A13: Packer, L. and G. Knerer. 1987. The biology of a subtropical population of Halictus ligatus Say (Hymenoptera; Halictidae). III. The transition between annual and continuously brooded colony cycles. Journal of the Kansas Entomological Society. 60:510-516.
Abstract: In north temperate regions Halictus ligatus has an annual colony cycle as found in almost all other social sweat bees. However, in the extreme south of Florida, this species is continuously brooded and multivoltine (i.e., it has overlapping colony cycles with one complete cycle lasting for a few months) and the matrifilial societies exhibit a markedly reduced reproductive division of labour. Several series of collections were made along the length of Florida to determine where the transition between the annual and continuously brooded colony cycles occurs. An annual colony cycle seems to be retained at least as far south as Tampa; the continuously brooded populations are restricted to the extreme south of Florida.