Moser B A, Koehler P G, Patterson R S
Department of Entomology and Nematology, University of Florida, Gainesville 32611.
J Econ Entomol. 1991 Jun;84(3):922-6. doi: 10.1093/jee/84.3.922.
Two methods to verify whether head width measurements fit Dyar's rule were evaluated for the separation of instars of the cat flea, Ctenocephalides felis (Bouché). Individual rearing was a reliable method of determining larval instar but was labor-intensive. The mean observed head widths were significantly different for each instar (first instar, 0.164 mm; second instar, 0.201 mm; third instar, 0.260 mm) and showed no sexual dimorphism. Head capsule width increased roughly 25% from instar to instar with geometrically progressing growth in accordance with Dyar's rule. However, head capsule width cannot be used to determine the instar of randomly selected larvae because the measurements overlap broadly between instars.
评估了两种验证头部宽度测量是否符合戴尔法则的方法，以区分猫栉首蚤（Ctenocephalides felis (Bouché)）的龄期。个体饲养是确定幼虫龄期的可靠方法，但劳动强度大。各龄期的平均观察头部宽度有显著差异（一龄，0.164毫米；二龄，0.201毫米；三龄，0.260毫米），且无性别二态性。头壳宽度从一个龄期到下一个龄期大致增加25%，呈几何级数增长，符合戴尔法则。然而，头壳宽度不能用于确定随机选择的幼虫的龄期，因为各龄期之间的测量值有很大重叠。
