蜂巢小甲虫幼虫龄期的划分

Division of larval instars of Aethina tumida (Coleoptera:Nitdiuldae)

蜂巢小甲虫(Aethina tumida Murray)是寄生蜜蜂的重要害虫,近年入侵我国并呈严峻的扩散蔓延态势。幼虫龄期的确定是进行发育生物学研究和害虫预测预报防治的基础。目前,国内外对蜂巢小甲虫龄期的划分鲜有报道。本研究通过测量蜂巢小甲虫幼虫头壳宽、体长、体宽和触角间距4个指标,并根据所测数据的频次分布图以及Dyar法则推断蜂巢小甲虫幼虫龄期数为3龄。1、2、3龄幼虫头壳宽度的平均值分别为265.37±1.62、441.41±3.67和709.74±4.63μm,触角间距的平均值分别为173.78±0.94、298.61±2.34和441.88±2.23μm。经Crosby法则、线性回归、二次多项式回归和指数回归的方法验证,结果均表明该幼虫分为3龄是合理的,头壳宽可作为龄期划分的最优形态特征指标,体长和体宽变异性较大,不宜作为幼虫龄数划分的标准。

The small hive beetle,Aethina tumida Murray,is a parasitic important pest of honeybee. In recent years,it invaded our country and formed spreading tendency. The determination of larval instar is the basic work before studying developmental biology,carrying out prediction and making control measures. However,division of larval instars of A. tumida has been reported rarely. In this study,instars of A.tumida were studied by measuring 4 indexes of head capsule width,body length,body width and antenna distance. The results showed that the larvae were divided into 3 instars based on the frequency distribution analysis and the Dyar’s rule. The head capsule mean width from the 1st to 3th instar was 265.37±1.62、441.41±3.67 and 709.74±4.63 μm,respectively. The antenna mean distance from the 1st to 3th instar was173.78 ±0.94、298.61 ±2.34 and 441.88 ±2.23 μm,respectively. The results is rational,which verified by the Crosby’s ratio,linear regression,quadric polynomial return analysis and exponential regression. The head capsule width can be used as the optimal index of larval instars division of A. tumida,while body length and body width have large overlap in measurements between instars,so they are not suitable to be used as the standard.