As the heart contracts, the blood is forced along the tube and out through the aorta. The blood first bathes the brain, and then flows to other parts of the body. It then re-enters the tube through the ostia. An insect's blood, like ours carries food and waste products to and from the cells of the body. But unlike our blood, it has little to do with bringing oxygen to the cells.
Insect blood is greenish, yellowish or colorless.
Few insects have red blood. Human blood contains a red pigment called hemoglobin, which carries oxygen to the cells. Yes, after a hard days work, grasshoppers can smell really bad. The sense of smell is located chiefly in the antennae of insects. Insects use smell to locate food and to find their way about and to locate places to lay their eggs.