Resumo. Cassava crops hold high agricultural importance in Paraná State, Brazil. However, cassava root production is adversely impacted by pests. Aleyrodids, in particular, cause great damage to cassava fields, necessitating better knowledge of predators found in these agroecosystems and novel biological control strategies for integrated pest management. This study reports the first occurrence of the predatory lady beetle Delphastus argentinicus Nunenmacher, preying on all life stages of whiteflies in cassava fields. Given the economic and social importance of cassava crops in Brazil and the deleterious potential of aleyrodid species, it is recommended to conduct behavioral and bioecological studies assessing the application of D. argentinicus as a biocontrol agent in integrated pest management programs.