lig·u·la 
(lĭgyə-lə)
(lĭgyə-lə)n. pl. lig·u·lae (-lē′) or lig·u·las
A strap-shaped or tonguelike structure, especially the terminal portion of the labium in the mouthparts of certain insects.
[Latin, diminutive of lingua, tongue; see dghū- in the Appendix of Indo-European roots.]