Irradiation as a quarantine treatment against Ceratitis capitata
As a quarantine treatment against Ceratitis capitata (EPPO A2 quarantine pest), gamma irradiation with a dose of 150 Gy has previously been proposed. Further studies have been carried out on eggs and larvae exposed at different ages to a series of gamma radiation doses ranging from 5 to 1280 Gy, in order to define the minimum doses required to prevent egg hatch, pupation and adult emergence. Results showed that relatively low doses could prevent development beyond the pupal stage. None of the eggs exposed to 20 Gy or larvae treated with 40 Gy survived to the adult stage. Tests in which more than 100000 mature larvae were treated in air with a dose of 40 Gy resulted in no adult emergence. In a small scale experiment, similar results were obtained when 3rd instars were irradiated inside natural host fruits (orange and peach). Previous studies took as an efficacy criteria the lack of egg hatch or pupation and proposed the dose of 150 Gy to ensure quarantine security. The authors felt that this dose may be injurious to many fruit species, and they consider that a more appropriate criterion for efficacy, such as lack of adult emergence, should be envisaged; and when this criterion is chosen, a minimum dose of 40 Gy is sufficient.
Sources
Mansour, M.; Franz, G. (1996) Gamma radiation as a quarantine treatment for the Mediterranean fruit fly (Diptera: Tephritidae)
Journal of Economic Entomology, 89(5), 1175-1180.