Diabetes is a large and growing health problem affecting an estimated 387 million people worldwide. One of the many complications caused by high blood sugar levels over a prolonged period is an impaired immune response. In our laboratory we are using Manduca sexta as a model to study the effects of hyperglycaemia on the innate immune response against microbial infections. We are manipulating the diet of the caterpillar to artificially induce hyperglycaemia and monitor susceptibility to microbial pathogens. We are also investigating the modifications of the immune proteins resulting from the high blood glucose concentrations in the haemolymph, to elucidate this effect on the immune system.