The phlebotomine sand fly, Lutzomyia shannoni (Dyar), is considered both zoophillic and anthropophillic and may be a potential vector of human and livestock pathogens. While the known range of this species in North America has recently been expanded, many aspects of its natural history, which are fundamental components for assessments of disease risk or development of integrated pest management programs for the vector, remain unclear. One is the time of day when individuals are active and searching for blood meals. Through the use of a rotating trap mechanism, male L. shannoni were found to be active earlier in the evening (1–4 h after sunset), whereas the majority of female activity occurred after midnight.