Legend
  1. labellum
  2. labium
  3. maxillar palp
  4. labrum
  5. subgenal area
  6. clypeus
  7. fronto-orbital area
  8. front-orbital bristles
  9. external vertical bristle
  10. internal vertical bristle
  11. postocellar bristles
  12. ocelli
  13. ocellar bristles
  14. compound eye
  15. frontal or ptilinal suture
  16. antenna
  17. arista
  18. vibrissa