Duration of development of two species of carrion-breeding scuttle flies and forensic implications

A procedure for rearing carrion-breeding scuttle flies (Diptera: Phoridae) under naturally fluctuating temperatures is described. Data on the duration of development of the egg stage, egg plus feeding larval stages, postfeeding larvae and total development from egg to adult, at different temperature regimes (means of daily means) are tabulated for Megaselia giraudii (Egger) and M. rufipes (Meigen). The variation is greater than previously supposed and involves larvae derived from the same egg batch leaving the bait in successive waves. Despite this variation the tables allow the provision of percentage probabilities of estimations of the earliest oviposition dates for specimens collected from a forensic case.