amon^C241Y/Df(3R)Tl-X third instar larvae (which have been rescued to this stage by expression of amon^hs.PS using a 35 minute heat shock every 24 hours until the third larval instar stage) show a normal radius of movement 1 day after the last heat shock (ALH), but at 2 days ALH, the mutant larvae have a reduced movement radius compared to the control larvae (which have entered the wandering stage). At 3 days ALH, the mutant larvae remain in the food, while control larvae have started to pupariate.

The predominant phenotype of arrested amon^C241Y animals is a failure to evert the head coupled with a failure to extend the legs and wings (91%). Interestingly, the failures in head eversion and leg and wing extension do not preclude further development of these structures as evidenced by tanning and bristle formation, nor did they prevent the differentiation and pigmentation of the eye.

Approximately 58% of amon^C241Y mutants do not complete abdominal differentiation. The undifferentiated abdomens resemble those of stage P5, which are transparent and lack segmentation and bristles. The failure in abdominal differentiation does not however, prevent the thoracic segment from acquiring pigment and bristles, indicating that these two body segments are governed by distinct developmental controls.

Approximately 15% of amon^C241Y mutants display a failure to displace the pre-pupal gas bubble, an event that typically marks the transition from the P2 to the P4 stage of development. All of the pupae failing to displace the mid-body gas bubble develop bristled abdomens, a characteristic of a much later developmental stage (P12i).

Approximately 14% of first instar amon^C241Y mutant larvae successfully complete the first to second instar larval molt and emerge as second instar larvae.