双条杉天牛幼虫龄数的划分(鞘翅目:天牛科)  

Determination of larval instar number Semanotus bifasciatus (Coleoptera: Cerambycidae)

作　　者：蒋琦 任利利[1] 骆有庆[1] JIANG Qi;REN Li-Li;LUO You-Qing(Beijing Key Laboratory for Forest Pest Control,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学林木有害生物防治北京市重点实验室,北京100083

出　　处：《环境昆虫学报》2021年第1期25-30,共6页Journal of Environmental Entomology

基　　金：北京市科技计划(Z191100008519004);国家重点研发计划(2018YFD0600200)。

摘　　要：双条杉天牛Semanotus bifasciatus Motschulsky是危害我国侧柏Platycladus orientalis和圆柏Sabina chinensis的重要钻蛀性害虫,其幼虫龄数及最佳分龄指标的确定是进一步研究其生物学特性、发生规律的基础。本研究通过室内木段饲养法获取不同发育阶段的双条杉天牛幼虫,分别测量幼虫的前胸背板宽、头壳宽和上颚宽3项形态指标。采用频次分析法确定幼虫龄数,运用Crosby生长法则和线性回归进行验证分析。结果表明:双条杉天牛幼虫有5龄,其前胸背板宽符合Dyar氏法则和Crosby生长法则并呈现明显的线性回归关系,可作为幼虫龄数划分的重要指标。1~5龄幼虫前胸背板宽分别为0.574±0.012 mm、1.162±0.013 mm、1.738±0.027 mm、2.760±0.011 mm和3.492±0.015 mm。前胸背板宽(Y 1)和幼虫龄数(X)的最佳线性回归方程为lgY 1=0.185X-0.340(r=0.9647)。本研究明确了双条杉天牛幼虫龄数及最佳分龄指标,为深入研究该虫各生长发育阶段的生物生态学特性提供了参考。Semanotus bifasciatus Motschulsky is an important wood boring pest of Platycladus orientalis and Sabina chinensis in China.The determination of its larval instar number and the best variables separating instars are the basis of further study on biology and damage patterns.In this study,larval samples of different instars were obtained by dissecting damage wood at different time in a year.Then we measured three variables including prothoracic plate width,head capsule width and mandible width.Analysis of frequency distribution was used to determine the larval instar number.Crosby rules and linear regression were taken to check the analysis.Results were as follows:The larvae of S.bifasciatus had five instars.The prothoracic plate width fitted the Dyar and Crosby rules,with obvious linear relationship.It could be regard as the important variable for separating larval instar number.The average width of prothoracic plate width of the 1 st instar larvae was 0.574±0.012 mm,the 2 nd instar 1.162±0.013 mm,the 3 rd instar 1.738±0.027 mm,the 4 th instar 2.760±0.011 mm and the 5 th instar 3.492±0.015 mm.The best linear regression equation of the prothoracic plate width(Y 1)against the instar numbers(X)was:lgY 1=0.185X-0.340(r=0.9647).This study determined the larval instar number of S.bifasciatus and revealed the best variables for instar separation.These findings would provide a reference for the further study of the biological and ecological characteristics of this pest at each development stage.

关 键 词：双条杉天牛 幼虫龄数 前胸背板 头壳宽 上颚宽 

分 类 号：Q968.1[生物学—昆虫学] S433[农业科学—农业昆虫与害虫防治]