The larva and/or puparium of the Neotropical syrphids Habromyia coeruleithorax Williston, 1888, Palpada furcata (Wiedemann, 1819), and six species of Meromacrus Rondani, 1848, are figured, described, and compared with other similar larvae. All of these larvae are similar in external form, having mouthparts adapted for filtering suspended items of food, retractile anterior spiracles, prolegs with crochets, and extended anal segments (=long-tailed larvae). Each species varied in the size and distribution of integumental setae and spicules and in the size and form of the pupal spiracles. Keys are provided to identify genera of Neotropical long-tailed syrphid larvae and to separate the six species of Meromacrus: M. acutus (Fabricius, 1805), M. currani Hull, 1942, M. draco Hull, 1942, M. laconicus (Walker, 1852), M. loewii (Williston, 1892), and M. obscurus Hine, 1924. Larvae of all these species were found in tree holes, except for M. draco, which was associated with decaying bananas, and P. furcata, which occurred in a waste heap of decaying coffee pulp.