Cold storage possibility of Cryptolaemus montrouzieri adults

Cryptolaemus montrouzieri (Col.: Coccinellidae) is the most important predator of mealybugs in citrus and tea orchards in north of Iran. Cold storage is necessary in order to have a sufficient numbers of this ladybird and its release at desired times. This study was therefore carried out to assess the possibility of storing adult stage of this ladybird under refrigerator conditions (5±1˚C, 60±10% RH and full darkness). Male and female adult ladybirds were stored at low temperature for different durations of 5, 7, 10, 14 and 30 days. After each storage period, the adults’ mortality was recorded in each treatment and was compared with the control. Survived ladybirds were then paired and transferred to the separate Petri dishes and kept in a growth chamber (26±2 °C, 60±5% RH, and 16:8 h L: D) and their fecundity data were recorded daily until the death of ladybirds. Results showed that cold storage significantly decreased their survival, longevity and fecundit. Mortality percent of males and females increased with storage duration from 29.39±5.2 and 25.78±4.8 percent in five days treatment to 100 percent in 30 days treatment, respectively. Female longevity ranged from 99.8±2.2 days in control to 51.5±2.3 days in 14-days treatment. Meanwhile, mean of oviposition in female ladybirds decreased from 4.99±0.06 to 4.51± 0.07 eggs/day. In conclusion, the adult stage of this ladybird was more susceptible to low temperatures than other stages and their long-term cold storage (longer than seven days) is not recommended.