A new generation of X ray irradiators for insect sterilization.
Recent fears of terrorism have provoked an increase in delays and denials of transboundary shipments of radioisotopes. This represents a serious constraint to sterile insect technique (SIT) programs around the world as they rely on the use of ionizing radiation from radioisotopes for insect sterilization. To validate a novel X ray irradiator, a series of studies on Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) were carried out, comparing the relative biological effectiveness (RBE) between X rays and traditional gamma radiation from 60Co. Male C. capitata pupae and pupae of both sexes of A. fraterculus, both 24-48 h before adult emergence, were irradiated with doses ranging from 15 to 120 Gy and 10-70 Gy, respectively. Estimated mean doses of 91.2 Gy of X and 124.9 Gy of gamma radiation induced 99% sterility in C. capitata males. Irradiated A. fraterculus were 99% sterile at approximately 40-60 Gy for both radiation treatments. Standard quality control parameters and mating indices were not significantly affected by the two types of radiation. The RBE did not differ significantly between the tested X and gamma radiation, and X rays are as biologically effective for SIT purposes as gamma rays are. This work confirms the suitability of this new generation of X ray irradiators for pest control programs that integrate the SIT.
Mastrangelo
T
T
Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Avenida Centenário 303, Caixa Postal 96, 13400-970 Piracicaba, SP, Brazil. piaui@cena.usp.br
Parker
A G
AG
Jessup
A
A
Pereira
R
R
Orozco-Dávila
D
D
Islam
A
A
Dammalage
T
T
Walder
J M M
JM
D000818:Animals; D033622:Ceratitis capitata / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D008297:Male; D010572:Pest Control, Biological / Q000379:methods*; D033621:Tephritidae / Q000528:radiation effects*; D014965:X-Rays