Expression of hug^Scer\UAS.cMa under the control of Scer\GAL4^αTub84B.PL results in reduced feeding and growth and larval lethality.

When hug^Scer\UAS.cMa is driven by either Scer\GAL4^αTub84B.PL or Scer\GAL4^105.1 a marked reduction in the number of eclosed adults is seen. Those that survive are slightly smaller than wild-type, but otherwise look normal. When two copies of hug^Scer\UAS.cMa are driven by Scer\GAL4^αTub84B.PL, only 5% of larvae survive until pupariation. The most prominent lethal phase, where about 44% of all larvae die is around the second larval moult. The earliest death is observed before the onset of ecdysis, when only duplicated mouth hooks and anterior spiracles are visible. T he most advanced larvae develop complete cephalopharyngeal skeletons and almost complete ecdysis before dying, partly surrounded by the old cuticle. Many larvae exhibit defects in morphology and molting behaviour. Larvae that have shed the old cuticle sometimes are still attached to the old cephalopharyngeal skeleton. Larvae also often develop brown spots on the new cuticle in a regular pattern late during the second instar. The heavily pigmented ones appear to be unable break the old second instar cuticle, although the cuticle with attached spiracles detach from the pigmented third instar cuticle. instead the larvae become trapped within the bag of old cuticle. Of the larvae that survive through ecdysis, the majority die early during third instar.