CONICET | Buscador de Institutos y Recursos Humanos

The South American fruit fly, Anastrepha fraterculus, constitutes an important fruit pest in many countries of the region. As the Sterile Insect Technique has shown to be an effective method to control Ceratitis capitata in Argentina, its implementation against A. fraterculus has been proposed. This technique relies on matings between sterile mass-reared males and wild females. Therefore it is essential to verify that artificial rearing does not affect male mating competitiveness. In this study, we evaluated several morphometric characters in order to detect differences between a wild population and a laboratory strain derived from it, and kept under artificial rearing since 1997. Eight morphometric traits were analysed as indicators of global size, head shape and potencial mobility: Thorax Length, Head Width, Face Width, Eye Length, Wing Length, Wing Width, 3rd Tibia Length, and Femur Length. The results were analyzed by MANOVA, linear multiple regression, and logistic multiple regression. As a general trend, laboratory flies were larger than wild ones, which may be related to larval diet being supplied ad libitum. Laboratory males showed significantly larger Head Width and Eye Length and lower Wing Width than wild males. Laboratory females only differed from wild ones on having narrower wings. These results could be the outcome of gradual adaptation to laboratory conditions, were flight ability could become less important (as resources are easily found at close distance). Conversely, short-distance interactions between individuals become more frequent, and that could favour an increase in facial trait sizes. As these morphological changes could represent the beginning of intraspecific differentiation, a periodical evaluation of the three characters detected here as selection targets should be carried out.