[a][1] Pyrrhocoris apterus is distributed throughout the Palaearctic from the Atlantic coast of Europe to northwest China.

It has also been reported from the United States, Central America, and India, and is also found in Australia.

[2][3] It has been reported as recently expanding its distribution northwards into mainland United Kingdom and eastward on to the coast of the Mediterranean Sea.

[5] P. apterus was the subject of an unexpected discovery in the 1960s when researchers who had for ten years been rearing the bugs in Prague, Czech Republic, attempted to do the same at Harvard University in the United States.

[6] The most potent chemical component was later identified as juvabione, the methyl ester of todomatuic acid, which is produced by the trees in response to wounding; it mimics juvenile hormone closely at the chemical level, defending against vulnerable pests.