Peterson R D, Newman S M
Biosciences Research Laboratory, USDA-ARS, Fargo, North Dakota 58105.
J Med Entomol. 1991 Jan;28(1):152-60. doi: 10.1093/jmedent/28.1.152.
The chorion of the Cochliomyia hominivorax (Coquerel) egg is described using observations from scanning and transmission electron microscopy and light microscopy. Included are the gross structure and surface characteristics of the chorion, the basic architecture and internal components of the chorion proper, the location and function of the hatch lines, and the functional morphology of the plastron region as a respiratory structure. In the regular hexagonal arrangement and form of individual structural units, the chorion of the screwworm egg exhibits basic architectural features common to other higher Diptera. Within the open spaces of the endochorionic layer, however, are previously undescribed membranous structures of unknown function which appear to line the cavities of the endochorion. The plastron region partially encircles the micropyle (anterior end) of the egg and extends along the dorsal surface to the posterior pole; it is delineated laterally by the hatch lines. The chorion ruptures along the anterior region of the hatch lines as the larva emerges. The plastron region is composed of elaborate stalked aeropyles above a highly dissected inner reticulum. This structure is believed to function as a respiratory organ when the egg is immersed in fluid.
利用扫描电子显微镜、透射电子显微镜和光学显微镜观察结果，对嗜人锥蝇（Coquerel）卵的卵壳进行了描述。内容包括卵壳的总体结构和表面特征、卵壳本身的基本结构和内部成分、孵化线的位置和功能，以及作为呼吸结构的气盾区的功能形态。在单个结构单元呈规则六边形排列和形态方面，螺旋锥蝇卵的卵壳展现出其他高等双翅目昆虫共有的基本结构特征。然而，在内卵壳层的空隙中，存在功能未知且此前未被描述的膜状结构，这些结构似乎排列在内卵壳的腔壁上。气盾区部分环绕卵的卵孔（前端），并沿背面向后极延伸；其侧面由孵化线界定。幼虫孵化时，卵壳沿孵化线的前部破裂。气盾区由精细的带柄气门在高度分支的内部网状结构上方构成。当卵浸入液体中时，这种结构被认为起到呼吸器官的作用。
