Enables insulin binding activity and insulin receptor activity. Involved in several processes, including germ cell development; negative regulation of behavior; and positive regulation of cell development. Located in plasma membrane. Part of insulin receptor complex. Is expressed in several structures, including adult fat body; corpus allatum; ganglia; gut section; and somatic precursor cell. Used to study several diseases, including alcohol dependence; diabetic neuropathy; glucose metabolism disease (multiple); high grade glioma; and sleep disorder. Human ortholog(s) of this gene implicated in several diseases, including dementia (multiple); glucose metabolism disease (multiple); kidney cancer (multiple); liver disease (multiple); and reproductive organ cancer (multiple). Orthologous to several human genes including IGF1R (insulin like growth factor 1 receptor) and INSRR (insulin receptor related receptor).