The development and adult emergence patterns of the alkali bee, Nomia melanderi Cockerell 1906, from diapausing prepupae for both laboratory and field reared individuals are compared. Males from both rearing conditions emerged approximately four days before females. Laboratory reared males began to pupate after 800 cumulative degrees centigrade (cdc) and 50 percent had pupated when 1200 cdc was reached. Female pupation began about 900 cdc and 50 percent had pupated when 1300 cdc was reached. Both male and females continued to pupate up to 1800 cdc. The field pupation rate was linear and did not show the sigmoid curve of the laboratory pupation rate. However, 50% pupation for both field and laboratory reared alkali bees was approximately the same at 1300 cdc.