Ovipositional behavior in the context of mass rearing of Anopheles arabiensis

Large-scale production of mosquitoes is a key factor for a successful sterile insect technique program. A manageable mass-production cage must contain appropriate features for adult resting, mating, feeding, and ovipositional activities. In order to maximize egg collections, tests were conducted to determine the physical characteristics of ovipositional sites for caged Anopheles arabiensis. Effects of texture, shade, height, and shape of the ovipositional container on female behavior were investigated. Results indicate a strong preference for oviposition on humid substrates over free-standing water. The shade and texture of the cup's walls also influenced site choice, with black rough inner vertical walls of the cup resulting in the largest number of eggs. Ovipositional sites with square shape were preferred rather than circular cups, and in the square cups, >60% of the eggs were laid in the corners. Height also affected oviposition, as An. arabiensis significantly favored the lowest sites even though some oviposition occurred at higher sites. Based on this study and from available literature, we determined the characteristics of an artificial ovipositional site that includes all these characteristics, which will yield large numbers of eggs required for mass production of this species.