A line ofPhaseolus vulgarisbred for resistance toZabrotes subfasciatus(RAZ 2) was tested in parallel in Uganda and Colombia to determine whether resistance identified in laboratory bioassays reflected in reduced losses when beans were stored for periods ranging from 4 months in Uganda to 8 months in Colombia. RAZ 2 was highly resistant to both insect strains. As compared to local susceptible cultivars, significantly lower numbers of insects emerged from RAZ 2. As a result, seed damage and weight losses in the resistant line were negligible. Results of the storage trials confirmed those of laboratory tests and illustrated the potential of resistance as a method of control to reduce losses caused byZ. subfasciatusin beans in the tropics.