);不同蔬菜上的蓟马优势种存在一定差异,其中辣椒和茼蒿上的蓟马优势种为西花蓟马;韭菜、茄子和四季豆上的蓟马优势种分别为花蓟马、棕榈蓟马和端大蓟马。各蔬菜上的蓟马种群数量以花期为多,盛花期达最大值,其中茄子花上的蓟马成虫平均虫口密度最高,为14.93头/朵。利用聚集度指标进行空间分布检测表明,不同蔬菜上蓟马成虫的空间分布型均为聚集分布,且聚集程度随密度的增加而增大。本研究可为深入探讨西花蓟马对本地蓟马的竞争取代机制积累资料,同时为西花蓟马的综合治理奠定理论基础。

Population dynamics and spatial distribution of thrips on vegetables flowers

The western flower thrip, Frankliniella occidentalis （Pergande）, is an invasive insect pest that currently occurs in several Chinese provinces where it causes serious economic loss. There have been only few studies on the population dynamics, spatial distribution and dominant species of thrips after invasion by F. occidentalis. We investigated the population dynamics and spatial distribution of thrips on vegetable flowers in the suburbs of Kunming in 2012. Our results show that four species of thrips, F. occidentalis , F. intonsa （ Trybom ） , Thrips palmi （Karny） and Megalurothrips distalis （Karny） were the main thrip species on vegetable flowers. The dominant species differed on different vegetables. The dominant thrip species on pepper and crowndaisy chrysanthemum was F. occidentalis, whereas F. intonsa, T. palmi, M. distalis were dominant on fragrant-flowered garlic, eggplant and kidney beans, respectively. Thrip populations increased rapidly when the plant flowering period started, peaking during the blooming stage. The highest density of thrip adults was found on eggplant flowers （14.93 individuals/flower）. Spatial distribution was tested with an aggregation index, the results of which show that adult thrips on vegetable flowers became progressively more aggregated with increasing density. Results of the present study may provide information for the study of competitive mechanisms between local thrips and the invasive F. occidentalis, and lay a foundation for the integrated pest management of F. occidentalis.