Influence of Temperature, Photoperiod, and Supplementary Nutrition on the Development and Reproduction of Scutellista caerulea Fonscolombe (Hymenoptera: Pteromalidae)

SIMPLE SUMMARY: Parasitoids are the natural enemies of many pests. Using parasitoids is a valuable method for controlling pests. However, to effectively use parasitoids, it is necessary to understand their optimal living conditions. Scutellista caerulea Fonscolombe (Hymenoptera: Pteromalidae) is an important enemy of pestiferous scale, Parasaissetia nigra Nietner (Hemiptera: Coccidae). To identify the optimal conditions for the population growth of S. caerulea, we assessed how temperature, photoperiod, and supplementary nutrition affected its development and reproduction. Our results revealed that the most suitable conditions for the population growth of S. caerulea was at 30 to 33 °C, with 12 to 14 h of daily light, and the provision of sucrose or honey as supplemental diet. These results provide a reference for the indoor rearing of S. caerulea. ABSTRACT: Scutellista ciruela Fonscolombe has a significant controlling effect on the rubber tree pest, Parasaissetia nigra Nietner. To identify the optimal conditions for the population growth of S. caerulea, we assessed how temperature, photoperiod, and supplementary nutrition affected its development and reproduction. The results demonstrated that the number of eggs laid and parasitism rates of S. caerulea were the highest at 33 °C. The developmental rate of S. caerulea was the fastest and the number of emerged adults the highest. The number of eggs laid and the parasitism rates increased when the light duration increased within a day. Females did not lay any eggs when the whole day was dark. At a photoperiod of 14:10 (L:D), the developmental duration was the shortest and the number of emerged adults was the highest. Adult life span was the longest under a 12:12 (L:D) photoperiod. During the adult stage, supplementary nutrition, such as sucrose, fructose, honey, and glucose, increased the life span of S. caerulea. The life span of S. caerulea was longer when provided with a supplementary diet of sucrose or honey, compared to other tested diets. The results suggested that the most suitable conditions for S. caerulea’s population growth were the following: 30 to 33 °C, with 12 to 14 h of daylight, and the provision of sucrose or honey as supplemental diet for the adults.