This genus is very close to Melanostoma Schiner, 1860, but it differs from this by possessing larger size of the body and the abdomen elliptic, wide and flat, arista bare, central portion of the epistoma moderately proeminent, face narrow and longer and wider styles. While Melanostoma has arista sometimes pubescent, not proeminent epistoma, terminalia with a style thin, straight and uniform, reduced metasternum, legs of males narrow, without bristles, and without patterns of hair or modified piles (from Borges and Pamplona 2003).
The most significant morphological characters to separate Xanthandrus specimens are: postpronotum bare, face and scutellum black, metaepisternum with some fine subappresses pile; metacoxa with a pile tuft at posteromedial apical angle; and antennal pits confluent.
X. nitidulus has the face, in the middle, golden pollinose and lateral margin white pollinose; pleura golden pollinose; wings with costal and subcostal cell pigmented. Abdomen of the male and female with similar yellow maculae on 2nd to 4th terga, or also on 5th tergum.