Effect of temperature on Lucilia sericata (Diptera : Calliphoridae) development with special reference to the isomegalen- and isomorphen-diagram

Developmental behavior of eggs, larva. and pupa of the blowfly species Luci lia sericata (Meigen) were studied under 10 different temperature regimes. Data from these studies were used to construct the isomegalen-diagram. In t his diagram, time from hatching to peakfeeding is plotted against temperatu re, each line representing identical larval length at various temperatures. If the temperature is roughly constant, as is the case with corpses found indoors, the age of the maggot can be read off instantly from its length, p rovided that the maggot has not entered the migratory phase. Where temperat ure is variable, an age range can be estimated between the points where the measured larval length cuts the graph at the maximum and minimum temperatu res recorded. Equally, the isomorphen-diagram representing all morphologica l stages from oviposition to eclosion should be used, if maggots in the mig ratory phase or pupae or puparia are recovered from the scene. The isomegal en- and the isomorphen-diagrams could facilitate a quick and more precise e stimate of the postmortem interval even for the inexperienced investigator. In addition, our results vary from those of other investigators, suggestin g a different thermal behavior of the holarctic blowfly L. sericata in vari ous zoogeographic regions. (C) 2001 Published by Elsevier Science Ireland L td.