Diptera as predators in biological control: applications and future perspectives

The role of dipteran predators in biological pest control programs is reviewed and discussed. Diptera encompasses a large number of potentially efficient predators for biological pest control, yet only a few species are routinary used. The families Syrphidae and Cecidomyiidae provide some of the most successful examples of biological control, but other families (e.g., Muscidae, Sarcophagidae, Sciomyzidae) also include species with that potential. Most applications of Diptera as predators involve the conservation biological control approach, while the augmentative approach has involved only a few species, almost exclusively of Syrphidae and Cecidomyiidae. In a few cases, classical biological control has been employed. Commercialization of species mainly to be used in the augmentative approach is discussed, also focusing on the critical issues linked to rearing methods. The dual services performed by Diptera (pollination as adults and biological control as larvae) have been studied in detail for Syrphidae only, but would deserve further study in other families, e.g., Sarcophagidae. This is the first review in which the use of predatory Diptera in biological control programs is investigated for all families and in all types of applications. This review recommends a multi-taxon approach in the use of Diptera in biological control since a large number of taxa have considerable potential, although this has not yet been tested in practical applications.