metapleural gland
From ZooTerms (Dictionary of Invertebrate Zoology)
metapleural gland: (Arthropoda: Insecta) In most Formicidae, a gland with an external bulla and a small orifice, opening on each side of the metathorax at its lower posterior corners; thought to function as a protection against microorganisms in the nest chamber due to fungistatic and bacteriostatic activity.
