imdunspecified mutant adults are more sensitive to Gram-negative bacterial infection (Ecc-15) than wild type controls.
Mutants show no detectable induction of Dpt, CecA1 and CecA2. Attacin levels are reduced compared to wild type and Drs induction is normal. Bacteria injected into mutant larvae or adults show increased survival compared to those injected into wild type. Phenotype is weaker than that shown by ird5 mutants.
The formation of melanin in the wounded area of abraded cuticle occurs in mutant larvae, as occurs in wild type.
Mutant flies show lower resistance to E.coli infections than wild-type flies. Mutant flies show the same level of resistance to B.bassiana (when their cuticles are coated with spores) as wild-type flies.