Cibdela janthina is a sawfly of the family Argidae.

This species originates from Sumatra in South-East Asia but had also been introduced to La Réunion in 2007 for biological pest control of Rubus alceifolius, a Rosaceae species that had become an invasive species.

It has a metallic dark-blue colour, the males have a length of approx.

[2] A parasitoid of C. janthina is Proterops borneoensis.

This sawfly-related article is a stub.