In a lemon grove located at Rio Bravo, Tamaulipas, Mexico, during 2011–2012, a study was conducted through direct observations and video films to determine the predatory behavior of the Mexican honey wasp, Brachygastra mellifica (Hymenoptera: Vespidae), on the various developmental stages of the Asian citrus psyllid, Diaphorina citri, one of the most devastating citrus pests in the world. New flushes infested by eggs and the 5 instars of D. citri were manually exposed to this predator to study its preference for the different developmental stages. Other observations on its feeding behavior were made directly on infested flushes in the trees, during the foraging activity of the vespid. Results indicated that B. mellifica preferred the 4th and 5th instar D. citri nymphs more than the 2nd and 3rd instars. Eggs and first instar nymphs were mostly passed over because of their size and position in the flush. Occasionally, B. mellifica consumed D. citri adults. This predator represents a potential tool for natural control of D. citri in northern Mexico and southern USA through a program of management and conservation of beneficial insects.