The genus Lasiodactylus contains four species, the type species L. brunneus Perty from Peru and Brazil, and three new species described here; L. centralis Cline from southern Mexico, Belize, and Honduras, L. falini Cline from Suriname and French Guiana, and L. kelleri Cline from Argentina. Lasiodactylus kelleri inhabits the burrow systems of dynastine scarabs in the genus Heterogomphus and feeds on plant sap flows caused by their feeding. The genus is characterized by at least two unambiguous characters, a well developed triangular supraocular region and mentum with a sulcate anterior margin. Other external characters shared with the Aethina-complex of genera also are described to assess the position of Lasiodactylus within the Nitidulinae. A key to Lasiodactylus species is provided and new country records for L. brunneus are listed.