At temperate latitudes, no life cycle is complete without the ability to exploit the favorable season, to avoid (migration) or mitigate (dormancy) the unfavorable season, and to make a timely transition between the two lifestyles. Many temperate arthropods, birds, fish, and mammals use the length of day as a seasonal clock to anticipate seasonal change and physiologically prepare in advance for that change. The genetically-determined "setting" of this clock varies with climate over the geographic ranges of animals, but it is not clear to what degree the clock mediating seasonal events is genetically independent of the (circadian) clock mediating daily events in the lives of animals. Towards understanding the genetic connection between the seasonal and daily clocks, replicate lines selected for divergent expression of the seasonal clock have been developed in the pitcher-plant mosquito, Wyeomyia smithii through prior NSF support. They are unique: No other such lines exist for any animal. Maintenance of the selected lines is essential for their future use in this and other labs for determining the physiological processes responsible for seasonal adaptation. Understanding these processes is important because, ultimately, they affect how animals are able to disperse over broad geographical ranges where they encounter novel seasonal environments, and to persist when confronted with rapid climate change, including global warming. This award will be used to support the maintenance of the selected lines, an important biological resource.