Behaviour of Local Drosophila melanogaster during Late Larval Stage

Abstract

DURING March 1935 a few local Drosophila flies which emerged from the soil and leaves of a millipede culture of Dr. N. F. Paterson were collected, and a culture was started. The stock proved to be of good viability; the flies were identified as Drosophila melanogaster. After the cultures had been kept for a few generations it was observed that the larvæ of this Witwatersrand stock displayed an interesting difference in behaviour compared with the standard D. melanogaster cultures. During their late larval stage, the larvæ of the latter, in order to pupate, creep up against the side of the culture bottle, whereas those of the Witwatersrand stock only very occasionally behave in this manner, the great majority pupating on or even in the culture medium. We tentatively labelled this behaviour as positive hydrotropism in contrast to the general negative hydrotropism of D. melanogaster.