The Melanostomini are a tribe of hoverflies. The tribe was first described as the subfamily Melanostominae by Williston in 1885. The tribe has at times been considered to be synonymous with Bacchini.

Description

Williston first described the group to include the genera Pyrophaena, Platycheirus (as Platychirus), and Melanostoma as follows:

Small, elongate, thinly pilose species, deep black or shining green, the abdomen usually slender, with interrupted bands of bright yellow, orange or greenish yellow color (Syrphus simplex from the West Indies has a black face and entire shining metallic abdominal cross-band); face uniformly black, or at least never with light ground-color. Antennae short, face tuberculate, marginal cell of wing open, third longitudinal vein of wing only gently curved, anterior cross-vein near the base of discal cell; legs slender, hind femora never thickened.

The modern concept of the group has changed considerably from this initial description.

A 2020 molecular phylogenetic study found that Bacchini sensu lato should be divided into two groups: Melanostoma and related genera (i.e., Melanostomini), and Baccha and related genera (i.e., Bacchini).