荔枝大造桥虫幼虫龄数的划分  

Division of larval instars of the litchi giant looper,Ascotis selenaria(Lepidoptera:Geometridae)

作　　者：董易之[1] 陈炳旭[1] 徐淑[1] 李鹏燕[1] 

机构地区：[1]广东省农业科学院植物保护研究所,广州510640

出　　处：《环境昆虫学报》2011年第4期552-556,共5页Journal of Environmental Entomology

基　　金：国家荔枝龙眼产业技术体系-虫害防控岗位(CARS-33-06)

摘　　要：近年来,大造桥虫Ascotis selenaria(Denis&Schiffermüller)在荔枝上发生严重危害。幼虫龄数的确定是开展害虫生物生态学研究和制定防治措施的基础。目前,国内外对大造桥虫幼虫龄数的划分存在争议。本研究通过田间取样和室内饲养,采集大造桥虫各龄幼虫。测定其头壳宽度,并根据头壳宽度的频次分布推测大造桥虫幼虫分6龄。利用Crosby指数和指数曲线拟合进行验证,结果均表明该幼虫分6龄是合理的。1～6龄幼虫的头壳宽度分别为0.301、0.534、0.940、1.544、2.307、3.374mm。Abstract： The litchi giant looper Ascotis selenaria （Denis ＆ Schiffermtiller） has become one of the seri- ous pests in Litchi in recent years, which infests young leaves and shoots. The larval instar numbers should be determined before further studying on its biology, ecology and IPM. However, division of larval instars of A. selenaria is in dispute. In this study, larval samples of different instars were collected from both the field and the laboratory, and the head capsule width of the larvae was measured. The results showed that the larvae were divided into 6 instars based on the frenquency histograms of head capsule width, which was verified by the Crosby＇s ratio and exponential curve fitting. The head capsule width of 1^st instar larvae was O. 301 mm, the 2^rd instar O. 534 mm, the 3^rd instar O. 940 mm, the 4th instar 1. 544 mm, the 5^th instar 2. 307 ram, the 6^th 3. 374 mm.

关 键 词：大造桥虫 幼虫龄期 头壳宽度 Crosby指数 指数曲线拟合 

分 类 号：Q968[生物学—昆虫学]