Application of extreme temperatures in date disinfestation: sustainability in practice

Abstract: Larvae and adults of Carpophilus hemipterus (L.) were tested on Medjool date
variety at -10 °C and -18 °C and at 45 °C, 50 °C, and 55 °C for 15 to 120 min of exposure times
for mortality and disinfestation of dates. After exposure to -18 °C within 2 h of exposure time
100 % mortality was obtained for the adult stage of C. hemipterus and 98.75 % for the larval
stage. At -10 °C, the adult stage was more susceptible (80.53 %) than the larva stage (45.35 %). The times required to produce control at LT99 of the different stages of C. hemipterus exposed at 45 °C were in the order of sensitivity was adult > larva for C. hemipterus, which was controlled within 8.2 h. At 50 °C, all stages are controlled within 0.514 h. Exposures to 55 °C were also carried out at time intervals of 7 and 15 min. In all trials, 100 % mortality was
achieved in both tested life stages. Complete control was achieved at elevated temperatures
after exposure to 50 °C and above. The disinfestation of the larvae stage was approximately
double at both tested temperatures of -10 °C and -18 °C compared to the adult stage of
C. hemipterus. When the disinfestation effect is compared among all tested temperatures,
results indicate that the higher the temperature, the greater is the disinfestation effect up to
50 °C, 98 % for adults and 97 % for larvae, and above it, it decreases.