The Syntermitinae, also known as the mandibulate nasutes, is a Neotropical subfamily of higher termites represented by 21 genera and 103 species.

[1][2][3][4] The soldier caste of members of this subfamily have a conspicuous horn-like projection on the head which is adapted for chemical defense, similar to the fontanellar gun of true nasute termites (Nasutitermitinae).

However unlike true nasutes, the mandibles of the soldiers are functional and highly developed, and they are unable to expel their chemical weaponry at a distance – instead relying on direct physical contact.

[3][5] Genera range from southern Mexico (Cahuallitermes) to Northern Argentina (Cornitermes, Procornitermes, Rhynchotermes, Syntermes) with the highest diversity occurring in the Brazilian Cerrado.

[3] The first proctodeal segment (P1) of the gut in workers are similar across all genera, distinguished by a generally inflated and globose shape with diverse ornamentation arrangements specialized to certain feeding strategies.