High temperature pulses decrease indirect chilling injury and elevate ATP levels in the flesh fly, Sarcophaga crassipalpis.

Indirect chilling injury commonly occurs during long-term exposure to low temperature in many organisms including insects. A previous study revealed increased rates of survival and reduced cold injury in flesh flies, Sarcophaga crassipalpis, that experienced an intermittent pulse of high temperature during a low-temperature regiment. We extended these studies by determining survival rates and ATP levels for flies that had undergone continuous long-term exposure at 0 degrees C versus those experiencing a 24-h warming pulse of either 15 or 20 degrees C. Survival among flies that had undergone a warming pulse was significantly greater than for flies that were maintained continuously at 0 degrees C. Furthermore, ATP levels of flies that had experienced a warming pulse were significantly higher than those of flies maintained at 0 degrees C. These data suggest that brief warming pulses during long-term cold storage allow regeneration of energy reserves that promote survival and reduce indirect chilling injury.