Preimaginal production ofCuliseta inornata(Williston) was investigated in temporary fall-flooded breeding sources in the Suisun Marsh and Sierra Nevada foothills of central California. Sources sampled on Suisun Marsh supported significantly more abundant populations of mosquitoes and phytoplankton and associated macroinvertebrates, and fewer predators. Suisun Marsh sources were also characterized by having low dominant taxon diversity. Foothill sources supported fewer mosquitoes, but were trophically more diversified, less productive, and contained a significantly higher number of predator taxa. First-instar larvae ofC. inornatacomprised a significantly high proportion of the preimaginal population in foothill sources, few of which apparently survive to later instars. Experiments with larvae ofC. inornataconfined in screened buckets demonstrated that shorter development time and increased survival occurred in one source sampled on Suisun Marsh. BothC. inornataandCulex tarsalisCoquillett exhibited classical resurgence after the dredging of one source in the Sierra Nevada foothills.