A solar-powered heat system for management of almond moth, Cadra cautella (Lepidoptera: Pyralidae) in stored dates

The almond moth, Cadra cautella is a worldwide pest that inflicts serious economic damage on dates while on the bunch and during storage. After phasing out of the potent fumigant methyl bromide, extreme temperatures remain an alternative option for the management of this insect pest. A solar-powered heat system was tested for the control of eggs and larvae of C. cautella on fruit of four cultivars, namely Khalas, Shishi, Shibibi, and Khashram. The heating system consisted of an insect treatment chamber, two similar solar collectors, horizontal and vertical air ducts, precision integrated-circuit temperature sensors (lm 35), axial suction fans, and automatic temperature control unit. The delay time required for heating to attain the target temperature of 55 degrees C in fruit of all cultivars was 120 min. The average lethal time (LT95) at 55 degrees C which 95% of the eggs and larvae of C. cautella has died was 52.1 and 52.3 min, respectively. Exposing dates to 55 degrees C for 60 min resulted in total mortality for both eggs and larvae without significant effect on total soluble solids, color, and sugars of all cultivars. Heat treatment of 55 degrees C for 60 min could be applied to dates immediately after harvest as a safeguard against C. cautella infestation.