The presence of two castes, the egglayers or queens and the nonegglayers or workerlike females, is demonstrated inA. striata andA. persimilis although the castes are poorly defined. One or more queens may be present in a nest during the spring, at which time all individuals of the colony may perform all nesting activities including the collecting of pollen for the cells. After the first brood has emerged in June, there is only one egglayer per colony, and this individual, although continuing to guard and build cells, does not collect pollen. The other females of the colony, although frequently mated, rarely lay eggs but do carry on all other nesting activities. The queens and nonegglaying females differ in size averaged over the season, but there are no gross morphological differences between the two castes.