The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is the vector of the pathogen presumably responsible for causing huanglongbing, a devastating disease affecting citrus (Sapindales: Rutaceae). It is well established that D. citri populations decrease significantly during winter because of the diminution of young emerging leaves, which are the only site of egg laying and nymphal development. Therefore, this period could be a weak link in the phenology of D. citri, and populations appear to be more sensitive to responsive actions such as insecticide sprays. However, little is known about the distribution of D. citri adults within citrus orchards during winter. We surveyed populations of D. citri in commercial citrus groves in central Florida over the course of 2 yr. In 4 groves, we sampled the citrus canopy at 3 heights and at the 4 cardinal directions. We also investigated the potential for alternative habitats for D. citri and sampled non-crop vegetation and potential alternative hosts over 2 seasons. We did not find a consistent pattern in the distribution of D. citri adults during winter in citrus, with one exception; canopies facing south harbored more psyllids than those facing north. We found that the presence of young emerging leaves was the major factor driving D. citri population increases during winter, but the abundance of D. citri adults was also positively correlated with relative humidity. We also found that the proportion of psyllids with the green-blue morphotype (the morph with greatest dispersal capability and likely the major driver of spring grove infestations) increased after insecticide application and after cold weather. Finally, we investigated the potential existence of alternative hosts on which D. citri could feed and/or reproduce in the absence of young emerging citrus leaves during winter. We did not find evidence of an alternative host during winter for D. citri in central Florida.