The current work was carried out to evaluate the histochemical impacts of five insect growth regulators; applaud (buprofezin), consult (hexaflumuron) and match (lufenuron) as chitin synthesis inhibitors (CSIs), mimic (tebufenozide) as ecdysone agonist (EA) and admiral (pyriproxyfen) as juvenile hormone analogue (JHA) on the polysaccarides, chitin, proteins and the nucleic acids of house fly larvae, Musca domestica. The IGRs were applied by feeding the 1st instar larvae on diets mixed with the selected IGRs at100 ppm. Following 72 hours of treatment, a noticeable variation in polysaccharide material was observed. Applaud, match, mimic and admiral decreased the polysaccharide content (chitin) in the integument (body wall) and in the fat body cells. In addition, a noticeable variation in neutral polysaccharide material was observed. Applaud and match decreased the chitin content, while consult increased the chitin content in the integument. Moreover, a noticeable variation in protein content was observed. Applaud, mimic and admiral induced a slight increase in the protein content in the integument and in the fat bodies. On the other hand, the two CSIs, consult and match induced a reduction in the protein content in the integument and in the fat bodies. Also, the obtained results indicated that treatment of 1st instar larvae of M. domestica with consult, match and mimic induced slight decrease of RNA content, while applaud elicited high decrease of RNA. Admiral led to disappearance of RNA completely from the cells of epidermis (body wall) and in the fat bodies. With respect to the effect of the tested IGRs on DNA, the effects were slight in the epidermal and the fat body cells.