CONICET | Buscador de Institutos y Recursos Humanos

We postulate that the physiological state of an insect could be determined independently of its chronological age, through evaluation of behavioural, cellular and molecular indicators. The main orchard pest, Ceratitis capitata, was used as biological model to study functional senescence. As general indicator of the normal state of tissues we determined the corresponding profile of structural, storage and signal lipids. Thus, the demographic parameters for single-sex flies populations maintained under standard laboratory conditions (23ºC, 60% RH, L:D 16:8 h), were correlated with age-dependent changes in lipid composition that may reflect the physiological decline. The components of main lipid categories of fly populations of different ages were analyzed by quantitative and semi-quantitative methods. Using multivariate analysis we found significant changes in the proportion of lipid categories with age, which were condensed in a reduced variable. At the same time, we performed behavioural experiments to correlate the decline in locomotor activity with these studies and with age. We determined an age-dependent reduction in negative geotaxis behaviour, as well as a trend to spontaneously remain at the bottom of the flasks. Differences between sexes in demographic, biochemical and behavioural parameters were found.