The Samia cynthia ricini chorion was observed for its surface and inner structures by scanning electron microscopy. A micropyle opening was present at the anterior pole region of the chorion surface, surrounded by 12 to 20 petal-shaped cell imprints forming a single rosette. There were 6 to 10 "sperm ducts," dangling from the inside surface of the chorion at the anterior pole region; these were connected to the micropyle and probably facilitated the polyspermy. All surface areas were confirmed to have network patterns made of comparatively uniform polygonal imprints. Aeropyles opened at the junction of three polygonal units, and there was an additional large hollow at the intermediate region of each polygonal unit. Cross-sections of the chorion revealed three layers, the outer, middle and inner layers. The middle layer, which was the thickest, was further divided into the upper, intermediate and lower parts; the aeropyles and the additional hollow penetrated almost to the intermediate part. The intermediate part was characterized by irregular lamellae, which were porous and thus may facilitate gas changes.
All Science Journal Classification (ASJC) codes
- Insect Science