Anterior spiracles do not develop knob-like structure typical of first and second larval instar, nor the retractable fingerlike structures characteristic of third instar larvae. The tracheal trunk terminates without opening to the exterior anteriorly, but the posterior spiracles look normal. Mouth hooks always exhibit features characteristic of first instar larvae. Some imaginal discs are smaller than wild type, particularly the dorsal mesothoracic discs. The size of the humeral disc appears normal. Pharate adult escapers are lacking wings and halteres, genital apparatus and anal plates are small or missing, tarsal segments are fused and eyes are rough and reduced.