Optimisation of storage conditions for Microplitis manilae (Hymenoptera: Braconidae) cocoons

To optimise the cold storage protocol for 3-day-old cocoons of Microplitis manilae (Ashmead), we evaluated the effects of four temperatures (5°C, 8°C, 11°C, and 14°C) and four storage durations (5, 10, 15, and 20 days) on key biological parameters, including emergence rate, emergence time, total emerged adults, and sex ratio. The results revealed that treatment T13 (14°C for 5 days) produced the most favourable outcomes among all 16 temperature–duration combinations, with emergence time (2.93 ± 0.94 days), emergence rate (73% ± 2.55%), total emerged adults (14.60 ± 0.51 individuals), and sex ratio (0.45 ± 0.05), all of which were the closest to those of the control group (CK; emergence time, 2.60 ± 0.89 days; emergence rate, 92% ± 3.16%; total emerged adults, 15.40 ± 1.03; sex ratio, 0.47 ± 0.03). These findings demonstrate that refrigeration under treatment T13 is the most suitable laboratory storage protocol for 3-day-old M. manilae cocoons and provides technical support for the mass rearing and field deployment of this parasitoid in practical noctuid pest management.