Unc-76G0158 and Unc-76G0158/Unc-76ex107 mutants die at the L2-L3 transition. As first instars, Unc-76G0158 mutants have no obvious visible or behavioral phenotype. During the second instar, larvae begin to suffer from a loss of vigour together with uncoordinated crawling behaviour; these symptoms progress to complete paralysis and death at the onset of the third instar.
Lethality occurs from the third larval instar through to the pupal stage. Mutant third instar larvae are short and dumpy-like.