Sterilization of fruit flies (Diptera: Tephritidae) with X-rays for Sterile Insect Technique Programs / Esterilização de moscas-das-frutas (Diptera: Tephritidae) com raios-X para Programas de Técnica do Inseto Estéril

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Recent fear of acts of terrorism provoked an increase of delays and denials in the shipment of radioisotopes. This truly represented a menace to sterile insect production projects around the world. In order to validate the use of a new kind of low-energy X-ray irradiator, a series of radiobiological studies on Ceratitis capitata (tsl-VIENNA 8 strain) (Wied., 1824) (Diptera: Tephritidae) and an Argentinean strain of Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae) were carried out, also comparing biological effectiveness between X-rays and traditional radiation from 60Co. Pupae 48-24 h before adult emergence of C. capitata males and both sexes of A. fraterculus were irradiated with doses ranging from 15 to 120 Gy and 10 to 70 Gy respectively. Doses that induce 50, 90 and 99% of sterility were estimated and the hypothesis of Parallelism for the Probit equations was tested. Doses of 82.7 Gy of X-rays and 128.2 Gy of rays (thus, a RBE =1.5) induced 99% sterility on medfly males. The fertility of A. fraterculus fertile females crossed with 41 Gy of X-rays and 62.7 Gy of rays decreased in 99% comparing with the control group (RBE=1.5). 99% sterility of A. fraterculus irradiated females was achieved with 60-80 Gy (RBE~0.7). The standard quality control parameters of fecundity, adult emergence, fliers and survival were not significantly affected by the two types of radiation (RBE~1) either for medfly or A. fraterculus (p>0.01), being averages in conformity with the values required by FAO/IAEA/USDA. Only fecundity of irradiated A. fraterculus females was severely reduced with increasing doses and no egg was laid at 70 Gy of both radiations. There were no significant differences between X-rays and rays regarding mating indices (RSI for medfly, RII, ISI, MRPI and FRPI for A. fraterculus) (p>0.05), what indicated more random matings for fertile and sterile insects. The results demonstrated that no significant difference in biological effectiveness exist for both kinds of radiations in the usual range of doses applied to produce sterile flies. A new generation of X-rays irradiators can attend now pest control programs of UN member states

ASSUNTO(S)

irradiação ceratitis capitata raios-x radiação gama x-rays irradiation anastrepha fraterculus gamma radiation anastrepha fraterculus ceratitis capitata

ACESSO AO ARTIGO

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