Species are distributed throughout much of the world, including much of the Northern Hemisphere and the Australian region.

Species are separated from those of other genera by the sometimes inconsistent comparison of questionable characters, such as the distribution of minute hairs.

[2] A definition of the genus used by some authors includes characters such as a hairy pronotum and elytra, gena (the spaces below the eyes) longer than the eyes themselves, and a labrum with a line of hairy pores.

[3] This is one of the largest genera of the leaf beetle subfamily Galerucinae, with about 111[4] to 115 species.

[5] The species Pyrrhalta viburni has received attention as a Eurasian beetle introduced to North America with the potential to do significant damage to native and cultivated viburnum plants.