عدم تاثیر وزن بر نقطه فوق سرمایی سوسک شاخدار خرما Oryctes elegans

The fruit stalk borer, Oryctes elegans is also called the butter beetle and the palm rhinoceros beetle. It is one of the important dates pests spread in date-growing areas of Asia such as Iran and causes an average of 5-20% damage. This pest causes irreparable damage to the date palm's bud, cluster, and petiole. In low temperatures, the probability of survival depends on factors such as temperature, exposure duration, and the species' cold hardiness. The supercooling point is the lowest temperature at which body fluid begins to freeze. In this research, larvae were collected from palm trees in Bam city and transported to the laboratory. Then the supercooling point of the larvae was determined after weighing each larva to compare the effect of weight on the supercooling point. The sensor end of the temperature recording device was fixed on the body of the larvae by adhesive tape, and to gradually reduce the temperature, the insects were placed in the programmable cooling device. Then, the temperature decreased from 20 °C at a rate of 0.5 °C per minute. The gradual decrease in temperature was recorded by the thermometer device and recorded by Comfort computer software at certain time intervals. The temperature at which a sudden increase in temperature was observed due to the release of the internal heat of the insect's body was recorded as the supercooling point. This experiment was performed in 18 repetitions. After recording the data in Excel software, the correlation of the data was analyzed using the correlation formula, based on which the correlation number was evaluated as -07, which confirms the lack of effect of weight on the super cold point of this pest. The average weight and supercooling point of larvae are respectively: 6.36 gr, and -7.25°C Some studies suggest a link between larval weight and supercooling point, but this study reveals that factors like cryoprotectants, water content, and ice nucleating agents may influence an insect's supercooling ability and body weight alone may not be the main factor determining this.