Lutzomyia verrucarum (Townsend) is an abundant anthropophilic phlebotomine sandfly in the Peruvian Andes between 1500 m and 3000 m asl, where it has been incriminated as a vector of both Leishmania peruviana (cutaneous leishmaniasis) and Bartonella bacilliformis (bartonellosis). Previous studies of this vector demonstrated that sandfly activity, measured by sticky traps, was related to crop type. In this paper, we report the results of a field experiment in Peru (Department of Ancash) which show that a single human host in a crop does not attract Lu. verrucarum from distances of 5 m or more, and that there is a positive correlation between the number of Lu. verrucarum collected by sticky traps and the number attracted to a human host in the same field. The results imply that variation in sandfly activity between crop types could lead to differential risk of both leishmaniasis and bartonellosis for humans working at night in different crops.