Corium

Definition

In entomology, the thickened, leathery basal portion of a hemelytron—the forewing of a true bug (Hemiptera). The corium lies between the clavus (inner basal lobe) and the membrane (distal membranous tip), and together with the clavus forms the hardened, protective part of the forewing that covers the hindwing and abdomen at rest. In many heteropterans, the corium bears distinctive color patterns, punctation, or setation useful for species identification.

Etymology

Latin corium, meaning leather or hide, referring to the thickened, hide-like texture of this wing region.

Example

In the stink bug genus Halyomorpha, the corium is typically mottled brown with dark punctures, while the membranous tip is transparent; damage to the corium during molting can impair flight and increase desiccation risk.

Synonyms

• corial region

Related Terms

• hemelytron
• Clavus
• Membrane
• Cuneus
• embolium
• Hemiptera
• forewing
• Hemelytra

Usage Notes

The corium is diagnostic for Hemiptera and should not be confused with the uniformly membranous forewings of other insect orders. In some families (e.g., Miridae), a small triangular cuneus separates the corium from the membrane; in others (e.g., Pentatomidae), the corium extends nearly to the wing apex with only a narrow membranous margin. The term is sometimes used loosely for any leathery basal wing region, but precise usage reserves it for the hemelytral structure of Heteroptera and related groups. Do not confuse with the unrelated nuclear engineering term corium (reactor meltdown material) or the anatomical term for dermis.