SixMedicagoL. species were evaluated in a no-choice oviposition test for the alfalfa blotch leafminer (ABL),Agromyza frontella(Rondani). TheMedicagospecies consisted of the annual diploidsM. disciformisDeCandolle andM. blancheanaBoissier; the annual tetraploidsM. rugosaDesrousseaux,M. noeanaBoissier, andM. scutellata(L.) Miller; and the perennial tetraploidM. sativaL. var. ‘Arc’. More eggs were laid onM. sativaleaflets than on the otherMedicagoentries. ABL preferred to oviposit on nonglandular-hairedMedicagoentries. Density and pinholes, numbers of simple, glandular, and procumbent glandular hairs, and area of the leaflets were measured for each species entry and analyzed by multiple-regression techniques to determine their importance in ABL oviposition. Density of glandular hairs appeared to affect ABL oviposition the greatest. The regression model, however, did not account for the total egg variation in this preference test (R2= 0.31).