The estimation of generation interval in experimental populations ofDrosophila

A method for the experimental estimation of generation interval is presented together with results obtained at 25° C. forD. melanogasterOregon-R-C maintained in population cages and in population bottles, and forD. simulans vin population bottles. Although there is significant variation between the replicate estimates obtained in population bottles, and although a number of potential sources of error have been discussed, it is suggested that this method provides useful operational estimates of the parameter, which may be taken as 23 days forD. melanogasterOregon-R-C in population cages, 14 days for the same stock in population bottles, and 16 to 18 days forD. simulans vin population bottles.