Is the number of possible QTL for asymmetry phenotypes dependent on thermal stress?

► Genetic basis of fluctuating asymmetry was explored for wing traits in D. melanogaster at both benign and high temperatures. ► Genetic variation in FA was induced by heat stress. ► Three QTL for FA were significant at stressful temperature only. ► FA-QTL may appear under stressful developmental conditions and disappear under benign conditions. ► FA levels did not differ between benign and high developmental temperatures.