Behavior of adult alfalfa weevils,Hypera postica(Gyllenhal), was observed in free-choice arenas containing 1)Medicago sativaL. and glandular-hairedM. rugosaDesr. and 2) 4 glandular-haired annualMedicagospecies:M. blancheanaBoiss.,M. disciformisDC.,M. rugosa, andM. scutellata(L.) Mill.The weevils made significantly fewer contacts withM. rugosathan withM. sativain the first 30 minutes of the test. Also, the mean duration of the visits onM. rugosawas significantly shorter than that onM. sativa. Both pre-contact cues (olfactory or visual) and contact cues (chemotactic or mechanical) appeared to be used by the adults in rejectingM. rugosain favor ofM. sativa.The number of initial weevil contacts with each species did not differ significantly in a free-choice test with 4 glandular-haired species. However, significantly more weevils stayed onM. disciformisthan onM. blancheanaandM. rugosa. Differences betweenM. disciformisandM. scutellatawere nonsignificant. Contact cues (unlike pre-contact cues) appeared important to the weevils since these four nonpreferred species differed in the mean number of weevils visiting plants.