Estimation of stage transition time: application to entomological studies

Consider the following experiment on an insect with observable stages (0, 1, ..., A). A cohort of insects begins in stage 0 and is sampled periodically in time until the cohort is in stage A. We describe and apply nonparametric estimators to determine the mean and standard error of the mean of the time to a particular stage and stage duration time. We also present an estimator for the variance of the time to a particular stage. Recommendations on constructing sampling regimens and a computer program to calculate estimates are presented.