ABSTRACTFour new species of Laboulbeniaare described, adding substantially to the known species recorded from Heteroptera hosts. Previously, only 12 species of Laboulbeniaand only 96 of the approximate 2325 known species of Laboulbeniales have been recorded on the Heteroptera. The addition of these four new species of Laboulbenia, occurring on two genera within Veliidae, brings the total number to 100 species. These species are recorded on the genera Paraveliaand Oioveliacollected from Brazil, Suriname, and Peru.