blow flies typically are the first to arrive when blood or body fluid is present. hence, blow flies are the primary means of estimating a time of death in case work. the life cycle from egg to maggot to adult has been researched thoroughly; therefore, the estimation from egg to adult is accurate within simply a few hours based upon temperature and climate during previous days. this estimation is crucial when determining a time of death to further an investigation. specifically, "lucilia illustris" is found on carrion located in sunlight or otherwise bright areas.