A 17bp stretch of the P{lacW}EcRk04504 element remains.
Imprecise excision of the P{lacW} element, resulting in a 1.8kb deletion that removes the EcR-B transcription start site.
lethal - all die before end of larval stage | recessive
some die during larval stage | recessive
Most EcR2/EcRM554fs animals fail to survive to the second larval instar stage and few mutant animals survive to the 3rd larval instar stage.