Longevity of Trissolcus japonicus

To evaluate the female longevity of the Beijing USDA and Manno lines of <i>T. japonicus</i>, as well as their hybrids, female wasps were isolated upon emergence and maintained at 25±1°C, 50-90% RH and a 16L:8D photoperiod. Females were provided either with food (honey) or just water. For the treatment with food, two to four females from each female isoline of the F2 and F3 generations were maintained together in 0.025l vials sealed with sponges (n = 96 ♀ / parental or hybrid line). A drop of liquid honey on the sponge served as food, and a small piece of cellulose paper was added to provide hiding spaces. For the ‘water only’ treatment, four female wasps from each female isoline of the F1 and F3 generations were individually placed in small Petri dishes (5cm diameter) containing water-soaked cotton rolls (n = 96 ♀ / parental or hybrid line). Food and water supplies were replenished three times weekly. At the same time wasp survival was recorded and dead individuals were removed. Longevity was calculated as the average lifespan per female isoline and filial generation. Since in some cases wasps were lost over the duration of the experiment due to unnatural reasons (e.g., wasps were stuck in the honey) the number of replicates per line and generation varied between 79 and 96.