Drosophila melanogaster (D. melanogaster, or the vinegar fly) is an excellent model organism for many reasons: it has a fully sequenced, well characterized genome; it is capable of learning and other complex behaviors; but perhaps most of all, it has a rapid life cycle.
At a temperature of 25°C (that’s ~77 degrees Fahrenheit for those of you science newbies) the complete life cycle of D. melanogaster spans about 9 or 10 days. That means, starting with a fertilized embryo on Day 1, you will have a fully developed adult fly on Day 9 or Day 10.
That’s pretty fast. Not as fast as C. elegans with its 3-day life cycle, but still impressive.
As an added bonus, the Drosophila melanogaster life cycle can be sped up or slowed down by adjusting the temperature: At 29°C or 18°C, it spans about 7 or 19 days, respectively.1 So feel free to set up your fly crosses, turn down the temperature, and take that summer vacation without worry!
Life cycle vs. life span
In my own teaching I’ve noticed confusion around the following concepts: life cycle, generation time, and life span. Let’s break down their definitions:
Life cycle: The sequential stages of development that an organism proceeds through. For D. melanogaster, those would be embryo, larva, pupa, and adult stages (see diagram above).
Generation time: The total time it takes to develop from a fertilized egg to a fully eclosed (i.e. hatched) adult fly capable of reproduction. For D. melanogaster, as noted above, this is about 9 to 10 days at 25°C.
Life span: The total length of time that a fly can be expected to live. For D. melanogaster, a healthy, well maintained stock will have a median lifespan of roughly 70 days, with a maximum of ~90 days.2
This concludes our brief summary of the Drosophila melanogaster life cycle. I hope you found it useful.
- From the Bloomington Stock Center, Live Culture Stockkeeping: “Temperature has a large effect on the rate of Drosophila development. Generation time (from egg to adult) is approximately: 7 days at 29°C, 9 days at 25°C, 11 days at 22°C, 19 days at 18°C.”
- From Drosophila as a model for aging: “A typical, healthy and well-maintained outbred Drosophila population will have a median lifespan of approximately 70 days and maximum of approximately 90 days at 25 °C.”