Insect can be used as alternative specimens for toxicological analysis when conventional post-mortem samples are not
available as drugs that can be detected in severely decomposed tissues of a corpse may still be found in the insects that did feed
on the corpse. Several studies illustrate the great potential importance of entomotoxicology for providing additional
information on cause of death. This study was aimed to study the effect of intoxication with codeine phosphate in decomposed
bodies on the development of carrion flies and on the evaluation of postmortem interval (PMI). The experiment was performed
during summer season from last of June to the mid of July. Four rabbits, two control and two injected with lethal dose of
codeine phosphate were used. Each one was placed in a cardboard box, floored with muddy soil and protected with a metal
cage. Different developmental stages of Chrysomya albiceps were collected and studied for both biological and morphological
changes using dissecting light microscopy. There were morphological changes in the form of disfiguring of segments, loss of
colouration and abnormalities in the shape of both anterior and posterior spiracles in the larvae, while the adult flies show
rudimentary wings, abnormal bands on the undersurface of the abdomen, fading of normal colour to complete loss of it. Also
th were biological changes in the form of acceleration in the development during life cycle and incomplete emerge of some
adult flies from their pupae in the injected group. These acceleration of development lead to bias in estimation of postmortem
interval up to 24h when estimation based on larval development and 48h when estimation based on pupal development. This
work should provide data for the use of morphological and biological changes that occur in Chysomya albiceps as indicator for
death from lethal dose of codeine phosphate and to estimate the post mortem interval.