Life cycle, population parameters, and predation rate of the hover fly Eupeodes corollae fed on the aphid Myzus persicae

Abstract

To improve the effectiveness of biological control procedures, it is necessary to quantify the survival rate of a natural enemy through the various stages of the life cycle, the fecundity rate, and the predation rate from birth to death. It is not only important to obtain all the parameters associated with a life table, but also to quantify the predation rate in the life table framework. For this purpose, the life history, population parameters, and predation rate of Eupeodes corollae (Fabricius) (Diptera: Syrphidae) were determined using Myzus persicae (Sulzer) (Hemiptera: Aphididae) as prey and the age-stage, two-sex life table methods. As predators released in biocontrol programs are mass-produced from small populations with a consequent loss of genetic variability, we used specimens from a laboratory colony with similar characteristics. The highest mortality was found in the egg stage (54%). The mean developmental time of the pre-adult stage was 13.70 ± 0.08 days. In the adult stage, the mean longevity was 23.81 ± 1.14 days, with the males living longer than the females. The total pre-oviposition period was 17.62 ± 0.45 days and the mean female fecundity was 169.81 ± 29.65 eggs per female. The population parameters indicated that the population grew with a net reproduction rate of 32.87 ± 7.25 offspring per individual and an average generation time of 23.05 ± 0.65 days. The values related to the number of aphid nymphs consumed by the larvae were: a mean predation rate (cxj) of 485.20 ± 11.61 nymphs, a net predation rate (C0) of 216.68 ± 16.89, and a finite predation rate (ω) of 28.03 ± 1.18. The obtained results support the use of E. corollae as valuable resource in the biological control of aphids, specifically M. persicae. Moreover, the technique implemented in this paper allows the objective comparison of E. corollae capacity as control agent with that of other aphidophagous hover fly species and other aphid natural enemies.