The Asian citrus psyllid, Diaphorina citri, is the vector for the bacteria causing the citrus greening disease Huanglogbing. This disease has devastated Florida’s citrus industry since D. citri was first introduced in 1998. Field research investigating the distribution and phenology of D. citri was conducted in north Florida over a 2-year period in 2017-2019. We found that Diaphorina citri adult population peaked in July but were still found throughout the winter months despite temperatures dropping to -5.5˚ C. Experiments were conducted with D. citri caged under ambient temperatures for 2 consecutive winters from December to March. 21% of D. citri survived the first winter, with 19% surviving the second. These survival rates are higher than what is expected from literature. Laboratory research into the cold tolerance of D. citri was conducted using reared psyllids. Results showed no significant differences in survival rate between psyllids color or gender. However, cold acclimation significantly increased the psyllid’s survival rate dramatically. Cold acclimated psyllids were exposed to gradual drops in temperature from 24 to 6˚ C. The control psyllids received no cold acclimation. When cold acclimated and control psyllids were exposed to -4 ˚ C for 6h, results show that cold acclimated psyllids have a 60% survival rate, compared to only 20% for the control group. These results suggest that the survival of Asian citrus psyllids in north Florida is facilitated by cold acclimation.
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