Abstract
Sphaerophoria macrogaster (Thomson) (Diptera: Syrphidae) is an important predator of Myzus persicae (Sulzer) (Homoptera: Aphididae). In this study, the morphological characteristics and living habits of S. macrogaster were observed and recorded. It evaluated the variations in developmental rate and predatory capacity of S. macrogaster when preying on M. persicae under five constant temperature regimes (16-32°C). Regression analyses assessing the relationship between temperature and the developmental rates of the egg, first, second, and third larval instars, and pupa of S. macrogaster were performed. In addition, the life table of hoverflies with M. persicae as prey at 28°C was determined. The results demonstrated that development rates at the egg, larval, and pupal stages gradually increased as the temperature increased from 16 to 32°C. The highest threshold temperature occurred at 7.93°C, in the egg stage. The threshold temperature and effective accumulated temperature of the whole generation of S. macrogaster were 5.56°C and 312.50° days, respectively. The larvae consumed more prey at 20°C than at other temperatures; however, the maximum value of the larva predation was 28.3 M. persicae per larva at 28°C, and the average duration of S. macrogaster development was 14.3 days from egg to adult emergence. The mortality of the egg stage of S. macrogaster was 18.0%, and the survival rate from the egg hatch to the adult stage was 58% at 28°C. These results provide valuable information for the release of S. macrogaster into managed systems to reduce M. persicae infestations under a wide range of temperature conditions.