Cornea of ommatidia in Lepidoptera (Insecta)--a scanning electron microscope study

Area of Science:

• Entomology
• Insect Morphology
• Surface Ultrastructure

Background:

• The external surfaces of insects play crucial roles in sensory perception, locomotion, and protection.
• Understanding the diversity of cuticular structures in Lepidoptera can provide insights into their evolutionary adaptations.

Purpose of the Study:

• To describe and illustrate the external surface structures of wing facets in 19 families of Lepidoptera.
• To identify and characterize distinct types of surface structures, noting their prevalence.
• To investigate the potential origins and ultrastructural details of these surface features.

Main Methods:

• Microscopic examination of the external surfaces of wing facets from representative species across 19 Lepidoptera families.
• Detailed illustration and description of observed morphological structures.
• Ultrastructural analysis, including descriptions of surface granulation.

Main Results:

• Two primary types of external surface structures were identified: nipple-like structures and pleats.
• Nipple-like structures were found to be the predominant type across the studied families.
• Pleat-like structures were also observed, with a hypothesis suggesting their development through a reduction process.
• The ultrastructure of the surface was characterized by granulation.

Conclusions:

• The external facet surfaces of Lepidoptera exhibit distinct structural types, primarily nipples and pleats.
• The prevalence of nipple structures suggests a significant functional or developmental role.
• The presence of pleats may indicate evolutionary reduction, a process worthy of further investigation.
• Granulation forms a key component of the ultrastructural surface morphology in these insects.