Characteristics & Similar species
Sobarocephala wirthi resembles the common S. latifrons in sometimes having a strong medial stripe on the scutellum (often reduced), dark bristles and a pale epandrium, but S. wirthi has a rounded (not hook-like) surstylus, the postpronotum is sometimes brown (always yellow in S. latifrons), the epandrium does not have a brown basal spot) and the female abdomen does not have a brown medial stripe.

Three other North American species also have a medial stripe on the scutellum. Sobarocephala pengellyi, known only from Alabama and Georgia, differs in having brown (not black) bristles, a light brown to orange face (sometimes yellow in female), a brown epandrium, a rounded surstylus, female tergites 2-4 are yellow with a thin medial stripe and tergite 6 is entirely brown (not brown laterally). Sobarocephala texensis and some S. setipes also have a faint medial mark on the scutellum, but these spots are ill-defined and darkest medially or anteriorly (not apically). Furthermore, the notal stripes of S. texensis extends anteriorly onto the scutellum and those of S. setipes are strongly divided.

Distribution
Sobarocephala wirthi is an uncommon eastern species found along the coastal states from New Jersey to northern Florida.