Queens ofDolichovespula maculata(L.) were collected before the hibernation period in the fall, before and shortly after nest initiation in the spring, and after colonies had produced more than two worker broods. Fresh and dry weights were determined for all queens, and a seasonal comparison of the energy reserves of lipids, sugar, and glycogen was performed on the thoracic and abdominal tagmata. Total nitrogen also was quantified to estimate protein changes by season. The results show that during hibernation, 70.1% (101.8 mg) of the lipid reserves, 79.4% (26.0 mg) of the sugar reserves, and 84.8% (6.9 mg) of the glycogen reserves were used. Furthermore, lipid use accounted for 35% of the dry-weight loss, sugar use 12%, and glycogen use 6%. Total thoracic nitrogen remained constant throughout the year, whereas abdominal nitrogen was the same in the fall and spring queens but increased in the summer queens. The results of this study suggest that most queens that survive the winter and successfully initiate nests have similar quantities of energy reserves. The implications of solitary foraging behavior are discussed.