Polyphenism ofHalictus (Seladonia) tumulorum (L.) (Hymenoptera,Halictinae)

Summary A population ofHalictus (S.) tumulorum, a species whose biology is poorly known, was studied in eastern France. The polyphenism was evaluated by comparing a sample of foundresses (1991) with two samples of summer females (1991 and 1992).H. tumulorum is a primitively eusocial species with castes differing only slightly in size, but more in function, and producing numerous males in the first brood. The social level of the species appears rather low.