Ir56b^MB09950 mutant flies do not show significant changes in the expected avoidance response to food laced with different acids (5% acetic acid, 5% glycolic acid, 10% citric acid, 20% lactic acid, 5% tartaric acid, 2% propionic acid, 2% butyric acid, or 10mM HCl), as compared to controls. GRNs enervating S6 and S10 sensilla do not show changes in the responses (frequency of spikes) to glycolic acid (1%), tartaric acid (1%), citric acid (5%), propionic acid (1%), butyric acid (1%), HCl (10mM), and lactic acid (20%), as compared to controls.

Adults homozygous for Ir56b^MB09950 do not have significant changes in proboscis extension rates in response to fatty acids, or to sucrose, compared to controls.