Abai, MR

6th International Congress of DipterologyDevelopmental stability and hybridization: a test case in twoCeratitis species (Tephritidae, Diptera)Erbout, N. (1), M. De Meyer (2) & L. Lens (1)(1) Terrestrial Ecology Unit, Department of Biology, Ghent University, K.L.Ledeganckstraat 35, 9000 Gent, Belgium(2) Entomology Section, Royal Museum for Central Africa, Leuvensesteenweg13, 3080Tervuren, BelgiumDevelopmental stability (DS) is defined as the ability of an organism tobuffer its development against genetic or environmental perturbations, andis most commonly estimated by the level of fluctuating asymmetry (FA),i.e. small random deviations from perfect symmetry in bilateral traits. DSis hypothesized to be affected by genome-wide properties such as the levelof heterozygosity and genetic co-adaptation. For instance, merging ofdifferent genomes as a result of hybridization may destabilisedevelopmental processes due to the disruption of co-adapted genecomplexes. We tested this hypothesis by comparing patterns of FA in threemeristic and four metric traits on the wings and legs of two Tephritidspecies (Ceratitis (Pterandrus) rosa Karsch and Ceratitis (Pterandrus)fasciventris Bezzi) and their lab-reared hybrids (males x females of eitherspecies). Within each cross type, unbiased FA estimates of male andfemale offspring were obtained through mixed regression analysis. Hybridsshowed higher levels of FA than parentals, especially so in meristic traits.Among hybrids, males showed higher levels of stability than females,possibly due to stronger buffering of traits that are functionally importantduring male display. These results hence provide evidence for the use ofFA as an estimator of disruption of developmental stability due to geneticstress.Key Words: fluctuating asymmetry, Ceratitis, hybridization,developmental stability∗∗∗∗∗∗∗∗∗∗72