LOCOMOTOR-ACTIVITY IN DROSOPHILA-MELANOGASTER SELECTED FOR DIFFERENT WING LENGTHS

Locomotor activity and its plasticity were investigated in Drosophila melanogaster lines selected for Long and for Short wings at two differ ent temperatures. Flies were tested in a locometer at two different Ac tivity temperatures. Locomotor activity, a physiological character, sh owed phenotypic plasticity: locomotor activity scores (l.a.s.) were hi gher at 25 degrees C than at 20 degrees C in all lines. Although at ea ch selection temperature the lines differed significantly in the morph ological character wing length, l.a.s.'s were similar in lines with Lo ng and with Short wings per selection temperature. However, a signific ant difference between selected and unselected control - lines was fou nd. At each selection temperature, plasticity of l.a.s.'s in all lines was similar, except for the Short line selected at 20 degrees C, whic h showed a higher plasticity. In contrast to earlier experiments no si gnificant correlations between l.a.s. and fresh body weight, and betwe en l.a.s. and wing length were found within each line.