Face

Pronunciation
/FAYSS/
Category
Anatomy
Singular
face
Plural
faces

Definition

The (frontal) surface of the in insects and other , bounded laterally by the and/or genae, dorsally by the , and ventrally by the and mouthparts. In many insects—especially flies (), , and (Hymenoptera)—the face is distinctly sclerotized and often bears important taxonomic characters including facial grooves, , or color patterns. The term is also applied to the corresponding anterior region of the prosoma in arachnids, though this usage is less precise than in insects.

Etymology

From Old French 'face', from Latin 'facies' (form, appearance), ultimately from facere (to make).

Example

In hoverflies (), the face often exhibits distinctive yellow or silver markings that serve as key identification characters; in crab spiders (Thomisidae), the flattened prosoma creates a broad, 'facial' aspect that accommodates the enlarged anterior .

Synonyms

  • facies (in some older literature)
  • front (less precise)

Related Terms

  • frons
  • clypeus
  • Gena
  • Vertex
  • Occiput
  • Prosoma
  • Facial tubercle
  • Facial groove

Usage Notes

In entomology, 'face' is more specific than 'front of ' and excludes the vertex and occiput. The term is sometimes loosely applied to the of the in arachnids, but prefer 'prosoma' or '' for . Facial characters are diagnostically important in many fly , where the face may be concave () or convex, bare or pollinose, and variously patterned.