E. Lebourg et J. Badia, DECLINE IN PHOTOPOSITIVE TENDENCIES WITH AGE IN DROSOPHILA-MELANOGASTER (DIPTERA, DROSOPHILIDAE), Journal of insect behavior, 8(6), 1995, pp. 835-845
Phototaxis was measured in young, middle-aged, and old Drosophila mela
nogaster flies of both sexes. The apparatus allowed us to measure the
tendency to go toward light, independently of the time needed to do so
; under such conditions, phototaxis is dissociated from locomotor acti
vity. The percentage of photopositive flies decreased slightly with ag
e (93.96, 80.17, and 78.97%, respectively, in young, middle-aged, and
old flies). Results are discussed in connection with previous data for
which the tendency to go toward light and the time to do so were not
dissociated.