Predicting death in female Drosophila.

We have previously described a phenomenon called the death spiral that is characterized by a rapid decline in female fecundity 6-15 days prior to death in Drosophila. To carry out destructive physiological analyses of females in the death spiral would require a method to reliably classify individual females via the prediction of their age at death. Using cohorts of Drosophila we describe how to use the observed mortality prior to some target day and a female's fecundity 3 days prior to the target day to determine if the female is in the death spiral. The method works at all ages and although the method does not result in perfect classification, with sufficient sample sizes any physiological trait whose means differ between the groups can be detected.